nrr nrr nrr nrrr r r r rr rr rr rrrn rn rn rn nrn nrn nrn nrn rnnnnnrnrrnr !nr ABSTRACT Monteverde, Costa Rica is home to a quintessential lower montane cloud forest that supports an amazing diversity of epiphytes. Windbreaks comprised of the exotic Cupressus lusitanica are common surrounding deforested areas. C. lusitanica appears to be poor epiphyte habitat when compared to a native species Myrsine coriacea. This survey was conducted using species richness a nd occurrence data collected using transparent acetates. This survey examines the idea that C. lusitanica supports reduced epiphyte diversity. The survey determined that the apparent difference in epiphyte richness and community composition is significant. ANCOVA analysis revealed several negat ive correlations for M. coriacea but not C. lusitanica. Lichen and moss abundance were affected by each oth ers abundance as well as by CBH. ------------------------------------------------------------------------------------------------------------------------------RESUMEN Monteverde, Costa Rica alberga un bosque montane ba jo unboso que sostiene una diversidad asombrosa de epiftas. Los rompe-vientos abarcados por la extic a Cupressus lusitanica son comunes en reas deforestadas de los alrededores. Cupressus lusitanica aparece ser un hbitat pobre en epiftas cuando se compara con la especie nativa Myrsine coriaceae Este estudio fue conducido usando la riqueza de e species y los datos de la ocurrencia recogidos usando los a cetatos transparentes. Este estudio examina adems la idea de que C. lusitanica disminuye la diversidad de epiftas. El estudio de termin que la diferencia evidente en riqueza de epiftas y la composicin de la comunidad es significativa. El anlisis de ANCO VA revel varias correlaciones negativas para M. coriaceae pero no en C. lusitanica La abundancia de lquenes y musgos se vi afectada por cada otras ab undancia as como por CBH. INTRODUCTION The lower montane cloud forest of Monteverde, Cost a Rica may support the most diverse epiphyte communities in the world with appr oximately 250 vascular (Ingram 1996) and 190 bryophyte (Gradstein 2000) species id entified from a single 4 hectare plot. However, epiphyte diversity in the areaÂ’s second gr owth forests, including native and planted non-native trees, appears to be greatly red uced. Deforestation in Monteverde
facilitated the negative effects of dry season wind s by promoting soil loss that reduced pasture grass production thereby reducing milk yiel ds (Burlingame 2000). In the 1980Â’s local farmers were encouraged to plant windbreaks i n order to protect soil and grasses, shield cattle, and restore forest coverage (Burling ame 2000). This effort resulted in over 500,000 trees being planted (Burlingame 2000) in ap proximately 1000 windbreaks that stretch a combined distance of 185 km (Harvey 2000) A handful of studies have examined the ecology of windbreaks of the Monteverd e area (Harvey 1999, Harvey and Haber 1999, Harvey 2000a, b), however, no study has been conducted on a species specific basis or focused on epiphytic communities. Cupressus lusitanica (Cupressaceae) is among the most commonly used windbreak species (Harvey 2000a, Harvey 2000b, Niel sen and DeRosier 2000, Burlingame 2000) and appear to be poor habitat for epiphytes ( personal observations ). Cupressus lusitanica is an exotic tree used because of a fast growth rat e, ease of cultivation on cleared land and extensive low branc hing (Burlingame 2000, Zuchowiski 2005). Myrsine coriacea is a native tree with similar growth patterns (Hab er et al. 2000) and, unlike C. lusitanica, appears to be good habitat for epiphytes ( personal observations ). Myrsine coriacea is not planted in windbreaks although the common n ame Â“ tapa viento Â”, Spanish for blocks wind, implies it has potentia l If M. coriacea is better habitat for epiphytes it may provide a native alter native to C. lusitanica. This study compares epiphyte communities between the two speci es in an attempt to determine whether the apparent reduction in epiphyte richness is significant. Since epiphytes are a dominant component of cloud forest ecosystems, a st udy of this nature will increase understanding of the role C. lusitanica windbreaks play in the ecosystem and help
