Tropical forests are notable for their high species diversity, even on small spatial scales, and right-skewed species and size abundance distributions. The role of individual species as drivers of the spatial organization of diversity in these forests has been explained by several hypotheses and processes, for example, stochastic dilution, negative density dependence, or gap dynamics. These processes leave a signature in spatial distribution of small trees, particularly in the vicinity of large trees, likely having stronger effects on their neighbors. We are exploring species diversity patterns within the framework of various diversity-generating hypotheses using individual species-area relationships. We used the data from three tropical forest plots (Wanang-Papua New Guinea, Barro Colorado Island-Panama, and Sinharaja-Sri Lanka) and included also the saplings (DBH ≥ 1 cm). Resulting cross-size patterns of species richness and evenness reflect the dynamics of saplings affected by the distribution of large trees. When all individuals with DBH ≥1 cm are included, ~50% of all tree species from the 25- or 50-ha plot can be found within 35 m radius of an individual tree. For all trees, 72%-78% of species were identified as species richness accumulators, having more species present in their surroundings than expected by null models. This pattern was driven by small trees as the analysis of DBH >10 cm trees showed much lower proportion of accumulators, 14%-65% of species identified as richness repellers and had low richness of surrounding small trees. Only 11%-26% of species had lower species evenness than was expected by null models. High proportions of species richness accumulators were probably due to gap dynamics and support Janzen-Connell hypothesis driven by competition or top-down control by pathogens and herbivores. Observed species diversity patterns show the importance of including small tree size classes in analyses of the spatial organization of diversity.

Biology Centre CAS Institute of Entomology České Budějovice Czech Republic

Department of Botany University of Peradeniya Peradeniya Sri Lanka

Department of Plant Biology Bell Museum University of Minnesota St Paul MN USA

Department of Science and Technology Uva Wellassa University Badulla Sri Lanka

Faculty of Science University of South Bohemia České Budějovice Czech Republic

New Guinea Binatang Research Center Madang Papua New Guinea

Zobrazit více v PubMed

Aarssen, L. W. , Schamp, B. S. , & Pither, J. (2006). Why are there so many small plants? Implications for species coexistence. Journal of Ecology, 94, 569–580. 10.1111/j.1365-2745.2006.01128.x. DOI

Anderson‐Teixeira, K. J. , Davies, S. J. , Bennett, A. C. , Gonzalez‐Akre, E. B. , Muller‐Landau, H. C. , Wright, S. J. , Salim, K. A. , Almeyda Zambrano, A. M. , Alonso, A. , Baltzer, J. L. , Basset, Y. , Bourg, N. A. , Broadbent, E. N. , Brockelman, W. Y. , Bunyavejchewin, S. , Burslem, D. F. R. P. , Butt, N. , Cao, M. , Cardenas, D. , … Zimmerman, J. (2015). CTFS‐ForestGEO: A worldwide network monitoring forests in an era of global change. Global Change Biology, 21, 528–549. 10.1111/gcb.12712. PubMed DOI

Baddeley, A. , Rubak, E. , & Turner, R. (2015). Spatial point patterns: Methodology and applications with R. Chapman and Hall/CRC Press.

Chacón‐Labella, J. , de la Cruz, M. , & Escudero, A. (2016). Beyond the classical nurse species effect: Diversity assembly in a Mediterranean semi‐arid dwarf shrubland. Journal of Vegetation Science, 27, 80–88. 10.1111/jvs.12337 DOI

Chacón‐Labella, J. , de la Cruz, M. , & Escudero, A. (2017). Evidence for a stochastic geometry of biodiversity: The effects of species abundance, richness and intraspecific clustering. Journal of Ecology, 105, 382–390. 10.1111/1365-2745.12710. DOI

Chanthorn, W. , Wiegand, T. , Getzin, S. , Brockelman, W. Y. , & Nathalang, A. (2018). Spatial patterns of local species richness reveal importance of frugivores for tropical forest diversity. Journal of Ecology, 106, 925–935. 10.1111/1365-2745.12886 DOI

Chesson, P. (2000). Mechanisms of maintenance of species diversity. Annual Review of Ecology and Systematics, 31, 343–366. 10.1146/annurev.ecolsys.31.1.343 DOI

Clark, D. A. , & Clark, D. B. (1992). Life history diversity of canopy and emergent trees in a Neotropical Rain Forest. Ecological Monographs, 62, 315–344. 10.2307/2937114 DOI

Comita, L. S. , Condit, R. , & Hubbell, S. P. (2007). Developmental changes in habitat associations of tropical trees. Journal of Ecology, 95, 482–492. 10.1111/j.1365-2745.2007.01229.x DOI

Comita, L. S. , & Hubbell, S. P. (2009). Local neighborhood and species' shade tolerance influence survival in a diverse seedling bank. Ecology, 90, 328–334. 10.1890/08-0451.1 PubMed DOI

Condit, R. (1998). Tropical Forest Census Plots: Methods and results from Barro Colorado Island, Panama and a comparison with other plots. Springer‐Verlag.

