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Long-term dynamics of density dependence suggest growth, rather than survival, is a better index for adult trees over time
  • Liping Wang,
  • Junjie Wu,
  • Fengxian Chen
Liping Wang
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Junjie Wu

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Fengxian Chen
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Abstract

Density dependence is a vital mechanism for explaining tree species diversity, and empirical studies have evidenced that neighbor density did influence plant survival and growth in different communities worldwide. However, it is still unclear that what and how neighbor density affect plant survival and growth in a long time. Thus, we used the data from Barro Colorado Island (BCI) plot censused every 5 years from 1981 to 2015 to identify how density dependence affected adult trees survival and growth by using generalized linear mixed models. Followed by, linear regression models were used to assess whether the effect of density dependence on tree survival and growth correlated with the species abundance. We found that the effects of tree sizes (DBH) and heterospecific neighbor densities (BAhet) on tree survival varied over time. The effects of DBH and BAhet had significantly negative impacts on tree growth, while densities of conspecific neighbors (BAcon) showed significantly negative effect both on tree survival and growth in seven intervals. The effect of density dependence on tree growth was more stable than on survival. Additionally, the effects of conspecific and heterospecific neighbor density on tree growth, but not on tree survival, respectively, were significantly negatively and positively related to tree abundance over time. Overall, our result revealed that tree growth was the better predictor for the effect of density dependence at the community level.