Nutrient enrichment undermines invasion resistance to Spartina alterniflora in a saltmarsh: Insights from modern coexistence theory

• Published in: The Journal of applied ecology 2023-11, Vol.60 (11), p.2472-2481
• Main Authors: Qiu, Shiyun, Huang, Jingxin, Lu, Meng, Xu, Xiao, Li, Xincheng, Zhang, Qun, Xin, Fengfei, Zhou, Chenhao, Zhang, Xi, Nie, Ming, Wu, Jihua, Li, Bo
• Format: Article
• Language: English
• Subjects: Aquatic plants; Biodiversity; Coexistence; Ecosystem management; Enrichment; Environmental changes; Estuaries; Geographical distribution; Impact analysis; Indigenous species; Introduced species; Invasive species; Nonnative species; Nutrient enrichment; Nutrients; Salt marshes; Spartina alterniflora; Wildlife conservation
• ISSN: 0021-8901; 1365-2664
• DOI: 10.1111/1365-2664.14509

The ability of native communities to maintain invasion resistance in the face of environmental changes is crucial for biodiversity conservation. However, previous studies have primarily focused on the inhibitive effects experienced by invaders, providing limited insights into the ultimate outcome of resistance. In this study, we integrated modern coexistence theory into biotic resistance research to investigate the impact of nutrient enrichment on the resistance of Phragmites australis marshes to Spartina alterniflora invasion in the Yangtze estuary saltmarshes of China. Our results demonstrated that under non‐enriched conditions, successful invasion resistance was facilitated by stable coexistence between native and invasive species in the field. This prediction of invasion resistance aligned with the distribution dynamics of the two species in the Yangtze estuary saltmarshes over the past two decades. However, nutrient enrichment was likely to lead to a fundamental shift in their coexistence and ultimately, the failure of resistance. Synthesis and applications . Integrating modern coexistence theory into biotic resistance studies advances the assessment of invasion resistance by shifting from quantifying relative strength to predicting explicit resistance outcomes. Ecosystem managers can draw explicit conclusions about the potential establishment and impact of invaders by analysing observational or experimental data within the framework of modern coexistence theory. This information aids in identifying the most efficient strategies for addressing invasive species. 在环境变化背景下，土著群落对于外来物种入侵的抵抗能力可能会发生变化，并对生物多样性产生重要影响。现有的入侵抵抗研究主要关注于入侵物种所受到的抑制效应，但这种方法无法明确预测入侵抵抗的后果会如何变化。 在本研究中，我们使用当代物种共存理论框架来分析土著植物群落的入侵抵抗能力，研究了营养输入如何影响长江口芦苇盐沼对外来植物互花米草入侵的抵抗能力。 野外实验结果显示，在当前条件下，芦苇群落可通过与互花米草稳定共存来成功地抵抗入侵。这一预测结果与过去二十年间两物种在长江口地区的分布动态一致，验证了当代物种共存理论在预测群落入侵抵抗能力方面的有效性。我们的研究还发现，营养输入会导致这两种植物的竞争共存结果发生根本性变化，从而导致入侵抵抗失败。 整合与应用:将当代物种共存理论纳入到对群落入侵抵抗能力的研究中，可以将我们对入侵抵抗能力的评估从简单的强弱对比推进到对明确抵抗结果的预测。生态系统管理者可以基于观测或实验数据来预测土著植物群落对外来物种入侵的抵抗能力，从而针对性地制定最有效的管理策略。