Diversity-biogeography of Ecuadorean bamboos (Poaceae: Bambusoideae) and their allies - Clark 1997

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Estud ios sobre ]" ·--··_.wersidad y

c.ologia .· .'_: de : I ntas

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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

Ecumlormn lHllllll(mS

Diversity and biogeography of Ecuadorean bamboos (Poaceae: Bambusoideae) and their allies Lynn G. Clark

Department o}' Botany, lowu State University, Ames, Iowa 50011-1020 USA, tel (+ 1) 515-294-8218, fax(+ 1) 515-294-1337, emaillgclark@iastate.edu Abstract The Ecuadorean bamboos (Bambuseae, Olyreae) and their allies (Streptochaeteae, Phareae) comprise 14 genera and an estimated 75 species. The O lyrcae, Streptochaeteae, and Phareae are all herbaceous tribes dis tributed mainly in the Pacific .and Amazonian watersheds of Ecuador, and rarely occu r above 1000 m elevation. Of the 21 species of herbaceous bamboos and allies, only one, Phnrus ewndoriws, is endemic to Ecuador. Six genera and approximately 54 species of the Bambuseae (woody bamboos) occur in Ecuador, and all but nine of the species are found only above 2000 min elevation. Because of their ecologica l and economic importance, a brief discus..s.ioJLOLeac!LoLthe..slx.wq ody genera is included. Clwsquen, with an estimated 30 species, is the most diverse genus of woody bamboos in Ecuador. Nine teen (35%) of the woody bamboo species a re endemic to Ecuador, which contmsts: ;trongly-wtth an overall average of about 5% endemism at the species level for the I'oaceae in ¡Ecuador. The combined provinces of Napo and Sucumbios present the greatest total diversity of bamboos and allies, with 11 genera and 27 species. This area retains the greatest diversity of herbaceous species, but for woody bamboos, Loja is most diverse, with six genera and 27 species. With respect to broad geographic areas, the eastern Cordillera (>500 m) by far has the greatest total diversity, with 10 genera and 39 species.

Resumen Los bambues ecuatorianos (Bambuseae, Oly reae) y sus aliados (Streptochaeteae, Phareae) comprenden 14 generos y unas 75 especies. Olyreae, Streptochaete;.e y Phareae son tribus herbaceas distribuidas principal mente en los drenajes del Pacifico y de Ia amazonia del Ecuador, y raramente ocurren sobre los 1000 m de altitud. De las 21 especies de bambues herbaceos y aliados, solo una, Plrnrus ecuntloriws, es endemica del Ecuad or. Seis generos y aproximad amente 54 especies de Bambuseae (baml:iues lefiosos) existen e n el Ecuador. Todas, excepto nueve, se encuentran solamente por encima de los 2000 m de altitud. Debido a su gran importancia eco16gica y econ6mica, se presenta una discusi6n breve de cada uno de los seis generos lefiosos.

Cl111squen, con unas 30 especies, es el genero mas diverso de los bambues lefiosos en el Ecuador.

Diecinueve (35%) de las especies lefiosas son endemicas del Ecuador, lo cual presenta un contraste fu erte con el p romedio general de aproximadamente 5% de endemismo a nivel espedfico de Poaceae en el Ecuador. Las provincias de Napo y Sucumbios con 11 generos y 27 especies, presentan Ia diversidad total mas alta de bambues y sus afines. Esta area tiene Ia diversdad mas alta de especies herbaceas; pero para los bambues leii.osos, Ia provincia de Loja es Ia mas diversa, con seis generos y 27 especies. Respecto a amp lias a reas geograficas de Ia Cordillera Oriental (> 500 m de altitud) sin duda tiene Ia diversidad total m as alta, con 10 generos y 39 especies.

Introduhion The bamboos, of all the groups of grasses, remain the least well collected and the least well understood, but they are of great ecological and economic

51

L G. C/nrk

importance, particularly in tropical areas. In the broad sense, bamboos are perennial, rhizomatous forest grasses with oroad, stalked leaves and arm and fusoid cell~ in the chlorenchy ma. They retClin certain ancestral floral features such as the presence of three !odicules. From five to 15 tribes have been included within the Bambusoideae in recent classifications (Table I ir. Clark e,' nl. 1995), indicative of the great heterogeneity among the tribes and the conft.:sior. surrounding their relationships.

