Herbaceous layer response to 17 years of controlled deer hunting in forested natural areas

Deleterious effects of overabundant deer populations within natural areas have been well documented and hunting programs have been initiated to control populations and facilitate the recovery of vegetation communities. However, few studies have examined whether recovery has occurred following sustained hunting. Hunting was initiated during the 1990s to reduce overabundant deer populations in Indiana state parks. In 2010, we resampled 108 plots established in 1996/97 across 15 state parks and five historically-hunted reference areas to quantify changes in herbaceous-layer vegetation. Species cover was measured along three, 10. m line transects nested within each plot. Data were pooled for all parks and reference areas. We calculated species richness (S), evenness (E), and Shannon-Weiner diversity (H\u27) in 1996/97 and 2010. Compositional changes between sample intervals and contemporary composition across environmental gradients were examined using nonmetric multidimensional scaling (NMS). We observed greater increases in herbaceous-layer cover in parks than in reference areas. S and H\u27 increased significantly in parks, but not reference areas. NMS ordinations revealed unidirectional changes in species composition between parks and their respective reference areas with the composition of parks becoming more similar to that of reference areas through time. Park size, cumulative deer harvest, initial deer abundance, and recent average of harvest/hunter effort were significantly correlated (p \u3c . 0.05) with ordination scores in four out of five natural regions (|. r|. \u3e . 0.5 for at least one axis). Browse-sensitive functional groups increased in cover while that of exotic species decreased. Changes were most pronounced for tree seedlings, which displayed a sixfold increase in cover within parks between sample intervals. These results suggest that hunting has allowed recovery of degraded vegetation communities. © 2014 Elsevier Ltd