|USFLDC Home | Tropical Ecology Collection [Monteverde Institute]||| RSS|
This item is only available as the following downloads:
xml version 1.0 encoding UTF-8 standalone no
record xmlns http:www.loc.govMARC21slim xmlns:xlink http:www.w3.org1999xlink xmlns:xsi http:www.w3.org2001XMLSchema-instance
leader 00000nas 2200000Ka 4500
controlfield tag 008 000000c19749999pautr p s 0 0eng d
datafield ind1 8 ind2 024
subfield code a M39-00138
McClure, Matthew S.
El hbitat y la diversidad de los invertebrados en un bosque nuboso
Habitat and diversity of cloud forest invertebrates
This study addresses the effects of abiotic conditions on canopy soil macro-invertebrate diversity by examining five Pacific and five Atlantic slope trees near the Biological Station in Monteverde, Costa Rica.
Trees were sampled using single rope climbing technique, and macro-invertebrate were separated from soil samples in Berlese funnels the same day of collection. The meta-community, both slopes as one community
showed that Coleoptera, Hymenoptera, and Hemiptera:Homoptera are the major taxa present. The two communities failed to show significant differences in their diversity (modified t-test = 1.03, p > 0.05), richness, and evenness from abiotic conditions. Biotic conditions must be the dominating factor controlling species overlap (8 species) between slopes. This is most likely due to interspecific interaction of invertebrates with plants. Random assortment probably controls most of the invertebrate assemblage for each individual tree.
Este estudio analiza los efectos de los factores abiticos en la diversidad de macroinvertebrados del suelo del dosel examinando cinco rboles de la pendiente del pacfico y cinco rboles de la pendiente del atlntico cerca de la Estacin Biolgica en Monteverde, Costa Rica.
Text in English.
Environmental impact analysis
Anlisis de impacto ambiental
Tropical Ecology 2007
Ecologa Tropical 2007
t Monteverde Institute : Tropical Ecology
Habitat and diversity of cloud forest invertebrates Matthew S. McClure Department of Ecology and Evolutionary Biology, University of Colorado ABSTRACT This study addresses the effects of abiotic conditions on canopy soil macroinvertebrate diversity by examining five Pacific and five Atlantic slope trees near the Biological Station in Monteverde, Costa Rica. Trees were sampled using single rope climbing technique, and macroinvertebrate were separated from soil samples in Berlese funnels the same day of c ollection. The meta community, both slopes as one community showed that Coleoptera, Hymenoptera, and Hemiptera:Homoptera are the major taxa present. The two communities failed to show significant differences in their diversity (modified t test = 1.03, p > 0.05), richness, and evenness from abiotic conditions. Biotic conditions must be the dominating factor controlling species overlap (8 species) between slopes. This is most likely due to interspecific interaction of invertebrates with plants. Random asso rtment probably controls most of the invertebrate assemblage for each individual tree. RESUMEN Este estudio dirige los efectos de condiciones no biticas en la diversidad de macroinvertebrate de tierra de dosel examinando cinco arboles pacfico y cinco r boles del atlnticos de la pencliente cerca de la Estacin Biolgica en Monteverde, Costa Rica. Los rboles utilizando una recuerdo para escalar y macroinvertebra dos fueron separado en muestras de suelo en tuneles de Berlese el misomo dia de la coleccion. La meta comunidad de, ambas las pendientes como una comunidad mostr que Coleoptera, Hymenoptera, y Hemiptera: Homoptera son las taxa mayormente presenteses. Las dos comunidades fallaron al mostrar las diferencias significativas en su diversidad (la T pr ueba modificada = 1,03, P> 0,05), riqueza, y la uniformidad de condiciones no biticas. Las condiciones biticas deben ser el factor que domina o que controla la superposicin de la especie (8 especie) entre cuestas. Esto es muy probable debido a la intera ccin de interspecific de los invertebrados con las plantas. La chistes bucion aleatoria controla probablemente la mayor parte de la coleccin del invertebrado para cada rbol individual. INTRODUCTION Many trees in tropical cloud forests harbor epiphytes that both create and maintain a layer of rotting organic matter along branches in the canopy. Epiphyte roots accumulate and hold plant litter but also contribute dead matter as they die or drop dead material on their host branches (Nadkarni and Matelson 1991). The presence of decaying matter encourages further growth of epiphytes and deposition of decomposing material; thus, a crown of organic humus begins to develop in these large canopy trees locked in place by the expanding root mass (Yanoviak et al. 2 004). These crowns of humus, much like the soil on the ground, are filled with decomposers and other organisms that are important to nutrient cycling (Wardle, et al. 2003). A study by Paoletii et al. (1991) comparing canopy and terrestrial soil invertebrat es demonstrated that invertebrate family diversity and composition were similar, despite the different abiotic conditions between the two microhabitats. The study did reveal, however, that densities of macro arthropods were much greater in canopy