Tn a r~cent analyBis of grass phylogeny using sequence data from the chloroplast e ncoded ;1dhF gene, Clark eta/. (1995) showed that certain tribes · _,previously regarded .as herbaceous bamboos, the Anomochloeae, the Streptochaeteae, and the Phareae, represent -the most ancient lineages of grasses, and that ot~er tribes considered to be bamboos are more closely related to~other grass groups, leaving us with a much more narrowly cir~ C~llJ1SCribed cor11:ept of the Bambusoideae. Other molecuial'-G·a ta-supper-t- th-isphylogeny (Davi$ & Soreng 1993, Duvall & Morton 1996, Soreng & Davis 1995). At present, this subfamily is consi"de~tk!Ge-three tribes (Zhang et al. 1995): Bamhuseae (woody bamb-oos), the Buergersiochloeae (a rare, m:motypic, herbaceous tr~ue endemic to New Guinea), and the Olyreae (a diverse tribe of monoecious, herbaceous bamboos). Of these, both the Bambuseac and Clyreae are found in the New World. Tribes such as the Anomochioeae, Streptochaeteae, Phareae, and · Streptogyneae are here r~garded as b:~mboo aliies, until a more formal taxonomic disposition is available.

Tlu.> woody b;nnboos (Bambuseae) are characterized by their well developed rhizomes, stro!1gly lignified culms, new shoots with culm leaves tha t are specialized for the protection of immature tissue, foliage leaves with an outer ligule in additi on to the inner ligule, complex vegetative branching, and usually cyclica~· gregarious, and monocarpic flowering (Clark 1995). Worldwide, over 1100 species are distributed from 46°N latitude to 47°S latitude, and from sea level to over 4000 m in equatorial highlands (Clark 1995).

The Olyreae is a tribe of native American herbaceous bamboos of over 100 species with one weedy species also occurring in Africa. These bamboos typically occur in moist forests between 29°N latitude and 34°S latitude, and only occasionally are found above 1000 m elevation, with an upper limit of about 1500 m. The olyroid bamboos are rhizomatous and perennial, bu t lack culm leaves, strongly lignified culms, and complex vegetative branching.

Flowering in most occurs annually, the spikelets are unisexual, and the females have a hardened an thecium. At least some members of this tribe ap pear to be secondarily insect-pollinated (Soderstrom & Calderon 1971), and a number of species are adapted for ant or bird dispersal of the fruits

52

(Davidse 1987). . . . . . .

Clark (1995) summarized cucr~nt ctata on the d1ver.:>1ty and d-1stn butron of Andean woody bamboos, but recen t work on the bamboos and bamboo allies in preparation for a treatment of the subfamily for the Flora ()f-Eco:adgr has provided a more detailed underst;;wding ?f ba_mboo d iversity_ end bioge~­ graphy in this country. In this ?a per, rhe d;~ers1ty of b~m?oo~ m Ecuador rs described, as are the pa~terns of en_clc:mrsm a11.d· drstnbt;tlon that have emerged from analysis of thP data.

Materials and methods The data p resented he.re are derived from field observations ·in Ecuador by LGC, examination of specimens p rincipally from the herbari a AAU, F, ISC, K, MO, QCA, QCNE, and US, and a ftortstic n'PM:tlent of th~ Bambusoideae -(including-bamb:o.~cud:trJ.i:1...pr.eparation by l:.Gf;aod:B.r. Emmet J. Judziewicz (Universrty of Wis.::or.si....-;t: Diversity Worldwide, there are 80-90 generz. of bambc,os and over 1200 speGies, with the number of species distr~buted nearly evenly between the western and eastern hemispheres. The Bambuseae, with at least 60 genera and 1100 species, include by far the majority of bamboo diversity; 21 genera and approximately 450 species occur :n the western hemisphere, with an estimated 40 genera and 500-600 species in the eastern hemisphere (Clark 1995 and referen ces therein). Among the Americar: ·,voody bL.mboos, somewhat more than 40% of the species belong to one genus, Chusquea, which includes an estimated 200 species (Clark 1996a). The single native North American woody bamboo, Arundinaria, also has species in the eastern hemisphere. The Olyreae, with 20 genera and over 100 species, are exclusively American except for one weedy species that also occurs widely in Africa. Arnong-.the bamboo allies, the Anomochloeae, Streptochaeteae, Pharus (Phareae), and Streptogyna americana C. E. Hubbard (Streptogyneee) are strictly American, whereas Leptaspis R. Br. and Scrotochloa Judz. (the other two genera of the Phareae) and Streptogyna crinita P. Beauv. (the other species of this genus) are restricted to the eastern hemisphere. Therefore, 45 genera and approximately 560 species of bamboos and bamboo allies are known from the western hemisphere.

