The interspecific growth–mortality trade-off is not a general framework for tropical forest community structure

Resource allocation within trees is a zero-sum game. Unavoidable trade-offs dictate that allocation to growth-promoting functions curtails other functions, generating a gradient of investment in growth versus survival along which tree species align, known as the interspecific growth–mortality trade-off. This paradigm is widely accepted but not well established. Using demographic data for 1,111 tree species across ten tropical forests, we tested the generality of the growth–mortality trade-off and evaluated its underlying drivers using two species-specific parameters describing resource allocation strategies: tolerance of resource limitation and responsiveness of allocation to resource access. Globally, a canonical growth–mortality trade-off emerged, but the trade-off was strongly observed only in less disturbance-prone forests, which contained diverse resource allocation strategies. Only half of disturbance-prone forests, which lacked tolerant species, exhibited the trade-off. Supported by a theoretical model, our findings raise questions about whether the growth–mortality trade-off is a universally applicable organizing framework for understanding tropical forest community structure

Interactions between all pairs of neighboring trees in 16 forests worldwide reveal details of unique ecological processes in each forest, and provide windows into their evolutionary histories

When Darwin visited the Galapagos archipelago, he observed that, in spite of the islands’ physical similarity, members of species that had dispersed to them recently were beginning to diverge from each other. He postulated that these divergences must have resulted primarily from interactions with sets of other species that had also diverged across these otherwise similar islands. By extrapolation, if Darwin is correct, such complex interactions must be driving species divergences across all ecosystems. However, many current general ecological theories that predict observed distributions of species in ecosystems do not take the details of between-species interactions into account. Here we quantify, in sixteen forest diversity plots (FDPs) worldwide, highly significant negative density-dependent (NDD) components of both conspecific and heterospecific between-tree interactions that affect the trees’ distributions, growth, recruitment, and mortality. These interactions decline smoothly in significance with increasing physical distance between trees. They also tend to decline in significance with increasing phylogenetic distance between the trees, but each FDP exhibits its own unique pattern of exceptions to this overall decline. Unique patterns of between-species interactions in ecosystems, of the general type that Darwin postulated, are likely to have contributed to the exceptions. We test the power of our null-model method by using a deliberately modified data set, and show that the method easily identifies the modifications. We examine how some of the exceptions, at the Wind River (USA) FDP, reveal new details of a known allelopathic effect of one of the Wind River gymnosperm species. Finally, we explore how similar analyses can be used to investigate details of many types of interactions in these complex ecosystems, and can provide clues to the evolution of these interactions

Data from: The contribution of rare species to community phylogenetic diversity across a global network of forest plots

Niche differentiation has been proposed as an explanation for rarity in species assemblages. Testing this hypothesis requires quantifying the ecological similarity of species. This similarity can potentially be estimated by using phylogenetic relatedness. In this study, we predicted that if niche differentiation does explain the co-occurrence of rare and common species, then rare species should contribute greatly to the overall community phylogenetic diversity (PD), abundance will have phylogenetic signal and that common and rare species will be phylogenetically dissimilar. We tested these predictions by developing a novel method that integrates species rank abundance distributions with phylogenetic trees and trend analyses to examine the relative contribution of individual species to the overall community PD. We then supplement this approach with analyses of phylogenetic signal in abundances and measures of phylogenetic similarity within and between rare and common species groups. We applied this analytical approach to 15 long-term temperate and tropical forest dynamics plots from around the world. We show that the niche differentiation hypothesis is supported in six forests but is rejected in nine forests, and that the three metrics utilized in this study each provide unique but corroborating information regarding the phylogenetic distribution of rarity in communities

The Contribution of Rare Species to Community Phylogenetic Diversity across a Global Network of Forest Plots

Niche differentiation has been proposed as an explanation for rarity in species assemblages. To test this hypothesis requires quantifying the ecological similarity of species. This similarity can potentially be estimated by using phylogenetic relatedness. In this study, we predicted that if niche differentiation does explain the co-occurrence of rare and common species, then rare species should contribute greatly to the overall community phylogenetic diversity (PD), abundance will have phylogenetic signal, and common and rare species will be phylogenetically dissimilar. We tested these predictions by developing a novel method that integrates species rank abundance distributions with phylogenetic trees and trend analyses, to examine the relative contribution of individual species to the overall community PD. We then supplement this approach with analyses of phylogenetic signal in abundances and measures of phylogenetic similarity within and between rare and common species groups. We applied this analytical approach to 15 long-term temperate and tropical forest dynamics plots from around the world. We show that the niche differentiation hypothesis is supported in six of the nine gap-dominated forests but is rejected in the six disturbance-dominated and three gap-dominated forests. We also show that the three metrics utilized in this study each provide unique but corroborating information regarding the phylogenetic distribution of rarity in communities

