Your PDF has successfully downloaded.

You may be interested in finding more content on these topics:


You are not currently logged in.

Access JSTOR through your library or other institution:


Log in through your institution.

Journal Article

Species Associations in a Heterogeneous Sri Lankan Dipterocarp Forest

Thorsten Wiegand, Savithri Gunatilleke and Nimal Gunatilleke
The American Naturalist
Vol. 170, No. 4 (October 2007), pp. E77-E95
DOI: 10.1086/521240
Stable URL:
Page Count: 19
Were these topics helpful?
See something inaccurate? Let us know!

Select the topics that are inaccurate.

  • Download PDF
  • Add to My Lists
  • Cite this Item
We're having trouble loading this content. Download PDF instead.


Abstract: We used point pattern analysis to examine the spatial distribution of 46 common tree species (diameter at breast height >10 cm) in a fully mapped \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $500\times 500$ \end{document} ‐m tropical forest plot in Sinharaja, Sri Lanka. We aimed to disentangle the effect of species interactions (second‐order effects) and environment (first‐order effects) on the species’ spatial distributions. To characterize first‐order associations (segregation, overlap), we developed a classification scheme based on Ripley’s K and nearest‐neighbor statistics. We subsequently used heterogeneous Poisson null models, accounting for possible environmental heterogeneity, to reveal significant uni‐ and bivariate second‐order interactions (regularity, aggregation and repulsion, attraction). First‐order effects were strong; overall, 53% of all species pairs occupied largely disjoint areas (segregation), 40% showed partial overlap, and 6% overlapped. Only 5% of all species pairs showed significant second‐order effects, but about half of the species showed significant intraspecific effects. Significant plant‐plant interactions occurred mostly within 2–4 m and disappeared within 15–20 m of the focal plant. While lack of significant species interactions suggests support for the unified neutral theory, species’ observed spatial segregation does not support the assumptions of the neutral theory. The strong observed tendency of species to segregate may have supplementary effects on other processes promoting species coexistence.

Notes and References

This item contains 66 references.

