A phytosociological study of the páramo in El Carchi province, N Ecuador - Moscol & Cleef 2009 by JPZ.

Phytocoenologia, 39 (1), 79–107 Berlin – Stuttgart, April 21, 2009

A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador by Marcela C. MOSCOL OLIVERA and Antoine M. CLEEF, Amsterdam, The Netherlands with 9 figures and 7 tables Abstract. We here present a plant composition study of páramo grasslands in the East Andean Cordillera of northern Ecuador that discerns altitudinal distribution patterns. This study took place at two locations: the relatively undisturbed Guandera Biological Reserve site and the highly disturbed El Angel Ecological Reserve site. The analysis included a field survey following the relevé method of Braun-Blanquet. The study focussed on altitudinal distributions of specific plant communities discernable by our analysis, as well as for traces of human influence in these communities. We examined 100 plots of zonal and azonal páramo vegetation located between 3400 and 4000 m altitude. The phytosociological classification by means of TWINSPAN revealed seven páramo communities at the association level (three for zonal páramo proper and three for azonal bogs), which clustered each into two alliances and one zonal order on the basis of both floristic composition and percentage of cover. The newly described phytosociological order Espeletio pycnophyllae-C a l a m a g ro st i e t a l i a e f f u sa e unifies all the zonal bunchgrass páramos of the Guandera-El Angel study area. There was no structural subpáramo community detectable in our study area. This can probably be explained by the frequent fires that affect the páramo-forest ecotone and which result into a sharp discontinuity in the vegetation at the upper forest line location in Guandera. For Guandera we described two distinct zonal páramo communities: a bamboo patch and páramo islands in high Andean Forest. In El Angel, the floristic composition of subassociation paspaletosum bonplandiani (bunchgrass páramo at 3430–3550 m) of the G y n o xy o Calam agrostietum suggests that the vegetation of this syntaxon was probably located on former forested land, as evidenced by the disappearance of high Andean forest and the upper part of Andean forest, combined with the presence of many native and exotic weedy species. The presence of distinct taxa in the subassociation of Paspalum bonplandianum undeniably was a response to habitat alteration induced by human activities. For the azonal páramo, we describe three communities at the association level; two of them belonging to the newly established alliance Paep alantho muscosi-Oreobolion c l e e f i i , marking a separate northern Ecuadorian alliance and including the first report of a Xyris cushion bog in Ecuador. eschweizerbartxxx ingenta

Keywords: Páramo, Andes, Ecuador, Upper Forest Line, Andean Rain Forest, grassland, cushion bogs, phytosociology Abbreviations: UFL = Upper Forest Line, SARF = Subalpine Rain Forest/high Andean Rain Forest, UMRF = Upper Montane Rain Forest/Andean Rain Forest

Introduction The páramo is a tropical high altitudinal grassland ecosystem that naturally occurs in Venezuela, Colombia, Ecuador and northern Peru between 3000–3500 m and 4800–5000 m (the permanent snow line), but can also be found in Panamá and Costa Rica (Troll 1973, Cuatrecasas 1968, Cleef 1978) and Bolivia (Beck 1995, García & Beck 2006). The vegetation consists of characteristic tussock grass communities with a high level of plant endemism (Luteyn et al. 1992; Luteyn 1999; Jørgensen & Ulloa Ulloa 1994). Because of their outstanding biodiversity value, the high grade of endemism, and the attractiveness of the landscape, some páramo areas are included in Andean countries’ Protected Area systems. Scientiﬁc evidence already proved the important role of páramo as a regulator of water availability due to the high retention capacity of its soils (Guhl 1968; Luteyn et al. 1992). In addition to this, Grabherr et al. (2003) suggested the páramo could be a promisDOI: 10.1127/0340 – 269X/2009/0039 – 0079

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ing indicator of global change if subject to permanent long-term ecological monitoring. Páramos in Ecuador cover approximately 12,600 km2 (Medina & Mena-Vásconez 2001), which is about 5 % of the country’s surface, and form an important agricultural and livestock area for indigenous farming communities (Medina et al. 1997). Unfortunately, inappropriate land use such as burning, agriculture and livestock grazing have resulted in high pressure on the natural and hydrological conditions of this fragile ecosystem, creating threats to their conservation and sustainable development (Buytaert et al. 2006, Lægaard 1992, Luteyn et al. 1992, Hofstede 2001). Some researchers believe that the grass páramo below 4100–4300 m represents, at least partially, secondary vegetation in formerly forested areas (Cuatrecasas 1958, Ellenberg 1979, Lægaard 1992) that has been created and maintained by man using ﬁre (Lægaard1992), but this hypothesis is still debated. Analyses of the ﬂoristic composition of the forestpáramo ecotone may offer insights into this topic. 0340 – 269X/09/0039 – 0079 $ 13.05 © 2009 Gebrüder Borntraeger, D-14129 Berlin · D-70176 Stuttgart

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M. C. Moscol Olivera & A. M. Cleef

However, such studies should be carried out in areas with enough remnants of natural woody vegetation since vegetation analysis on its own cannot provide conclusive evidence (Wille et al. 2002). Some earlier páramo vegetation studies have already addressed the descriptive aspects of plant communities (Cleef 1981; Balslev & de Vries 1989; Ramsay 1992; Rangel-Ch. et al. 2005, Berg 1998; Sklenar 2000, LAuer et al. 2001) whereas other studies monitored páramo vegetation dynamics under disturbance regimes (Hofstede 1995; Verweij 1995; Ramsay & Oxley 1996, Suárez & Medina 2001). Different fire frequencies are mentioned to occur in the Ecuadorian páramos: every 2 to 5 years (Keating 2007) and every 2–3 years for northern Ecuador according to Koenen & Gale Koenen (2000). Instead, the páramo of the Guandera Reserve is reported to burn every 3–6 years (Di Pasquale et al., 2008), while for El Angel Miller & Silander (1991) reported fires burning at low intensity and so removing almost all the woody shrub and leaving a vegetation cover dominated by giant rosette plants and graminoid tussocks. Phytosociological studies according to the Braun-Blanquet approach (Westhoff & Van der Maarel 1973) are notably lacking in Ecuadorian páramos, except for the northern extreme of Podocarpus National Park (Bussmann 2002). Our study was carried out in two reserves, Guandera and El Angel, which are located close to the Colombian border. Guandera represents an almost pristine site, while El Angel has been subject to intense human intervention. The objective was to identify the different plant communities present in the zonal and azonal páramo of our study area, and to recognise the syntaxonomical similarities with other plant communities reported for the Ecuadorian and Colombian Andes. We also searched for specific patterns in plant species composition related to human influence or former land use. In the wider frame of the “Reconstruction of Upper Forest Line (UFL) in Ecuador” program, our interest is focused on finding evidence of the upper limit of montane forest during the last 3000 years. In this context, the phytosociological analysis presented here is a basic tool to understand the ecological dynamics of the forestpáramo ecotone.

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Study area Two research sites were selected from the páramo of the El Carchi province situated in the high Andes of northern Ecuador. These sites are the Guandera Biological Reserve and El Angel Ecological Reserve including the adjacent Los Encinos Scientiﬁc Station, as well as their surrounding privately held areas with páramo cover (Fig. 1). The study area is part of the so called “global epicenter of biodiversity”, the biologically richest and most diverse areas of the Earth (Mittermeier et al. 1998, Myers 1990). The páramos in El Carchi contain

phyto_39_1.indb 80

a high proportion of restricted range species and are still a habitat of singular and threatened fauna like the rare spectacled bear Tremarctos ornatus. Since there are no meteorological stations in the study area, we have based our climatic characterization on the maps from the Ministerio de Agricultura y Ganaderia (MAG). Precipitation is high all year round. However, Guandera receives 1900 mm and El Angel 1000 mm. Diurnal temperature fluctuations are strong, as experienced in Guandera (Fig. 2, Bader et al. 2007), while annual temperature fluctuations are low. Monthly means of maximum temperature vary between 12 ° and 15 °C (Luteyn, 1999; Di Pasquale et al., 2008; Bader et al., 2007). Annual variations in temperature and precipitation are mainly forced by the annual migration of the Intertropical Convergence Zone (ITCZ). The predominant soils in the study area classify as Andosols (Fao 1998), soils formed in volcanic ash and typically rich in organic matter. Preliminary results characterizing soil properties in El Angel and Guandera (Tonneijck et al. 2006) show high levels of organic carbon for the A and B horizons (4–25 %), low bulk densities (< 0.85 g/cm3, which is diagnostic) and acid to very acid conditions (pH 3.2 – 4.9). Volcanic systems in Ecuador and southern Colombia are part of the ‘Northern Volcanic Zone’, extending from 5 ºN to 2 ºS (Stern 2004). The northern part of the Ecuadorian Andes is covered by Cenozoic volcanic rocks (Hörmann & Pichler 1982). Rocks of the Western Cordillera belong to a calc-alkaline andesite-dacite series, while in the Eastern Cordillera they are members of the andesite-dacite-rhyodacite series (Hörmann & Pichler 1982; Stern 2004). The soil profiles in the study area were formed within three distinct tephra deposits of Holocene age (Tonneijck et al. 2008). Guandera Guandera is a private reserve of the non-governmental organization (NGO) Jatun Sacha Foundation, and is located in the Eastern Cordillera, approximately 11 km East of San Gabriel. It encompasses complex natural habitats, predominantly páramo (covering around 10 km2) with Espeletia pycnophylla stem rosettes, and extensive areas of relatively intact Andean cloud forest. These forests occur from 3300 m up to 3640 m, and include the Andean rain forest and the high Andean rain forest, regional terms, which are equivalent to the Upper Montane Rain Forest (UMRF) and the Subalpine Rainforest (SARF) defined by Grubb (1977). Above 3640 m, the prevailing grass páramo is occasionally interrupted by scattered forest islands which occur up to about 3700 m. The summit area reaches about 4000 m. In this paper, we use the general name ‘Guandera’ to refer to the reserve and its surrounding areas (buffer zone and privately held areas at the lowest part of the transect), while ‘Guandera Reserve’ indicates the proper protected area.

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

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Fig. 1. Study area in northern Ecuador: relevant sites mentioned in the text are shown by circles: (1) El Angel; (2) Guandera; (3) Papallacta; (4) Antisana; (5) Cotopaxi; (6) Loja; (7) Chiles; (8) Cumbal; (9) Azufral; (10) Galeras; (11) Puracé; (12) Eastern Cordillera; (13) Parque Nacional Los Nevados; (14) Tatamá.

El Angel The Ecological Reserve of El Angel is separated from the Guandera Reserve by the fertile, agricultural Central Valley and is situated on the southern slopes of the volcanic El Voladero Basin. The latter probably constitutes a caldera in the southern outliers of Volcano Chiles massif in the Western Cordillera. This reserve, together with the adjacent Los Encinos Scientiﬁc Station, covers approximately 160 km2 of páramo and is characterized by Espeletia pycnophylla stem rosettes. For centuries, and especially since the El Angel-Tulcán road was built, this area has experienced direct impact from human activities, including the annual burning of several hectares of páramo, native vegetation clearing and conversion of land to agriculture, exploitation of forest products and cattle grazing. It is most likely that páramo now occurs in many areas that were once covered by natural Andean forest (Ellenberg 1979, Lægaard 1992, López

phyto_39_1.indb 81

Fig. 2. Climate diagram at 3370 m in Guandera Biological Station (for the year 2002, a normal-weather year). Lines show daily mean maximum and mean minimum temperature; bars show monthly precipitation.

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M. C. Moscol Olivera & A. M. Cleef

Sandoval 2004). Extant forest is present as patches smaller than 7 ha, surrounded by páramo, on small hills or steep slopes located between 3300 and 3700 m. In this paper, we use the general name ‘El Angel’ to refer to the reserve and its surrounding areas (Los Encinos Scientiﬁc Station, the buffer zone and privately held areas at the lowest part of the transect), while ‘El Angel Reserve’ indicates the proper protected area.

Methods Preliminary field inspection and site selection At each locality a field survey was performed in order to select the best altitudinal transects for the 3400 m to 4000 m interval. We selected páramo sites and defined units that represent the different natural vegetation zones, according to the method of Zürich-Montpellier school, also known as the Braun-Blanquet approach (Westhoff & Van der Maarel 1973, Braun Blanquet 1979). The selected sites differ visually in vegetation structure and composition, but have -as much as possible- similar aspect and slope. Data collection Fieldwork was conducted between April and December 2004, and between January and March 2006. Our research sites were situated along two separate and discontinuous altitudinal transects: one in Guandera Reserve and the other in El Angel Reserve (including the adjacent Los Encinos Scientific Station). Both transects encompass the entire vertical range of grass páramo vegetation (from 3430 m to 4000 m). Following the criteria of Walter (1954), we considered the subdivision made mainly by the soil-water regime into zonal and azonal páramo vegetation. For each homogeneous compartment of vegetation located usually at every altitudinal section of 100 m, we established a minimum of five replicate 5 m x 5 m plots placed at random to obtain a fair representation of each compartment. After the first fieldwork campaign in 2004 and preliminary analysis of the data, additional plots were surveyed to distinguish possible unrecognised communities. The number of replicate plots reached up to 13 in the case of the largest azonal communities. According to Mueller-Dombois & Ellenberg (1974), the cover (%) of all plant species in 25 m2 plots was recorded, yielding in this case a total of 100 relevés, distributed over 14 sites. For every plot, a complete species list of vascular plants as well as of prominent bryophytes and other non-vascular species was recorded along with their corresponding

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phyto_39_1.indb 82

cover percentage. Basic environmental information on altitude (m), slope (degrees) and aspect (degrees) was also recorded. Additional information on cover of bare soil and evidence of human impact was collected by visual observations in situ. Plant identification Voucher specimens (fertile when possible) of unidentified vascular plants were collected and identified with the help of taxonomic keys and preserved plant collections stored at the Herbario Nacional del Ecuador (QCNE) and Herbarium of the Pontificia Universidad Católica del Ecuador (QCA). The specimens collected during our study are currently kept at these institutions. Nomenclature for vascular plants follows Jørgensen & León Yáñez (1999). The most conspicuous terrestric bryophytes and other nonvascular species have been recognised at genus level, as far as previous experience allowed for. For El Angel study area, we used the list of vascular species by Balslev (2001). Data analysis Plant species composition and their percentage cover at each location, were subjected to two-way indicator analysis (TWINSPAN, Hill 1979) to classify them into community groups. The TWINSPAN arrangement was an important tool for a first grouping of páramo types along the altitudinal transect and regionally between both transects. Then, applying usual phytosociological techniques, hand refinement was used to produce two tables with the conventional diagonal structure, one containing the zonal páramo types, and the second containing most of the azonal páramo types. Species occurring only once and having less than 3 % of cover were omitted from the table. The resulting vegetation types or plant communities were classified and described following the Braun-Blanquet approach (Westhoff & Van der Maarel 1973). We applied Weber et al. (2000) and the explanation by Izco & Del Arco (2003) for a nomenclatural correct description of the different páramo communities. We used the term ‘diagnostic species’ instead of ‘character species’, because we are unaware which vascular species are exclusive. With respect to the diagnostic bryophyte species, plot sampling was not complete and therefore bryophyte information has to be used with care. The running number of the relevés has been used to indicate type relevés. We compared the described vegetation types from El Carchi with other relevant plots recorded in other sites from the Ecuadorian and Colombian Andes.

