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ESTUDIOS SOBRE DIVERSIDAD Y ECOLOGIA DE PLANTAS Memorias del II Congreso Ecuatoriano de Botanica realizado en la Pontificia Universidad Catolica del Ecuador, Quito 16—20 Octubre 1995
editores Renato Valencia & Henrik B aislev
Publicado por PONTIFICIAUNiVERSIDADCATOLICADEL ECUADOR en colaboracidn con UNIVERSIDADDEAARHUS,DINAMARCA (PROYECTO ENRECA) Y PROGRAMADANESDEINVESTIGACIONDELMEDIOAMBIENTE (PROYECTO DIVA)
1997
CONTENIDO
p. Contenido Introduccion y presentacion Dedicatoria Agradecimientos Asesores cientfficos Florfstica y taxonomia 1. Cornelia Ott- Notes on the systematics and ecology of Menispermaceae of Ecuador 2. Laurence E. Skog & Lars Peter Kvist - The Gesneriaceae of Ecuador 3. Vicky A. Funk- Wemeria s.l. (Compositae: Senecioneae) in Ecuadof 4. Maximilian Weigend -Some aspects of the biogeography. morphology and systematics of Loasoideae in northern ~th~~a
iii v
-vi viii
1
i3 25
r
5. Lynn G. Clark - Diversity and biogeography of Ecuadorean bamboos (Poaceae: Bambusoideae) and their ~~
6. J-:Iarold Robinson & Vicky A. Funk- Compositae of Ecuador I: Key to frequently collected genera 7. Vicky A. Funk - Compositae of Ecuador II: Diversity and distribution 8. Lars W. Chatrou, Paul J. M. Maas, Carola P. Repetur & H. Rainer - Preliminary list of Ecuadorean Annonaceae Descripcion de Ia vegetacion 9. John Littner Clark- Preliminary floristic inventory of the Bilsa Biological Station, Esmeraldas, Ecuador 10. Blanca Leon, Kenneth R. Young & Asuncion Cano - ¡ Fitogeografia y conservaci6n deJa Costa Central del Peru 11. Tamara Nunez- Inventario florfstico y zonificacion de Ia vegetacion en Isla La Plata, Parque Nacional Machalilla 12. Carlos E. Ceron & Consuela Montalvo A. - Composici6n y estructura de una hectarea de bosque en la Amazonia Ecuatoriana - con informacion etnobotanica de los Huaorani
~
65 79 97
123 129 143
153
13. Rena to Valencia, Henrik Balslev & Guille rmo Paz y Mino C.Tamaiio y distribucion vertica l de los arboles en una hectarea de un bosque muy d.ivers o de Ia Amaz onia ecuatoriana 14. Katya Romoleroux, Robin Foster, Renato Valencia, Richar d . Condi t, Henrik Balslev & Elizabeth Losos- Especies leiiosas (dap ~1 em) encon tradas en dos hectareas de un bosque de Ia Amaz onia ecuatoriana Dinam ica de la vegeta cion 15. Margaret J. Stern & Mauricio Guerrero G.- Sucesion primaria en el Volcan Cotopaxi y sugerencias para el manejo de habita ts fragiles dentro del Parque Nacional 16. Richard Cond it- Cambios en un bosque tropical con un clima variable: Resultados de los censos realiza dos en Ia parcela de 50 h.ectareas en Ia fsla de Barro Colora do en Panam a 17. Carme n Josse - Dimimica de un bosque seco, semideciduo y secun dario en el oeste del Ecuador 18. Matthias Dieme r - Plant microclimate and growth conditions in the param o zone of Ecuador Ecologia de especies 19. }ens-Christian Svenn ing & Henrik Balslev - Small-scale demographic disequ ilibriu m of Iriartea deltoidea (Arecaceae) in Amaz onian Ecuador 20. Tjitte de Vries - Crecimiento de plantu las de Macrolobium acaciÂŁ1efolium (Benth.) Benth . (Caesalpiniaceae), en el igapo de Laguna Grand e, Cuyabeno, en la Amaz onia ecuatoriana 21. Juan E. Malo & Jose Migue l Olan o- Prediccion de la frecuencia d e especies nemorales del bosqu e amazonico a partir de variables topograticas sencillas
ii
173
189
217
231
241 255
263
275
279
Paramo microclimntc
Plant microclimate and growth conditions in the paramo zone of Ecuador Matthias Diemer
Botanisches Institut der Universitiit Basel, Sr.honbeinst r. 6, CH-4056 Basel, Switzerland, tel (+061) 267-3516 Abstract Soil temperatures and quantum flux density (QFD) of three paramo and superparamo sites at 4100-4600 m altitude were monitored over a five-month period. Soil temperatures tended to decrease with altitude, whereas quantum flux density (QFD) showed no consistent altitudinal pattern. Leaf temperatures of Hypoclweris at 4510 m altitude exhibited highest diurnal amplitudes of 30K. Leaf temperatures of other herbaceous perennials and shrubs which were locatea above the soil surface had lower da1ly amphtudes. Hourly maxima ranged from 11 °C to 23°(, while hourly minima reached 1.6°( below zero. This indicates that in bright sunlight paramo plants experience growth conditions comparable to those at lower elevations. -However, during overcast conditions and at night, leaf temperatures are lower than soil