Seed Dispersal of an Invasive Shrub, Amur Honeysuckle (Lonicera maackii ), by White-tailed Deer in a Fragmented Agricultural-forest Matrix

摘要

Ungulates are potentially important seed dispersers for many invasive plant species. While our understanding of which invasive plant species are dispersed by ungulates has improved over the last decade, the factors influencing this process remain poorly understood. To address this, we explored whitetailed deer (Odocoileus virginianus) seed consumption and dispersal of an invasive shrub (Lonicera maackii) in fragmented agricultural-forest matrices in western Ohio. In a pairwise browse preference experiment, deer browsed at similar levels on branches of L. maackii with fruits removed and fruits intact (mean ± 95 % CI 57 ± 14 and 62 ± 14 %, respectively). We found no evidence that white-tailed deer disperse L. maackii seeds along an invasion front, but 31 % of deer pellet groups collected in an invaded area contained germinable L. maackii seeds (maximum number of germinable seeds = 30). By combining hourly movement data specific to fragmented landscapes and gut retention time data, we projected that female deer disperse 91 %of ingested seeds further than 100 m from seed sources (i.e., long-distance seed dispersal), and rarely disperse seeds up to 7.9 km. We conclude that white-tailed deer can be important long-distance seed dispersal vectors of L. maackii, and that invader abundance and/or patch connectivity likely influence patterns of seed dispersal by white-tailed deer.