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

Results

Zonal páramo vegetation

Phytosociological classification

Esp eletio p y cno p h y llae-Calamagrostietalia effu sae ord. nov. Typus: Dip losteph io rho d o d end ro ides-Calamagrostion effusae (this study) Order of Espeletia pycnophylla -Calamagrostis effusa páramo Table 1, col. 1- 64

A total of 215 taxa of vascular plants and bryophytes was recorded from the 100 páramo plots of which 50 were located in the Guandera transect, and 50 in the El Angel transect (Fig. 3). TWINSPAN allowed for delineation of 1 order, 2 alliances and 7 associations: 3 for zonal páramo (grass páramo, Table 1), one for ‘páramo islands’ in the uppermost forest (Table 1) and 3 for azonal bogs (Table 2). The new zonal and azonal páramo syntaxa of El Carchi study area are summarized in Tables 6 and 7. All identiﬁed syntaxa are described below.

Physiognomy: Zonal bunchgrass páramo with Espeletia stem rosettes and some low shrub on morainic substrates on top of volcanic bedrock. Composition and syntaxonomy: Diagnostic species for the order (and a number of them also for the class)

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Fig. 3. Schematic altitudinal transects sampled in Guandera Biological Reserve and El Angel in northern Ecuador. The vertical arrows indicate the beginning and end of each transect.

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Area (m2) Slope (°) Aspect (°) rosette/shrub cover (%) herb cover (%) ground cover (%) Fire evidence

C A L A M A G R O S T I E T A L I A

C A L A M A G R O S T I O N

Gynoxyo buxifoliae - Calamagrostietum effusae

Association Subassociation Variant Column number (col. nr) Relevé field number (Typus *) Locality: GU=Guandera; EA= El Angel; LE=Los Encinos Altitude (x10 m)

P Y C N O P H Y L L A E

R H O D O D E N D R O I D E S

typicum

E F F U S A E

E F F U S A E Jamesonio goudotii Neurolepidetum aristatae

Jamesonio imbricatae - Calamagrostietum effusae

paspaletosum bonplandiani

1 22

2 23

3 24

4 55

5 56

6 7 8 57 58* 66

9 67

10 68

11 19

12 20

13 21

14 25

15 26

16 50

17 18 19 51 52* 53

20 70

21 71

22 23 24 25 26 99 100 101 131 1

27 10

28 15

29 16

30 17

31 30

32 31

33 32

34 34

35 35

36 36

37 38 39 37 38* 74

40 75

41 76

42 43 44 45 77 102 133 4

variants Oritrophium peruvianum 46 47 48 49 50 51 52 13 104 110 111 112* 113 6

EA 375 25 15 270 15 90 30 -

EA 375 25 15 280 12 90 45 -

EA 375 25 15 270 12 100 35 -

EA 375 25 20 250 10 80 2 -

EA 375 25 20 250 10 70 1 -

EA 385 25 20 250 15 75 0,5 -

EA 385 25 20 250 15 80 1 -

EA 385 25 20 240 10 100 1 -

EA 343 25 15 260 10 60 30 +

EA 343 25 15 260 8 70 15 +

EA 343 25 15 260 40 45 20 +

LE 357 25 12 270 25 65 20 -

LE 357 25 12 260 20 85 15 -

EA 343 25 15 260 12 75 18 +

EA 343 25 15 260 8 70 12 -

LE 357 25 15 260 15 70 8 -

LE 357 25 15 260 10 80 8 -

EA 360 25 25 250 10 75 2 -

GU 385 25 8 270 30 75 3 -

GU 375 25 10 270 15 95 5 -

GU 370 25 10 270 25 70 0,5 -

GU 370 25 10 290 10 75 5 -

GU 370 25 10 270 25 75 25 -

GU 370 25 10 280 12 80 60 -

GU 370 25 8 290 20 55 10 -

GU 370 25 8 270 15 65 1 -

GU 380 25 20 280 25 60 10 -

GU 380 25 20 280 15 70 5 -

GU 380 25 20 280 15 75 3 -

GU 375 25 10 280 25 80 1 -

GU 375 25 10 280 10 85 3

GU 375 25 10 270 25 75 3 -

GU 390 25 12 240 8 90 3 -

EA 385 25 25 250 12 75 0,5 -

EA 385 25 20 250 25 80 1 -

EA 343 25 15 240 5 75 15 -

EA 343 25 15 280 5 70 5 -

typicum

EA 355 25 20 300 20 70 1 -

EA 350 25 15 240 10 70 1 -

LE 357 25 15 260 10 90 3 +

GU 380 25 10 225 20 80 35 -

GU 380 25 20 280 15 65 2 -

GU 375 25 8 240 15 80 2 -

GU 365 25 15 250 8 80 5 -

EA 351 25 12 260 20 85 3 -

GU 380 25 4 270 20 80 10 -

GU 385 25 18 270 8 75 2 -

GU 390 25 12 240 8 80 2 -

GU 390 25 12 240 5 80 1 -

GU 390 25 12 260 5 75 3 -

GU 390 25 12 260 4 75 3 -

EA 370 25 3 135 20 90 10 -

Espeletio pycnophyllae Diplostephietum floribundi

Chaptalia cordata 53 54 55 56 93 94 95 96

57 58 59 60 61 62 63 64 65 97 105 108 109 145 14* 106 107 44

66 45

67 46

68 69 70 11 40* 41

71 42

72 43

EA 380 25 25 250 12 70 1 -

EA 395 25 15 240 15 75 2 -

GU 355 25 5 240 15 70 3 -

GU 355 25 5 250 35 60 2 -

GU 355 25 4 270 8 12 65 -

GU 355 25 5 240 30 5 35 -

GU 355 25 5 240 25 40 7 -

EA 380 25 25 250 8 80 0,5 -

EA 365 25 8 270 5 80 1 -

EA 365 25 8 270 4 80 0,5 -

GU 400 25 10 270 3 90 2 -

GU 400 25 10 280 25 70 3 -

GU 395 25 10 240 10 80 2 -

GU 400 25 10 280 13 40 10 -

GU 400 25 10 360 10 25 1 -

GU 400 25 15 20 3 85 0,5 -

GU 400 25 15 350 5 70 2 -

GU 355 25 5 240 13 75 5 -

GU 355 25 5 250 35 7 30 -

GU 355 25 5 250 20 0,5 3 -

Diagnostic species of Gynoxyo buxifoliae - Calamagrostietum effusae Gynoxys buxifolia Hieracium frigidum Cortaderia nitida* Jamesonia sp.1 Geranium sp.1* Lachemilla andina Hydrocotyle sp.4 Hydrocotyle sp. Unknown 43 Brachyotum alpinum

0,1 0,1 0,1 1 0,1 0,1 0,1 10 8 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1

0,1 1 0,1 0,1 2 0,1 2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 1 2 0,1 8 4 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1 0,1

0,1

0,1 1 1 0,1 0,1 0,1

0,1 0,1

0,1

0,1 0,1

0,1

0,1 0,1

D. S.a of subass. typicum 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1

0,1 0,1

0,1

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Hydrocotyle sp.1 Pinguicula calyptrata Azorella aretioides Miconia chionophila Unknown 48 Valeriana microphylla Sisyrinchium trinerve Juncus cyperoides Hydrocotyle bonplandii

0,1

D. S.a of paspaletosum bonplandianum 15 1 2 10 10 15 10 12 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1 0,1

1 5 7 1 0,1 0,1 2 2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1

0,1

2 0,1 0,1

0,1 0,1 0,1 0,1 0,1

0,1 0,1 0,1 0,1

0,1 0,1 0,1 0,1 0,1

0,1

3 0,1 0,1

0,1

D. S.a of Jamesonio imbricatae - Calamagrostietum effusae Jamesonia imbricata Carex pichinchensis* Loricaria thuyoides*

0,1

0,1 0,1 0,1 0,1 0,1 8 3 3 0,1 1

2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 1 0,1 3 0,1 2 1 5 2 0,1 1 0,1

1 2

0,1 0,1 1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1 0,1 0,1 0,1 0,1 0,1 1 0,1

0,1 0,1 0,1 0,1 0,1

D. S.a of subass. typicum Brachyotum lindenii Nertera granadensis* Huperzia sp.1 Gaiadendron punctatum Geranium sp.2 Epidendrum sp.3

0,1 0,1 0,1 0,1 0,1

0,1 0,1

0,1 0,1 0,1 0,1

0,1

1 0,1 0,1 0,1 0,1 0,1

0,1 0,1

0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 1 0,1 10 3 1 0,1 0,1 0,1

0,1

1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1

0,1 1 0,1 0,1

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Paspalum bonplandianum Hypochaeris sonchoides* Castilleja fissifolia* Orthosanthus chimboracensis* Holcus lanatus Bidens andicola Eleocharis albibracteata* Lasiocephalus cf. ovatus Dicranaceae sp.1 Monnina crassifolia Unknown 50 Hydrocotyle sp.3 Nasella inconspicua Bomarea multiflora

D I P L O S T E P H I O

Table 1. Zonal páramo vegetation in Guandera and El Angel study areas, northern Ecuador.

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E S P E L E T I O

Order Alliance

0,1 0,1

0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1

0,1 0,1 0,1

0,1

0,1 0,1

D. S. of Chaptalia cordata Unknown 36* Bartsia laticrenata* Valeriana sp.4* Unknown 51* Unknown 35*

0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1 0,1 0,1 0,1 0,1

0,1 0,1

D. S. of Jamesonio goudotii - Neurolepidetum aristatae Neurolepis aristata Hypericum silenoides* Huperzia crassa* Jamesonia goudotii Arcytophyllum setosum Lachemilla nivalis Hypochaeris sessiliflora* Monticalia stuebelii Ourisia sp.

4 18 25 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1

0,1 0,1

20 10 0,1 0,1 0,1

0,1 0,1

0,1 0,1 0,1 0,1 0,1 0,1 0,1

D. S.a of Diplostephio rhododendroides - Calamagrostion effusae 0,1 0,1 0,1 1 0,1 0,1

1 1 2 0,1 0,1 0,1

10 6 18 1 0,1 0,1

0,1 0,1

0,1 0,1 0,1 0,1 3 1 0,1 0,1 8 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

1 0,1 0,1 0,1

0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1 0,1

0,1 6 3 0,1 0,1 1 0,1 0,1 0,1 0,1 2 0,1 0,1 1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

18 4 4 4 3 5 2 5 20 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 2 2 1 3 1 3 1 0,1 0,1 0,1 0,1 0,1 4 0,1 0,1 1 2 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

4 5 3 4 12 0,1 0,1 0,1 0,1 0,1 1 1 1 3 3 1 1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

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Puya hamata Diplostephium rhododendroides Hypericum laricifolium* Lycopodium contiguum Monticalia vaccinioides Lupinus pubescens Halenia weddeliana* Chaptalia cordata* Geranium sibbaldioides Calamagrostis bogotensis

3 8 1 1 4 0,1 2 1 1 1 0,1 0,1 5 2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 3 0,1 1 1 0,1 0,1 3 0,1 2 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 0,1

0,1 0,1 0,1 0,1 0,1 0,1

2 0,1 3 0,1 2 0,1 0,1 0,1 0,1 0,1

0,1 2 0,1 0,1 0,1 0,1

0,1 0,1

1 0,1

0,1

0,1 0,1 0,1

D. S.a of Espeletio pycnophyllae - Diplostephietum floribundi Blechnum schomburgkii Diplostephium floribudum Vaccinium floribundum Cladina sp. Asteraceae sp.3 Myrteola nummularia* Weinmannia cochensis Asteraceae sp.4 Hieracium avilae Carex sp.2 Uncinia sp.1 Elleanthus sp. Asteraceae sp.5 Disterigma acuminatum

0,1

0,1 0,1

0,1

1 10 20 50 12 4 4 4 1 1 1 0,1 5 10 10 5 1 0,1 0,1 1 0,1 2 2 2 1 1 35 15 15 0,1 0,1 0,1 1 0,1 8 4 1 0,1 2 3 15 6 0,1 0,1 0,1 0,1 2 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 3 1 0,1 0,1 0,1 0,1 0,1 0,1 1

0,1 0,1

0,1

0,1 0,1 0,1

1 0,1

0,1

D. S.a of Espeletio pycnophyllae - Calamagrostietalia effusae Calamagrostis effusa Espeletia pycnophylla Oreobolus goeppingeri Pernettya prostrata Breutelia sp. Disterigma empetrifolium Blechnum loxense Rhynchospora ruiziana Monticalia andicola* Campylopus sp. Sisyrinchium jamesonii Cortaderia sericantha