Condit, R. , Perez, R. , Aguilar, S. , Lao, S. , Foster, R. , & Hubbell, S.P. (2019). Complete data from the Barro Colorado 50‐ha plot: 423617 trees, 35 years, 2019 version. 10.15146/5xcp-0d46. DOI

Condit, R. , Ashton, P. S. , Baker, P. , Bunyavejchewin, S. , Gunatilleke, S. , Gunatilleke, N. , Hubbell, S. P. , Foster, R. B. , Itoh, A. , LaFrankie, J. V. , Lee, H. S. , Losos, E. , Manokaran, N. , Sukumar, R. , & Yamakura, T. (2000). Spatial patterns in the distribution of tropic tree species. Science, 288, 1414–1418. 10.1126/science.288.5470.1414. PubMed DOI

Das, A. J. , Larson, A. J. , & Lutz, J. A. (2018). Individual species‐area relationships in temperate coniferous forests. Journal of Vegetation Science, 29, 317–324. 10.1111/jvs.12611 DOI

Espinosa, C. I. , de la Cruz, M. , Jara‐Guerrero, A. , Gusmán, E. , & Escudero, A. (2015). The effects of individual tree species on species diversity in a tropical dry forest change throughout ontogeny. Ecography, 39, 329–337. 10.1111/ecog.01328 DOI

Fibich, P. , Lepš, J. , Novotný, V. , Klimeš, P. , Těšitel, J. , Molem, K. , Damas, K. , & Weiblen, G. D. (2016). Spatial patterns of tree species distribution in New Guinea primary and secondary lowland rain forest. Journal of Vegetation Science, 27, 328–339. 10.1111/jvs.12363. DOI

Gray, A. N. , & Spies, T. A. (1997). Microsite controls on tree seedling establishment in conifer forest canopy gas. Ecology, 78, 2458–2473. 10.2307/2265906. DOI

Hillebrand, H. , Bennett, D. M. , & Cadotte, M. W. (2008). Consequences of dominance: A review of evenness effects on local and regional ecosystem processes. Ecology, 89, 1510–1520. 10.1890/07-1053.1 PubMed DOI

Hubbell, S. P. (2006). Neutral theory and the evolution of ecological equivalence. Ecology, 87, 1387–1398. https://doi.org/10.1890/0012‐9658(2006)87[1387:ntateo]2.0.co;2 PubMed

Hubbell, S. P. , Foster, R. B. , O'Brien, S. T. , Harms, K. E. , Condit, R. , Wechsler, B. , Wright, S. J. , & Loo de Lao, S. (1999). Light‐gap disturbances, recruitment limitation, and Tree Diversity in a Neotropical Forest. Science, 283, 554–557. 10.1126/science.283.5401.554. PubMed DOI

Janzen, D. H. (1970). Herbivores and the number of tree species in tropical forests. The American Naturalist, 104, 501–528. 10.1086/282687 DOI

Kirwan, L. , Lüscher, A. , Sebastià, M. T. , Finn, J. A. , Collins, R. P. , Porqueddu, C. , Helgadottir, A. , Baadshaug, O. H. , Brophy, C. , Coran, C. , Dalmannsdóttir, S. , Delgado, I. , Elgersma, A. , Fothergill, M. , Frankow‐lindberg, B. E. , Golinski, P. , Grieu, P. , Gustavsson, A. M. , Höglind, M. , … Connolly, J. (2007). Evenness drives consistent diversity effects in intensive grassland systems across 28 European sites. Journal of Ecology, 95, 530–539. 10.1111/j.1365-2745.2007.01225.x DOI

Kohyama, T. (1993). Size‐structured tree populations in gap dynamics forest: The forest architecture hypothesis for the stable coexistence of species. Journal of Ecology, 81, 131–143. 10.2307/2261230. DOI