Literature Cited
  • ['Ashton, P. S. 1964. Ecological studies in the mixed dipterocarp forests of Brunei state. Oxford Forestry Memoirs 25. Clarendon, Oxford.']
  • ['Baddeley, A., J. Møller, and R. Waagepetersen. 2000. Non‐ and semi‐parametric estimation of interaction in inhomogeneous point patterns. Statistica Neerlandica 54:329–350.']
  • ['Bazzaz, F. A. 1996. Plants in changing environments. Cambridge University Press, New York.']
  • ['Bruno, J. F., J. J. Stachowicz, and M. D. Bertness. 2003. Inclusion of facilitation into ecological theory. Trends in Ecology & Evolution 18:119–125.']
  • ['Callaway, R. M., and L. R. Walker 1997. Competition and facilitation: a synthetic approach to interactions in plant communities. Ecology 78:1958–1965.']
  • ['Chave, J. 2004. Neutral theory and community ecology. Ecology Letters 7:241–253.']
  • ['Chave, J., H. C. Muller‐Landau, and S. A. Levin. 2002. Comparing classical community models: theoretical consequences for patterns of diversity. American Naturalist 159:1–22.']
  • ['Chesson, P. 2000. General theory of competitive coexistence in spatially varying environments. Theoretical Population Biology 58:211–237.']
  • ['Clark, J. S., and J. S. McLachlan. 2003. Stability of forest biodiversity. Nature 423:635–638.']
  • ['Condit, R. 1998. Tropical forest census plots. Springer, Berlin, and Landes, Georgetown, TX.']
  • ['Condit, R., S. P. Hubbell, and R. B. Foster. 1992. Recruitment near conspecific adults and the maintenance of tree and shrub diversity in a Neotropical forest. American Naturalist 140:261–286.']
  • ['Condit, R., P. S. Ashton, P. Baker, S. Bunyavejchewin, S. Gunatilleke, N. Gunatilleke, S. P. Hubbell, et al. 2000. Spatial patterns in the distribution of tropical tree species. Science 288:1414–1418.']
  • ['Condit, R., N. Pitman, E. G. Leigh Jr., J. Chave, J. Terborgh, R. B. Foster, P. Núñez, et al. 2002. Beta diversity in tropical forest trees. Science 295:666–669.']
  • ['Condit, R., P. Ashton, S. Bunyavejchewin, H. S. Dattaraja, S. Davies, S. Esufali, C. Ewango, et al. 2006. The importance of demographic niches to tree diversity. Science 313:98–101.']
  • ['Connell, J. H. 1971. On the roles of natural enemies in preventing competitive exclusion in some marine animals and in rain forest trees. Pages 298–312 in P. J. den Boer and G. R. Gradwell, eds. Dynamics of populations. Proceedings of the Advanced Study Institute on Dynamics of Numbers in Populations, Oosterbeek, Netherlands. Pudoc, Wageningen.']
  • ['———. 1978. Diversity in tropical rainforests and coral reefs. Science 199:1302–1310.']
  • ['Connell, J. H., J. G. Tracey, and L. J. Webb. 1984. Compensatory recruitment, growth, and mortality as factors maintaining rain forest tree diversity. Ecological Monographs 54:141–164.']
  • ['Dale, M. R. T. 1999. Spatial pattern analysis in plant ecology. Cambridge University Press, Cambridge.']
  • ['Dalling, J. W., and S. P. Hubbell. 2002. Seed size, growth rate and gap microsite conditions as determinants of recruitment success for pioneer species. Journal of Ecology 90:557–568.']
  • ['Dassanayake, M. D. and F. R. Fosberg. 1980–2000. A revised handbook to the flora of Ceylon. Vols. 1–12. Amarind, New Delhi.']
  • ['De Rosayro, R. A. 1942. The soils and ecology of the wet evergreen forests of Ceylon. Tropical Agriculturist 98:70–80, 153–175.']
  • ['Diggle, P. J. 2003. Statistical analysis of point patterns. 2nd ed. Arnold, London.']
  • ['Diggle, P. J., V. Gómez‐Rubio, P. E. Brown, A. G. Chetwynd, and S. Gooding. 2007. Second‐order analysis of inhomogeneous spatial point processes using case‐control data. Biometrics 63:550–557.']
  • ['Guisan, A., and W. Thuiller. 2005. Predicting species distribution: offering more than simple habitat models. Ecology Letters 8:993–1009.']
  • ['Gunatilleke, C. V. S., I. A. U. N. Gunatilleke, A. U. K. Ethugala, and S. Esufali. 2004. Ecology in Sinharaja rain forest and the forest dynamic plot in Sri Lanka’s world heritage site. Wildlife Heritage Trust of Sri Lanka, Colombo.']
  • ['Gunatilleke, C. V. S., I. A. U. N. Gunatilleke, S. Esufali, K. E. Harms, P. M. S. Ashton, D. F. R. P. Burslem, and P. S. Ashton. 2006. Species‐habitat associations in a Sri Lankan dipterocarp forest. Journal of Tropical Ecology 22:371–384.']
  • ['Harms, K. E., R. Condit, S. P. Hubbell, and R. B. Foster. 2001. Habitat associations of trees and shrubs in a 50‐ha Neotropical forest plot. Journal of Ecology 89:947–959.']
  • ['He, F., and P. Legendre. 2002. Species diversity patterns derived from species‐area models. Ecology 83:1185–1198.']
  • ['Hubbell, S. P. 1997. A unified theory of biogeography and relative species abundance and its application to tropical rain forests and coral reefs. Coral Reefs 16:S9–S21.']
  • ['———. 2001. The unified neutral theory of biodiversity and biogeography. Princeton University Press, Princeton, NJ.']
  • ['———. 2005. Neutral theory in community ecology and the hypothesis of functional equivalence. Functional Ecology 19:166–172.']
  • ['Hubbell, S. P., and R. B. Foster. 1983. Diversity of canopy trees in Neotropical forest and implications for conservation. Pages 25–41 in S. Sutton, T. Whitmore, and A. Chadwick, eds. Tropical rain forest: ecology and management. Blackwell Scientific, London.']
  • ['———. 1986. Biology, chance and history and the structure of tropical rain forest tree communities. Pages 314–329 in J. M. Diamond and T. J. Case, eds. Community ecology. Harper and Row, New York.']
  • ['Hubbell, S. P., R. Condit, and R. B. Foster. 1990. Presence and absence of density dependence in a Neotropical tree community. Philosophical Transactions of the Royal Society B: Biological Sciences 330:269–281.']