establish how effective this species is as a refore station tool. In addition studies investigating why the richness is reduced can not b e undertaken until the difference is established to be significant. A variety of biological phenomena support the idea that epiphyte richness and occurrence should be the same between species. For instance, epiphytes are not dependent on their hosts for nutrients. In addition epiphyte communities become more complex with age and the specimens analyzed are of equal age (potentially younger in the case of M. coriacea ). Other phenomena support the idea C. lusitanica should have increased richness. For instance, Island Biogeography Theory (IBT) pred icts that targets of an equal distance from propagule sources and equal size and equal age should harbor equal richness and abundance. The average size of C. lusitanica in the study area is nearly double that of M. coriacea Therefore, IBT predicts increased richness and ab undance on C. lusitanica Personal observations as well as biological phenom ena contradict the idea that richness and abundance is increased. Cupressus lusitanica has very fast growth rates and studies conducted by Gentry and Vasquez (1993) show ed that epiphyte diversity is reduced on species with rapid growth rates. In addi tion C. lusitanica lacks resources that might attract disperser further supporting the idea that C. lusitanica would have reduced richness and abundance. Finally, conifers have been known to alter their environmental chemistry which may prevent epiphyte growth. Since biological phenomena exist to explain equal, reduced, or increased richness and a bundance I conducted a survey to determine if the observed richness and abundance ar e reduced on C. lusitanica. METHODS
This survey was conducted during the rainy season in a second growth lower montane forest adjacent to the Estacin Biolgica, Monteverde, Costa Rica (GPS). The site was chosen because succession on this property has progressed for a known amount of time allowing for assumptions to be made about t ree ages. The C. lusitanica examined were planted in 1987; the M. coriacea examined grew as a result of natural succession that began in 1987. This led to the assumption that all M. coriacea were of the same age, or younger than the C. lusitanica The area was paralleled, on one side, by interven ed but intact forest. The remainder of the site surroundin g consisted of second growth forest, a road and several residential establishments. This study analyzed epiphyte communities on 36 ind ividual trees (18 per species). Richness estimations were conducted on a morphospec ies basis. Total richness was determined by visual analysis of tree boles in an a rea between 0 m and 3 m from the tree base. Occurrence data were collected using transpar ent acetates with 304, 1 cm2, cells and recorded on a presence or absence basis. For this p resence or absence data was collected for lichen, moss, ferns, orchids and non-orchid ang iosperms. Bryophytes were considered present if they occupied 50% of the area of a cell; vascular plants were co nsidered present if found regardless of the percent of the c ell they occupied. Acetates were pinned to the east side of trees at 30 cm and 80 cm above ground. Occurrence data was pooled. Tree size measurements were taken using the circumf erence at breast height (cbh) method. In this study Â“BHÂ” is defined as eye level for an individual who 1.75 m tall. In the event that a tree forked before this height the larger of the two forks was measured. The data were analyzed using ANCOVA, linear regress ion, and T-test. RESULTS
A total of 26 morphospecies were identified and co nsisted of seven orchids, six lichen, five mosses, five ferns and three non-orchi d angiosperms. However, in occurrence surveys, non-orchid angiosperms were absent and orc hids were least abundant (n = 47), followed by ferns (n = 186). Lichens (n = 4078) and mosses (n = 13,329) were most abundant. Richness, total epiphyte abundance, and l ichen abundance were found to be significantly higher on M. coriacea while moss abundance was found to be significantly greater on C. lusitanica (Fig. 1) ANCOVA revealed no significant relationship betwee n variables for C. lusitanica (Table 1). ANCOVA revealed several significant rel ationships for M. coriacea (Table 2). All relationships reported by ANCOVA we re negative (Fig. 2). DISCUSSION The results support the impression that C. lusitanica harbors reduced epiphyte richness and abundance. A negative correlation goes against predictions that arise from IBT. Since hundreds of studies support IBT, I argue this is a result of a unique characteristic of C. lusitanica. The idea that C. lusitanica has unique characteristic is further supported by ANCOVA results since the corre lations between moss, lichen, DBH, and richness that were found on M. coriacea were not found on C. lusitanica. Now that the apparent reduction in epiphyte growth has been established future studies can investigate ecological explanations for this result. This may be due to conifers ability to alter the surrounding chemistry. In addi tion I observed bark peeling off of C. lusitanica. A reduction of animal traffic in these areas may a lso be responsible for this reduction. It is for these reasons I recommend futu re studies focus on bark characteristics such as chemistry and adhesion as well as the prese nce of dispersers.
