Legacy effects of an invasive legume more strongly impact bacterial than plant communities in a Mediterranean-type ecosystem

作者：Florencia A. Yannelli, Jan‐Hendrik Keet, Suzaan Kritzinger‐Klopper, Johannes J. Le Roux · 发表于：Journal of Environmental Management · 年份：2024 · DOI：10.1016/j.jenvman.2024.123802 · 被引用次数：6 · 研究领域：Plant Parasitism and Resistance、Legume Nitrogen Fixing Symbiosis、Genetic and Environmental Crop Studies

The impacts of invasive plants on ecosystem processes and functions may persist as “legacy effects” after their removal. Understanding these effects on native plant-soil interactions is critical for guiding ecological restoration efforts. This study examines the legacy effects of the invasive legume Acacia saligna (Labill.) H.L. Wendl. in South Africa's Cape Fynbos to evaluate restoration potential post-removal. We compared cleared, invaded, and uninvaded reference sites across three conservation areas, examining soil chemical properties, nitrogen (N) isotope signatures (as a proxy for the sources of N uptake by a native plant and A. saligna ), and the diversity and composition of plant and soil bacterial communities. The effects of A. saligna removal was contingent on conservation area, though consistent patterns emerged for plant and bacterial diversity across sites. Recovery toward reference site levels were evident for soil organic carbon and potassium, but nitrate and available phosphorous only improved in one area. Invader removal was linked to higher soil pH in one area and higher phosphorus availability in two. Soil conditions in cleared sites influenced the nitrogen sources used by A. saligna , shifting towards soil-derived nitrogen, but did not influence those used by the native species assessed. While we observed signs of native plant community recovery after clearing, soil bacterial communities remained comparable to those in invaded sites. The lag in bacterial co...