LaManna, J. A. , Mangan, S. A. , Alonso, A. , Bourg, N. A. , Brockelman, W. Y. , Bunyavejchewin, S. , Chang, L.‐W. , Chiang, J.‐M. , Chuyong, G. B. , Clay, K. , Condit, R. , Cordell, S. , Davies, S. J. , Furniss, T. J. , Giardina, C. P. , Nimal Gunatilleke, I. A. U. , Savitri Gunatilleke, C. V. , He, F. , Howe, R. W. , … Myers, J. A. (2017). Plant diversity increases with the strength of negative density dependence at the global scale. Science, 356, 1389–1392. 10.1126/science.aam5678. PubMed DOI

Law, R. , Illian, J. , Burslem, D. F. R. P. , Gratzer, G. , Gunatilleke, C. V. S. , & Gunatilleke, I. A. U. N. (2009). Ecological information from spatial patterns of plants: Insights from point process theory. Journal of Ecology, 97, 616–628. 10.1111/j.1365-2745.2009.01510.x DOI

Lieberman, M. , & Lieberman, D. (2007). Nearest‐neighbor tree species combinations in tropical forest: The role of chance, and some consequences of high diversity. Oikos, 116, 377–386. 10.1111/j.2006.0030-1299.15370.x. DOI

Lieberman, M. , Lieberman, D. , & Peralta, R. (1989). Forests are not just Swiss cheese: Canopy stereogeometry of non‐gaps in tropical forests. Ecology, 70, 550–552. 10.2307/1940201 DOI

Loosmore, N. B. , & Ford, E. D. (2006). Statistical inference using the G or K point pattern spatial statistics. Ecology, 87, 1925–1931. https://doi.org/10.1890/0012‐9658(2006)87[1925:siutgo]2.0.co;2 PubMed

Lutz, A. J. , Furniss, T. J. , Johnson, D. J. , Davies, S. J. , Allen, D. , Alonso, A. , Anderson‐Teixeira, K. J. , Andrade, A. , Baltzer, J. , Becker, K. M. L. , Blomdahl, E. M. , Bourg, N. A. , Bunyavejchewin, S. , Burslem, D. F. R. P. , Cansler, C. A. , Cao, K. , Cao, M. , Cárdenas, D. , Chang, L.‐W. , … Zimmerman, J. K. (2018). Global importance of large‐diameter trees. Global Ecology and Biogeography, 27, 849–864. 10.1111/geb.12747. DOI

McGill, B. J. (2010). Towards a unification of unified theories of biodiversity. Ecology Letters, 13, 627–642. 10.1111/j.1461-0248.2010.01449.x PubMed DOI

Murphy, S. J. , Wiegand, T. , & Comita, L. S. (2017). Distance‐dependent seedling mortality and long‐term spacing dynamics in a neotropical forest community. Ecology Letters, 20, 1469–1478. 10.1111/ele.12856 PubMed DOI

Myllymäki, M. , Mrkvička, T. , Grabarnik, P. , Seijo, H. , & Hahn, U. (2017). Global envelope tests for spatial processes. Journal of the Royal Statistical Society Series B. Statistical Methodology, 79, 381–404. 10.1111/rssb.12172. DOI

Oksanen, J. , Blanchet, F. G. , Friendly, M. , Kindt, R. , Legendre, P. , McGlinn, D. , Minchin, P. R. , Gavin, R. B. O. , Simpson, L. , Solymos, P. , Stevens, M. H. H. , Szoecs, E. , & Wagner, H. (2017). vegan: Community Ecology Package. R package version 2.5‐2.

Perry, G. L. W. , Miller, B. P. , Lamont, B. B. , & Enright, N. J. (2017). Community‐level spatial structure supports a model of stochastic geometry in species‐rich shrublands. Oikos, 126, 833–842. 10.1111/oik.03680. DOI

Pielou, E. C. (1969). An introduction to mathematical ecology. Wiley‐Interscience.

Plotkin, J. B. , Chave, J. , & Ashton, P. S. (2002). Cluster analysis of spatial pattern in Malaysian tree species. The American Naturalist, 160, 629–644. 10.1086/342823. PubMed DOI

Punchi‐Manage, R. , Getzin, S. , Wiegand, T. , Kanagaraj, R. , Savitri Gunatilleke, C. V. , Nimal Gunatilleke, I. A. U. , Wiegand, K. , & Huth, A. (2013). Effects of topography on structuring local species assemblages in a Sri Lankan mixed dipterocarp forest. Journal of Ecology, 101, 149–160. 10.1111/1365-2745.12017 PubMed DOI