temperatures. In general, growing conditions appear to be constant and more moderate th~n in the more seasonal paramos of Venezuela. Resumen Las temperaturas del suelos y Ia luz (QFD) en tres sitios de paramos y superparamo s (altura 4100-4600 m) fueron medidos durante cinco meses. La temperatura d el suelos fue mas baja en los lugares mas altos, pero Ia luz practicamente no cambi6 con Ia altura. Las temperaturas de las hojas de Hypochoeris a 4510 m present6 una varia cion diu rna de 30K. La temperatura de las hojas de hierbas perennes y arbustos aumenta a mcd ida que se encuentran mas cerca del suelo, con maxi mas (promedio por hora) entre 11 oc y 23°C. Las mfnimas durante Ia noche bajaron a 1,6°( bajo 0 (cero). Cuando Ia luz es fuerte las plantas de paramo tienen condiciones de c r~cimiento similar a las de sitios mas bajos. Sin embargo, con nubes o neblina y durante las noch~s, las temperaturas de las hojas son mas bajas que las de los suelos. Aparentemente las condiciones de crccimiento en los paramos ecuatorianos estudiados son constantes y mas moderadas que las de los paramos de Venezuela.
Introduction Recent reviews of tropical mountain climates in the context of plant growth (Rundel1994, Sarmiento 1986) focus primarily on patterns of air temperatu re and precipitation. With respect to Ecuador both ·cite data of Johnson (1976). ) Accordingly, annual precipitation p atterns follow a bimodal trend, with peaks during April and October throu gh November. Fur1hermore Runde! (1994) suggests that it is the presence of frost, which distinguishes paramos from nonrparam o sites. However neither air temperatures nor precipitation adequately describe growth conditions, since temperatures of plant tissues ('epiclimates') and soils, as well as evaporatio n can differ significantly as a
255
Diemer
result of rad iant heating (Grace 1987). Particularily at high elevati ons plant physiognomy can compensate for altitudinal differences in air tempe r~ turc (Korner & Larche r 1988, Salisbury & Spomer 1964). Yet, publis hed microclimatic data from the param os of Ecuador ~re qtJite scarce and date back rough ly 70 years (Heilborn 1925). The purpose of this contrib ution is t0 - describe the plant microclimate in three truely-tropical, aseaso nal param o sites in centra l Ecuador. Mater ials and metho ds
Ptiramo microc/imr.tc
de Ia Virgen' and 'Guagua Pichincha' (see Dieme r 1996 for details ). Result s Results of microclimate measurements are summarized in Table I. During . daytime soil tempe ratures were-.low.est-al---~Cayambe'-J---wh ile differences between 'Param o de Ia Virgen' and 'G-uagua fltchin chc\w ere not significant (Diemer 1996). However, night-time differences show an altitud inal trend. Mean daytime quantu m flux densities (QFD) were similar among sites (Table 1).
Study sites Plant microclimate was monitored at the following three localiti es, situate d in param o and superp aramo sites. The lowest study site 'Param o de la Virgen' (0°18'S 78°15'W, also termed 'Paramo de Guamani' by Leon Yanez 1993). is located at an altitud e of 4060 m approxirnateiy 45 km east of Quito, Ecuador. The vegetation consists primarily of cushio n plants (Werneria humilis, Plantago rigida) interspersed with ·,rari·o\15-herb--curd shrub specie s (for detaile d site descriptions. see Diemer 1996). Microclimate measurements weic done on a level plateau. Precipitation during the period 26 March to 26 April amoun ted to 94 mm, while merely 8 mm were recorded from 27 April to 14 May 1995 The second site 'Guagua Pichincha' (0°10'N 78°35'W) is located at an altitude of 4510 m on the eastern slope of the vo!ca~o Guagu a Pichin cha rough ly 10 km west of Quito. The vegetation is composed primar ily of herbaceous and rosette growt h forms (Plantago rigida, Werneria humilis, Hypoch oeris sonchoides, Culcitum n'ivale, C. reflexum), ;yith some graminoid species present. Precipitation from 28 March to 24 April amoun ted to 149 mm, but declined to 3 mm in the 3-week interval from 25 April to 13 May 1995. The highest study site 'Cayambe' (0°0l'N 78°01'W) is situate d at the base of volcan Cayambe in the vicinity of the mountaineers hut at an altitude of 4570 m . The sparse vegeta tion (cover <40%) is composed of herbaceous perenn ials and grasses. Precipitation from 22 March to 25 April1 995 amounted to merely 20 mm, althou gh tampering of the rain gauge by tourists cannot be exclud ed (see also Results).