90 90 90 80 15 12 10 8 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 30 40 30 0,1 0,1 1 0,1 2 0,1 0,1 0,1 0,1

70 65 75 80 8 15 10 13 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

0,1

5 5 0,1 0,1

80 80 50 60 45 60 80 70 70 75 70 55 75 10 10 4 3 6 12 20 6 3 4 3 10 10 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 15 15 1 5 1 2 4 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 4 5 15 15 0,1 2 2 2 1 8 1 0,1 0,1 2 5 0,1 3 3 2 1 2 1 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 5

75 8 0,1 0,1 0,1

70 6

70 85 7 10 0,1 1 0,1 0,1 0,1 0,1

80 12 30

65 90 60 70 70 7 8 4 3 12 2 4 0,1 5 25 0,1 0,1 2 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 7 4 0,1 2 8 0,1 0,1 1 0,1 6 4 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 4

75 50 60 60 70 75 60 75 80 80 75 75 85 75 80 75 80 80 75 75 90 70 4 10 5 5 5 8 10 5 8 4 15 5 15 10 7 5 6 2 4 4 15 8 60 10 0,1 5 4 2 2 1 0,1 2 2 4 1 3 2 2 1 0,1 2 2 3 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 4 0,1 0,1 0,1 0,1 0,1 3 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 4 0,1 2 1 3 4 5 2 2 4 0,1 2 1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 10

80 80 75 75 50 60 75 20 1 65 5 4 2 15 2 25 8 12 10 1 0,1 0,1 2 2 8 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 1 1 0,1 0,1 0,1 1 1 1 0,1 0,1 0,1 0,1 0,1 0,1 0 0,1 0,1 0,1 0,1 0,1 0,1 3 0,1 0,1 0,1

60 5 1

75 10

65 4

60 12

8 5 0,1 5 40 4 15 5 5 7 1 0,1 0,1 0,1 0,1 0,1 0,1 5 0,1 0,1 0,1

0,1 0,1 2 0,1

0,1 0,1 0,1 5 5

A phytosociological study of the pรกramo along two altitudinal transects in El Carchi province, northern Ecuador

phyto_39_1.indb 85

D. S.a of Oritrophium peruvianum Geranium sp.3 Oritrophium peruvianum Eryngium humile* Paepalanthus muscosus* Hypericum lancioides*

Other species present (rel. numb. / %):

* = present also in azonal pรกramo

Calamagrostis sp.2 (70/15) Campylopus richardii (109/0.1, 145/1) Carex pygmaea (75/0.1, 41/0.1) Carex sp. (50/0.1, 51/0.1) Cladia aggregata (6/0.1) Cladina polia (4/0.1)

= Diagnostic Species

Cladonia pyxidata (6/0.1) Distichia muscoides (56/0.1) Elaphoglossum sp.1 (57/0.1, 66/0.1) Galium sp.1 (66/0.1, 67/0.1) Gnaphalium antennarioides (25/0.1, 26/0.1) Gnaphalium sp. (19/0.1, 25/0.1)

Gnaphalium sp.1 (23/0.1, 55/0.1) Hesperomeles obtusifolia (111/1) Lachemilla sp.1 (56/0.1, 70/0.1, 95/0.1) Lupinus microphyllus (53/0.1, 97/0.1) Lycopodium sp. 4 (110/0.1, 145/0.1) Miconia tinifolia (11/0.1)

Orchidaceae sp. 10 (99/0.1, 93/0.1, 94/0.1) Phyllobaeis imbricata (131/0.1) Riccardia sp. (131/0.1, 1/0.1, 145/0.1) Sphagnum magellanicum (1/3) Uncinia tenuis (24/0.1, 55/0.1) Usnea sp. (133/0.1)

Valeriana bracteata (6/0.1) Unknown 32 (99/0.1, 95/0.1) Unknown 33 (100/0.1, 95/0.1) Unknown 34 (100/0.1, 101/0.1) Unknown 38 (52/0.1, 53/0.1) Unknown 44 (67/0.1, 106/0.1)

Unknown 45 (106/0.1) Unknown 46 (57/0.1, 108/0.1) Unknown 47 (75/0.1, 6/0.1) Unknown 49 (66/0.1, 67/0.1) Unknown 52 (52/0.1, 53/0.1) Unknown 53 (66/0.1, 68/0.1, 19/0.1)

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Arcytophyllum muticum (6/1) Arcytophyllum sp. 1 (55/0.1, 56/0.1) Asteraceae sp.2 (97/0.1, 105/0.1) Baccharis macrantha (23/0.1, 24/0.1) Bartsia sp.1 (75/0.1, 13/0.1) Calamagrostis cf. intermedia (55/0.1, 56/0.1)

M. C. Moscol Olivera & A. M. Cleef

include: Calamagrostis effusa, Carex pichinchensis, Diplostephium rhododendroides, Disterigma empetrifolium, Espeletia pycnophylla ssp. angelensis, Oreobolus goeppingeri, Monticalia andicola, M. vaccinioides, Pernettya prostrata. Diagnostic are also Chaptalia cordata, Halenia weddelliana, Hypericum laricifolium, Pinguicula calyptrata, Rhynchospora ruiziana and Sisyrinchium jamesonii. Ecology and distribution: Mesic to humid bunchgrass páramos on black Andosols, on slopes as well as on level ground. The bunchgrass páramo of this order was present in both the páramo areas of El Angel and Guandera from the UFL up to 4000 m. Fires are common in these habitats as observed during the ﬁeld surveys in 2004 and 2006. Bunchgrass páramos near El Angel Reserve entrance above the town of El Angel had been burnt 1–2 years before while those of Guandera páramo were reported to burn every 3–6 years (Bader et al. 2007). D i p l o s t ephi o rhodode ndroi des – C a l a m a grosti on e ffus ae all. nov. Typus: G y no x y o bu x i fo l i a e -Ca l amagrostie t u m e f f usa e (this study) Diplostephium rhododendroides – Calamagrostis effusa alliance of bunchgrass páramo Physiognomy: The same as the order. In the highest part at 4000 m of Guandera also bamboos are mixed up with the bunchgrasses. This is not the case in El Angel.

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Composition and syntaxonomy: Diagnostic species include: Carex pichinchensis (transgr. Puya bogs), Diplostephium rhododendroides, Lupinus pubescens, Monticalia andicola (transgr. high Andean forest ‘páramo islands’), Monticalia vaccinioides (transgr.), Puya hamata (transgr. Puya bogs). Below 4000 m, the suballiance ‘H a l e nio wed d ell ia n a e - C al a m a g rosti e ni o n e ffu sa e’ could be recognised with diagnostic species such as Chaptalia cordata, Halenia weddelliana, Hypericum laricifolium (transgr.), Pinguicula calyptrata, and Sisyrinchium jamesonii. Ecology and distribution: Bunchgrass páramos from the UFL up to 4000 m in El Angel and Guandera study areas. The grasslands also have been established on extensions of former forested land in El Angel Reserve. G y n o x y o bux i fol i a e-Ca l am agrostietu m e f f u s a e ass. nov. Table 1, col. 1–25; Typus: rel. 7 Gynoxys buxifolia-Calamagrostis effusa bunchgrass páramo Physiognomy: Bunchgrass páramo with stem rosettes and low shrub or treelets.

phyto_39_1.indb 86

Composition and syntaxonomy: Diagnostic species include: Aethanthus sp., Bomarea multiflora (rare), Brachyotum alpina (rare), Cortaderia nitida, Eleocharis albibracteata, Geranium sp.1, Gynoxys buxifolia, Hieracium frigidum, Hydrocotyle sp. 1 and Lachemilla andina. The association has been subdivided into two subassociations: subass. ty p icu m and pas paletosum b o n p lan d ian i, both described below. Ecology and distribution: Frequently burnt bunchgrass páramo from the current UFL in El Angel at 3450 m up to 3850 m. The highest zone looked more intact. The lower páramos of this association were found next to forest patches of Andean forest. Burning mostly occurs every year (rangers of El Angel Reserve, pers. comm.). Gy n o x y o b u x ifo lia e -Ca lamag rostietum e ffu sa e Subassociation typicum. nov. Table 1, col. 1–10; Fig. 4; Typus: see association Subassociation of typicum Physiognomy: natural zonal stem rosette-bunchgrass páramo with low shrub. Composition and syntaxonomy: Diagnostic species include: Azorella aretioides, Diplostephium rhododendroides (against paspaletosum), Hydrocotyle sp.1, Miconia chionophila, Nertera granadensis, Pinguicula calyptrata and Valeriana microphylla. This bunchgrass páramo type is ﬂoristically most closely related to the bunchgrassland of the paspaletosu m bo n p lan d ian i subassociation. Ecology and distribution: This type of lower bunchgrass páramo is slightly inﬂuenced by burning. Bunchgrasses are well developed. This bunchgrass páramo type is found between 3750 and 3850 m in the area of El Voladero lake basin of El Angel Ecological Reserve. Gy n o x y o b u x ifo lia e -Ca lamag rostietum e ffu sa e Subassociation p aspaletosu m b o nplandiani subass. nov. Table 1, col. 11–25; Typus: rel. 18 Subassociation of Paspalum bonplandianum Physiognomy: Open bunchgrass-stem rosette páramo, heavily burnt and degraded. The remains of the bunches are fresh green at burnt sites with open ground covered by herbs and bryophytes. In other places with well developed bunches, plant cover was hardly found in the darkness under the dense tussocks. Composition and syntaxonomy: Diagnostic species include Bomarea multiflora, Brachyotum lindenii, Castilleja fissifolia, Eryngium humile, Halenia wed-

01.04.2009 11:57:18

A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

Fig. 4. Espeletia pycnophylla bunchgrass páramo at 3850 m in El Angel Reserve, northern Ecuador, showing G y n o x y o b u x if o lia e Calamagrostietum effusae typicum.

delliana, Hypericum laricifolium, Hypochaeris sonchoides, Lupinus pubescens, Monnina crassifolia, Monticalia andicola, Nasella inconspicua, Orthrosanthus chimboracensis and Paspalum bonplandianum. The páramo grassland is impoverished by the absence of original native species (cf. typicum). Other generalist species arrived and have occupied this disturbed habitat, together with invasive species such as native weeds (Bidens andicola, Gnaphalium spp., Lachemilla andina, Paspalum bonplandianum) and northern temperate introductions as e.g. Holcus lanatus, Anthoxanthum odoratum, and Lolium multiflorum. Ecology and distribution: This type of páramo vegetation was only found in the lowermost páramo of El Angel Ecological Reserve between the current UFL at 3430 m and 3600 m. J a m e s o ni o i m bri ca tae C a l a m a g r osti e tum effusa e ass. nov. Table 1, Fig. 5; Typus: rel. 38 Jamesonia imbricata-Calamagrostis effusa bunchgrass páramo Physiognomy: Zonal stem rosette-bunchgrass páramo with low shrub. The woody component is higher in cover compared to the bunchgrass páramo at higher altitude.

phyto_39_1.indb 87

eschweizerbartxxx ingenta

Composition and syntaxonomy: This bunchgrass páramo is poorer in species than the previously described association from El Angel. Diagnostic are: Carex pichinchensis (transgr.), Jamesonia imbricata, Loricaria thuyoides and Myrteola nummularia (transgr.). One subassociation and two variants have been recognised. Ecology and distribution: Zonal Espeletia pycnophylla bunchgrass páramo in Guandera Reserve occurs between the UFL at 3650 m and 3900 m. The bunchgrass páramo covers mostly steep terrain and allows the development of dense Espeletia stem rosette populations on gently sloping moraines (e.g. close to the bog enclosed by moraines at 3800 m). Environmental conditions along the sampled sites being rather similar (except temperature), they permit only one association to be subdivided in an altitudinally lower and higher subassociation. The altitudinally lower one contains more woody elements, but the dominance of bunchgrasses prevails. Six relevés from the bunchgrass páramo of El Angel belong to this association. They are distributed between 3650 and 3950 m. Ja mes o n io imb rica ta e Calamag ro s tietu m effu sa e Subassociation ty p icu m Table 1, col. 26–44; Fig. 6; Typus: see association

01.04.2009 11:57:18

M. C. Moscol Olivera & A. M. Cleef

Fig. 5. Espeletia pycnophylla bunchgrass páramo at 3700 m in Guandera Reserve next to the upper forest line, showing J a m e s o n io imb ricatae-Calamagrostietum effusae.

Subassociation typicum eschweizerbartxxx ingenta

Composition and syntaxonomy: The diverse woody component of the grassland is diagnostic and consists of some 10 species which occur frequently. Diagnostic are Brachyotum lindenii, Epidendrum sp. 3, Gaiadendron punctatum (seedlings), Geranium sp. 2, Huperzia sp. 1, and Nertera granadensis. Diagnostic by higher presence and cover (compared to the remaining communities of this association) are: Blechnum loxense, Disterigma empetrifolium, Monticalia vaccinioides and Rhynchospora ruiziana. On the basis of the present relevés it was difﬁcult to rank this community of the Guandera Reserve as an association or as subassociation. The last option was chosen due to the low number of relevés available between 3850 and 3950 m and also because of a number of not identiﬁed species. Ecology and distribution: This Espeletia bunchgrass páramo has also been repeatedly burnt, mainly by man (Christopher James, pers. comm. 2006). Fire maintains the UFL border very sharp and slows or prevents recovery of the woody component in the bunchgrass páramo, which largely dominates. On other volcanoes of Ecuador and Colombia, the woody subpáramo component is mostly almost absent by burning and grazing, but probably also by volcanic events. Brachyotum lindenii is a subpáramo shrub 1–2 m in height, occurring together in the same stratum with Diplostephium rhododendroides, Hypericum laricifolium, Monticalia andicola, M. vac-

phyto_39_1.indb 88

cinioides, and Loricaria thuyoides. Monocot species, as grasses, invade easier after burning and are able to outcompete the woody species under recurrent ﬁres (Hofstede et al. 1998, Salamanca et al. 2003). The vegetation of this subassociation is only found between 3650 m and 3800 (3850) m on the western slopes of Guandera Reserve. The remaining relevés of J ameso n io imbricatae-Calamagrostietu m effu sae allow for recognition of two variants. One of Oritrophium peruvianum (representative rel. 40, Table 1), characteristic of more open grass páramo between about 3800 and 3900 m with presence of e.g. Eryngium humile, Hypericum lancioides, Oritrophium peruvianum, and Paepalanthus muscosus. The variant of Chaptalia cordata (representative relevé 47, Table 1) is from the proper grass páramo in El Angel and Guandera. Most relevés, however, are from Guandera and Bartsia laticrenata, Chaptalia cordata and Monticalia andina are characteristic. Ja mes o n io g o u d o tii-Ne u ro lep idetum arista ta e ass. nov. Table 1, col. 58–64; Fig. 6; Typus: rel. 62 Jamesonia goudotii-Neurolepis aristata bamboo páramo Physiognomy: Bamboo-stem rosette vegetation in the upper humid grass páramo.

