Environmental filtering and competitive exclusion drive biodiversity-invasibility relationships in shallow lake plant communities

1. Understanding the processes that influence the diversity of ecological communities and their susceptibility to invasion by exotic species remains a challenge in ecology. In many systems, a positive relationship between the richness of native species and exotic species has been observed at larger spatial (e.g., regional) scales, while a negative pattern has been observed at local (e.g., plot) scales. These patterns are widely attributed to (1) biotic interactions, particularly biotic resistance, limiting invasions in high-diversity locations, producing negative local-scale relationships, and (2) native and exotic richness covarying at larger spatial scales as a function of environmental conditions and heterogeneity, producing positive large-scale relationships. However, alternative processes can produce similar patterns and need to be critically evaluated to make sound inferences about underlying mechanisms. 2. We aggregated a large dataset of aquatic vegetation surveys from 1,102 Mi...1. 解析调控生态群落多样性及其对外来物种（exotic species）入侵敏感性的过程，始终是生态学领域的核心研究难题。在多数生态系统中，研究者已在较大空间尺度（如区域尺度）观测到本地物种（native species）丰富度与外来物种丰富度呈正相关关系，而在局部尺度（如样方尺度）则呈现负相关格局。此类格局普遍被归因于两大机制：其一为生物相互作用（biotic interactions），尤其是生物抗性（biotic resistance），可抑制高多样性生境中的生物入侵，进而形成局部尺度的负相关关系；其二为在大空间尺度下，本地与外来物种丰富度会随环境条件与环境异质性（environmental heterogeneity）发生协变，最终形成大尺度的正相关关系。不过，其他潜在过程同样可催生类似格局，因此若要对生物入侵背后的核心机制做出严谨可靠的推论，需对各类替代过程开展批判性评估。 2. 本研究整合了一套源自1,102个（原文截断为Mi...）样点的大型水生植被调查数据集。