Climate measurements Soil temperatures (-5 em depth) and quantu m flux density (QFD) were determined over the period November 1994 to April1 995 with autom ated datalogger s (,uLogger, Maure r Instr. AG, Baar, Switzerland) at the three sites. In additi on, anothe r datalogger, equipped with two miniat ure thermi stors was emplo yed from March to April1995 to monito r leaf tempe rature s at 'Paramo
256
Table I. Hourly mean soil temperatures (at -Scm depth) and quantu m flux density (QFD, ftmo! m-2s-1) at the three aramo sites. Instantaneous soil maximaare 11g er, w 1i e minima are 1-2 K lower.
SITE
SOIL.TEMPERP.TURES
QFD
n (Days)
(OC)
Daytime mean
Nightime mean
Max.
Min.
Daytime mean
Paramo de Ia Virgen
8.1±0.1
6.3±0.1
13.3
3.8
695:.+-25
142
Guagua Pichincha
7.8±0.2
5.7±0.1
11.2
4.1
692±31
114
Cayafl!be
5.6±0.4
3.7±0.3
9.4 -
-O.li-
759±28
39-78
As a result of measu remen t defects and tampe ring by tourists from the nearby mount aineer s hut, the data set from 'Cayambe' was drastic ally reduced, thus compa risons are not equivalent with respect to sample size. I u tilized a variety of smoothing functions to detect periodic pheno mena in the tem poral course of daily mean soil tempe ratures at 'Param o de la Virgen' af,ld 'Guagu a Pichincha'. Results utilizi ng a three-b inomia l function are depicfed in Figure 1. There was no indica tion of a periodism, in addition, long-term progression of daytime soil tempe rature at the two sites do not appea r to be correlated.
'157
Dicma
Ptimlltomicrodima.·,.
Mean daytime soil temverature (0 ( : ) w
~
\0
29. 11.94
-
N
V\
It
6.12.94 13.12.94
C)
c:
"'
20.1 2.94
0~
27.12.94
"'~
g.
3. 1.95
()
::r
"'
10.1.95
Table II. Hou rly mea ns of pla nt microclimate measurements of leaf surfaces. Instantaneous absolute maximum leaf temperatu res arc 3-l3K highet~ whi le minima are up to 1K lower.
'1:1
i·
0 0.
(>
;-
<
~::;·
(JQ (1>
::s
Species
Altitude
C.rowth form
(m.a.s.l)
Leaf tcm pcr~ turc (0 C) Max./ Min. Daytime
Nighttime (days)
Wemcrin t11tbigc11n
Herb
4060
9.0±0.8
22.9/ 0.3
2.7±0.2 .
4
Vnlerinun pilosn
Herb
4060
9.2±0.8
22.0/0.2
2.7±0.2
4
Culcililllltllilmlr
Herb
4510
6.1±0.2
10.7/-1.6
1.1±0.1
10
H!Jp()c/weris souchoides Herb
4510
11.7±0.6
26.6/ -3.2_
JlA±0...2....
J.(b
DiplostcpltitJm r11pestrc Shrub
4060
8.7±0.3
20.8 / -0.2
3.5±0.1
12
Bnccltnris nrbutifolin
406Cr
- 7:9±03
17.8/-0.8
3.4±0.1
12
11
17.1.9.'i 24. 1.95 31.1.95
Shntb
Mean leaf tempera tures of the four herbaceous perennial and two shrub taxa during daytime ranged from 6°C to l2°C (Table II) and corresponded roughly to daytime soil temperatures. No altitudi nal trehds were apparent during daytime, but nigh-time temperatures reflected an altitudinal trend. During daytime the extent of radiant heating, resulting fn daily maxima, was related to growth form and physiognomy. The three rosette herbs (Wemeria, Valeriano, Hypochoeris) reached instantaneous maximum daytime leaf temperatures in excess of 30°C (absol. maximum 34.8°C) and hourly mean maxill1a of 22°C to 27°C (Table It Fig. 2). The more erect leaves of Cu/citipm and the snrub species (Diplostephium, Baccharis), which are aerodynamically coupled to the atmosphere, attained lowe r mean daytime temperatures and lower maxima. At night (QFD <30 fimol m·2 s·t) leaf temperatures of all taxa were consistently lower than soil tem~eratures (Table II). Lowest leaf temperatures occu red at the highest site, both with respect to hourly means and minima. In addition, mimima were twice as low and incidents of frost were h igher in the rosette species (Hypocl10eris), compared to the more erect Culcitium · at 'Guagua Pichincha' (Table II).
