Forest dynamics and ungulate herbivory: from leaf to landscape

Abstract

Due primarily to anthropogenic influences such as land use change, exotic species introductions, livestock grazing, altered hunting regimes, and predator control, wild ungulate populations have undergone tremendous shifts in recent decades. Although the result has been endangerment or extirpation in some regions, ungulate numbers have increased to locally or regionally high levels in other areas, causing shifts in plant species composition, problems for forest regeneration, and conflict with humans and domestic livestock. Our ability to find solutions to these problems is limited because we lack sufficient understanding of how ungulate species interact with predators, habitat, forage, competing species, and humans at multiple scales from small foraging patches to large regions. To bring together new findings in this area, encompassing various scales and foci of investigation, an international conference on “Forest Dynamics and Ungulate Herbivory” was held from 3 to 6 October 2001 in Davos, Switzerland. We provide a synthetic overview of the papers contained in this Special Issue, arising from that conference. A companion Special Issue of the Journal for Nature Conservation is devoted to the more management-oriented aspects of forest–ungulate interactions, entitled “Forest–Ungulate Interactions: Monitoring, Modeling and Management.” From the papers in this issue, a number of important generalizations emerge to guide our understanding and further research. Our predictive understanding of foraging ecology needs to be generalized and scaled up, if it is to become useful for predicting the consequences of herbivory for broad-scale vegetation dynamics. Further, it is important to move beyond single-factor studies, to embrace the complexity of ungulate–vegetation interactions. The direction and magnitude of ungulate influences can be difficult to gauge because of complex interactions among species, structural units of vegetation or landscapes, ecosystem processes, and natural disturbances. Researchers need to look beyond the simplistic concept of “game damage”, and comprehensively address the direct and indirect effects of ungulates on communities, ecosystems and landscapes. This may require a more systems-oriented, and less species-oriented approach. Ungulate–vegetation interactions need to be better understood over multiple scales, and particularly at the coarser scales that are of interest to managers and policy-makers. Finally, a long-term view of ungulate–vegetation interactions, where past, present, and future effects are considered in their appropriate temporal context, is absolutely essential.