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The strength of density‐dependent mortality is contingent on climate and seedling size
Author(s) -
Song Xiaoyang,
Johnson Daniel J.,
Cao Min,
Umaña Maria Natalia,
Deng Xiaobao,
Yang Xiaofei,
Zhang Wenfu,
Yang Jie
Publication year - 2018
Publication title -
journal of vegetation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 115
eISSN - 1654-1103
pISSN - 1100-9233
DOI - 10.1111/jvs.12645
Subject(s) - seedling , biology , density dependence , ecology , precipitation , agronomy , geography , demography , population , sociology , meteorology
Questions Density‐dependent processes may promote species diversity in plant communities. Here, we tested whether seedling survival was density‐dependent and varied by seedling size, species and climatic factors. Location Tropical rain forest, Xishuangbanna, southwest China. Methods Generalized linear mixed‐effects models were used to examine seedling survival (232 tree species) across 9 years of seedling census data from a 20‐ha tropical forest dynamics plot. Our predictor variables were conspecific and heterospecific neighbour density, size of the seedling and annual variation in climatic factors. Results We found significant negative effects of conspecific tree density, but positive effects of heterospecific seedling density on the survival of tree seedlings in this plot. In general, conspecific negative density dependence ( CNDD ) was observed most frequently for large size classes of seedlings (≥20‐cm high), while heterospecific positive density dependence ( HPDD ) was similar at all size classes. CNDD for large seedlings was stronger during warm years, and HPDD for large seedlings was stronger during dry years. Conclusions Our study suggests that the strength of density dependence varied through time, and this strength was influenced by water availability and temperature. Our results highlight the potential for changes in species composition and species co‐existence that could result from increasing temperature‐strengthening CNDD effects and decreasing precipitation strengthening HPDD effects.