7.2.95 14.2.95 21.2.95 2R.2.95 7.3.95 14.3.95 21.3.95 28.3.95 4.4.95 11.4.95 18.4.95 25.4.95
Figure 1. Time course of daily mean daytime soil temperatures of two paramo sites. Unsmoothed data and results of a 3-binomial model fit for 'Paramo de Ia Virgen' and 'Guagua Pichincha' are depicted.
258
Discussion Soil temperature data of Ecuadorean paramo sites (Table I) indicate that temperatures in the rooting zone are generally above 0°C. Hence water availability and nutrient mineralization is not curtailed by soil freezing. Heilbom
259
Diemer
Plirmrw microc/imntc
--o--
Wemerin leilf
--· Soil (·5cm)
0
2L3.
22.3.
23.3.
24.3.95
Figure 2. Time curse of QFD, leaf temperatu-re of Werneria nubigena and soil temperatu re (at -Scm depth) at 'Paramo de Ia Virgen' during a 4-day period in March 1995. Depicted values represent hourly mea ns of l O·minute measurement mtervals.
(1925) determined d~ytime soil temperatures (-Scm depth) ranging from 9oc to 14oc at 3650 m altitude on Rucu Pichincha. In the Andes of Venezuela soil temperat ures at 4250-4400 m altitude during the dry season ranged from 4°C to 1s oc (Perez 1989), which lies within the range observed in Ecuador (Tables I, II). However, night-time air temperatures are much lower in the more seasonal Andes of y enezuela (Sarmiento 1986). Le~f temperatures in e~cess of 20°C have been documen ted for alpine taxa of vanous growth forms m a number of mountain ranges, e.g. the European Alps (Larcher & Wagner 1976), Australia (Korner & Cochrane 1983) Rocky Mountai ns (Salisbury & Spomer 1964) and the Venezuelan Andes (Hedberg & Hedberg.1979). In the Andes of Venezuela, Hedberg and Hedberg (1979) observed dmrnal temperat ure amplitudes in excess of 20K, correspo nding to t~e ran?es observed at Gu~gua Pichincha (Table II). Hence during bright sunlight paramo plants expenence growth condition s which are compara ble not only to other mountain ranges, but also to lower elevations (e.g., Quito).
260
During overcast condition s and fog, however, leaf temperat ures approach soil temperatures (e.g., 6°C to l2°C}. It is at night, that altitudinal differences in leaf and soil temperat ures are most apparent (Tables I, II). However, night-time minima at equivalen t-al titudes at Mt. Kenya and in the p aramos of Venezuela are much lower than observed in this study, reaching 10°C below zero (Beck 1994, Larcher & Wagner 1986). Nevertheless the ecophysiology and growth of high elevation plants are well adapted even to these extreme temperature regimes (Korner & Larcher 1988). The effects of physiognomy on plant temperat ures are quite apparent in high elevation environm ets (Korner & Cochrane 1983, Grace 1987). Radiant heating of prostate vegetatio n can lead to leaf temperat ure in excess of 30°C in full sunlight, while erect tissues situaded- furthenrbo-vefhe soil surface.... maintain leaf temperat ures approaching ambient air temperature. At nighttime leaf temperat ures of prostate plants can be lower than in more erect growth forms, as a result of radiant cooling. This explains the differences between Hypochoeris and Culcitium at 'Guagua Pichicha' and the overall differences among herbaceous and woody (shrub) growth forms in Table II. Effects of radiant heating on the semi-erect forb, Wemeria nubigena, are documented in Figure 2. H ighest leaf temperatures were observed on 22 March, when mid-day QFD was highest. Under overcast conditions (QFD <500 pmol ro-2s·l) leaf temperat ures of Werneria were similar to soil temperature s, while during night-time leaves were consistently cooler than soils. Overall, diumal fluctuations of lea~ and soil temperatures in Ecuadorian paramos appear to be