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Boulanger V, Dupouey JL, Archaux F, Badeau V, Baltzinger C, Chevalier R, Corcket E, Dumas Y, Forgeard F, Mårell A, Montpied P, Paillet Y, Picard JF, Saïd S, Ulrich E. Ungulates increase forest plant species richness to the benefit of non-forest specialists. Glob Chang Biol 2018; 24:e485-e495. [PMID: 28892277 DOI: 10.1111/gcb.13899] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 08/16/2017] [Indexed: 06/07/2023]
Abstract
Large wild ungulates are a major biotic factor shaping plant communities. They influence species abundance and occurrence directly by herbivory and plant dispersal, or indirectly by modifying plant-plant interactions and through soil disturbance. In forest ecosystems, researchers' attention has been mainly focused on deer overabundance. Far less is known about the effects on understory plant dynamics and diversity of wild ungulates where their abundance is maintained at lower levels to mitigate impacts on tree regeneration. We used vegetation data collected over 10 years on 82 pairs of exclosure (excluding ungulates) and control plots located in a nation-wide forest monitoring network (Renecofor). We report the effects of ungulate exclusion on (i) plant species richness and ecological characteristics, (ii) and cover percentage of herbaceous and shrub layers. We also analyzed the response of these variables along gradients of ungulate abundance, based on hunting statistics, for wild boar (Sus scrofa), red deer (Cervus elaphus) and roe deer (Capreolus capreolus). Outside the exclosures, forest ungulates maintained higher species richness in the herbaceous layer (+15%), while the shrub layer was 17% less rich, and the plant communities became more light-demanding. Inside the exclosures, shrub cover increased, often to the benefit of bramble (Rubus fruticosus agg.). Ungulates tend to favour ruderal, hemerobic, epizoochorous and non-forest species. Among plots, the magnitude of vegetation changes was proportional to deer abundance. We conclude that ungulates, through the control of the shrub layer, indirectly increase herbaceous plant species richness by increasing light reaching the ground. However, this increase is detrimental to the peculiarity of forest plant communities and contributes to a landscape-level biotic homogenization. Even at population density levels considered to be harmless for overall plant species richness, ungulates remain a conservation issue for plant community composition.
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Affiliation(s)
- Vincent Boulanger
- Office National des Forêts, Département Recherche, Développement et Innovation, Fontainebleau, France
| | - Jean-Luc Dupouey
- INRA - Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
| | - Frédéric Archaux
- Irstea, UR EFNO, Domaine des Barres, Nogent-sur-Vernisson, France
| | - Vincent Badeau
- INRA - Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
| | | | | | - Emmanuel Corcket
- Université de Bordeaux, UMR1202 BioGeCo, Allée Geoffroy St-Hilaire, Pessac Cedex, France
| | - Yann Dumas
- Irstea, UR EFNO, Domaine des Barres, Nogent-sur-Vernisson, France
| | - Françoise Forgeard
- Laboratoire d'Ecologie Végétale, Université de Rennes I, Rennes Cedex, France
| | - Anders Mårell
- Irstea, UR EFNO, Domaine des Barres, Nogent-sur-Vernisson, France
| | - Pierre Montpied
- INRA - Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
| | - Yoan Paillet
- Irstea, UR EFNO, Domaine des Barres, Nogent-sur-Vernisson, France
| | - Jean-François Picard
- INRA - Université de Lorraine, UMR 1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
| | - Sonia Saïd
- Office National de la Chasse et de la Faune sauvage, DRE Unité, Ongulés sauvages, Birieux, France
| | - Erwin Ulrich
- Office National des Forêts, Département Recherche, Développement et Innovation, Fontainebleau, France
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