Spatial patterns in neighbourhood effects on woody plant selection and bark stripping by deer in a lowland alluvial forest

摘要

Abstract Questions Ungulate herbivory and its impact on one plant species may be driven by other plants in the neighbourhood. Although such neighbourhood effects have long been recognized, there is limited understanding of how spatial variation in these effects relates to local plant density and distances between plants. Our goal was to examine if the density of or distance to conspecific and heterospecific neighbouring woody individuals produces neighbourhood effects on bark stripping by deer, and how these effects differ in spatial scale and type (reduce/increase herbivory). Location Lowland old‐growth forest, Czech Republic. Methods Woody individuals were assessed for evidence of bark stripping and the level of damage done by deer in a square 4‐ha plot, mapping all woody stems ≥1 cm diameter at breast height. The spatial distribution of stripping was used to examine neighbourhood effects using spatial point pattern methods. Results The density and distance to neighbours and species identity of focal and neighbouring individuals contributed to a large spatial variation in neighbourhood effects (up to distances of 2–30 m from neighbours). Neighbourhood effects arose mainly from the interactions between neighbouring shrub species and all tree species, and interactions between individual species pairs. Neighbourhood effects more often increased than reduced the stripping of focal individuals. The stripping of Ulmus laevis, Acer campestre and Crataegus laevigata increased near conspecifics, while the stripping of all tree species was more likely near Ulmus laevis, Fraxinus angustifolia and shrubs. Heterospecific tree species were less susceptible to stripping near Tilia cordata and especially Carpinus betulus. Conclusion Our study provides new insight into neighbourhood effects by showing how and at which spatial scales woody plant interactions modify deer herbivory. We advocate considering the life stage and relevant plant traits with multivariate spatial methods in order to elucidate the role of neighbourhood effects in complex plant communities.