Holden Emily M, Salimbayeva Karina, Brown Charlotte, Stotz Gisela C, Cahill James F
Department of Biological Sciences University of Alberta Edmonton Alberta Canada.
Départment de Biologie Université de Sherbrooke Sherbrooke Quebec Canada.
Ecol Evol. 2024 Jul 22;14(7):e70070. doi: 10.1002/ece3.70070. eCollection 2024 Jul.
Many pathways of invasion have been posited, but ecologists lack an experimental framework to identify which mechanisms are dominant in a given invasion scenario. Plant-soil feedbacks (PSFs) are one such mechanism that tend to initially facilitate, but over time attenuate, invasive species' impacts on plant diversity and ecosystem function. PSFs are typically measured under greenhouse conditions and are often assumed to have significant effects under field conditions that change over time. However, direct tests of PSFs effects in natural settings and their change over time are rare. Here we compare the role of PSFs with the effects of biomass in limiting the dominance of an invasive species and impacts on resident species diversity. We characterized the effects of the invader (Leyss.) on native plant communities over time and measured changes in its conspecific PSFs and vegetative growth to understand their integrated effects on community diversity. To do so, we combined data from a 6-year field study documenting the rate and impacts of invasion with a short-term greenhouse experiment quantifying PSF as a function of time since invasion in the field. We found that the nature and strength of PSFs did not change over time and were not mediated by soil microbial communities. Though PSFs impacted reproduction, they did not sufficiently limit vegetative growth to diminish the negative impacts of biomass on native species. experienced the full strength of its negative PSFs immediately upon invasion, but they were ineffective at reducing vigor to facilitate the recovery of the native plant community. We recommend that conservation efforts focus on limiting vegetative growth to facilitate community recovery.
人们提出了许多入侵途径，但生态学家缺乏一个实验框架来确定在特定的入侵情景中哪些机制起主导作用。植物 - 土壤反馈（PSFs）就是这样一种机制，它往往在入侵初期起到促进作用，但随着时间推移会减弱入侵物种对植物多样性和生态系统功能的影响。PSFs通常在温室条件下进行测量，并且常常被认为在随时间变化的野外条件下具有显著影响。然而，在自然环境中对PSFs效应及其随时间变化的直接测试却很少见。在这里，我们比较了PSFs与生物量在限制入侵物种优势以及对本地物种多样性影响方面的作用。我们描述了入侵物种（Leyss.）随时间对本地植物群落的影响，并测量了其同种植物的PSFs和营养生长的变化，以了解它们对群落多样性的综合影响。为此，我们将一项为期6年的记录入侵速率和影响的野外研究数据与一项短期温室实验相结合，该温室实验将PSF量化为自野外入侵以来的时间函数。我们发现，PSFs的性质和强度不会随时间变化，也不受土壤微生物群落的介导。虽然PSFs影响繁殖，但它们不足以限制营养生长以减轻生物量对本地物种的负面影响。入侵物种在入侵时立即经历了其负面PSFs的全部强度，但这些PSFs在降低其活力以促进本地植物群落恢复方面无效。我们建议保护工作应专注于限制营养生长以促进群落恢复。
