Density‐driven facilitations increase ecological resilience under eutrophic stress

作者：Chaoyue Cheng, Wei Si, Haojie Su, Jianfeng Chen, Jianfeng Chen, Qingyang Rao, Lin Yu, Shufa Xu, Zhaohui Hua, Yi Peng, Ning Xu, Ping Xie, Jun Chen, Jun Chen · 发表于：Freshwater Biology · 年份：2024 · DOI：10.1111/fwb.14340 · 被引用次数：2 · 研究领域：Ecosystem dynamics and resilience、Sustainability and Ecological Systems Analysis、Land Use and Ecosystem Services

Abstract Eutrophication has been observed to decrease the ecological resilience of macrophyte‐dominated freshwater ecosystems, thereby resulting in more vulnerability to external perturbations and easily tipping into an algae‐dominated state. The stress‐gradient hypothesis (SGH) posits that plants exhibit positive plant–plant interaction (facilitation) in response to stress, potentially buffering the detrimental impacts of eutrophication. However, few studies attempted to link plant density with species‐species interactions and ecological resilience in the context of eutrophic stress. Here, we investigated how the density of neighbour plant species ( Potamogeton lucens ) affects the change rate of nutrients or Chl a (chlorophyll‐a) and target plant species ( Potamogeton maackianus ) along a gradient of nutrient levels (oligotrophic, mesotrophic, eutrophic) via a 42 days mesocosm experiment. Our objective was to corroborate: (1) species interactions may shift from competition to facilitation with the increased eutrophic stress. (2) High plant density is indispensable to generate facilitation and thereby augment ecological resilience under high eutrophic stress. Results showed that eutrophic scenarios significantly augmented chlorophyll‐a concentration and inhibited plant height, number of branches and leaves, showing that submerged macrophytes in eutrophic states are exposed to stressful conditions. However, the increasing density of neighbouring vegetation reduced nutrient an...