Predicting invasion risk of grasses in novel environments requires improved genomic understanding of adaptive potential

Abstract

Many invasive grasses drastically transform the ecosystems they invade, putting native communities across the globe at risk (Fusco et al., 2019). Climate change will likely increase invasion risks for many regions as climates in temperate zones become warmer (Bellard et al., 2012) and tropical and semi-tropical species are able to expand their distributions. However, other axes of environmental variation could delay invasions. For example, invaders from low-latitude-adapted source populations may not flower at higher latitudes because of differences in photoperiod sensitivity (Brandes, 1950; Box 1). Though many nonnative and invasive grasses can quickly establish and persist asexually by rhizomatous reproduction and local spread, their ability to flourish and become widespread in new locations may depend on sexual reproduction and influx of novel genetic variation from other populations or species. Gene flow among introduced lineages and subsequent selection in new environments may have facilitated success of several established perennial grass invaders including Bromus tectorum (Novak and Mack, 1993) and Imperata cylindrica (Lucardi et al., 2014) throughout the United States and Saccharum spontaneum (Saltonstall et al., 2021) in Panama (Figure 1). These species have all had incredibly damaging impacts by altering fire regimes and displacing native communities in their invaded ranges (Hooper et al., 2005; Fusco et al., 2019). With inherent challenges when predicting the fitness of an organism in new environments, incorporating adaptive potential into predictions of invasion risk remains a challenging frontier in an era of global change (Prentis et al., 2008).

Citation

Bellis, Emily S.; Lucardi, Rima D.; Saltonstall, Kristin; Marsico, Travis D. 2022. Predicting invasion risk of grasses in novel environments requires improved genomic understanding of adaptive potential. American Journal of Botany. 109(12): 1965-1968. https://doi.org/10.1002/ajb2.16079.