Abstract Detail

Interactions of White-Tailed Deer and Invasive Plants in Forests of Eastern North America

Waller, Don [1].

Separate and combined effects of deer and invasive plants on native forest plants.

Both white-tailed deer (Odocoileus virginianus) and weedy invasive plants can affect the growth, survival, reproduction, and/or persistence of many native plant species. These impacts vary greatly, however, depending on both ecological circumstances (e.g., deer and invasive plant densities or the availability of light) and the susceptibility of different native species to deer and exotic competitors. Deer and invasive plants may also interact to affect natives, as via apparent competition favoring unpalatable exotic species when deer feed preferentially on natives. Deer also indirectly affect native and exotic species by compacting and enriching soils, spreading seeds, and enhancing light levels. We examine these interactions using several approaches. Analyses based on C-scores show diverse interactions that depend on the species involved. The three most common invasives in southern Wisconsin forests (Alliaria, Lonicera, and Rhamnus) have mostly negative associations with native species and particularly those that are habitat-specific and declining. In contrast, interactions with common increasing native species are often positive. Exclosure studies show less soil compaction, lower soil nitrogen, and fewer exotic earthworms in areas protected from deer. These factors plus greater shade and a dense set of native competitors may reduce invasions by exotic plants. We used a replicated 2x2 experimental design to assess the separate and combined effects of herbivory by deer and competition from Alliaria petiolata on five native species that vary in palatability and life form. Deer depressed survival and branching in Uvularia, growth in Geranium and Quercus, and tillering in Carex. Surprisingly, dense Alliaria sometimes protected palatable species from deer herbivory. Oak seedlings and Uvularia, both in regional decline, were more affected by deer than Alliaria but Alliaria reduces oak growth more when deer are absent. Such differentiated responses suggest that we should tailor deer and weedy plant control efforts to particular taxa or communities of concern. In particular, managers seeking to sustain deer-sensitive species should first strive to reduce deer densities – which could itself help control weedy plant invasions. Because deer and weedy plants cumulatively affect native plant communities, their interactive effects will grow along with their populations.

Related Links:
Link to article on Research Gate

1 - Department Of Botany, 430 Lincoln Drive, Madison, WI, 53706, USA

Keywords:
white-tailed deer
invasive plant
cumulative effect
forest ecology
community ecology.

Presentation Type: Colloquium Presentations
Session: C1, Interactions of white-tailed deer and invasive plants in forests of eastern North America
Location: Chatham Ballroom - C/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 3:00 PM
Number: C1006
Abstract ID:278
Candidate for Awards:None