White-Tailed Deer (Odocoileus virginianus) Browsing Preferences and Spatial Patterns in a Kansas Flint Hills Riparian Woodland

Abstract

In many eastern North American forests white-tailed deer (Odocoileus virginianus) populations are large and their browsing reduces tree regeneration and alters sapling species composition. In comparison to forested communities further east, deer effects in Great Plains riparian woodlands are poorly understood. These woodlands may experience greater browsing pressure than regional deer densities suggest because deer are associated with wooded habitats in this otherwise open landscape. To explore potential effects of deer in these riparian woodlands, we quantified deer preference among tree species and spatial patterns in browsing in the Kings Creek riparian zone at Konza Prairie Long-Term Ecological Research Site. Our objectives were to determine how 1) browsing intensity differs among tree species and 2) browsing intensity varies in relation to a woodland edge – center gradient, an upstream – downstream gradient and proximity to deer trails. In June 2016, we quantified the proportion of twigs with new growth that had been browsed on saplings 15 -150 cm tall in 10 m2 plots along pairs of transects that extended from the stream to the woodland edge. Transect pairs were arranged in a downstream progression. We found significant differences among tree species in proportion of twigs browsed with bitternut hickory (Carya cordiformis), black walnut (Juglans nigra) and burr oak (Quercus macrocarpa) being most browsed. Hackberry (Celtis occidentalis) and honey locust (Gleditsia triacanthos) were least browsed. Xerophytic tree species (oaks, hickories) were browsed more than mesophytic species (all other species). Browse intensity was greatest within 3 m of deer trails and increased downstream, but was unaffected by proximity to woodland edges. Strong differences among tree species in browse intensity suggest the potential for deer to affect tree species composition, possibly accelerating mesophication. Even in these wooded habitats, deer browsing is concentrated near deer trails.