Data from: Resilience of tropical dry forests – a meta-analysis of changes in species diversity and composition during secondary succession

Assessing the recovery of species diversity and composition after major disturbance is key to understanding the resilience of tropical forests through successional processes, and its importance for biodiversity conservation. Despite the specific abiotic environment and ecological processes of tropical dry forests, secondary succession has received less attention in this biome than others and changes in species diversity and composition have never been synthesised in a systematic and quantitative review. This study aims to assess in tropical dry forests 1) the directionality of change in species richness and evenness during secondary succession, 2) the convergence of species composition towards that of old-growth forest and 3) the importance of the previous land use, precipitation regime and water availability in influencing the direction and rate of change. We conducted meta-analyses of the rate of change in species richness, evenness and composition indices with succession in 13 tropical dry forest chronosequences. Species richness increased with succession, showing a gradual accumulation of species, as did Shannon evenness index. The similarity in species composition of successional forests with old-growth forests increased with succession, yet at a low rate. Tropical dry forests therefore do show resilience of species composition but it may never reach that of old-growth forests. We found no significant differences in rates of change between different previous land uses, precipitation regimes or water availability. Our results show high resilience of tropical dry forests in term of species richness but a slow recovery of species composition. They highlight the need for further research on secondary succession in this biome and better understanding of impacts of previous land-use and landscape-scale patterns.

评估大型扰动后热带森林的物种多样性与群落组成恢复情况，是理解其通过演替过程展现的恢复力，以及该恢复力对生物多样性保护的重要意义的核心前提。尽管热带旱生林具备独特的非生物环境与生态过程，但相较于其他生物群区，该生境的次生演替研究仍未得到足够重视，且学界尚未对其物种多样性与组成变化开展系统性定量综述。本研究针对热带旱生林展开三项评估：1）次生演替过程中物种丰富度与均匀度的变化方向；2）物种组成向原始林群落的趋同程度；3）既往土地利用方式、降水格局与水分可获得性对物种组成变化方向与速率的影响。我们对13个热带旱生林演替序列中，物种丰富度、均匀度及组成指数随演替的变化速率开展了元分析（meta-analyses）。结果显示，物种丰富度随演替进程逐步提升，呈现物种持续积累的趋势，香农均匀度指数（Shannon evenness index）亦呈现相同变化规律。演替林与原始林的物种组成相似性随演替逐步升高，但提升速率较为缓慢。由此可见，热带旱生林的物种组成确实具备恢复力，但可能永远无法达到原始林的物种组成水平。我们未发现不同既往土地利用类型、降水格局或水分可获得性之间的变化速率存在显著差异。本研究结果表明，热带旱生林在物种丰富度层面具备较高的恢复力，但物种组成的恢复速率较为缓慢。研究同时强调，需进一步开展该生境的次生演替研究，并加深对既往土地利用与景观尺度格局影响的理解。