Data from: Reorganization of interaction networks modulates the persistence of species in late successional stages

1.Ecological interaction networks constantly reorganize as interspecific interactions change across successional stages and environmental gradients. This reorganization can also be associated with the extent to which species change their preference for types of niches available in their local sites. Despite the pervasiveness of these interaction changes, previous studies have revealed that network reorganizations have a minimal or insignificant effect on global descriptors of network architecture, such as: connectance, modularity, and nestedness. However, little is known about whether these reorganizations may have an effect on community dynamics and composition.

2.To answer the question above, we study the multi-year dynamics and reorganization of plant-herbivore interaction networks across secondary successional stages of a tropical dry forest. We develop new quantitative tools based on a structural stability approach to estimate the potential impact of network reorganization on species persistence. Then, we investigate whether this impact can explain the likelihood of persistence of herbivore species in the observed communities.

3.We find that resident (early-arriving) herbivore species increase their likelihood of persistence across time and successional stages. Importantly, we demonstrate that, in late successional stages, the reorganization of interactions among resident species has a strong inhibitory effect on the likelihood of persistence of colonizing (late-arriving) herbivores.

4.These findings support earlier predictions suggesting that, in mature communities, changes of species interactions can act as community-control mechanisms (also known as priority effects). Furthermore, our results illustrate that the dynamics and composition of ecological communities cannot be fully understood without attention to their reorganization processes, despite the invariability of global network properties.

1. 生态相互作用网络（Ecological interaction networks）会随种间相互作用（interspecific interactions）在演替阶段（successional stages）与环境梯度（environmental gradients）间发生变化而持续重构。这种重构还可能与物种对其所在局域生境中可利用生态位（niche）类型的偏好改变程度相关。尽管这类相互作用变化普遍存在，但已有研究表明，网络重构对网络结构的全局描述指标——如连接度（connectance）、模块化（modularity）和嵌套性（nestedness）——的影响极小或无显著影响。然而，目前尚不清楚这类重构是否会对群落动态与群落组成产生影响。
2. 为解答上述问题，本研究聚焦热带旱林次生演替阶段（secondary successional stages）的植物-草食动物相互作用网络（plant-herbivore interaction networks）的多年动态与重构过程。我们基于结构稳定性（structural stability）方法开发了全新的定量工具，用以评估网络重构对物种存续的潜在影响。随后，我们探究该影响能否解释观测群落中草食动物物种的存续概率。
3. 研究发现，定居（早期到达）的草食动物物种在随时间推移和演替阶段推进的过程中，其存续概率会升高。尤为重要的是，我们证实，在演替后期阶段，定居物种间的相互作用重构会对定植（后期到达）的草食动物的存续概率产生显著的抑制作用。
4. 本研究结果印证了此前的预测：在成熟群落中，物种相互作用的变化可作为群落调控机制（community-control mechanisms，亦称为优先效应（priority effects））发挥作用。此外，我们的研究结果表明，尽管网络的全局属性保持稳定，但如果不关注其重构过程，便无法完全理解生态群落的动态与组成。