soils. A lthough environmental conditions played a role in the density of arthropods between ground and arboreal soils, comparisons between two distinct canopy communities that experience different climatic conditions should provide insight if variable environmenta l conditions alter community density alone, or if they are responsible for community composition and diversity. I believe that a comparison of crown humus between two climatically different habitats would reveal a significant difference in arthropod abunda nce, if not also richness at the order level. I propose to compare the composition diversity, abundance, and richness of invertebrate communities in canopy soil of trees located on windward and leeward slopes behind the Biological Station, in Monteverde, Costa Rica. Each slope has a significantly different habitat; the Pacific (leeward) being more seasonal and typically less wet than the aseasonal Atlantic (windward) slope (Clark et al. 2000). Wind and water levels are more exaggerated in canopy soil du e to their exposed location at the top of trees, making them more vulnerable to changes in the environment. A study of canopy arthropod densities along a vertical stratification showed that arthropod populations peaked in size in the coolest and wettest p art of the tree (Dial et al. 2006). Dramatic in soil moisture should create different levels of decomposition, which should have a strong influence on soil nutrient availability. This should alter diversity, abundance, richness, and composition for each s lope's crown humus. METHODS I studied ten trees in the lower montane wet forest Holdridge life zone during the late dry season and very early wet season (April 9th May 5 th ) (Clark et al. 2000; Haber 2000). Five trees were selected on the Atlantic slope around 1680 m and five trees were selected on Pacific slope ranging from 1460 1700 m in the forest behind the Monteverde Biological Station Monteverde, Costa Rica. Trees were climbed based on their accessibility and possibly quantity of canopy soil avail able for extraction. I climbed each tree using a single rope technique (Moffett and Lowman 1995). I removed about one liter of soil from each tree by hand at heights ranging from nine to 18 m. Soil was removed from tree crotches and epiphytic root mats, with an emphasis on avoiding moss covered soil. On the day of collection, I placed the soil in a Berlese funnels set up, which was six plastic funnels with light bulbs (70 watts) suspended above them and allowed the sample to sit for 24 hours (Southwood 1978). After 24 hours, I removed the soil and sorted the dried remains by hand for remaining invertebrates. All other invertebrates were collected from the Berlese funnel collection bottle. Invertebrates were placed in collection vial with alcohol, and the dry soil samples were stored in plastic bags and both were labeled with their corresponding slope. After invertebrates were separated from the soil mats, I used a dissecting scope and classified them to Class, Order, and morphospecies. I also did soil tests on the dry soil for nitrogen, potassium, pH, and phosphorous using a La Motte soil testing kit and classified amounts in a qualitative form (e.g. trace, low, medium, high) with a corresponding numerical value for quantitative tests. I calculate d a Sorenson's similarity index value, evenness, species richness. I also conducted a Shannon Weiner test for the meta community, each slope, and each tree individually. I did a modified t test using the H' values from the Shannon Weiner test
0 0.5 1 1.5 2 2.5 3 H' E ATLANTIC PACIFIC 0 5 10 15 20 25 30 35 40 45 N S Atlantic Pacific between the two slopes. I calculated species area curves for each slope for the cumulative number of new species found in the order that the trees were sampled. RESULTS The diversity of between the Pacific slope (H' = 3.10) and the Atlantic slope (H' = 2.99) was n ot significantly different (Modified t test, t =1.03, p > 0.05) I calculated H', eveness, total number of individuals, and species richness for each slope, and each individual tree (Table1,Figures 1, 2). Sorenson's quantitative diversity index for the At lantic and Pacific slopes (C N = 0.282) showed some overlap in the diversity of species on each slope. I tabulated and calculated overlapping species of each community and their Order's relative percentages in regards to overall canopy composition (Table 2 ). A species area curve (Figure 3) shows the cumulative species acquisition after sampling ten canopy soils. Soil tests showed variable pH and phosphorous levels and uniformly low nitrogen and high potassium concentrations across all canopy soils conce ntrations in all canopy soils regardless of slope (Table 3). At the community level I calculated Spearman's Rank correlations for species richness, evenness, abundance, and diversity to see if the pH, potassium, nitrogen, and phosphorous and height had any relationship to species richness, evenness, abundance, or diversity; no trend was found for any parameter (Table 4). I also did the same correlation test for the Orders Coleoptera and Hemiptera: Homoptera versus the soil chemistry and height, and again, no trend was found (table 4). Figure 1. The Shannon Weiner diversity index (H') and eveness (E) values for Atlantic and Pacific canopy soil macroinvertebrate communities in a cloud forest near Monteverde, Costa Rica. (N = 5 trees for each slope ) Figure 2. The number of individuals (N) and the number of species (S) for the Atlantic and Pacific canopy soil macroinvertebrate communities in a cloud forest near Monteverde, Costa Rica. (n = 5 trees for each slope).
