Data from: Experimental insight into the process of parasite community assembly

1.Community assembly is a fundamental process that has long been a central focus in ecology. Extending community assembly theory to communities of co-infecting parasites, we used a gastrointestinal nematode removal experiment in free-ranging African buffalo to examine community assembly patterns and processes.
2.We first asked whether reassembled communities differ from undisturbed communities by comparing anthelmintic-treated and control hosts. Next, we examined the temporal dynamics of assembly using a cross-section of communities that reassembled for different periods of time since last experimental removal. Next, we tested for evidence of assembly processes that might drive such reassembly patterns: environmental filtering based on host traits (i.e. habitat patches), interspecific interactions, priority effects, and chance dispersal from the environmental pool of infective stages (i.e. the regional species pool).
3.On average, reassembled parasite communities had lower abundances, but were more diverse and even, and these patterns varied tightly with reassembly time. Over time, the communities within treated hosts progressively resembled controls as diversity and evenness decreased while total abundance increased. Notably, experimental removal allowed us to attribute observed differences in abundance, diversity, and evenness to the process of community assembly.
4.During early reassembly, parasite accumulation was biased towards a subordinate species and, by excluding stochastic assembly processes (i.e. chance dispersal and priority effects), we were able determine that early assembly is deterministic. Later in the reassembly process, we established that host traits, as well as stochastic dispersal from the environmental pool infective stages, can affect community composition.
5.Overall, our results suggest there is a high degree of resiliency and environmental dependence to the worm communities of buffalo. More generally, our data show that both deterministic and stochastic processes may play a role in the assembly of parasite communities of wild hosts, but their relative importance may vary temporally. Consequently, the best strategy for managing reassembling parasite communities may also need to shift over time.

1. 群落组装（community assembly）是生态学领域长期以来的核心研究议题之一。本研究将群落组装理论拓展至共感染寄生虫群落，通过对自由放养的非洲水牛开展胃肠道线虫移除实验，探究寄生虫群落的组装模式与过程。
2. 研究首先通过对比驱虫药处理组与对照组宿主，验证重组后的寄生虫群落与未受干扰的原始群落是否存在差异；其次，利用末次实验移除后不同恢复时长的群落横断面样本，解析群落组装的时间动态特征；最后，检验可能驱动此类重组模式的组装过程证据：基于宿主性状（即生境斑块）的环境过滤作用、种间相互作用、优先效应，以及来自感染性阶段寄生虫环境库（即区域物种库）的随机扩散过程。
3. 平均而言，重组后的寄生虫群落丰度更低，但多样性与均匀度更高，且这些特征随恢复时长紧密变化。随着时间推移，处理组宿主内的群落逐渐趋近对照组：群落多样性与均匀度逐步下降，而总丰度持续升高。值得注意的是，本实验通过寄生虫移除操作，可将观测到的丰度、多样性与均匀度差异直接归因于群落组装过程本身。
4. 在重组早期，寄生虫的种群积累偏向于从属物种；通过排除随机组装过程（即随机扩散与优先效应），本研究得以确定早期群落组装为确定性过程。在重组后期，研究证实宿主性状以及来自环境库的随机性感染源扩散，均可影响群落组成。
5. 综合来看，本研究结果表明非洲水牛的寄生虫群落具备极高的恢复韧性与环境依赖性。更具普适性的结论是：野生宿主的寄生虫群落组装可同时受确定性与随机性过程共同调控，但二者的相对重要性随时间动态变化。因此，针对重组寄生虫群落的管理策略，或许也需要随时间推移进行动态调整。