Assessing vulnerability and resistance to plant invasions: a native community perspective

Abstract

Risk assessments of biological invasions rarely account for native species performance and community features, but this assessment could provide additional insights for management aimed at decreasing vulnerability or increasing resistance of a plant community to invasions. To gather information on the drivers of native plant communities’ vulnerability and resistance to invasion, we conducted a literature search and meta-analysis. From the data collected we compared native and invasive plant performance between sites with high and low levels of invasion. We then investigated under which conditions native performance increased, decreased, or did not change with respect to invasive plants. We analyzed data from 214 publications summing to 506 observations. There were six main drivers of vulnerability to invasion: disturbance, decrease in resources, increase in resources, lack of biotic resistance, lack of natural enemies, and differences in propagule availability between native and invasive species. The two mechanisms of vulnerability to invasion associated with a strong decline in native plant performance were propagule availability and lack of biotic resistance. Native plants marginally benefited from enemy release and from decreases in resources, while invasive plants strongly benefited from both increased resources and lack of enemies. Fluctuation of resources, decreases and increases, were strongly associated with higher invasive performance while native plants varied in their response. These differences were particularly strong in instances of decreasing water or nutrients, and of increasing light and nutrients. We found overall neutral to positive responses of native plant communities to disturbance; but natives were outperformed by invasive species when disturbance was caused by human activities. We identified ecosystem features associated with both vulnerability and resistance to invasion, then used our results to inform management aimed at protecting the native community.

Combining local, landscape, and regional geographies to assess plant community vulnerability to invasion impact

“…Recognition is growing that this invader-focused approach is, in many cases, ineffective and unsustainable and that there is a need for research and practice to inform alternatives (Barney & Tekiela, 2020;McGeoch et al, 2016). In contrast, vulnerability to invasion impact depends largely on features of the community affected, that is, biotic resistance, abiotic constraints, and native propagule availability (Ib añez et al, 2021;Levine, 2001). By considering invasion from the perspective of community vulnerability, we could address invasion in a proactive rather than reactive manner, with a focus on prevention (Mack et al, 2000), and practitioners could use vulnerability predictions to identify which, within their management units, are the most vulnerable communities to plant invasions; such information could help prioritize limited resources for early detection, monitoring, and/or control of invasions.…”

“…Vulnerability to invasion impact depends largely on features of the community affected, that is, biotic resistance, abiotic constraints, and native propagule availability (Ibáñez et al, 2021; Levine, 2001). As a result, the strongest impacts of plant invasions take place at the local scale, with impact weakening as larger areas are sampled (Crystal‐Ornelas & Lockwood, 2020; Powell et al, 2013).…”

Assessing the mechanisms and impacts of shrub invasion in forests: A meta‐analysis

“…To limited to be ≥0 (Ibáñez et al, 2021;Ibáñez, Katz, et al, 2014). Lastly, we investigated publication bias by visually checking funnel plots, plotting the precision (i.e.…”

Role of priority effects in invasive plant species management: Early arrival of native seeds guarantees the containment of invasion by Giant ragweed

“…Biotic resistance to invasion refers to the ability of native communities to limit invasion success through a biological process, such as competition (Levine et al, 2004 ; Yannelli, 2021 ). One of the reasons for the vulnerability of native plant communities to invasion is the lack of biological resistance (Ibáñez et al, 2021 ). Resident plants employ biotic resistance to control invasive species spread.…”