  • ['Hubbell, S. P., R. B. Foster, S. O’Brien, B. Wechsler, R. Condit, K. Harms, S. J. Wright, and S. Loo de Lau. 1999. Light gaps, recruitment limitation and tree diversity in a Neotropical forest. Science 283:554–557.']
  • ['Hubbell, S. P., J. A. Ahumada, R. Condit, and R. B. Foster. 2001. Local neighborhood effects on long‐term survival of individual trees in a Neotropical forest. Ecological Research 16:859–875.']
  • ['Janzen, D. H. 1970. Herbivores and the number of tree species in tropical forests. American Naturalist 104:501–528.']
  • ['John, R., J. W. Dalling, K. E. Harms, J. B. Yavitt, R. F. Stallard, M. Mirabello, S. P. Hubbell, et al. 2007. Soil nutrients influence spatial distributions of tropical tree species. Proceedings of the National Academy of Sciences of the USA 104:864–869.']
  • ['Levins, R., and D. Culver. 1971. Regional coexistence of species and competition between rare species. Proceedings of the National Academy of Sciences of the USA 68:1246–1248.']
  • ['Lieberman, M., and D. Lieberman. 2007. Nearest‐neighbor tree species combinations in tropical forest: the role of chance, and some consequences of high diversity. Oikos 116:377– 386.']
  • ['Loosmore, N. B., and E. D. Ford. 2006. Statistical inference using the G or K point pattern spatial statistics. Ecology 87:1925–1931.']
  • ['Lortie, C. J., R. W. Brooker, P. Choler, Z. Kikvidze, R. Michalet, F. I. Pugnaire, and R. M. Callaway. 2004. Rethinking plant community theory. Oikos 107:433–438.']
  • ['Manokaran, N., J. V. LaFrankie, K. M. Kochuman, E. S. Quah, J. E. Klahn, P. S. Ashton, and S. P. Hubbell. 1992. Stand table and distribution of species in the 50‐ha research plot at Pasoh Forest Reserve. Forest Research Institute Malaysia, Kepong.']
  • ['McGill, B. J. 2003. A test of the unified neutral theory of biodiversity. Nature 422:881–888.']
  • ['Missa, O. 2005. The unified neutral theory of biodiversity and biogeography: alive and kicking. Bulletin of the British Ecological Society 36:12–17.']
  • ['Møller, J., and R. Waagepetersen. 2003. Statistical inference and simulation for spatial point processes. Chapman & Hall/CRC, Boca Raton, FL.']
  • ['Pacala, S. W., C. D. Canham, J. Saponara, J. Silander, R. Kobe, and E. Ribbens. 1996. Forest models defined by field measurements. II. Estimation, error analysis and dynamics. Ecological Monographs 66:1–43.']
  • ['Peters, H. A. 2003. Neighbour‐regulated mortality: the influence of positive and negative density dependence on tree populations in species‐rich tropical forests. Ecology Letters 6:757–765.']
  • ['Purves, D. W., and S. W. Pacala. 2005. Ecological drift in niche‐structured communities: neutral pattern does not imply neutral process. Pages 106–138 in D. Burslem, M. A. Pinardand, and S. E. Hartley, eds. Biotic interactions in tropical forests: their role in the maintenance of species diversity. Cambridge University Press, Cambridge.']
  • ['Ripley, B. D. 1976. The second‐order analysis of stationary point processes. Journal of Applied Probability 13:255–266.']
  • ['———. 1977. Modelling spatial patterns. Journal of the Royal Statistical Society B 39:172–212.']
  • ['———. 1981. Spatial statistics. Wiley, New York.']
  • ['Schurr, F. M., O. Bossdorf, S. J. Milton, and J. Schumacher. 2004. Spatial pattern formation in semi‐arid shrubland: a priori predicted versus observed pattern characteristics. Plant Ecology 173:271–282.']
  • ['Stoll, P., and D. M. Newbery. 2005. Evidence of species‐specific neighborhood effects in the dipterocarpaceae of a Bornean rain forest. Ecology 86:3048–3062.']
  • ['Stoyan, D., and H. Stoyan. 1994. Fractals, random shapes and point fields: methods of geometrical statistics. Wiley, Chichester.']
  • ['Svenning, J.‐C. 2001. On the role of microenvironmental heterogeneity in the ecology and diversification of Neotropical rain‐forest palms (Arecaceae). Botanical Review 67:1–53.']
  • ['Tilman, D. 2004. Niche tradeoffs, neutrality, and community structure: a stochastic theory of resource competition, invasion, and community assembly. Proceedings of the National Academy of Sciences of the USA 101:10854–10861.']
  • ['Uriarte, M., R. Condit, C. D. Canham, and S. P. Hubbell. 2004. A spatially explicit model of sapling growth in a tropical forest: does the identity of neighbours matter? Journal of Ecology 92:348–360.']
  • ['Valencia, R., R. Foster, G. Villa, R. Condit, J. C. Svenning, C. Hernandez, K. Romoleroux, E. Losos, E. Magard, and H. Balslev. 2004. Tree species distributions and local habitat variation in the Amazon: a large plot in eastern Ecuador. Journal of Ecology 92:214–229.']
  • ['Volkov, I., J. R. Banavar, F. He, S. P. Hubbell, and A. Maritan. 2005. Density dependence explains tree species abundance and diversity in tropical forests. Nature 438:658–661.']
  • ['Whitmore, T. C. 1984. Tropical rain forests of the Far East. Clarendon, Oxford.']
  • ['Wiegand, T., and K. A. Moloney. 2004. Rings, circles, and null‐models for point pattern analysis in ecology. Oikos 104:209–229.']
  • ['Wills, C., K. E. Harms, R. Condit, D. King, J. Thompson, F. He, H. C. Muller‐Landau, et al. 2006. Non‐random processes maintain diversity in tropical forests. Science 311:527–531.']
  • ['Wong, Y. K., and T. C. Whitmore. 1970. On the influence of soil properties on species distribution in a Malayan lowland dipterocarp forest. Malayan Forester 33:42–54.']
  • ['Wootton, J. T. 2005. Field parameterization and experimental test of the neutral theory of biodiversity. Nature 433:309–312.']
  • ['Wright, S. J. 2002. Plant diversity in tropical forests: a review of mechanisms of species coexistence. Oecologia (Berlin) 130:1–14.']
Part of Sustainability