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

Fig. 6. Bamboo páramo of Jamesonio goudoti i -N e u ro l e p i d e t u m a ri st a t a e at 4000 m in Guandera Reserve, northern Ecuador.

Composition and syntaxonomy: Diagnostic species include: Arcytophyllum setosum, Huperzia crassa, Hypochaeris sessiliflora, Hypericum silenoides, Jamesonia goudotii, Lachemilla nivalis, Monticalia stuebelii, Neurolepis aristata and Ourisia muscosa. The assemblage of species and growth forms (bamboos) separates this association easily from both previous zonal bunchgrass associations. Bussmann (2002) described the Neurolepidetum aristatae of the forest-páramo transition, at around 3000 m, in the Podocarpus National Park, near Loja. This association is very similar to the Neurolepis aristata bamboo grove at 3635 m described by Cleef (1981) from the UFL on Nevado de Sumapaz, Colombia. Both the N e uro l e p i de tum aristatae Bussmann 2002 and the Sumapaz bamboo grove are markedly different in vegetation structure and composition compared to the here newly described bamboo páramo association Ja m e so ni o gou d o tiiN e u r o l e p ide tum a ri sta ta e . Ecology and distribution: In the summit area of the Guandera Reserve, at about 4000 m, the vegetation becomes edaphically more humid and allows for dense bamboo clumps up to 0.5 m height. The occurrence of this plant community is beyond any doubt related to the Amazon exposed summit zone which implies a greater atmospheric humidity due to vertical and horizontal precipitation and mist deposition. These superhumid conditions at 4000 m are combined with low daily temperatures. In absence of direct insolation, the daily temperature amplitude is only of few

phyto_39_1.indb 89

eschweizerbartxxx ingenta

degrees centigrade. Similar atmospheric and ﬂoristic phenomena have been described for Podocarpus National Park (Bussmann 2002) and for Páramo de Sumapaz, Colombia (Cleef 2008; Cleef et al. 2008). Páramo islands This denomination refers to the open spaces with páramo-like vegetation mainly found in high Andean forest and Andean forest on the western slope of Guandera Reserve between the UFL and about 3550 m. The vegetation includes taxa from both high Andean forest and páramo. Therefore, vegetation has been phytosociologically ranked as a new association Espeletio p y cno p h y llae-Dip lostephietum floribu n d i, described below. Esp eletio p y c n o p h y lla e Dip lo s te p h ietu m flo rib u n d i ass. nov. Table 1, col. 65–72; Fig. 7; Typus: rel. 69 High Andean Espeletia pycnophyllaDiplostephium floribundum ‘páramo islands’ Physiognomy: Open shrub and low arboreal vegetation with stem rosettes up to 3 m, without signs of previous burning on the vegetation. Large grass tussocks and occasionally patches of Sphagnum are present.

01.04.2009 11:57:19

M. C. Moscol Olivera & A. M. Cleef

Composition and syntaxonomy: Diagnostic species are: Asteraceae sp. 3, sp. 4 and sp. 5, Blechnum schomburgkii, Carex sp. 2, Disterigma acuminata (rare), Diplostephium floribundum, Elleanthus sp., Gaiadendron punctatum, Hieracium avilae, Jamesonia imbricata, Lycopodium clavatum, Myrteola nummularia, Neurolepis aristata, Vaccinium floribundum and Weinmannia cochensis. Species of Cladonia and Cladina may be very common too. According to Table 1, there are two variants, one with Neurolepis aristata (3 out of 8 relevés) and Asteraceae sp. 5; the other one with Carex sp. 2, Cortaderia sericantha and Gaiadendron punctatum. Provisionally we ranked this association under the order of E s p e l eti o-Ca l a m a g rosti e ta l i a effusae because of the open aspect. Ecology and distribution: The so-called ‘páramo islands’ in the Guandera Andean forest and high Andean forest were found as open patches on ridges but also on sloping (level) ground. In the last case also whitish sediments were deposited by sheets of water after torrential rain. These dynamic and unstable places in the high Andean forest contrast with the more exposed ridges. Single Calamagrostis bunches are present but without the assemblage of the accompanying species of the association J ameso n io im b r i c a t ae -Ca l a m a g rosti e tum e ffusae (except Jamesonia imbricata). Blechnum schomburgkii, Disterigma acuminata, Diplostephium floribundum, Gaiadendron punctatum and Weinmannia cochensis represent the high Andean forest component.

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Azonal páramo As in most páramos, azonal conditions are in general characterized by a high phreatic level, close to or at the surface or much higher like in ponds or lakes. Exposed conditions and/or thin soils may also cause azonal vegetation types (Walter 1954) The azonal syntaxa that were identiﬁed at the study sites are described below. Cortaderio nitidae-Puyetum hamatae ass. nov. Table 2, col. 24–28; Fig. 8; Typus: rel. 26 Cortaderia nitida-Puya hamata bog Physiognomy: Giant spiny-leaved ground rosette bog with large, conspicuous grass tussocks in depressions in the grass páramo. The columnar inﬂorescences of Puya are up to 4 m tall. Composition and syntaxonomy: Diagnostic species are: Calamagrostis bogotensis, Carex pichinchensis, Carex pygmaea, Cortaderia nitida, Cotula mexicana, Eryngium humile, Festuca andicola and/or F. asplundii, Gentiana sedifolia, Hypericum lancioides, Hypericum laricifolium, Juncus cyperoides, Lycopodium sp. 5, Monnina crassifolia, Plagiocheilus solivaeformis, Puya hamata (by size, height and cover) and Valeriana sp. 6 and 7. Among the diagnostic non-vascular taxa we included Phyllobaeis imbricata and species of Riccardia.

Fig. 7. Páramo islands of Espeletio pycnoph y l l a e -D i p l o st e p h i e t u m f l o ri b u n d i association at 3550 m in high Andean forest of Guandera Reserve northern Ecuador.

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

similarities. An alliance and two associations are described below.

Most of the species recorded are shared with the surrounding grass páramo except for Arcytophyllum muticum, Cotula mexicana, Equisetum bogotensis, Greigia sp., Jensenia erythrophyllus, Juncus cyperoides, Plagiocheilus solivaeformis, Phyllobaeis imbricata, and Valeriana sp. 6 and 7 (Tables 1 and 2). Two variants could be distinguished, but we have not described them as more relevés from other localities are needed.

Pae p alan th o mu s c o si – Oreo b o lion c lee fii all. nov. Typus: Oreo b o lo cleefii–Xyridetum subulatae (this study); Table 2, col. 1–23 Paepalanthus muscosus-Oreobolus cleefii alliance

Ecology and distribution: The Cortaderia-Puya hamata bogs that were observed around 3500 m in the El Angel Reserve form one of the most spectacular communities of the grass páramo landscape. These bogs occur in humid to wet depressions between moraines. Curiously, Puya hamata developed as a giant ground rosette, while this species in the bunchgrass páramo only attained rosettes with a diameter of about 30–50 cm, and columnar inﬂorescences up to 1 m high. In the bogs, rosettes have been observed reaching a diameter up to 1 -1.5 m.

Physiognomy: cushion bog (with hollows) on glacial lake sediments in bunchgrass páramo. Composition and syntaxonomy: Diagnostic species include: Disterigma empetrifolium (transgr.), Loricaria thuyoides (transgr.), Myrteola nummularia (transgr.), Oreobolus cleefii, Oritrophium peruvianum, and Paepalanthus muscosus. The moss Campylopus richardii is also diagnostic. The alliance consists of two associations: Oreobolo cleefii-Xyridetum sub u latae and Plantagini rigid ae-Oreo b o letu m cleefii.

Guandera and El Voladero páramo bogs Grass páramo bog communities occur at 3810 m on the western slope of Guandera Reserve, and at 3750 m in El Voladero Basin of El Angel Ecological Reserve. Both communities occur on top of former glacial lakes that are ﬁlled in with mineral and organic sediments. They share the presence of a number of species and show physiognomical and ecological

Ecology and distribution: These cushion bogs have been sampled between 3750 and 3810 m altitude. Coombes & Ramsay (2001) published a study on the composition and ecology of a cushion mire at 3600 m on the lower slope of volcano Chiles, very similar in species composition to that of El Voladero at 3750 m. eschweizerbartxxx ingenta

Fig. 8. Páramo bog of Cortaderio nitidae-Puye t u m h a m a t a e association at 3500 m in El Angel Reserve, northern Ecuador.

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Table 2. Azonal plant communities in the páramo of Guandera and El Angel, northern Ecuador. PAEPALANTHO MUSCOSI - OREOBOLION CLEEFII

Alliance Association

Oreobolo cleefii - Xyridetum subulatae typicum

Subassociation

Area (m2) Slope (º) Aspect (º) rosette/shrub cover (%) herb cover (%) ground cover (%) Fire evidence Appproximate number of vascular species

hypochaeretosum sessiliflora Azorella aretioides

Variant Column number (col. nr) Relevé field number (Typus *) Location: GU=Guandera; EA=El Angel Altitude (x10 m)

1 3 GU 381 25 1 280 10 12 80 8

2 142 GU 381 25 1 320 0,5 25 35 14

3 143 GU 381 25 1 340 1 4 50 10

4 144 GU 381 25 1 300 0,5 5 50 13

5 84 GU 381 25 1 290 0,5 2 85 16

6 86* GU 381 25 2 300 3 5 50 15

7 87 GU 381 25 2 300 1 10 12 19

8 12 GU 381 25 2 280 2 50 80 16

9 85 GU 381 25 1 270 0,5 15 80 11

Cortaderio nitidae Puyetum hamatae

Plantagini rigidae - Oreoboletum cleefii

10 2 GU 380 25 2 270 3 12 70 12

11 79 EA 375 25 2 280 15 12 60 13

12 80 EA 375 25 2 290 25 2 75 9

13 115* EA 375 25 1 290 15 30 50 16

14 65 EA 375 25 2 280 0,5 10 20 18

15 60 EA 375 25 2 270 2 8 15 21

16 62 EA 375 25 2 260 2 8 45 18

17 63 EA 375 25 2 260 3 3 20 17

Huperzia crassa 18 64 EA 375 25 2 280 2 5 3 16

19 18 EA 375 25 2 280 0,5 25 45 15

20 21 116* 117 EA EA 375 375 25 25 1 <1 290 280 13 0,1 10 8 110 35 14 18

22 136 EA 372 25 <1 263 3 2 60 14

23 137 EA 372 25 1 250 3 2 55 15

24 81 EA 353 25 3 45 75 30 3 26

25 82 EA 353 25 3 45 50 20 40 29

26 124* EA 364 25 1 320 12 25 10 + 23

0,1

0,1 0,1

27 125 EA 364 25 1 290 30 10 4 + 22

28 126 EA 364 25 1 250 25 8 3 + 22

Diagnostic species of Oreobolo cleefii - Xyridetum subulatae Xyris subulata Sphagnum magellanicum Rhacocarpus purpurascens Pernettya prostrata Agrostis sp. Carex oligantha Cortaderia hapalotricha Puya cf. clava-herculis Asteraceae sp.1 Monticalia andicola Carex crinalis Breutelia sp. Hypericum silenoides Juncus sp.1 Calamagrostis jamesonii Breutelia lorentzii Cladia aggregata Cladina sp.