Ecuador, for its size, possesses an impressive diversity of bamboos and bamboo~ allies (Table I), with a total of 14 genera and 75 species. Two tribes, two genera, and eight species of bamboo allies are known from Ecuador, with Pharus ecuadoricus and Streptochaeta spicata subsp. ecuatoriana as the only

53

L. G. Clark

1

Ecumlorcmr l•nml•t~JS

endemic taxa (Table II). Although Streptogynn P. Beauv. is not documented from Ec~1ador, it is .to be expected as it is widely distributed and occurs in Colo.mb1a (Londono. 1990). Two tribes, 12 genera and approxim!'ltely 67 spe~1es of Bambus~.1dcae- are. found in Ecuador. (Table I). No species of Ol~reae are. endem1c, but approximately 20 taxa (including as yet undescnbe~ speCies) of Bambuse~e are !estricteq to Ecuador. Including bamboos, an estnnated 125 genera ~nd 600 species of grasses are known from Ecuador (S. Lregaard, per~. comm.); of these, about 5% of the species are endemic to the country. Th1s contrasts strongly with the estimated 35% endemism an:ong species of woody bamboos in Ecuador (Tables I, II). Thus, about twothirds of the known endemic grasses in Ecuador are actually woody bamboos.

Table I. Di~e.rsity. and e'~demism of bamboo tribes and their allies in Entad or.

(Numbers mclude estimates of undescribed-specie:; of Bambuseae.) .

Taxa

-

# of Species .

# of Endemic Species

Bamboo Allies Streptochaeteae Streptochaeta Schrad. ex Nees

2

0

Phareae Pharus P. Br.

6

Bambusoideae Olyreae Cryptochlon Swallen Lithaclme P. Beauv.

Olyra L. Pnrinna Aubl.

Parodiolym Soderstr. & Zuloaga Piresia Swallen .

Table II. Tnxa of bamboos and their allies endemic to Ecuador.

________ __ _______ ---.·- -·_.;.__

Phareae.

Streptochneteae Bambuseae

___:_

Phnrus ecuadoricus Judz.

Strcptoclweta spicata Nees subsp. ecuatoriana Judz.

Arthrostylidium ecuadorense Judz. & L. G. Clark"' Aulonemia longinristnta L. G. Clark & Londonob Chusquen fnlcnta L. G. Clark · Clwsquen leonardiorum L. G. Clark Chusquea loxcnsis L. G. Clark Chusquen macclurei L. G. Clark Clmsquen perligulntn (Pilger) McClure Neumlepis asymmelricaL. G. Clark Neurolcpis elatn (Kunth) Pilger Neurolepis fimbriligulata L. G. Clark subsp. fimbriligultffil Neurolepis lncganrdii L. G. Clark Neurolepis nann L. G. Clark Neurolepis rigida L. G. Clark Neurolepis villosa L. G. Clark Rhipidocladum sp. nov aff. harmonicum (Parodi) McClure.

aPossibly to be found in southern Colombia. brossibly to be found in northern Peru.

2 1 4 2 1 3

0 0 0 0 0 0

3 4 ca.30 2 12

Bambuseae Arthrostylidium Ruprecht Aulonemia Goudot Chusquea Kunth Guadua Kunth Neurolepis Meissner Rhipidocladum McClure

3

1 1 ca. 10 0 7 1

Total

65

21

54

Biogeography • The Olyreae, Streptochaeteae, and Phareae are found primarily in the lowlands on both the Pacific and Amazonian watersheds (Table III), rarely ocurring above 1000 in in elevation. Ten species occur in the Pacific lowlands (Table III); five of these are restricted to this area in Ecuador and the one endemic species of herbaceous bambusoids, Pharus ecuadoricus, is found there. Streptochaeta is found only in the Pacific watershed in Ecuador, and S. spicata subsp. ecuatoriana is endemic (Table III). Sixteen species are found in the Amazonian watershed, of these 12 are restricted to this side of the Andes in Ecuador. Five species, all either weedy or widespread in the Americas, occur in both watersheds (Table III). Eleven species of herbaceous bamboo and allies are found at elevations above 500 m in Ecuador, including the five species that occur in both watersheds.