Punchi‐Manage, R. , Wiegand, T. , Wiegand, K. , Getzin, S. , Huth, A. , Gunatilleke, C. V. S. , & Gunatilleke, I. A. U. N. (2015). Neighborhood diversity of large trees shows independent species patterns in a mixed dipterocarp forest in Sri Lanka. Ecology, 96, 1823–1834. 10.1890/14-1477.1 PubMed DOI

R Core Team (2018). R: A language and environment for statistical computing. R Foundation for Statistical Computing. https://www.R‐project.org/

Rajala, T. , Olhede, S. C. , & Murrell, D. J. (2018). When do we have the power to detect biological interactions in spatial point patterns. Journal of Ecology, 107, 711–721. 10.1111/1365-2745.13080. PubMed DOI PMC

Reardon, S. F. , & O'Sullivan, D. (2004). Measures of spatial segregation. Sociological Methodology, 34, 121–162. 10.1111/j.0081-1750.2004.00150.x. DOI

Shimatani, K. , & Kubota, Y. (2004). Quantitative assessment of multIEARcies spatial pattern with high species diversity. Ecological Research, 19, 149–163. 10.1111/j.1440-1703.2003.00619.x. DOI

Velázquez, E. , & Wiegand, T. (2020). Competition for light and persistence of rare light‐demanding species within tree‐fall gaps in a moist tropical forest. Ecology, 101, e03034. 10.1002/ecy.3034 PubMed DOI

Vincent, J. B. (2015). Community ecology of New Guinea rainforest trees: Carbon storage, dynamics, and fungal endosymbionts. PhD thesis, University of Minnesota.

Vincent, J. B. , Henning, B. , Saulei, S. , Sosanika, G. , & Weiblen, G. D. (2015). Forest carbon in lowland Papua New Guinea: Local variation and the importance of small trees. Austral Ecology, 40, 151–159. https://dx.doi.org/10.1111%2Faec.12187. PubMed PMC

Wang, X. , Wiegand, T. , Kraft, N. J. B. , Swenson, N. G. , Davies, S. J. , Hao, Z. , Howe, R. , Lin, Y. , Ma, K. , Mi, X. , Su, S.‐H. , Sun, I. , & Wolf, A. (2016). Stochastic dilution effects weaken deterministic effects of niche‐based processes in species rich forests. Ecology, 97, 347–360. 10.1890/14-2357.1. PubMed DOI

Wiegand, T. , Gunatilleke, C. V. S. , Gunatilleke, I. A. U. N. , & Huth, A. (2007). How individual species structure diversity in tropical forests. Proceedings of the National Academy of Sciences of the United States of America, 104, 19029–19033. 10.1073/pnas.0705621104. PubMed DOI PMC

Wiegand, T. , Gunatilleke, S. , & Gunatilleke, N. (2007). Species associations in a heterogeneous Sri Lankan dipterocarp forest. The American Naturalist, 170, 77–95. 10.1086/521240. PubMed DOI

Wiegand, T. , Huth, A. , Getzin, S. , Wang, X. , Hao, Z. , Savitri Gunatilleke, C. V. , & Nimal Gunatilleke, I. A. U. (2012). Testing the independence species’ arrangement assertion made by theories of stochastic geometry of biodiversity. Proceedings of the Royal Society. B, Biological Sciences, 279, 3312–3320. 10.1098/rspb.2012.0376. PubMed DOI PMC

Wiegand, T. , & Moloney, A. K. (2014). Handbook of spatial point‐pattern analysis in ecology. Chapman & Hall/CRC Press.

Wills, C. , Condit, R. , Foster, R. B. , & Hubbell, S. P. (1997). Strong density‐ and diversity‐related effects help to maintain tree species diversity in a Neotropical forest. Proceedings of the National Academy of Sciences of the United States of America, 94, 1252–1257. 10.1073/pnas.94.4.1252 PubMed DOI PMC

Yang, J. , Swenson, N. G. , Cao, M. , Chuyong, G. B. , Ewango, C. E. N. , Howe, R. , Kenfack, D. , Thomas, D. , Wolf, A. , & Lin, L. (2013). A phylogenetic perspective on the individual species‐area relationship in temperate and tropical tree communities. PLoS One, 8, e63192. 10.1371/journal.pone.0063192 PubMed DOI PMC

Zhang, Y. U. , Chen, H. Y. H. , & Reich, P. B. (2012). Forest productivity increases with evenness, species richness and trait variation: A global meta‐analysis. Journal of Ecology, 100, 742–749. 10.1111/j.1365-2745.2011.01944.x DOI