75 20 1 0,1 2 0,1 5 3 3

1 0,1 1 1

25 35 75 45 1 30 40 40 8 0,1 0,1 0,1 2 3 4 1 1 3 2 3 0,1 0,1 0,1 0,1 0,1 0,1 2 5 2 20 12 5 1 30 0,1 2 1 2 2 0,1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2 1 0,1 1 0,1 0,1 0,1 0,1 0,1 0,1 5 2 0,1 1 0,1 0,1

3 0,1 0,1

3 1 0,1

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0,1

D. S.a of Plantagini rigidae - Oreoboletum cleefii Hypericum lancioides Plantago rigida Juncus stipulatus Geranium sibbaldioides Gentiana sedifolia Loricaria illinisae Carex pygmaea Gentianella sp.2 Puya sp. Festuca sp. Sphagnum sp.3 Juncus sp.2

0,1

2 10

0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 1 2 6 2 5 2 3 0,1 10 10 3 1 5 2 0,1 0,1 0,1 20 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 15 0,1 0,1 2 1 1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 10 3 0,1 3 2

0,1

2 0,1 0,1

0,1

0,1 0,1

1 0,1

0,1

D. S.a of hypochaeretosum sessiliflora Hypochaeris sessiliflora Eryngium humile Halenia weddelliana Castilleja cf. pumila Distichia muscoides D. S.a of variant of Azorella aretioides Azorella aretioides Unknown 51 Valeriana sp.4 Agrostis sp. 2 Bartsia laticrenata

phyto_39_1.indb 92

0,1 0,1 0,1

0,1 0,1 0,1 1

5 0,1

1 0,1 1 0,1 0,1 0,1 0,1 18

8 2 1

0,1

0,1 0,1

0,1

0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 4 0,1 0,1 0,1 0,1

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A phytosociological study of the pรกramo along two altitudinal transects in El Carchi province, northern Ecuador D. S.a of variant of Huperzia crassa Huperzia crassa Valeriana bracteata Calamagrostis cf. intermedia Campylopus fragilis

0,1

0,1 0,1 0,1 50 40 0,1 0,1 0,1 0,1 0,1 0,1 5 5 0,1 0,1 0,1

0,1

D. S.a of Paepalantho muscosi - Oreobolion cleefii Campylopus richardii Oreobolus cleefii Myrteola nummularia Oritrophium peruvianum Loricaria thuyoides Disterigma empetrifolium Paepalanthus muscosus Cortaderia sericantha Oreobolus goeppingeri Calamagrostis simpsoniana Monticalia vaccinioides Unknown 48

10 8 5 3 5 2 2 0,1 0,1 0,1 1 1 1 6 0,1 0,1 0,1 5 0,1 0,1 0,1 0,1 1 18 3

8 1 0,1 0,1 0,1

1 2 0,1 15 0,1 0,1 50 25 0,1 1 0,1 0,1 0,1 0,1 1 0,1 1 0,1 0,1 0,1 0,1 0,1 4 0,1 0,1

4 1 2 2 15

7 30

10 5 2 10

15 20 35 10 20 0,1 3 15 3 0,1 4 12 25

0,1 0,1 0,1 4 0,1 0,1 0,1 0,1 0,1 0,1 0,1 2

0,1

4 0,1 1 0,1 0,1 0,1 12 0,1

0,1 0,1

8 2 0,1 2 2 0,1 0,1 1 0,1 2 0,1

45 0,1 0,1 0,1 2 0,1 0,1 3 0,1 4

10 4 0,1 0,1 3 0,1 0,1 1 0,1 2

1 18 85 3 4 2 2 10 15 8 0,1 0,1 0,1 0,1 0,1 6 5 3 1 0,1 1 0,1 0,1 3 1 0,1 0,1 0,1 0,1 0,1 0,1 2 0,1 1 0,1 5 1 4 0,1 0,1 0,1 0,1 0,1

1 1

0,1

D. S.a of Cortaderio nitidae - Puyetum hamatae Puya hamata Espeletia pycnophylla Cortaderia nitida Valeriana sp.6 Calamagrostis effusa Riccardia sp. Carex pichinchensis Monnina crassifolia Cotula mexicana Hypericum laricifolium Juncus cyperoides Unknown101 Calamagrostis bogotensis Festuca asplundii Plagiocheilus solivaeformis Phyllobaeis imbricata Agrostis breviculmis Arcytophyllum muticum Campylopus sp. Blechnum loxense Breutelia chrysea Unknown 50 Geranium sp.1 Gnaphalium sp. Rhynchospora ruiziana Lycopodium sp.5 Nertera granadensis Jensenia erythropus Valeriana sp.7 Lachemilla orbiculata Hydrocotyle bonplandii Other species (rel. numb. / %): Bidens andicola (124/1) Brachyotum lindenii (124/0.1) Cladina polia (2/1) Cladonia pyxidata (80/0.1) Diplostephium rhododendroides (124/1) Equisetum bogotense (81/2) Gentianella sp. 1 (81/0.1) a

0,1

0,1 0,1 0,1

40 3 12 5 1 1 1 1 0,1 20 2 5

eschweizerbartxxx ingenta

0,1

0,1 0,1 0,1 0,1

0,1

20 0,1

20 7 20 1 3 8 3 3 3 1 2 0,1 1 0,1 0,1 0,1 1 8 3 7 1 0,1 0,1

8 15 6 0,1 2 0,1 0,1 0,1

0,1 0,1 0,1

0,1 0,1 0,1 2 30

4 1 0,1

0,1 0,1 1

20 7 5 1 4 0,1 0,1 0,1 0,1

3 1

5 3

1 1

2 1

0,1

0,1 0,1 2 1 1 1 0,1 0,1 0,1 0,1 0,1 0,1

0,1

0,1 0,1 0,1

Geranium sp. 3 (126/0.1) Hypochaeris sonchoides (81/0.1) Miconia chionophila (82/0.1) Paspalum bonplandianum (126/0.1) Pinguicula calyptrata (125/0.1) Unknown 55 (12/0.1) Unknown 49 (87/3)

= Diagnostic Species

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The ecology of Plantago rigida and Oreobolus cleefii cushion bogs has been described in the Páramo de Palacio, near Bogotá (Bosman et al. 1993). Oreobolus cleefii is a matrix species and plays a role in the successional cycle of these equatorial cushion bogs. Distichia muscoides, another cushion forming species, is also weakly present in the Guandera bog. There is also another syntaxonomic study concerning cushion bogs with low cover of Oreobolus cleefii at higher altitude from southern Colombia by Rangel-Ch. & Ariza-N. (2000), but they are different from the Oreobolus bogs of the El Carchi study area. Cleef (1981) and Cleef et al. (2005) described Oreobolus cleefii cushion bogs from the Colombian Eastern Cordillera and the Tatamá páramo in the Western Cordillera respectively. This is the ﬁrst report of Oreobolus cleefii cushion bog for Ecuador.

Pla n tag in i rig id ae -Ore o b o le tu m cleefii Subassociation hypochaeretosum sessiliﬂorae subass. nov. Table 2, col. 14–23; Typus: rel. 20 Subassociation of Hypochaeris sessiliflora Physiognomy: See the association. Composition and syntaxonomy: Diagnostic are: Castilleja cf. pumila, Distichia muscoides, Eryngium humile, Halenia weddelliana and Hypochaeris sessiliflora.

P la n t a g i ni ri gi da e-Ore obol e tum clee fii ass. nov. Table 2, col. 11–13; Typus: rel. 13 Plantago rigida-Oreobolus cleefii cushion bog Physiognomy: cushion bogs in bunchgrass páramo Composition and syntaxonomy: Diagnostic species (versus Oreobolo-Xyridetum) include: Agrostis sp. 2, Azorella aretioides, Carex pygmaea, Castilleja cf. pumila, Distichia muscoides, Eryngium humile, Gentiana sedifolia, Gentianella sp. 2, Geranium sibbaldioides, Huperzia crassa, Hypericum lancioides, Hypochoeris sessiliflora, Juncus stipulatus, Loricaria illinissae, Plantago rigida, Valeriana bracteata, Valeriana sp. 4. The association contains two subassociations, one of which is subdivided in two variants.

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Ecology and distribution: The cushion mires of El Angel developed in the old caldera of El Voladero at 3750 m. They occur on top of lake sediments either with open water or mud in the hollows, depending on the season. This is usual where glacial lakes are abundant. According to Ramsay (1992), on Volcano Chiles this type of cushion bog extends up to close to 4000 m. P l a n t a g ini ri gi da e-Ore obol e tum c lee fii Subassociation typicum typicum subassociation Table 2, col. 11–13 Physiognomy: See the association. Composition and syntaxonomy: Only three relevés support this subassociation in which Cortaderia sericantha, Disterigma empetrifolium, Loricaria thuyoides, Oreobolus cleefii and Paepalanthus muscosus attain the highest cover.

phyto_39_1.indb 94

Ecology and distribution: The vegetation of this subassociation occurs closer to the edges of El Voladero cushion mire system at 3750 m, evidenced by the presence of high cover of Cortaderia sericantha tussocks. These big tussocks are usually present where there is a moderate availability of cations and nitrogen combined with high phosphorus concentrations (Coombes & Ramsay 2001).

In this subassociation two variants can be recognised: (1) Azorella aretioides variant and (2) Huperzia crassa variant. Diagnostic taxa for Azorella aretioides variant are: e.g. Agrostis sp. 2, Azorella aretioides, Bartsia laticrenata and Valeriana sp. 4. The variant of Huperzia crassa is characterised by Calamagrostis cf. intermedia, Campylopus fragilis, Huperzia crassa (showing a facies for relevés 136 and 137) and Valeriana bracteata. Floristic differences between these two variants can easily be noted from Table 2. Ecology and distribution: Species-rich subassociation of the water-logged flat cushion mire at 3750 m in El Voladero lake basin (El Angel). According to Coombes & Ramsay (2001), the cushion species of this subassociation occur more in the central area of Voladero bog system. The Azorella aretioides variant also contains Juncus stipulatus. Within this subassociation, three different patterns are present. First, dense growth of Valeriana bracteata representing in part predominance of Plantago rigida cushions; second, predominance of a Distichia muscoides cushion (in col. 21); and finally predominance of Huperzia crassa with absence of Oreobolus cleefii and almost absence of Plantago rigida. This implies the presence of different environmental and successional conditions in these bogs. Ore o b o lo c lee fii-Xyrid e tu m su bulatae ass. nov. Table 2, col. 1–10; Fig. 9; Typus: rel. 6 Oreobolus cleefii-Xyris subulata cushion bog. Physiognomy: flat cushion bog in bunchgrass páramo. Composition and syntaxonomy: Diagnostic (versus the P lan tagini rigid ae-Oreo b o letum cleefii

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

Fig. 9. Oreobolus cleefii-Xyris subulata cushion bog at 3810 m in Guandera Reserve, northern Ecuador.

association) are the following vascular taxa: Carex crinalis, Cortaderia hapalotricha, Hypericum silenoides, Monticalia andicola, Puya cf. clava-herculis and Xyris subulata. Cladia aggregata, Rhacocarpus purpurescens and Sphagnum magellanicum are diagnostic among the bryophyte and lichen taxa. The new association consists of two variants: (1) variant of Cortaderia sericantha and (2) variant of Rhacocarpus purpurescens. Ecology and distribution: The flat cushion bog structure consists of Oreobolus cleefii, Xyris subulata and Campylopus richardii. Phreatic level is close to the surface. A former glacial lake at 3810 m on the West slope of Guandera is enclosed by lateral moraines with Espeletia-Calamagrostis effusa páramo. This lake has been filled in with sediments and is at present covered by a flat Oreobolus-Xyris cushion bog. Locally hollows of about 1 m2 in size occur. The variant of Rhacocarpus purpurescens is more complex in structure and richer in species and certainly represents a successionally older phase compared to the variant of Cortaderia sericantha.

Discussion Plant communities of zonal páramo and interregional comparison The synoptic presence of both zonal bunchgrass páramo communities and azonal páramo cushion bogs on relevant volcanoes of Ecuador and Colombia

phyto_39_1.indb 95

eschweizerbartxxx ingenta

is shown in Tables 3 and 4. All the study sites mentioned for comparison are shown in Fig. 1. The páramos of El Angel and Guandera are basically bunchgrass páramos made up of Calamagrostis bunchgrasses (mainly C. effusa) and stem rosettes of Espeletia pycnophylla ssp. angelensis. These páramos extend from the current UFL up to about 4000 m (and slightly higher on the slopes of Volcano Chiles). There is one exception: at 4000 m in Guandera Reserve, where a patch of bamboo páramo with Neurolepis aristata occurs. The new phytosociological order Espeletio py cno p h y llae-Calamagrostietalia effu sae described here occurs in the whole zonal bunchgrass páramos of our study area (Table 1). Azonal páramo communities (Table 2) have only been studied for understanding the present-day vegetation types and as a tool for interpretation of the pollen records (Moscol Olivera & Hooghiemstra, in prep.). Former glacial lakes at 3750 and 3810 m in the study area are today mainly covered by cushion bog communities. The main references for regional páramo vegetation communities comparable to ours are RangelCh. & Garzon (1995) and Rangel-Ch. & ArizaN. (2000) dealing with Nariño páramos (Colombia) and Ramsay (2001) for Volcano Chiles just north of El Angel study area. Ramsay (2001) recognised in the Volcano Chiles study area both Calamagrostis intermedia (most common on Volcano Chiles) and C. effusa. However, the same author indicates the overall presence of Calamagrostis effusa on the high volcanoes of Nariño (Colombia), which is a misidentiﬁcation or a conse-

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M. C. Moscol Olivera & A. M. Cleef

quence of different land management (Ramsay 2001). In our study Calamagrostis effusa is the main bunchgrass species. Although in general at lower elevations with a more humid climate this is one of the most prominent species. However, we do not rule out that bunches of C. intermedia can also occur in the highest relevé areas (>3750 m). Interesting in this context is the observation by Galán de Mera et al. (2003), that Calamagrostis intermedia occurs in disturbed areas in the puna of Peru. Out of the three páramo zones distinguished by Cuatrecasas (1934, 1954, 1958, 1968) we have recognised only the grass páramo or páramo proper. Vegetation structures characteristic of subpáramo were not distinct. Among the zonal vegetation described above, two minor communities with characteristic ﬂoristic features deserve special attention: the bamboo patches and the páramo islands. The bamboo patches (Ja m e son i o go u d o tiiN e u r o le p i de tum a ri sta ta e , Table 1) in the summit zone of the Guandera Reserve probably represent the uppermost part of a bamboo páramo which is exposed to air masses from the humid Amazonian lowlands. Humid lower superpáramo is absent even if the atmospheric conditions (zone often shrouded by clouds and mist) and daily temperatures are similar to those favorable for its development (Ramsay 2001, Sklenar & Balslev 2007, Cleef 2008). In the Guandera Reserve, the so-called ‘páramo islands’ are situated on exposed ridges in high Andean forest (Espe l e ti o p yc no ph yl l a e -Diplostep h ie t u m fl ori b un di , Table 1) and are composed of a selection of high Andean forest and bunchgrass páramo taxa, representing easily pioneering species. Other open patches are found on level and sloping ground in high Andean forest. Part of the level surface is without vegetation and lacking the black color of the Andosols. These level patches are very dynamic with occasional ﬂooding and sheet-like sedimentation during long lasting showers. More research is needed in order to clarify the origin and nature of these patches. We consider them as an association under the order E sp e l e ti o p yc no phy llae-Cala m a g r o s ti e ta l i a e ffusa e . Table 3 compares páramo bunchgrass sites on volcanoes from Parque Los Nevados (Salamanca et al. 1992, 2003), Puracé (Rangel-Ch. & Franco-R. 1985), Galeras, Azufral and Cumbal (Rangel-Ch. & Garzón 1995, Rangel-Ch. & Ariza-N. 2000), all located in Central and South Colombia, with páramo sites of Ecuador: Chiles (Ramsay 2001), El Angel and Guandera study area (this publication), Papallacta (Lauer et al. 2001), Antisana (Muñoz et al. 1985) and Cotopaxi (Balslev & De Vries 1989). Table 3 shows the order Espeletio pycnophyllae-Calamagrostietalia represented by diagnostic species such as Azorella aretioides, Blechnum loxense, Espeletia pycnophylla, Nertera granadensis, Geranium sibbaldioides, Oreobolus goeppingeri, Paspalum bonplandianum/P. hirtum, Sisyrinchium jamesonii, and Rhynchospora macrochaeta (R. ruiziana). The distribution area of