Species name and abundance in 15 forest dynamic plots

1.The data were used in paper "Xiangcheng Mi, Nathan G. Swenson, Renato Valencia, John Kress, David L. Erickson, álvaro J. Pérez, Haibao Ren, Sheng-Hsin Su, Nimal Gunatilleke, Savi Gunatilleke, Zhanqing Hao, Wanhui Ye, Min Cao, H S Suresh, H S Dattaraja, S Sukumar, Keping Ma. 2012. The contribution of rare species to community phylogenetic diversity across a global network of forest plots. American Naturalist (accepted for publication)." | 2. Data in each of 15 plots were provided with a "csv" file with plot name, and species name, genus,family and abundance and a species code were provided in each "csv" file. | 3. data sources: (1) data of Luquillo, Barro Colorado Island,La Planada, Yasuní,Huai Kha Khaeng, Mudumalai,Pasoh plots, are from "Smithsonian Institute Global Earth Observatories. URL http://www.sigeo.si.edu/." (2) data of Changbaishan plot from "Hao Z.Q., Li B.H., Zhang J., Wang X. G., Ye J., and Yao X. L., 2008. Broad-leaved Korean pine (Pinus koraiensis) mixed forest plot in Changbaishan (CBS) of China: community composition and structure. Chinese Journal of Plant Ecology, 32:238-250 (in Chinese with English abstract)"; (3) data of Gutianshan plot from "Legendre, P., X. Mi, H. Ren, K. Ma, M. Yu, I.-F. Sun, and F. He. 2009. Partitioning beta diversity in a subtropical broad-leaved forest of China. Ecology 90:663-674. Appendix A." (4) data of Dinghushan plot from "Wang, Z. G. 2007. Species diversity and mechanisms for maintenance of monsoon evergreen broadleaved forest in Dinghushan. Ph. D. Dissertation, South China Botanical Garden, Chinese Academy of Sciences. (In Chinese with English abstract)" (5) data of Xishuangbanna plot from "Cao, M., H. Zhu, H. Wang, G. Lan, Y. Hu, S. Zhou, X. Deng et al. 2008, Xishuangbanna tropical seasonal rainforest dynamics plot: Tree distribution maps, diameter tables and species documentation. Kunming, China, Yunnan Science and Technology Press." (6) data of Fushan plot from "Su, S.-H., C.-H. Chang-Yang, C.-L. Lu, C.-C. Tsui, T.-T. Lin, C.-L. Lin, W.-L. Chiou et al. 2007, Fushan subtropical forest dynamics plot: tree species characteristics and distribution patterns. Taipei, Taiwan Forestry Research Institute." (7) data of Palanan plot from "Co, L. L., V. L. James, D. A. Lagunzad, K. A. C. Pasion, H. T. Consunji, N. A. Bartolome, S. L. Yap et al. 2006, Forest trees of Palanan, Philippines: A study in population ecology. Quezon, Philipines, University of the Philippines-Diliman. " (8) data of Sinharaja plot from "Gunatilleke, C. V. S., I. A. U. N. G. A. U. K. Ethugala, and S. Esufali. 2004, Ecology of Sinharaja rain forest and the forest dynamics plot in Sri Lanka's Natural World Heritage site. Sri Landka, WHT Publications." (9) data of Lambir plot from "Lee, H. S., P. S. Ashton, T. YamaKura, S. Tan, S. J. Davies, A. Itoh, E. O. K. Chai et al. 2002, The 52-hectrare forest research plot at Lambir Hills, Sarawak, Malaysia: Tree distribution maps, diameter table and species documentation. Sarawak, Malaysia, Forest Department Sarawak & The Arnold Arboretum-CTFS Asia Program." | 4. Notice: the data of Yasuní plot used in paper were more precisely identified than different those in website of Smithsonian Institute Global Earth Observatories, but their results were very similar