Spatiotemporal Trajectories of Invasive Tree Species Reveal the Importance of Collective Action for Successful Invasion Management

Abstract

Biological invasions are complex processes requiring coordinated and spatially targeted management. This study assessed spatiotemporal tra- jectories and determinants of Prosopis cover in Baringo County, Kenya. Land cover data for every seven years between 1988 and 2016 revealed the presence of Prosopis. We tested for trajectory clusters using spatial autocorrelation and overlaid the trajectory categories with landscape features. Generally, most plots were only temporarily managed or not managed at all, while continuous management of Prosopis occurred mainly near rivers and on plots suitable for cultivation. Parcels within 250 m from roads, which are dispersal pathways for Prosopis seeds, were rarely cleared of Prosopis. We conclude that successful management requires incentives for stakeholders’ engagement in collective manage- ment action at a landscape level. Trajectory mapping should be integrated into planning tools to foster the prioritization of timely and context- specific response mechanisms.