0 5 10 15 20 25 0 1 2 3 4 5 6 7 TREES NUMBER OF SPECIES 0 5 10 15 20 25 30 0 1 2 3 4 5 6 TREE # NUMBER OF SPECIES H' E N S P1 0.34 0.10 4 3 P2 0.00 0.00 0 0 P3 0.67 0.20 9 5 P4 0.76 0.23 10 7 P5 1.20 0.37 16 11 A1 0.52 0.17 4 4 A2 0.81 0.26 7 8 A3 0.72 0.23 7 7 A4 0.95 0.31 9 8 A5 0.28 0.09 3 3 OverallAtlantic 2.99 0.97 39 24 Overall Pacific 3.10 0.95 39 26 Figure 3. These species area curves show the rate of cumulative species accumulation in the order the trees were sampled in (n = 5 trees). The top graph (A) is for the Atlantic slope species accumulation and the bottom graph (B) is for the Paci fic slope. Samples were taken from a cloud forest near Monteverde, Costa Rica. Table 1. Values for the Shannon Weiner diversity test (H'), eveness (E), number of individuals (N), and number of species (S) for Pacific(P1 P5) and Atlantic(A1 A5) slop e canopy soil macroinvertebrate communities in a cloud forest near Monteverde, Costa Rica. (n = 5 trees for each slope). A B
Nitrogen Phosophorous Potassium pH A1 Trace Medium(2) Very High 5.2 A2 Trace High(3) Very High 4.6 A3 Trace Low(1) Very High 4.8 A4 Trace High(3) Very High 7.4 A5 Trace Medium(2) Very High 5.2 P1 Trace Low(1) Very High 5.2 P2 Trace Medium(2) Very High 4.6 P3 Trace Low(1) Very High 4.3 P4 Trace Low(1) Very High 5.1 P5 Trace Medium(2) Very High 4.8 Table 2. The number of shared species between Atlantic and Pacific slope canopy soil macroinvertebrates from a cloud forest near Monteverde, Costa Rica. The relative percentages of shared species in regards to both communities' S is presented in the far right column. Beetles and their larvae are responsible for the largest percentages. Table 3. Soi l data for ten soil samples collected from a cloud forest near Monteverde, Costa Rica. The numbers next to the qualitative descriptions in Phosphorous are a ranking of 1 3, with regards to each trees relative concentration in terms of their description. The far left column shows Atlantic slope trees (A1 A5) and the Pacific Slope trees (P1 P5). Shared Species Pacific Atlantic Totals Overall Percentage Beetle Larvae 3 2 5 0.06 White Spotted Beetle 2 1 3 0.04 Tiny Long Snout Beetle 2 1 3 0.04 Elongated Beetle 4 3 7 0.09 Striped Spider 1 1 2 0.03 Spiny Third Leg 1 1 2 0.03 Centipede 1 1 1 0.01 Millipede 1 3 4 0.05
Table 4. Spearman's Rank correlations comparing soil chemistry with its effects on species richness, diversity, evenness and overall ab undance of canopy soil collected from Monteverde, Costa Rica. It also looked for any patterns associated with the Orders Coleoptera and Hemiptera. The p values for all these correlations were above 0.05, with no significant relationship. DISCU SSION There are three levels to analyze this diversity data, at the meta community level, the local level with slope comparisons, and then at the individual level with tree to tree comparisons. The meta community, both slopes as one community, had a composition that was dominated at the Order level by three major taxa, Coleoptera, Hymenoptera, and Hemiptera:Homoptera. This domination matches current known abundances of insect Orders (Arnett et al. 1981). Species area curves show that not enough sampl ing has taken place, but there has been enough sampling to show that the invertebrates are at or very close their theoretical distributions. At the local community level, each slope is a community, Shannon Weiner diversity values, evenness, species abun dance, and species richness can be compared. These values did not differ between the communities significantly. The difference between the two local communities was what types of morpho species were present. There was an overlap of eight morpho species between the two communities. Commonness within the community appears to not determine overlap, because abundant taxa and non abundant taxa are present. Abiotic conditions probably did not result in the overlap of each slope. Besides soil moisture, each s ide was significantly the same in terms of their soil chemistry. There was a presence of a notable beetle population in both communities. This may be related to possible host specific interactions between beetles and epiphytes that are present in both comm unities (Odegaard 2000). The other species present may be there through random chance, although Odegaard in 2000 does mention Rho Value P pH Height(m) S 0.31 -0.04 0.18 H' 0.29 0.01 0.17 E 0.29 0.01 0.17 N -0.10 -0.10 -0.09 Coleoptera -0.14 0.34 -0.07 Hemiptera -0.17 0.68 -0.03
