Forest, Ungulates and Human Activity Interactions


The number and geographical spread of red deer (Cervus elaphus) and roe deer (Capreolus capreolus) populations have increased significantly in France since the 1970s. Following a long period of population restoration with only small improvements that were generally localized in forest environments, these recent increases have raised new questions. These questions concern the effects these populations have on vegetation diversity in the underbrush and on forest species in particular, and what methods can be implemented to contribute to a better understanding of these populations. The concurrent growth of wild boar (Sus scrofa) populations in forests is worrying, which is why the species has also been included in our research.


The FONA team is focusing its research on the direct and indirect effects of wild ungulates (primarily red deer, roe deer and wild boar) and to a lesser extent, rodents (micromammals and beavers), on forest ecosystems. Their research will contribute to basic scientific knowledge to improve the management of wild ungulate populations and their habitat. It will take into account the socioeconomic consequences of their impact and the services they provide to humans.
Our long-term aim is to consolidate our approach to the ecological footprint of wild ungulates within a wide variety of landscapes, integrating societal expectations for similar regional areas. Our goal is to pinpoint more accurately the circumstances in which wild ungulates help maintain and restore the operation and biodiversity of terrestrial ecosystems.
This goal breaks down into 4 main points:
  • How can we adapt forest renewal when wild ungulates are present in a context of climate change?
  • What effects do wild ungulates have on the operation and biodiversity of forest ecosystems?
  • How do wild ungulates change the dynamics of ecosystems?
  • What management support tools should be recommended to improve the management of wild ungulate populations and their impact on the environment?

Main projects

Forest renewal when wild ungulates are present

Young female roe deer eating hornbeam branches

This research program will closely study the effects of herbivores on the demographic parameters (survival, growth) of certain forest species during a regeneration phase, in conjunction with routes taken and abiotic and biotic factors. Over time, this study will be used to supply data to forest stand dynamics models to improve resistance and tolerance to herbivores. The program also aims to refine existing management support tools and develop new tools that meet forest owners' needs to reduce impacts, monitor damage and measure stress during forest renewal across multiple scales (forest stands, areas, regions, etc.). The long-term aim for our research on forest renewal is to improve current knowledge and develop original methods to ensure forest renewal without having to resort to closures and individual protection for plants, while also maintaining wild ungulate populations at adequate levels for other forest users.


For more information:

Scientific leader: Anders Mårell

Related projects 
  • Diagnosing the impact of deer on the future of forest stands in the Massif du Donon, Donon project (2009-2012)
  • Oak Pine Tree Mixture experiment, OPTMix Project (2011-),

The effects of wild ungulates on the operation and biodiversity of forest ecosystems

Forest photo

Wild ungulates affect the operation and biodiversity of forest ecosystems. The repercussions can be seen in a variety of environments such as as prairies, forests and tundras. Our work focuses on the direct effects of herbivores on plant demographics (e.g., anemones, brambles, oaks, etc.), plant community dynamics (self-seeding vascular and bryophyte plants in the undergrowth) and forestry practices (forest regeneration). It includes experimental defensive measures (enclosures/exclosures), observations of the spatial and/or temporal gradients of herbivory (natural and simulated) and modeling. The indirect consequences of herbivory on plant-plant interactions (competition, facilitation) are also addressed as a result of changes in forestry practices, climate change and the overabundance of animals. We also look at the repercussions of these direct and indirect effects on other components of the ecosystems with a particular focus on bird fauna.

