Climate and soil mediate the effects of liana density on forest dynamics

Forest community dynamics is a topic of great interest in times when the global carbon budget is a widespread concern due to climate change. Among its effects, longer periods of drought and liana proliferation, coupled with land-use change, may endanger tropical forest carbon sinks. Here, in a 10.3 ha sampling of six Atlantic semideciduous forests, we investigated the effects of liana crown occupancy and large-stemmed lianas, as well as their interactions with climate and soil, on forest dynamics. We expected that harsh environmental conditions would enhance the negative effects of lianas on forest productivity. Our hypothesis was corroborated by the findings that the positive effect of lianas on tree mortality increases under drier conditions, as well as their negative effect on tree recruitment. In addition, liana crown occupancy was the best predictor of net above-ground woody biomass productivity, which decreases as liana crown occupancy increases. Our study provides additional evidence of indirect climate change impacts on the tropical forest carbon sink by increasing the negative effects of liana crown occupancy on tree biomass productivity.

Methods
Details in the paper: Climate and soil mediate the effects of liana density on forest dynamics on Biotropica

tree_level_survivals_growth.csv: tree individual level data (survivals)

plot_level.csv: plot level aggregated data

在气候变化导致全球碳预算广受关注的当下，森林群落动态是极具研究价值的课题。其中，干旱周期延长、藤本植物（liana）的扩张蔓延，叠加土地利用变化，可能会对热带森林碳汇功能造成威胁。本研究针对6片大西洋半落叶林布设了总计10.3公顷的采样样地，探究了藤本冠层占比、大茎干藤本，以及二者与气候、土壤的交互作用对森林动态的影响。我们提出研究假设：严酷的环境条件会加剧藤本植物对森林生产力的负面影响。研究结果验证了该假说：在更干旱的环境中，藤本植物对树木死亡率的正向促进作用显著增强，同时其对树木更新的抑制作用也同步加剧。此外，藤本冠层占比是地上木质净生物量生产力的最优预测因子，该生产力指标会随藤本冠层占比的提升而下降。本研究进一步补充了相关证据，证实气候变化可通过增强藤本冠层占比对树木生物量生产力的负面影响，间接影响热带森林碳汇功能。

方法
详见刊载于Biotropica的论文《Climate and soil mediate the effects of liana density on forest dynamics》

tree_level_survivals_growth.csv：树木个体水平数据（存活相关数据）
plot_level.csv：样地水平汇总数据