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phyto_39_1.indb 96

the order includes the páramos on the volcanoes of the Nariño Department in Colombia and the páramos of El Carchi province in North Ecuador. The Papallacta bunchgrass páramo seems transitional to the bunchgrass páramos of Central Ecuador (Antisana, Cotopaxi), which are different in composition. The same applies to the páramo bunchgrass vegetation of Puracé and Los Nevados in Central Colombia. Conclusions are hampered by the low available number of published relevés (Puracé, Antisana, Cotopaxi) and the limited number of species recognised in quickly taken relevés. For a safe recognition of syntaxa at the class level, a synoptic presence table covering all the páramo areas from Venezuela to north Peru would be needed. In this context the TWINSPAN subdivision of zonal páramo communities of Ecuador based on 196 páramo quadrats by Ramsay (1992) is relevant. This study , from north to south four separates main groups of bunchgrass páramo communities (Ramsay 1992, his Fig. 2.16). The first group from the Chiles volcano includes ‘Calamagrostis sp. and Espeletia pycnophylla tussock grassland with Paspalum tuberosum’ (=P. bonplandianum) (3600–3700 m). At higher altitude (3800–3900 m) he reported the community of ‘Calamagrostis sp. and Espeletia pycnophylla tussock grassland with Viola sp.’ (= V. glandularis). Both communities correspond to the here described Gyno xyo b u xifo liae-Calamagro stietum effusae with both subassociations. The second group consists of Calamagrostis sp. tussock grassland with different diagnostic herb species and is distributed between Cotocachi and Cajas. The drier Chimborazo volcano contains various types of a ‘Calamagrostis sp. and Chuquiraga jussieui desert páramo’. Finally, the lower south Ecuadorian páramos (Zapote-Naida, Cajas, Cumbe and Oña) share a ‘Calamagrostis sp. tussock grassland with Paspalum tuberosum and Chrysactinium acaule’. Plant communities of azonal páramo and interregional comparison In the study area, azonal páramo communities (Table 2) are constituted by bogs and mires whose nature and floristic affinity with other sites studied in the region are discussed below. The main references are the studies by Bosman et al. (1993), Rangel-Ch. & Ariza-N. (2000), Ramsay (2001), Cleef (1981), and Cleef et al. (2005). In the El Angel Reserve giant Puya hamata rosette bogs occur around 3500 m in depressions between moraines. Outside the relevés, some Sphagnum magellanicum hummocks and few plants of S. cuspidatum have been observed. This confirms the original nature of such bogs, as they have been studied by the second author in the subpáramo and grass páramos of the Eastern Cordillera of Colombia (Cleef 1981). Here we observe that giant rosettes of Puya developed presumably under higher nutrient concentra-

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

Table 3. Synoptic presence table of zonal bunchgrass páramos on volcanoes in the equatorial Andes. Relevant study sites and syntaxa mentioned are: (1) Parque Nacional Los Nevados (3920–4250 m), Esp e l e t i o h a rt w e g i a n a e -C a l a m a g ro st i e t u m e f f u s a e (Salamanca et al. 1992, 2003); (2) Puracé 3300–3380 m (Rangel-Ch. & Franco-R. 1985); (3) Galeras* (3550–3810 m), Va c c io n io f lo ribundi-Espeletietum hartwegianae, (Rangel-Ch. & Garzón 1995, Rangel-Ch. & Ariza-N. 2000); (4) Azufral (3600–3820 m), Pentacalio vaccinioidis-Calamagrostie t u m e f f u sa e (Rangel-Ch. & Garzón 1995, Rangel-Ch. & Ariza-N. 2000); (5) Cumbal* (3470–3520 m), community of Espeletia pycnophylla and Orthrosanthus chimboracensis, (Rangel-Ch. & Garzón 1995, Rangel-Ch. & Ariza-N. 2000); (6) Chiles 3600 m (Ramsay 2001); (7) Chiles 3700–3900 m (Ramsay 2001); (8) El Angel (3430–3850 m), Gy noxyo buxifoliae-Calamagrostietu m e f f u sa e (this study); (9) Guandera* (3515–3950 m) J a m e so n i o im b r ic a t a e Calamagro stietum effusae, (this study); (10) Papallacta (3550–4050 m), “Festucion” (Lauer et al. 2001); (11) Antisana 4200 m (Muñoz et al. 1985); (12) Cotopaxi 4000 m (Balslev & De Vries 1991).

Number of relevés Site number

2 3

P. N. LOS NEVADOS PURACE GALERAS AZUFRAL CUMBAL EL ANGEL GUANDERA CHILES < CHILES > PAPALLACTA ANTISANA COTOPAXI

*: indicates the name of the site with the majority of the relevés considered.

Number of relevés

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1

Site number

1 2 3 4 5 8 9 6 7 0 1 2

2 3

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1 1 2 3 4 5 8 9 6 7 0 1 2

Niphogeton dissecta

Huperzia cf. capellae

Pernettya prostrata

V .

II IV 2 V IV 5 IV I

Hypericum thuyoides

Ranunculus peruvianus

Jamesonia pulchra

4 III .

Hypericum decandrum

5 III .

Lachemilla tanacetifolia

Baccharis rupicola

Lachemilla uniflora

5 V .

Cardamine bonariensis

Lupinus prostratus

2 V .

Carex cf. peucophila

III .

Lycopodium sp.

Cerastium cf. subspicatum

Cotula mexicana

Espeletia hartwegiana

V 5 V .

Halenia campanulata

Hieracium avilae

IV .

Hypericum strictum

Lepicolea pruinosa

Lucilia kunthiana

Lysipoma muscoides

Monticalia arbutifolia

Myrrhidendron glaucescens

Neurolepis aperta

Ophioglossum crotalophoroides

Sisyrinchium tinctorium

Sisyrinchium trinerve

Oreobolus goeppingeri

Sphagnum sp.

Paspalum bonplandianum

Campylopus spp.

. III I

Rhynchospora macrochaeta/ruiziana

Puya hamata

. III V .

Lycopodium magellanicum

Viola sp.

. IV .

Agrostis foliata

Agrostis sp.

Altensteinia fimbriata

Aphanactis jamesoniana

Arcytophyllum aristatum

Carex pygmaea

Cotula mexicana

. I

Monticalia stuebelii

5 III .

Orchidaceae

Oritrophium hieracioides

Poa sp.

. IV .

Sibthorpia repens

. III .

4 II

Blechnum loxense

5 IV .

4 V II 5 II

Geranium sibbaldioides

III . IV III 2 II

5 V .

Oritrophium peruvianum

IV .

5 IV I

Nertera granadensis

. III III . III I

5 IV I

Disterigma empetrifolium

. V III .

Sisyrinchium jamesonii

. III .

. III II

. V II

Azorella aretioides

. IV II

. IV I

Espeletia pycnophylla

4 V V 5 V .

Lycopodium clavatum/ contiguum

. IV III 5

. IV V 5 IV .

4 III .

. IV IV 5 IV II 5 IV .

Arcytophyllum nitidum

. III I

Baccharis genistelloides

. III .

Bomarea linifolia

. IV .

Brachyotum strigosum

. IV .

5 IV .

Breutelia spp.

3 II V . V IV .

Cora pavonia

. IV I

Diplostephium glandulosum

. III .

Fuchsia vulcanica

. III .

5 III .

Galium hypocarpium

. V .

Gaultheria amoena

eschweizerbartxxx ingenta

. IV 4

II IV . II

5 II

Diplostephium sp.

Geranium multiceps

. IV .

Gamochaeta pensylvanica

4 III .

Geranium rhomboidale

Gynoxys fuliginosa

4 III .

Gynoxys sancti-antonii

. III .

Halenia kalbreyeri

5 V .

Halenia asclepiadea

II 2

phyto_39_1.indb 97

II .

01.04.2009 11:57:19

Number of relevés Site number

2 3

P. N. LOS NEVADOS PURACE GALERAS AZUFRAL CUMBAL EL ANGEL GUANDERA CHILES < CHILES > PAPALLACTA ANTISANA COTOPAXI

Table 3 (Cont.)

M. C. Moscol Olivera & A. M. Cleef P. N. LOS NEVADOS PURACE GALERAS AZUFRAL CUMBAL EL ANGEL GUANDERA CHILES < CHILES > PAPALLACTA ANTISANA COTOPAXI

Number of relevés

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1

Site number

1 2 3 4 5 8 9 6 7 0 1 2

2 3

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1 1 2 3 4 5 8 9 6 7 0 1 2

Hesperomeles obtusifolia

. IV .

Lycopodium thuyoides

Hypochaeris setosus

Lycopodium sp. 4

Jamesonia bogotensis

. IV II

Miconia chionophila

Jamesonia goudotii

Miconia latifolia

Jamesonia scammanae

Monnina sp.

Lachemilla galioides

Myrteola nummularia

Lachemilla hispidula

. III .

Nasella inconspicua

Lachemilla sp.

Neurolepis aristata

Loricaria colombiana

. III .

Lupinus colombiensis

. IV II

Lupinus humifusus

Monnina revoluta

. III .

Monticalia vaccinioides

. V .

Oreobolus cleefii

II V 2

Oreopanax ruizianum

Polytrichum juniperinum

. III .

Rubus nubigenus

. III .

Senecio isabelis

. IV .

Stereocaulon vesuvianum

Xenophyllum humile

Agrostis tolucensis

Orchidaceae sp. 10

Orthrosanthus chimboracensis

5 II

. IV .

Ottoa oenanthoides

Ourisia muscosa

II IV .

Paepalanthus muscosus

Paspalum sp. 1

Phyllobaeis imbricata

Pinguicula calyptrata /elongata

Riccardia sp.

Senecio canescens

Sphagnum magellanicum

II III .

. III .

Uncinia tenuis

Usnea sp.

Arcytophyllum muticum

Valeriana bracteata

Arcytophyllum setosum

Valeriana sp.4

Arcytophyllum sp. 1

Diplostephium hartwegii

. IV II 2

Asteraceae sp. 2

Hypericum lancioides

Brachyotum alpinum

Hypericum laricifolium

2 IV IV . III IV .

Brachyotum lindenii

II III .

Monticalia andicola

Calamagrostis bogotensis

Gunnera magellanica

. IV .

Calamagrostis sp.2

Huperzia crassa

Carex sp.

Lupinus pubescens + sp.

4 II IV .

Chaptalia cordata

Satureja nubigena

Clinopodium nubigenum

Halenia weddeliana

. IV II

II III .

Dicranaceae sp.1

Elaphoglossum mathewsii

. III .

Diplostephium floribudum

Loricaria thuyoides

. IV II

. III .

eschweizerbartxxx ingenta

II II .

4 III II

. .

Diplostephium rhododendroides

. III V .

Vaccinium floribundum

. V .

Distichia muscoides

Eryngium humile

II II

Elaphoglossum sp.1

Hypochaeris sessiliflora

Eleocharis albibracteata

Bartsia varias spp.

II II

. III II 1 4

5 IV IV 5 2

Elleanthus sp.

Calamagrostis effusa + intermedia

V 4 V V 4

Epidendrum sp.3

Cotula australis

3 III .

2 II II

Gaiadendron punctatum

Lachemilla nivalis

. III II

Galium sp.1

Carex pichinchensis

III .

II III .

Holcus lanatus

Diplostephium schultzii

II 2

. 3

I .

Huperzia cf. tetragona

Gnaphalium spp.

V 3 II

Hydrocotyle sp.

Senecio formosus

Hydrocotyle sp.1

Baccharis macrantha

Hydrocotyle sp.3

Bomarea multiflora

Hydrocotyle sp.4

Gynoxys buxifolia

. III I

Hypericum thuyoides

Lachemilla andina

Jamesonia imbricata

I IV .

Lasiocephalus ovatus

Juncus cyperoides

Bidens andicola

phyto_39_1.indb 98

01.04.2009 11:57:20

Number of relevés Site number

2 3

P. N. LOS NEVADOS PURACE GALERAS AZUFRAL CUMBAL EL ANGEL GUANDERA CHILES < CHILES > PAPALLACTA ANTISANA COTOPAXI

Table 3 (Cont.)

P. N. LOS NEVADOS PURACE GALERAS AZUFRAL CUMBAL EL ANGEL GUANDERA CHILES < CHILES > PAPALLACTA ANTISANA COTOPAXI

A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

Number of relevés

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1

Site number

1 2 3 4 5 8 9 6 7 0 1 2

2 3

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1 1 2 3 4 5 8 9 6 7 0 1 2

Luzula racemosa

II IV .

1 5

Epilobium denticulatum

Monnina crassifolia

Equisetum bogotense

Puya clava-herculis

I III .

Erigeron ecuadorensis

Valeriana microphylla

. III .

. IV .

Erigeron pinnatus

4 .

Hieracium frigidum

Festuca procera

Lachemilla sp.1

Gamochaeta purpurea

Aa maderoi

Gentianella cerastioides

Aa sp.

Gentianella rapunculoides

Aciachne flagellifera

Geranium angelense

Aetheolaena involucrata

Geranium hirtum

Agropyron attenuatum

Geranium reptans

Agrostis breviculmis

1 5

Geranium stramineum

Aphanactis villosa

Geum peruvianum

Arcytophyllum thymifolium

Gynoxys acostae

Asplenium fragile

Halenia pulchella

Asteraceae sp.