Studies of Monteverde windbreaks have shown that t hey are a powerful reforestation tool by providing habitat for a varie ty of forest tree species, including those associated with primary growth forests (Harvey 2000 a). This is reportedly because of the shade they provide (Harvey 2000a). This study has s hown that M. coriacea supports greater biodiversity. For this reason I propose tha t it would be a better windbreak species. Beyond the increase in epiphyte richness M. coriacea has fruits that attract frugivorous birds (Haber et al. 2000). Removal of C. lusitanica windbreaks might disturb characteristics that allow primary growth forest tr ees to grow. Therefore I argue that M. coriacea should be added to C. lusitanica windbreaks in order to increase the occurrence and variety of these species. Unfortunately, M. coriacea is a light loving species and current windbreak structure may prevent its prolife ration. It is for this reason that I recommend future studies also investigate thinning effects on C. lusitanica windbreaks If thinning of C. lusitanica windbreaks does not alter their ability to support primary growth trees and increases the ability to support M. coriacea then the combination of these two species may prove to be a more powerful r eforestation tool. ACKNOWLEDGEMENTS I would like to thank CIEE for providing me with th e opportunity to come to Costa Rica and conduct thi s study. This research would not have been possible w ithout economic assistance provided by the Ping and Stafford foundations. The Estacin Biolgica provid ed housing as well as library and internet resource s. Pablo Allen and Jos Carlos Caldern provided much needed guidance during brainstorming and writing process. Finally, I would like to thank Karen Maste rs for being a great inspiration as well as providi ng invaluable assistance in field identifications, exp erimental design and a suitable study site. LITERATURE CITED Burlingame, J. L. 2000. Conservation in the Monteve rde area: Contributions of conservation organizations. In: Monteverde: Ecolog y and Conservation of a Tropical Cloud Forest Nadkarni, M. N., and N. T. Wheelwright, eds. Oxfo rd University Press, New York, page 351-376 Gradstein, S. R., M. I. Morales, and N. M. Nadkarni 2000. Diversity and habitat differentiation of mosses and liverworts in the clo ud forests of Monteverde, Costa
Rica. Caldasia 23(1): 203-212 Haber, A. W., W. Zuchowiski, and E. Bello. 2000. An Introduction to Cloud Forest Trees of Monteverde Costa Rica. Mountain Gem Publications, Monteverde page 134 Harvey, A. C. 2000a. Colonization of agricultural w indbreaks by forest trees: effects of connectivity and remnant trees. Ecol. Appl. 10(6): 1762Â–1773 Harvey, A. C. 2000b. Windbreaks enhance seed disper sal into agricultural landscapes in Monteverde, Costa Rica. Ecol. Appl. 10(1), 155Â–173 Nielsen, K., and D. DeRosier. 2000. Windbreaks as c orridors for birds. In: Monteverde: Ecology and Conservation of a Trop ical Cloud Forest Nadkarni, M. N., and N. T. Wheelwright, eds. Oxford Universit y Press, New York, page 351-376 Ingram, W. S., K. F. Ingram, and N. M. Nadkarni. 19 96. Floristic composition of vascular plants in a neotropical cloud forest, Mont everde, Costa Rica. Selbyana 17: 88-103 Zuchowiski, W. 2005. A Guide to Tropical Plants of Costa Rica A Zona Tropical Publications, San Jose. page 223
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Comunidades de epfitas en el rompe vientos Cupressus lusitanica y Myrsine coriacea, Monteverde, Costa Rica
Epiphyte communities in Cupressus lusitanica windbreaks and Myrsine coriacea, Monteverde, Costa Rica
Monteverde, Costa Rica is home to a quintessential lower montane cloud forest that supports an amazing diversity of epiphytes. Windbreaks comprised of the exotic Cupressus lusitanica are common surrounding deforested areas. C. lusitanica appears to be poor epiphyte habitat when compared to a native species Myrsine coriacea. This survey was conducted using species richness and occurrence data collected using transparent acetates. This survey examines the idea that C. lusitanica supports reduced epiphyte diversity. The survey determined that the apparent difference in epiphyte richness and community composition is significant. ANCOVA analysis revealed several negative correlations for M. coriacea but not C. lusitanica. Lichen and moss abundance were affected by each others abundance as well as by CBH.
Monteverde, Costa Rica alberga un bosque nuboso montano bajo que sostiene una diversidad asombrosa de epfitas. Los rompe vientos abarcados por la extica Cupressus lusitanica son comunes en reas deforestadas de los alrededores. Cupressus lusitanica parece ser un hbitat pobre en epfitas cuando se compara con la especie nativa Myrsine coriacea. Este estudio fue conducido usando la riqueza de especies y los datos recogidos de la ocurrencia usando los acetatos transparentes. Este estudio examina adems la idea de que C. lusitanica disminuye la diversidad de epfitas.
Text in English.
Epiphytes--Costa Rica--Puntarenas--Monteverde Zone
Cupressus lusitanica--Costa Rica--Puntarenas--Monteverde Zone
Myrsine coriacea--Costa Rica--Puntarenas--Monteverde Zone
Windbreaks, shelterbelts, etc.
Cloud forest ecology--Costa Rica
Epfitas--Costa Rica--Puntarenas--Zona de Monteverde
Cupressus lusitanica--Costa Rica--Puntarenas--Zona de Monteverde
Rompe vientos, corta vientos, etc
Ecologa del bosque nuboso--Costa Rica
Tropical Ecology 2008
Ecologa Tropical 2008
t Monteverde Institute : Tropical Ecology