more moderate than at equivale nt altitudes in the Andes of Venezuela or in the puna to the south (Ruthsatz 1977). Temperat ure regimes of the paramo sites studied were well above the low-temperature thresholds of alpine e lants (Larcher & Wagner 1976), su ggesting that the climate permits continou s growth. In addition, no periodicities were observed within the 5-month temperature record (Fig. 1), which are reminiscent of the more seasonal Andes -of Venezuel a ot the puna. Indeed long-term measurements of leaf growth in Loricaria ilinissae at 'Paramo de Ia Virgen' (Diemer 1996) suggest that these shrubs grow continously at a relatively constant rate year-roun d. Acknow ledgemen ts Renato Valencia (Herbario QCA, P. Univ. Catolica, Quito) and Benjamin 0llgaard :(now Aarhus University) generous ly provided the infrastructure and necessary collecting permits in Ecuador, while S. Leon identified the plant species. L. Zimmerm ann (Univ. Basel) modified the climate loggers and
261
Diemer
helpe d with in the data analysis. Travel fund s and equip ment were made avail able by the Schweiz. Natio nalfo nds (P3139493.93 to MD). Literature cited BECK, E. 1994. Cold tolerance. Pp. 77-110 in Rundc l, P. W., Smith, A. P. & Meinzer. E C. (eds.). Tropical Alpine EHviroi/11/CII/S. Camb ridge Unive rsity Press, Cambridge. DIEMER, M. 1996. Microclimatic convergence of high-e levation aseasonal tropical pilramo and seasonal tempemte zone alpine environments. joumn l of Vcgctntion Science (in press) CRACE,). '1987. Climat ic toleran ce and the distrib ution of plants.. New l'llytologist106: 113-130 (suppl.). HEDBERG, I. & HEDBERG, 0. 1979. Tropical-alpine life-forms of vascular plants. Oikos 33: 297307. HEILBORN, 0. 1925. Contributions to the ecology of the Ecuadorian paramos with special reference to cushion-plants and osmotic pressure. Svc11sk Botn11isk Tidsskrift19: 153-170. JOHNSON, A.M. 1976. The climate of Peru, Bolivia and Ecuador. Pp. 147-218 in Schwerdtfeger, W. (ed.). World S11rvey ofClinmtology, Vol.12 . Elsevi er, Amsterdam. KORNER, Ch .. & COCHRANE, P. 1983. Influence of plant physiognomy on leaf temperature-enclear midsummer days in the Snowy Mountains, in south-eastern Australia. Occo/. Pln11t. 4: 117-124. KORNER, Ch. & LARCHER, W. 1988. Plant life in cold climates. Pp. 25-57 in Long, S. F. & Woodward, F. I. (eds.). Plnllls n11d Tcmpcrnlurc. Symp. Soc. Exp. Bioi. Vol. 42. CBL, Cambridge. LAHCHEn, W. & WAGNER, J. 1976. Temperaturgrcnzc n der C02-Aufnahme und Temperaturrcsistenz dcr Blatter voi1 Gebirgspflanzen im vegcta tionsaktiven Zustand. Deco/. PfaHl. 11: ~ 361-374. LE6N YANEZ, S. 1993. Estudio Eco/6gico y Fitogcogrrifico de In Vcgctnci611 del Prirnmo de Gun111m1i, Picllinclln-Nnpo, Ecuador. Tesis, Pontificia Uni versidad Cat6lica. Quito, Ecuador. · PEREZ, F. L. 1989. Some effects of giant Andean stem-r osettes on ground microclimate, and their ecological significance. illlcmnlionnl joumnl of Biomc/ corology 33: 131-135. RUNDEL, P. W. 1994. Tropical alpine climates. Pp. 21-44 in Runde!, P. W., Smith, A. P. & Meinzer, F. C. (eds.). Tropical Alpi11c Environ/llellfs. Cambridge Unive rsity Press, Cambridge. ·RUTHSATZ, B. 1977. Pflanzengesellschaften und ihre Lebensbedingungen in den Andinen Halbwi.isten Nord~est-Argentiniens. Disserlnlioncs Botnnicae 39. SALISBURY, F. B. & SPOMER, G. G. 1964. Leaf tempe ratures of alpine plants in the field. Plnnln 60: 497-505. SARMIENTO, G. 1986. Ecological features of climat e in high tropical mountains. Pp. 11-45 in_ Vuilleumier; F. & Monasterio, M. (eds.). Higlt Altitude Tropical Biogeogrnplty. Oxford University Press, Oxford.
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