Huperzia cf. tetragona

Azorella multifida

Hydrocotyle bonplandii

Azorella pedunculata

. III 1 5

Lachemilla holosericea

Baccharis arbutifolia

Lachemilla paludicola

Lachemilla sp. 2

Loricaria ilinissae

. 4

Baccharis buxifolia

Baccharis caespitosa var. andicola

1 5

Baccharis latifolia

Lupinus kunthii

Berberis sp.

Lupinus sp. 1

Bidens humilis

Monnina obtusifolia

Bomarea glaucescens

Muehlenbeckia tamnifolia

Brachyotum ledifolium

Muehlenbeckia volcanica

eschweizerbartxxx ingenta

Bromus lanatus

2 5

Musci

. III .

Calamagrostis coarctata

Myrosmodes sp.

Calamagrostis coarctata

Oxalis sp.

Calceolaria crenata

Phyllactis rigida

Campyloneurum angustifolium

Plagiobothrys linifolius

Carex sp.

Plantago australis

Carex triquetra

Plantago linearis

1 4

Caryophyllaceae sp. 1

Poaceae sp. 1

Caryophyllaceae sp. 2

Polypodium murorum

Caryophyllaceae sp. 3

Polystichum polyphyllum

Cerastium mollissimum

Ranunculus praemorsus

Cerastium sp.

Ranunculus sp.

Chuquiraga jussieui

Relbunium ciliatum

Clinopodium nubigenum

. III .

Relbunium sp.

Colobanthus quitensis

Ribes andicola

Chrysactinium acaule

Rubiaceae

Cystopteris fragilis

Rubus coriaceus

Daucus montanus

Senecio rhizocephalus

Diplostephium ericoides

Silene andicola

Diplostephium glutinosum

Solanum americanum

Diplostephium rupestre

Stachys elliptica

Disterigma alaternoides

Stellaria recurvata

Dorobaea pimpinellifolia

Stenomesson aurantiacum

Elaphoglossum paleaceum

Stipa sp.

Ephedra rupestris

Taraxacum officinale

phyto_39_1.indb 99

01.04.2009 11:57:20

Table 3 (Cont.)

Number of relevés Site number

M. C. Moscol Olivera & A. M. Cleef P. N. LOS NEVADOS PURACE GALERAS AZUFRAL CUMBAL EL ANGEL GUANDERA CHILES < CHILES > PAPALLACTA ANTISANA COTOPAXI

100

2 3

2 4 5 6 3 5 2 3 9 8 1 4 1 1 1 1 2 3 4 5 8 9 6 7 0 1 2

Taraxacum vulgare

Trifolium repens

Tristerix longebracteatus

Valeriana adscendens

Vicia andicola

Werneria nubigena

II 1 2

Xenophyllum crassum

Lachemilla orbiculata

II III 1 4

Cerastium danguyi

II II

Gentiana sedifolia

2 II

Rumex acetosella

Senecio chionogeton

II II

Azorella crenata

Festuca spp.

III 5

. IV .

Plantago rigida

Valeriana plantaginea

Castilleja fissifolia

V 2

2 II

. .

1 5

Geranium spp.

Hypochaeris sessiliflora

V .

2 III II 1 5

Lupinus microphyllus

III 3

4 eschweizerbartxxx ingenta

tions, as mentioned by Miller & Silander (1991), and largely outcompete the Sphagnum mosses. The same applies to the tall columnar inflorescences, which commonly achieve a height up to 5 m. Miller & Silander (1991) studied the distribution of two species of Puya in the Ecuadorian páramos, and mentioned that the lower elevational limit of P. hamata in El Angel appears to be the direct result of constant burning by man. They noticed that these fires remove almost all the woody shrubs and leave a vegetation cover dominated by the giant rosettes and graminoid tussocks. In the páramos of the Colombian Eastern Cordillera, giant Puya ground rosettes (Puya goudotiana or P. aristiguietae) are mainly found in Sphagnum bogs in bamboo páramo. In contrast, the bog habitat of our study was almost completely occupied by the large Puya hamata rosettes, together with the species of the order E spe l e ti o py c n o p h y llaeC a la m a g r o sti e ta l i a e ffu sa e . The composition of these bogs (Table 2) has floristic affinities with the zonal páramo communities of the study area. In their generic composition Puya hamata bogs are very similar to the Colombian Puya-Sphagnum bogs. They share Blechnum loxense, Calamagrostis effusa, Pernettya prostrata and vicariant species of Espeletia and Puya, but Chusquea tessellata and Xyris subu-

phyto_39_1.indb 100

lata are absent (Cleef 1981). In our study area, Puya hamata, which has much smaller ground rosettes, and frequently attains only up to 50 cm when flowering and fruiting, is also a diagnostic species of the order of zonal bunchgrasslands (Table 1). Seed production of the big columnar inflorescences is abundant, which explains the near full occupation of the bog surface by Puya hamata. Cushion bogs have been described for grass páramo and lower superpáramo in the equatorial Andes and Costa Rica (Cuatrecasas 1958, Cleef 1978, 1981, Rangel-Ch. & Ariza-N. 2000, Salamanca et al. 2003, Cleef et al. 2005, Rangel-Ch et al. 2005, Chaverri & Cleef 1996). The cushion bogs studied in the Guandera Reserve at 3810 m and in El Voladero (El Angel Reserve) at 3750 m belong to the newly established alliance P aepalanth o muscosiOreo b o lio n cleefii, marking a separate northern Ecuadorian alliance. The name already implies that at these altitudes in the midst of the grass páramo zone, Oreobolus cleefii is the most characteristic cushion forming plant, at least in the northern Andes. Cushion bogs conformed by that species are here for the first time reported for Ecuador. Two new associations described above (P lantagini rigid ae-Oreoboletu m cleefii and Oreo b o lo cleefii-Xyridetu m su b u latae) have a striking similarity with the Oreobolus and Xyris cushion bogs described from low extrazonal humid páramo of Tatamá in the Colombian Western Cordillera (Cleef et al. 2005). The flat, water-logged Xyris cushion bog of Guandera is the first example reported for Ecuador. In the same extrazonal Tatamá páramo, Myrteolo nummulariae-Xyridetum subulatae cushion bogs (3485–3565 m) have been described for the first time (Cleef et al. 2005). In Tatamá, the cushion bog matrix consisted mainly of Xyris plants with only a low cover of Plantago rigida and Oreobolus cleefii, while in our study area the Xyris bog does not include Plantago rigida and is mainly composed by small Xyris subulata var. breviscapa plants in a matrix of Oreobolus cleefii. Furthermore, another Xyris subulata bog has been reported for the páramo zone of Farallones de Cali in the Western Cordillera (Calderón 2005). There is at present photographical documentation of Xyris subulata bogs from Cerro Toledo area in south Ecuador, just north of the Peru-Ecuadorian border (C. Schoenbrun, pers. comm. 2007) and from Las Lagunas area NW of the Yanacocha mine near Cajamarca, northern Peru (J. Sevink, pers. comm. 2008). In spite of similarities between páramo cushion bogs in southern Colombia (Rangel-Ch. & Ariza-N. 2000) and northern Ecuador (this study), the communities are syntaxonomically different, probably because of their different altitudinal position. From Table 4 we recognise the northern Ecuadorian alliance of P aep alanth o muscosi-Oreobolio n cleefii (this study) as well as the species shared by two associations described from the Colombian Andes. The first one is Oritrop h io peruviani-

01.04.2009 11:57:21

A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

8 3 . . . . . . . . . . . . . . . . . . . . . . I V IV I . . . . . . IV I

O r e o b o l e t um c l e e fi i Cleef 1981 with two subassociations, one in the Eastern Cordillera (site number 1) and the other in the perhumid Tatamá páramo in the Western Cordillera (site number 2). The second association, Myrteolo nummulariae-Xyridetum subulatae Cleef, Rangel-Ch. & Salamanca 2005, has also been described from Tatamá páramo (site number 7). The high number of species shared between the Colombian and Ecuadorian Oreobolus bogs suggests a

phyto_39_1.indb 101

eschweizerbartxxx ingenta

NARIÑO

5 7 . I . . . I . . . . . . . . . . . . . . . . V I . III III IV III . . . . .

TATAMA <

NARIÑO

2 2 . . . . . . . . . . . . . . . . . . . . . . 3 . . 3 5 3 . . . . . .

TATAMA >

TATAMA <

13 1 . . . . . . . . . . . . . . . . . . . . . . II II II . . . I II II II I I

EASTERN CORDILLERA

TATAMA >

4 6 4 4 2 . 2 3 . . 3 2 . . . . . . . . 5 5 3 2 . . . . . . . . . . . .

CHILES

EASTERN CORDILLERA

18 5 IV V III IV . . I III I I . . . . II II II II . . . . . . . . . . . . . . . .

EL ANGEL

CHILES

10 4 III II II V II II II I . . II II I I . . . . . . . . . . . . . . . . . . . .

Table 4 (Cont.)

GUANDERA

EL ANGEL

Number of relevés Site number Paepalanthus muscosus Disterigma empetrifolium Juncus stipulatus Loricaria thuyoides Carex crinalis Carex microglochin Asteraceae sp. 1 Oreobolus goeppingeri Festuca spp. Puya hamata Hypericum silenoides Monticalia andicola Breutelia lorentzii/karsteniana Cladina spp. Azorella aretioides Gentianella sp.2 Loricaria illinisae Valeriana sp.4 Amblystegiaceae Cladonia spp. Dicranaceae Distichium capillaceum Calamagrostis effusa Oritrophium limnophilum Xenophyllum humile Gentianella corymbosa Loricaria complanata Carex bonplandii Xenophyllum crassa Carex peucophila Huperzia cruenta Myrosmodus paludosa Lachemilla sp. Nertera granadensis

GUANDERA

Table 4. Synoptic presence table of azonal páramo cushion bogs consisting of Oreobolus cleefii and Xyris subulata on volcanoes in the equatorial Andes. Relevant study sites and syntaxa mentioned include: (1) Eastern Cordillera, Colombia (3150–4350 m), Oritrophio peruviani-Oreoboletum c l e e f i i Cleef 1981 (Cleef 1981); (2) Tatamá, Western Cordillera, Colombia (3755–3780 m), Oritrophio peruviani-Or e o b o l e t u m cleefii Cleef 1981, subassociation valerianetos u m b ra c t a tae (Cleef et al. 2005); (3) Nariño, Colombia: volcanoes Chiles and Azufral (3850–4100 m), Distichio muscoi d e s-P l a n taginetum rigidae Rangel-Ch. & Ariza-N. 2000 (RangelCh. & Ariza-N. 2000); (4) Guandera (this study, 3800–3810 m); (5) El Angel (this study, 3720–3750 m); (6) Volcano Chiles, Ecuador, Oreobolus bog, 3600 m (Coombes & Ramsay 2001); (7) Tatamá, Western Cordillera, Colombia (3485–3565 m) M y rteolo nummularoides-Xyridetum subulat a e Cleef et al. 2005 (Cleef et al. 2005).

101

Number of relevés Site number g

10 4

18 5

4 6

13 1

2 2

5 7

8 3

Carex collumanthus Castratella piloselloides Floscaldasia hypsophila Lucilia kunthiana Luzula vulcanica Lysipomia sphagnophila Muhlenbergia cleefii Pinguicula elongata Rhynchospora oreoboloides Sphagnum cyclophyllum Werneria pygmaea Poa sp. Oreobolus cleefii Campylopus spp. Cladia aggregata Rhacocarpus purpurascens Calamagrostis spp. Agrostis spp. Plantago rigida Monticalia vaccinioides Castilleja spp. Gentiana sedifolia Geranium spp. Puya cf. clava-herculis Eryngium humile Myrteola nummularia Oritrophium peruvianum Hypericum lancioides Sphagnum spp. Breutelia spp. Pernettya prostrata Cortaderia hapalotricha/sericantha Xyris subulata Riccardia spp. Valeriana bracteata Carex pygmaea Hypochaeris sessiliflora Halenia spp. Huperzia crassa Bartsia spp. Lycopodium sp. Distichia muscoides Diplostephium rupestre Loricaria lagunillensis Thamnolia vermicularis Huperzia saururus Hypericum aciculare Hypochaeris radicata Racomitrium spp. Rhynchospora macrochaeta Arcytophyllum nitidum Chorisodontium Dyctionema pavonia Frullania sp. Jamesonia canescens Loricaria colombiana Lupinus humifusus Luzula racemosa Niphogeton ternata

. . . . . . . . . . . . IV V I IV II III . III . . . II . V IV I IV II IV II V I . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . V V I I II II V II II III III . II IV V V I I . IV . I III II IV II III I I I . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . 5 4 5 . 4 3 . . . . . . . 4 . . 5 . 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I I I I I I I I I I I . V III II III I . II . II I I . . . IV IV II II II II I III . I I II I II . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . 3 5 5 3 5 . . . . . . . . . 5 3 5 . 3 3 . 3 . 5 . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . II I . I . . II I . . . . . III II IV II II . III V III IV I . . . . I . . . . . . . . I . . . . . . . . .

