Invasion complexity at large spatial scales is an emergent property of interactions among landscape characteristics and invader traits

Authors: MUTHUKRISHNAN, R - University Of Minnesota; Davis, Adam; JORDAN, N - University Of Minnesota; FORESTER, J - University Of Minnesota

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/3/2018
Publication Date: 5/17/2018
Citation: Muthukrishnan, R., Davis, A.S., Jordan, N.R., Forester, J. 2018. Invasion complexity at large spatial scales is an emergent property of interactions among landscape characteristics and invader traits. PLoS One. 13(5):e0195892.

Interpretive Summary: The sustainable deployment of bioenergy crops includes making sure that they are not invasive. Predicting the invasive potential of bioenergy crops at large spatial scales requires consideration of crop traits related to invasion success as well as characteristics of the habitats into which the crop could potentially escape. To understand this interaction of plant traits and landscape features on invasion risk for the bioenergy crop Miscanthus x giganteus, we created a spatial model, simulating invasions on 1000 U.S. landscapes described in the METALANDS database. Our model showed that overall habitat quality was generally the strongest predictor of invasion risk but there were also more subtle interactions between landscapes and invader traits. Effective prevention of bioenergy crop escapes and management of invasions will require understanding both the ecology of the species of interest and the particular goals or risks for which efforts need to be optimized.

Technical Abstract: Understanding the potential for invasive spread is an important consideration for novel agricultural species that may be translocated or introduced into new regions. However, estimating invasion risks remains a challenging problem, particularly in the context of real, complex landscapes. There is a suite of plant traits that are generally considered to increase invasive potential and an understanding that landscapes influence invasions dynamics, but very little research has been done to explore how those drivers of invasions interact. We evaluate the relative roles of, and potential interactions between, plant invasiveness traits and landscape characteristics on invasions in real landscapes. We use a model parameterized for the potentially invasive biomass crop, Miscanthus × giganteus, to simulate invasions on 1000 replicate landscapes to evaluate how landscape characteristics, including both composition and spatial structure effect invasion outcomes. We then repeat simulations in the same landscapes while changing plant invasiveness traits (dispersal ability, establishment ability, population growth rate, and the ability to utilize dispersal corridors) to explicitly evaluate how the importance of landscape characteristics for predicting invasion patterns changes depending on the invader details. We show that overall habitat quality is generally the strongest determinant of invasion dynamics but there are also more subtle interactions between landscapes and invader traits. These effects can also vary between different aspects of invasion dynamics (short vs long time scales and population size vs spatial extent of invasion). Our results illustrate that invasions are complex emergent processes with multiple drivers and effective management will require understanding both the ecology of the species of interest and the particular goals or risks for which efforts need to be optimized.