In contrast, the Ecuadorian woody bamboos are largely montane, with only nine of the approximately 54 species found below 2000 m in elevation

55

L. G. Chi'/:

Ewadorenu /mm/roos

Table HI. Dis tribution of he rbaceous barn!:loos·;md their allies;,~ ..;CL <.·::c ·.

20

- - - - - - - - - - - - - -· "" --~-..:..._~~....,.,....-~=== Pacific Watershed

Plwrtts ecundoriws• P!tnrus urczii Phnrus pnrvJfolius · subsp. e/ongntus Streptochnetn sodironnn Streptocl;~eTn spicntnsubsp. spicntn Streptochnctn spicnta. subsp. ewatorinnn..

Cryptocltlon strict iflorn

Plmrus !niifoiiu~. · Phnms parvifolius P/;nrus viresccns Lillmclllle pnuciflora Qlym !atifolir.

------·- -----

• Taxa endemic to Ecu,1dor

'F1111rus :appulnc;::t; . f'!inms pnrvifolins 3ll!'~P· pr.rt•ijolius Cryptoc!tlon unispiotlr.!n Parinnn cnmpestris Pnriann mtlicif!om Parotliolyra Intern/is Piresia goddii Piresin Jeptopl:!flla Piresin sympodicn Olyrn cnudntn O!yrn ecmtdn!.a...

Oiym longijoiia

15

."'

0

Total No. of Species

~~ endemic species

:I)

8.

(/) 10 0

_o

-

-- -----:---··------ ~.

1000

(Fig. 1). All of the 20 endemic woody species occur above 2000 m (Fig. 1).

Over one-half of the woody species can o~ found between 2500 m and ~500 m (Fig. 1~, although a few of these taxa also occur at somewhat lower or higher elevations. When diversity among broad regions of Ecuador is examined, differences in total diversity and endemism are evident (Table IV). AlthouO'h additional fieldwork may uncover new records extending distributions fo~a few of these species, it is clear that the greatest diversity of woody bambo~ in Ecu.ador is found in the eastern cordillera, where a total of 31 species occur, of whrch 20 are restricted to that cordillera . Eleven of the 21 are endemic tu....

Ecuador. A total of 16 species is documented for the western cordillera, of which five are restricted there, with two endemic. Eleven species occur in both cordilleras, although a few are mostly in one cordillera with one or a few scattered populations in the other; three of these species are endemic to Ecuador. Two species are known from the Pacific lowlands (<500 m in elevation), and four are known from the Amazon Basin (<500 m), although the bamboo flora of the latter region is not well explored, and additional species, especially of Arthrostylidium and Guadua, may be discovered there.

Elytrostachys McClure, a widespread but uncommon genus, is known from Colombia and Peru (Clark 1995) and may be expected in the Amazonian watershed of Ecuador.

56

2000

3000

4000

Allitude in m

Figure 1. Altitudinal distribution and endemism of Bambuseae in Ecuador (described species only).

-with~cucrdm-;-the combined provinces of. Napo and Sucumbios have the greatest diversity, with 11 genera and 27 species. These two provi':lces were kept together for the purposes of this paper because it was not always possible to assign a province to collection localities cited on older specimens.

With reference to the Olyreae, Napo/Sucum bios has the greatest diversity, with five genera and 11 species, but the diversity of Bambuseae is greatest in Loja, where six genera and 27 species occur, although six genera and 20 species are known from Zamora-Chinchipe, and the provinces of Azuay, Napo/Sucum bfos and Pichincha each have between 11 and 13 species of woody bamboos. In terms of total bamboo diversity (including bamboo allies) in broad geographic regions, the Pacific watershed (<500 m) is the least diverse,; with 12 species in 7 genera, with the eastern cordillera (>500 m) being most diverse, w1th 39 species in 10 genera. The western cordillera (>500 m) and the Amazonian watershed ( <500 m) each have 10 genera, with 21 and 20 species respectively.