For more information:

Scientific leaders: Anders Mårell and Christophe Baltzinger

Related projects
  • Research Group on Introduced Species (RGIS), Haïda Gwaii Project (2005-201x):
  • Management, Nature and Biodiversity, GNB Project (2009-):
  • Diagnosing the impact of deer on the future of forest stands in the Massif du Donon, Donon project (2009-2012)
  • Oak Pine Tree Mixture experiment, OPTMix Project (2011-):
  • Spatial and temporal dynamics of enclosures in Sologne and ecosystem services, DYSPERSE project (2012-2015):
  • Ungulate contributions to ecosystem operations and services provided in Chambord, COSTAUD project (2015/6-2018)

Wild ungulates: ecosystem engineers

Although situations of high abundance are damaging to ecosystem dynamics, wild ungulates play an essential role in maintaining large natural terrestrial spaces by making a variety of contributions depending on their characteristics: size, food strategy, shape and behavior. Wild ungulates interact with their habitats in a varied and diverse manner; we are interested in how wild ungulates change the dynamics of their ecosystems, primarily in temperate lowland forests. Their impact on the ecosystem is mainly a result of their position in the food chain as consumers of plants and prey for larger predators. However, they can also change their environment. For example, they can transport matter from one place to another.

For this reason, we see them as ecosystem engineers. Furthermore, by trampling, turning over plant litter or even wallowing, they change the physical properties of the ground, while their excretions of fecal matter and urine can affect the nutrient cycle and soil chemistry. Our work also shows that wild ungulates are involved in dispersing seeds by transporting them externally (epizoochory) or by ingesting them (endozoochory). All these activities come together to shape the environment through direct and indirect impacts on the structure, composition and diversity of vegetation and other ecosystem components.

For more information:

Scientific leader: Christophe Baltzinger

Related projects
  • Plant dispersal by wild ungulates: comparative approach to three vectors, deer, roe deer and wild boar, DIPLO 1 (2009-2011) and DIPLO 2 (2012-2014) projects.
  • Spatial and temporal dynamics of enclosures in Sologne and ecosystem services, DYSPERSE project (2012-2015):
  • Ungulate contributions to ecosystem operations and services provided in Chambord, COSTAUD project (2015/2016-2018)


Our research has contributed to the development of management support tools (indicators). These tools are used by hunters and forest rangers to manage the population of wild ungulates sustainably and evaluate their effects and impacts on the environment. They are used to describe a situation or trend objectively: developments of herbivore stress on flora (consumption index), impact of deer on regenerating stands (forestry diagnosis), etc.
They can be used and integrated into participatory approaches. For example, if hunters and forest rangers assess forest damage differently, implementing a forestry assessment that the stakeholders share can be an effective way to reach a consensus.
We are also participating in the improvement of Ecological Change Indicators (ICE symposium in Chambord,
Research on seed dispersal by wild ungulates is part of the debate on ecological continuity and used to support public policies implementing the Green and Blue Belt. 
For more information:
Scientific leaders: Jean-Pierre Hamard and Agnès Rocquencourt
Related projects
  • National observatory for forest damage caused by deer, Observatoire project (1998-2004)
  • Forest stand renewal assessment, Sylviculture Régulière [Regular Forestry] project (2006-2010), Sylviculture Irrégulière [Irregular Forestry] project (2011-2014),
  • Diagnosing the impact of deer on the future of forest stands in the Massif du Donon, Donon project (2009-2012)
  • Defining a protocol to implement an observatory of forest-cynegetic balance in the Cévennes National Park (2010-2012)
  • Analysis of the pilot process for deer-forest balance in Seine-Maritime, EquiForCe 76 project (2015-2016)

Research topic

Terrestrial Ecological Systems: dynamics, vulnerability and engineering

Research units

Forest ecosystems

Team composition

Leader Researchers/engineers

/Assistant engineers

PhD students

Anders Mårell



Jean-Pierre HAMARD




PhD theses from 2005 to present 


Ongoing PhDs

  • Marie BALTZINGER – La biodiversité face au phénomène d’engrillagement: conséquences écologiques des clôtures et leurs répercussions en termes de services écosystémiques (Biodiversity and the enclosure phenomenon: ecological consequences of fences and their repercussions on ecosystem services) 
  • Lisa LAURENT – Rôle des interactions écologiques multiples dans la dynamique de l’écosystème forestier soumis aux changements de climat et de pratiques (The role of multiple ecological interactions in a forest ecosystem dynamic subject to changing climate and practices)

