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

Authors: IBANEZ, INES - University Of Michigan; PETRI, LAIS - University Of Michigan; BARNETT, DAVID - Neon, Inc; BEAURY, EVELYN - Princeton University; Blumenthal, Dana; CORBIN, JEFFREY - Union College; DIEZ, JEFFREY - University Of Oregon; DUKES, JEFFREY - Purdue University; EARLY, REGAN - University Of Exeter; PEARSE, IAN - Us Geological Survey

Submitted to: Ecological Applications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2023
Publication Date: 2/19/2023
Citation: Ibanez, I., Petri, L., Barnett, D.T., Beaury, E.M., Blumenthal, D.M., Corbin, J.D., Diez, J., Dukes, J.S., Early, R., Pearse, I.S. 2023. Combining local, landscape, and regional geographies to assess plant community vulnerability to invasion impact. Ecological Applications. 33. Article e2821. https://doi.org/10.1002/eap.2821.
DOI: https://doi.org/10.1002/eap.2821

Interpretive Summary: Vulnerability of plant communities to invasive species impacts depends on factors acting across spatial scales, from local to regional. We introduce an analytical framework that quantifies the scale-dependent impact of biological invasions from the shape of the native species-area-relationship (SAR). We leverage newly available, biogeographically extensive vegetation data from the US National Ecological Observatory Network to assess plant community vulnerability to invasion across the USA. Results show that high abundance of invasive species is consistently associated with a decrease in number of native species within a community. Ecoregions that are colder and wetter seem to be most vulnerable to losses of native plant species at the local level, while warmer and wetter areas seem most susceptible at the landscape level. This cross-scale analysis provided outputs that can be used to inform policy and management aimed at reducing vulnerability to the impact of plant invasions.

Technical Abstract: Invasive species science is heavily geared toward the invasive agent. However, management to protect native species also requires a proactive approach focused on understanding the features affecting community vulnerability to invasion impacts. Vulnerability is likely the result of factors acting across spatial scales, from local to regional, and it is the combined effects of these factors that will determine the magnitude of vulnerability. We introduce an analytical framework that quantifies the scale-dependent impact of biological invasions from the shape of the native species-area-relationship (SAR). We leverage newly available, biogeographically extensive vegetation data from the US National Ecological Observatory Network to assess plant community vulnerability to invasion impact as a function of factors acting across scales. We analyzed more than 1000 SARs widely distributed across the USA along environmental gradients and under different levels of invasion. Results show that a decrease in native richness is consistently associated with invasive species cover, but it is only at relatively high levels of invasion that native richness is compromised. After accounting for variation in baseline ecosystem diversity, net primary productivity, and human modification, ecoregions that are colder and wetter seem to be most vulnerable to losses of native plant species at the local level, while warmer and wetter areas seem most susceptible at the landscape level. We also document how the combined effects of cross-scale factors result in a heterogenous spatial pattern of vulnerability. This pattern cannot be predicted by analyses at any single scale, underscoring the importance of accounting for factors acting across scales. Simultaneously assessing differences in vulnerability between distinct plant communities at local, landscape and regional scales provided outputs that can be used to inform policy and management aimed at reducing vulnerability to the impact of plant invasions.