57

L. G. CJqri;

"'

The Olyreae usually grow in humid lowland forests in the herbaceous layer; ·and can f.orm large colonies. Some species such as 0/yra laf!Jolia a!hl _[jthaclme pauciflora are widespre.a.d_an_d_ey~}'~CCu.rri.ng in -..saGQfl..@..r;:Y.lta~.,~~~ t the major if¥ of O ly.reae and.tbe her.b..aceo~ fer relativ~Jy yndisturbed forests . allhougl:[several c_at:Lp.e.rsjsfJn._s_econdary \l'egetatiOrt:-Ri.gormis-erologica-J-stmites-oftlretrerbaceous bambtros-rem:ain tobe done, and· the reproductive biology of these species begs tor tartltet mves.tigation: The· economic importance of the herbaceous bamboos is limited.

The typically montane Bambuseae, on the other hand, are extremely important both ecologically and econ omically in Ecuador. A number of species, particularly of Chusquea, can be aggressive colonizers of disturbed areas in montane forests (Veblen 1982, Young 1991, Stern 1992, 1995), and at higher elevations, Neurolepis can be a domjrnmt-=eJ.ernenhn-pokamo=vegetation (Lcegaard 1992). ·Especially--i-n--the Pacjfj, lowlands, Grmdwz • an form large stands,.....<ul.d---.is-rommonly u sed for constructmg low-cos t housmg (Parsons 1991, Young 1992). Because of the importance of these woody-genera, a brief summary of each genus in Ecuador is included her~-fsee-Glark-1-995 for additional information and refer ences and McClure 1973 fo r illustrations). ~ Arthrostylidium. Three species are known from Ecuador (Table I). The genus in Ecuador can be recognized by the relatively slender, clambei'i:Dg culms, erect culm leaf blades, and non-apsidate branch complements derived from a promontory. Arthrostylidium eauadorense is a delicate vinin g species with the highest altitudinal range (up to 3700 m) in the genus-(€tark 1995, Judziewicz & Clark 1993). The middle elevation species, A. youngianum, is known- enJ.y- fro m n orthern- Ecuador. Art11rostyliaium simpliciusculum is known only from low altitudes in Napo/Sucumbfos, but is likely to be more widespread within the Amazonian watershed of Ecuador.

Au/anemia. The four Ecuadorian species of Aulonemia are easily recognized by their reflexed culm leaf blades, prominent, curly fimbriae on both culm and foliage leaf sheaths, usually broad and reflexed foliage leaf blades, and non-apsidate branch complem ents. All four species are found between 2200 m and 3500 m in elevation, u s ually in scattered, discrete clumps, although A.longiaristata can form extensive stands on ridgetops (Clark 1995).

Aulonemia queko or "duda" is prized for its long internodes, which can reach up to two meters in length, and is u sed extensively for m aking baskets, other handicr~fts, and musical instruments. This species is becoming threatened througllout its r ange due to h abita t destruction and overharvesting (Londono 1990).

Chusquea. This genus is easy to recognize based on its solid culms and the

"0

r: {: ~

...J

c•

:

:.;::;

v...

'-<

~ -~ c~.~

~~ :::._ :.<

:::

t; rJ

·~ ~ ~j

fruadoremr bamboos

0

s::

..

'<ii 1%)

§ N

s"'

<

58

59

L. C. C!nrk

presence of multip~, dimorphic buds /branches at each node. About 30 s pecies of C/1/lsquca RP.! thought to occur in Ecuador. Sixteen of these are described and confirmed, another 12 or so remain to be described, and two additional species from neighboriug Peru and Colombia are expected to be bund in Ecuador. All but two of the 30·siJecies tire strictly Andean, and about 10, or 33%, are endemic to Ecuador. A few of the larger species may be used for making baske~s and fences, c'.lt generally the importance of Chusquea is more ecologica!, given the colonizing ability of some species. Although the aggregate altitudinal range of Chusqu~a in Ecuador is from sea level to 3500 m, only four species ara found below 2000 m. See Clark (1995) for more detail ori diversity within Chusquea.

Guadua. At least two species of this _thorny genus are known from Ecuador. The low diversity of this genus in Ecuador belies its economic and cultural importance (M':Clure 1-%6;-P.a-rstms 1991, Young 1992). Guadua angustifolia is of major economic importunce in the Pacific region, where it is used in construction of ho.)ses. Projects are underway to exploit this bamboo as a material. for low-incom e prefabricated housing. Guadua weberbaueri, known only from lowland Loja and Za;:r.ora-Chi•-.chipe, is relatively uncommon in Ecuador. A third species, G. superba Huber, likely occurs in Amazonia n Ecuado~but diagnostic collections have not been made.