in his study that it is a possibility that community structure in a tree may be dependent on the presence of certain organisms. At the individual community level, each tree represents a single community that due to sampling, is separate from other study trees. These individual communities varied quite a bit in their individual abundances and richness. Correlations revealed that the height of sample, pH, and phosphorous were not related to diversity, evenness, richness and abundance values. Nor were the Orders Coleoptera and Hemiptera:Homoptera related to abiotic conditions. This puts an emphasis that these trees assemblages are not dominated by abiotic conditions, but probably by random chance and biological interactions. While many physical pathways such as lianas may connect these two communities, it appears that each individual patch of soil's invertebrates is not dominated by mere connections alone (Paoletti et al. 1991). Random assortment is possible, but colonization rates of the canopy soil may influence each tree's soil diversity (Moran and Southwood 1982; Wardle et al. 2003). If colonization is the main driving force t hen size of the soil and its relative age in the tree would be factors in how many species would be present in the soil. A biological explanation is possible, but there was no strong trend of certain individuals being present across all the samples like t here was at the local community level with the beetles, random assortment is probably the most logical and easier explanation (Moran and Southwood 1982). Aseasonality and seasonality may not be a contributor to strong changes in the soil chemistry that may influence the diversity of the two communities. The lack of significant difference between the two communities shows that biological factors affect to these communities. There was evidence that some beetles are related to possible biological assortin g due to possible host specific interactions due to their presence on both slopes. The possibility of a stochastic model existing for the assembly of a general tree is quite possible, due to the variation of recorded of each tree. ACKNOWLEDGEMENTS I wo uld like to thank Tom McFarland for helping with the Berlese funnel set up, climbing instruction, and statistical error prevention and Sara Weinstein for climbing with me and keeping wonderful notes. Also, I would like to thank Karen Masters for project c onsulting, Nick Sullender for his peer review, and finally the Biological Station in Monteverde for housing. LITERATURE CITED Arnett, R. H. and R. L. Jacques. 1981. Simon & Schuster's Guide to Insects pp. 19. Simon & Schuster Inc., New York, USA. C lark, K. L., R. O. Lawton, and P. R. Butler. 2000. The physical environment. In N. Nadkarni, and N. Wheelwright (Eds.). Monteverde Ecology and Conservation of a Tropical Cloud Forest, pp. 15 21. Oxford University Press, New York, USA. Dial, R. J., M. D. F. Ellwood, E. C. Turner, and W. A. Foster. (2006). Arthropod abundance, canopy structure, and microclimate in a Bornean lowland tropical rain forest. Biotropica : 38(5) 643 652. Haber, B. 2000. Plants and vegetation. In N. Nadkarni, and N. Wheelwright (Ed s.). Monteverde Ecology and Conservation of a Tropical Cloud Forest, pp. 42. Oxford University Press, New York, USA. Moffet, M. W., and M. D. Lowman. 1995. Canopy access techniques. In Lowman, M. D.,
and N. M. Nadkarni (Eds.). Forest canopies, pp 9 10. A cademic Press, San Diego, California. Moran, V. C. and T. R. E. Southwood. 1982. The guild composition of arthropod communities in trees. Journal of Animal Ecology 51: 289 306. Nadkarni, N. M., and J. T. Longino. 1990. Invertebrates in canopy and groun d organic matter in a neotropical montane forest, Costa Rica. Biotropica 22(3): 286 289. Nadkarni, N. M., and T. J. Matelson. 1991. Fine litter dynamics within the tree canopy of a tropical cloud forest. Ecology 72(6): 2071 2082. Paoletti, M. G., R.A.J. Taylor, B. R. Stinner, D. H Stinner, and D. H. Benzing. 1991. Diversity of soil fauna in the canopy and forest floor of a Venezuelan cloud forest. Journal of Tropical Ecology 7(3) : 373 383. Southwood, T. R. E. 1978. Ecological methods, pp. 184 187. Unive rsity Printing House, Cambridge, Great Britain. Wardle, D. A., G. W. Yeates, G. M. Barker, P. J. Bellingham, K. I. Bonner, and W. M. Williamson. 2003. Island biology and ecosystem functioning in epiphytic soil communities. Science 301:1717 1720. Yanoviak S. P., N. M. Nadkarni, and R. J. Solano. 2006. Arthropod assemblages in epiphyte mats of Costa Rican cloud forests. Biotropica 36(2): 202 210. Yanoviak, S. P., H. Walker, and N. M. Nadkarni. (2004). Arthropod assemblages in vegetative vs. humic port ions of epiphyte mats in a neotropical cloud forest. Pedobiologia 48: 51 58.