. . . . . . . . . . . . II I I IV III III V I II IV I I I . . . . . . . . . . . . . . . II IV IV IV IV III II II II . I I I I I I I I I

syntaxon at the level of an undescribed order of Oreobolus cleefii with Myrteola nummularia and/or Xyris subulata belonging to the class P lanta gini rigid ae-Distich ietea muscoides Rivas-Martínez & Tovar 1982 (Rivas-Martínez & Tovar 1982). The association Distich io muscoides-P lan taginetum rigidae Rangel-Ch. & Ariza-N. 2000 was mainly recorded around 4000 m in Nariño, Colombia. Presence and cover of Oreobolus cleefii is more limited in

01.04.2009 11:57:21

102

M. C. Moscol Olivera & A. M. Cleef

our study area. This association is readily separated from the other syntaxa belonging to the same class but not to the same alliance and order (Table 4). Human influence on plant species composition Plants considered as disturbance indicators (by absence or increased presence) and introduced native and exotic weedy species are shown in Table 5. Data have been complemented by Balslev (2001). Nowadays, the páramo ecosystems in our study area are under increasing anthropogenic pressure (López-Sandoval 2004, Medina & Mena-Vásconez 2001) and consequently vegetation displays patterns directly attributed to human intervention as well as traces of former natural habitats. The most important studies on burning and cattle grazing in dry bunchgrass páramo are Hofstede (1995), Verweij (1995), Ramsay & Oxley (1996), Suárez-R. & Medina (2001) and Vargas et al. (2002), and for impact of potato cultivation the papers by Ferwerda (1987) and Jaimes & Sarmiento (2002). Suárez R. & Medina (2001) is the main reference for the El Angel study area. In the Guandera Reserve, the Brachyotum lindenii grassland ranges from 3650 to 3850 m. It represents the altitudinal lower grassland type belonging to J a m e s o ni o i m bri c a ta e -Ca l a m a gro stietu m e f f u s a e . The grasslands of this subassociation contain much more woody species than the variant of Orithrophium peruvianum at higher elevation (Table 1). We hypothesize that in the absence of ﬁre this bunchgrass páramo could develop as a kind of subpáramo with a much higher cover of shrubby species cover than appears today. Fires could have surpressed the slow recovery of woody species and ﬁnally they are outcompeted by the bunchgrasses, which within few years attain a maximally developed tussock.

eschweizerbartxxx ingenta

Shrubs suffer considerable losses when exposed to fire due to the aerial position of their meristems, while bunchgrasses have their buds at ground level, protected at the center of the tussock. Shrub growth is much lower than bunchgrasses in páramo (Verweij 1995, Lægaard 1992, Heisler et al. 2004). Because of the steepness of the western slope of the Guandera Reserve, the forest-páramo transition is relatively short and the forest boundary is marked. Repeated fire has penetrated the UFL as much as environmental humidity of high Andean forest allowed for. This is what we understand and can explain of the sudden, sharp forest-páramo boundaries characterising UFLs according to Lægaard (1992) and Bader (2007). Normally high Andean forest decreases in height towards the UFL (Grubb 1977, Cleef et al. 2005). This can hardly be observed in Guandera, which means that the upper fringe of the high Andean forest has been influenced by fire in the course of the time (Moscol Olivera & Cleef, in press). In the absence of fire and consequently with a well developed shrubby component we believe that high Andean forest can develop more easily. The shrubby structures provide more shaded forest-like conditions and another type of litter than what is provided by the bunches of the páramo grassland. Migration of the UFL under increasing mean temperatures (due to this microclimate effect) also will favor the woody species of the Gy n o xyo -Calamagrostietum ty p icu m grassland, which gradually migrates upslope as well. We suppose that the woody species of the Jameso n io-Calamagro stietu m typ icu m under natural conditions (rare natural fires) show a gradient from more woody species and more cover close to the UFL to less woody species and less cover with increasing distance to the UFL. A clear subpáramo subdivision between elements of shrubpáramo and dwarfshrub páramo as reported in Colombia (Cleef 1981) is presently absent in our study area. On (old)

Table 5. Disturbance indicators (by absence or increased presence) and introduced native and exotic weedy species in páramo vegetation of northern Ecuador (additional data are from Balslev (2001).

phyto_39_1.indb 102

Category

Taxa

Native páramo species

Azorella aretioides, Geranium sibbaldioides, Calamagrostus bogotensis, Puya hamata, Pinguicula calyptrata, Diplostephium rhododendroides, Valeriana microphylla, Sisyrinchium trinerve, Jamesonia sp. 1, Hydrocotyle bonplandii, Arcytophyllum sp. 1.

Native disturbance indicators

Eryngium humile, Cortaderia sericantha, Castilleja fissifolia, Halenia weddelliana, Lupinus pubescens, Hypericum laricifolium (also a species of former SARF-UMRF), Paspalum bonplandianum, Eleocharis albibracteata, Orthrosanthus chimboracensis, Bromus lanatus, Plantago linearis.

Native weeds

Nasella inconspicua, Gnaphalium spp., Gamochaeta americana, Bidens andicola (b. humilis), Lachemilla aphanoides, L. orbiculata.

Northern temperate exotics

Holcus lanatus, Achillea millefolium, Anthoxanthum odoratum, Lolium multiflorum, Rumex acetosella, Urtica urens.

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

volcanoes both subzones of (sub)páramo have rarely been documented till now (Løtjnant & Molau 1983; Ramsay 1992, Salamanca et al. 2003). Studies on the effect of fire in afroalpine vegetation of respectively Mt. Kilimanjaro and Mt. Kenya show similarities with low páramo shrub and bunchgrasses by surpressing woody regrowth (Hemp & Beck 2001) and of fire-induced reproduction of bunchgrasses of Festuca pilgeri (Young 2004) after recurrent fires. In El Angel, the lowermost open bunchgrass páramo belongs to the subassociation pa spaleto su m b o n p l a n d ia ni of the G yn ox yo -Ca l a magrostie t u m (Table 1) and this floristic composition suggests it was mainly located on former forested land. The páramo grassland of this subassociation extends down to the remains of Andean forest in Los Encinos Scientific Station and the entrance of El Angel Reserve at 3400 m. The nature and possible history of these patches of Andean forest has been discussed in a parallel paper (Moscol Olivera & Cleef in press). As far as we have observed in El Angel study area, high Andean forest is largely absent and also the uppermost zone of Andean forest has been removed in larger part by logging for timber. The process of deforestation was studied in El Angel area for the period of 1965–1993. Aerial photointerpretation showed that 42 % of forest areas and 28 % of shrub vegetation disappeared during these 28 years due to human impact. This implies an annual deforestation rate of 1 to 2 % of the 1965 woody vegetation surface (Arellano 2000). After tree clearing, Espeletia bunchgrass páramo usually invades the forest ground left (Troll 1973, Stern 1995). This process, known as ‘paramización’, has many examples from elsewhere in the páramo region (Verweij & Kok 1992, Hernández 1997, Van der Hammen 1998, Rangel-Ch 2000, Hofstede et al. 2002). We have identified two communities that include particular taxonomic groups or species in their floristic composition whose presence is undeniably a response to habitat alteration caused by human land use activities. Such taxa have an important practical significance as indicators for assessing the degree to which páramo vegetation can be considered as undisturbed (natural). The composition of the bunchgrass páramo of paspeletosum subassociation of G y noxyo -Cala m a g r o s t ie tu m (Table 1), is characterised by four groups of species which together determine the vegetation cover of these former forested lands (see Table 5 for an overview of the species of these groups). This observation is mainly based on the literature on impact in bunchgrass páramo referred to above. The first group is the natural native species group present in the lower páramo close to the natural UFL. The most related source vegetation is the Gy n o xyo C a l a m a g r o sti e tum ty pi c um , especially the five lowest relevés at 3750 m (Table 1). It is obvious that some species do not extend (or only rarely or limited) downslope, which has to be expected in the case of a natural páramo. The second group includes the native

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disturbance indicators mainly appearing after burning and grazing of bunchgrass páramo. These taxa are propagated by wind, man and animals. Road, mule tracks and paths are causing an important diaspore input. A third group concerns the native weedy species, among them a few species of Lachemilla (Rosaceae). Finally, there are the northern temperate species mostly originated from Europe, which now have been spread almost pantemperate. Outside their natural ecosystems they behave as invasive species. There are always some species persisting in the dark ground layer under the bunchgrasses that can be taken as a reliable indicator of the former shelter of the uppermost forests, e.g. species of Hydrocotyle, Aethanthus and of some pleurocarpous mosses.

Conclusions

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This study helped elucidating the floristic composition and patterns of plant communities along two altitudinal transects in one of the regions holding the best preserved páramos of Ecuador. The newly described phytosociological order Esp eletio pycn o p h y llae-Calamagro stietalia effusae unifies all the zonal bunchgrass páramos of the GuanderaEl Angel study area (Table 1, 3 and 6). We did not find a direct phytosociological relationship between the cushion bogs described here for Guandera and El Angel (Table 2 and 7) and those studied by Rangel-Ch. & Ariza-N. (2000) around 4000 m on the Colombian side of volcano Chiles (Table 4). Our analysis showed that all the sampled plots belong to the “páramo proper” belt (sensu Cuatrecasas 1934, 1954). No subpáramo or superpáramo zones were found. For Guandera Reserve, we suppose that in the absence of fire the bunchgrass páramo close to the UFL would have developed as a kind of shrubby subpáramo. In El Angel, the floristic composition of subassociation paspaletosu m b o n p lan d ian i (lowermost open bunchgrass páramo) of the Gy n o xyo-Calamagro stietu m suggests that it was probably located on former forested land, as evidenced by the disappearance of high Andean forest and the upper part of Andean forest combined with the presence of many weedy species (Table 5). The presence of distinct taxa in the subassociation of Paspalum bonplandianum was an undeniably response to habitat alteration induced by human activities. Resumen. Los patrones de composición de las especies vegetales de los páramos de la Cordillera Oriental en el Norte del Ecuador fueron estudiados en la reserva Biológica Guandera y la Reserva Ecológica El Angel. La primera representa un área relativamente poco perturbada y la segunda un área con severa alteración. El análisis realizado implicó un estudio de campo de acuerdo al método de levantamientos según el enfoque de Braun-Blanquet. Buscamos discernir zonas altitudinales o comunidades particulares mediante nuestro análisis así como hue-

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Table 6. Overview of hierarchical zonal páramo syntaxa of the Carchi study area, northern Ecuador.

Espeletio pycnophyllae - Calamagrostietalia effusae ord. nov. Diplostephio rhododendroides - Calamagrostion effusae all. nov. Gynoxyo buxifoliae-Calamagrostietum effusae ass. nov. Subassociation typicum Subassociation paspeletosum bonplandiani subass. nov. Jamesonio imbricatae-Calamagrostietum effusae ass. nov. Subassociation typicum variant of Oritrophium peruvianum variant of Chaptalia cordata Jamesonio goudotii-Neurolepidetum aristatae ass. nov. --------------------------------------------------------------------------------------------------------------Espeletio pycnophyllae - Diplostephietum floribundi ass. nov.

Table 7. Overview of hierarchical azonal páramo syntaxa of the Carchi study area, northern Ecuador.

Cortaderio nitidae-Puyetum hamatae ass. nov. ----------------------------------------------------------------------------------------------Paepalantho muscosi - Oreobolion cleefii all. nov. eschweizerbartxxx ingenta

Plantagini rigidae - Oreoboletum cleefii ass. nov. Subassociation typicum Subassociation hypochaeretosum sessiliflorae subass. nov. Oreobolo cleefii - Xyridetum subulatae ass. nov.

llas de la influencia humana en ellas. Examinamos 100 parcelas de páramo zonal y azonal ubicadas entre 3400 y 4000 m de altitud. La clasificación fitosociológica por medio de TWINSPAN reveló siete comunidades de páramo a nivel de asociación (tres para páramo propiamente dicho y tres para pantanos azonales), las cuales se agruparon cada una en dos alianzas y un orden zonal en base a la composición florística y el porcentaje de cobertura. El nuevo orden fitosociológico descrito E sp e l e t i o p ycnophyllae-Calamagrostietalia effusae unifica todos los pajonales de páramo de Guandera y El Angel. La comunidad de subpáramo no fue detectada estructuralmente en el área de estudio. En Guandera, esto se explica probablemente por los frecuentes incendios que afectan el ecotono páramo-bosque y que originan un abrupta discontinuidad en la vegetación al nivel donde se localiza el límite superior del bosque. Para Guandera describimos dos comunidades peculiares de páramo zonal: un parche de bambúes e islas de páramo en Bosque Altoandino. En El Angel, la composición florística de la subasociación paspaletosum bonplandiani (pajonal de páramo a 3430–3550 m) de

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la asociación G y n o x y o -C a l a m a g ro st i e t u m sugiere que la vegetación de este syntaxon estuvo probablemente localizada en un área que fue anteriormente boscosa, como lo evidencia la desaparición del bosque altoandino y de la parte superior del bosque andino combinada con la presencia de varias especies de maleza nativa como exótica. La presencia de taxa distintivos en la subasociación de Paspalum bonplandianum constituye una respuesta innegable a la alteración del habitat inducida por actividades humanas. Para el páramo azonal, describimos tres comunidades a nivel de asociación; dos de ellas pertenecen a la nueva alianza Paepalantho muscosi-Oreobolion cleeﬁi establecida en este estudio, la cual constituye una alianza separada, propia del Norte ecuatoriano e incluye el primer reporte de un pantano de Xyris para el Ecuador. Acknowledgements. We thank the Ministerio del Ambiente del Ecuador, Fundación Jatun Sacha, in particular Christopher James and Marta Muñoz, and Corporación Grupo Randi Randi, in particular Susan Poats and David Suárez, for per-

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

mitting and facilitating the fieldwork. We are grateful to the staff of Corporación Ecopar for their cooperation throughout the project. The Herbario Nacional del Ecuador (QCNE) and Herbario QCA from Universidad Católica del Ecuador provided facilities. Dr. Jürgen Homeier, Julio Bentancur, Hugo Navarrete, Germán Toasa and Milton Chicaiza helped with species identification. Alex Luzuriaga, Miguel Cavascango, Emilio Muñoz and José Cando provided valuable help and good companionship in the field. We gratefully acknowledge Femke Tonneijck and Henry Hooghiemstra for their help providing photographs. Fjällräven generously supplied clothing for the field work. Constructive comments on an earlier draft of this paper by Henry Hooghiemstra, Ulrich Deil and an anonymous reviewer improved this paper substantially. We thank Carina Hoorn for improving the English text. This study was financially supported by grant WAN 84–572 of The Netherlands Foundation for the Advancement of Tropical Research (WOTRO/NWO, The Hague).

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A phytosociological study of the páramo along two altitudinal transects in El Carchi province, northern Ecuador

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