Neurc!epis. This unusuai genus is remarkable for its often large leaves and the lack of branching in its aerial culms. The twelve Ecuadorian species grow in up?er montane forests and pilramcs where they can be common and even dominant, especially in southern and central Ecuador .(Clark 1996b).

According to Lcegaard (1992), species of Neurolepis probably do not survive repeated fires. Neurolepis is found between 2000 m and 4300 m in elevation, but most of the species orcur between 2500 m and 3600 m. Two ·species, N. aristata and N. villosa, both grow above 4000 m, but N. aristata, reaching 4300 min elevation, has the highest altitudinal limit known for any woody bamboo. The leaves of N. nobilis, which may attain 3-4m in length, are sometimes used for thatch. Ecuador is unquestionably a center of diversity, if not evolution, for the genus; seven of the 12 species are endemic·to Ecuador, and no other country has as many species, although Colombia, with an estimated 10 species, is a close second.

Rhipidocladum. The three species of Rhipidocladum in Ecuador can be distinguished by their thin-walle d culms, erect culm leaf blades, and apsidate branch complements without a promontory. Rhipidocladum racemiflorum is found at elevations from 500 m to 1250 m in Ecuador, and often persists in quebradas and along roadsides in secondary vegetation. Rhipidocladum harmonicum is typical of lower and upper montane forests from 1700 m to 2950

60

t wadCJrcmr />m11boos

rn. The third species, as yet undescribed, is related to R. ~~r.rmonicum and is known only from two populations in southern Ecuactm:~.-

Discussion The very high level of endemism among woody bamboos in Ecttador, and probably elsewhere in the Andes, is striking, and I specula te that it is likely related to their long flowering cycles, montane habitats with often isolated, island-like populations, and apparently lower dispersal abilities relative to. other grasses. While the Andes may have provided a significant barrier to dispersal of the herbaceou s bamboos, the woody bamboos adaptively radiated into the varied montane habitats of the Andean cordilleras. In particular Neurolepis, probably one of the more recently evolved genera of woody 15amboos -- giVenthat TtShigh montaue habitats did not become available u_ntil about hve mtlhon years before present (GE:?ntry 1982) has-s eiated exten.. sively in cua or. e re tive recency of origin o~ N~urolepis-and ossibl ' some of the other genera may_make it difficult to ad1ieve robust generic-level phylogenies, even with molecular techniques, but s:.1ch phylogenieS-are needed in order to test hypt)theses concerning the cvc!ution and biocgeography of these montane bamboos.

The high endemism in the Ecuadoria n woody bamboos has implication s fo1: both in situ and ex situ conservation priorities. To my knowledge, none of the bamboo species endemic to Ecuador is in cultivation, either in Ecuador or elsewhere. Some effort to remedy this situation is recommended, although American bamboos, w ith the exception of Guadua, are notoriously difficult to transplant and cultivate. More preferable would be the preservation of montane habitats, especially in the eastern cordillera, for woody ~mboos, and lowland habitats for Pharus ecuadoricus· and other herbaceous bamboo divers'ity, especially in the Amazonian watershed. Parque Nacional Podocarpu s in southern Ecuqdor; where a number of woody bamboo species are found, is an excellent example of protected montane vegetation, but additional such protected sites are needed.

The forthcoming floristic treatment of the bamboos of Ecuador will be useful for ecological and phytosociological studies and conservation efforts, · but should also serve as the fou ndation for· continuing study of the systematics, biogeography, and reproductive biology of the bamboos.

Acknowle dgments Fieldwork and research were supported by National Science Foundation Grants BSR-8906340 and DEB-9218657, a Foreign Travel Grant from Iowa State University, and a grant from the Center. for Tropical Biodiversity,

61

L. G. Clark

Denm ark (SNF 11-0390). I thank the herba rium staff at the Ponti ficia Universid ad Catol ica del Ecua dor for their assis tance durin g my visits to Ecuador, and the Aldv ar family for their hosp itality . I am especially grate ful to Simo n Lcegaard, Benja min 0 Ilgaa rd, Henr ik- Balslev and the herba rium . staff at Aarh us Univ ersity, Denm ark for maki ng possible my stay there in 1995 durin g which time most of these data were compiled.

Literature cited

Ecuadoreau hmuboos Notlwfngus forests and their influences in fo rest dynam ics. Bulletin of tl1e Torrey Bo:anical Club 109: 474-487. .

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