Rangelands in a fragmented grass‑dominated landscape are vulnerable to tree invasion from roadsides

Authors

Katharine F. E. Hogan, University of Nebraska-LincolnFollow
Dillon T. Fogarty, University of Nebraska-LincolnFollow
Hugh Ellerman, University of Nebraska-LincolnFollow
Christopher Fill, University of Nebraska - LincolnFollow
Dina Morales, University of Nebraska-LincolnFollow
Baxter Seguin, University of Nebraska-LincolnFollow
Daniel R. Uden, University of Nebraska - LincolnFollow
Craig R. Allen, University of Nebraska-LincolnFollow

ORCID IDs

Katharine F. E. Hogan http://orcid.org/0000-0002-9140-1744

Document Type

Article

Date of this Version

2022

Citation

Biol Invasions 2022

doi:10.1007/s10530-022-02869-5

Comments

Open Access

Abstract

Roadsides can be vectors for tree invasion within rangelands by bisecting landscapes and facilitating propagule spread to interior habitat. Current invasive tree management in North America’s Great Plains focuses on reducing on-site (i.e., interior habitat) vulnerability through on-site prevention and eradication, but invasive tree management of surrounding areas known to serve as invasion vectors, such as roadsides and public rights-of-ways, is sporadic. We surveyed roadsides for invasive tree propagule sources in a central Great Plains grassland landscape to determine how much of the surrounding landscape is potentially vulnerable to roadside invasion, and by which species, and thereby provide insights into the locations and forms of future landcover change. Invasive tree species were widespread in roadsides. Given modest seed dispersal distances of 100–200 m, our results show that roadsides have potential to serve as major sources of rangeland exposure to tree invasion, compromising up to 44% of rangelands in the study area. Under these dispersal distances, funds spent removing trees on rangeland properties may have little impact on the landscape’s overall vulnerability, due to exposure driven by roadside propagule sources. A key implication from this study is that roadsides, while often neglected from management, represent an important component of integrated management strategies for reducing rangeland vulnerability to tree invasion.