Presented theses

  • Mélanie PICARD – (2014). Influence de la dispersion endozoochore sur la composition des communautés végétales:: une approche fonctionnelle basée sur trois ongulés sauvages (Influence of endozoochorous dispersal on the composition of plant communities: a functional approach based on three wild ungulates) – PhD in Ecology, University of Orléans
  • Simon CHOLLET – (2012). De la mise en évidence à la gestion de l’effet de cerf – Leçons pratiques et théoriques fournies par l’introduction du cerf à queue-noire sur Haïda Gwaii. (From awareness to management of deer impacts – practical and theoretical lessons provided by the introduction of blacktail deer in Haïda Gwaii) PhD in Population Biology and Ecology, University of Montpellier
  • Vincent BOULANGER - (2010). Pression d'herbivorie et évolution des communautés végétales – Influence à court et moyen termes des populations de cervidés sur la diversité des communautés végétales en forêt. (Herbivory stress and evolution of plant communities – short- and medium-term influence of deer populations on diversity in forest plant communities)  PhD in Plant and Forest Biology in the RP2E PhD program, University of Nancy


Recent publications


  • Albert, A., Auffret, A., Cosyns, E., Cousins, S., D'hondt, B., Eichberg, C., Eycott, A., Heinken, T., Hoffmann, M., Jaroszewicz, B., Malo, J., Mårell, A., Mouissie, M., Pakeman, R., Picard, M., Plue, J., Poschlod, P., Provoost, S., Schulze, K.A., Baltzinger, C. (2015). Seed dispersal by ungulates as an ecological filter: a trait-based meta-analysis. Oikos. doi:10.1111/oik.02512
  • Albert, A., Mårell, A., Picard, M., Baltzinger, C. (2015). Using basic plant traits to predict ungulate seed dispersal potential. Ecography 38:440-449.
  • Bideau, E., Maublanc, M.L. Picot, D., Hamard, J.P., Ballon, P., Gerard, J.F. 2015. Short-term browsing by roe deer has little effect on survival and growth of sessile oak seedlings. Scandinavian Journal of Forest Research. doi: 10.1080/02827581.2015.1054873
  • Boulanger, V., Baltzinger, C., Said, S., Ballon, P., Picard, J.F., Dupouey, J.L. 2015. Decreasing deer browsing pressure influenced understory vegetation dynamics over 30 years. Annals of Forest Science 72:367-378.
  • Picard, M., Papaïx, J., Gosselin, F., Picot, D., Bideau, E., Baltzinger, C. (2015). Temporal dynamics of seed excretion by wild ungulates: implications for plant dispersal. Ecology and Evolution.


  • Boulanger, V., Said, S., Baltzinger, C., Dupouey, J.L. 2014. Effets des populations de cervidés sur la biodiversité végétale. Enseignements de deux suivis à moyen terme (10 et 30 ans). Faune sauvage 303:36-41.
  • De Frenne, P., Coomes, D.A., De Schrijver, A., Staelens, J., Alexander, J.M., Bernhardt Römermann, M., Brunet, J., Chabrerie, O., Chiarucci, A., Den Ouden, J., Eckstein, R.L., Graae, B.J., Gruwez, R., Hedl, R., Hermy, M., Kolb, A., Mårell, A., Mullender, S.M., Olsen, S.L., Orczewska, A., Peterken, G., Petrík, P., Plue, J., Simonson, W.D., Tomescu, C.V., Vangansbeke, P., Verstraeten, G., Vesterdal, L., Wulf, M., Verheyen, K. (2014). Plant movements and climate warming: intraspecific variation in growth responses to non-local soils. New Phytologist 202:431-441.


  • Ballon, P., Klein, F., Picard, O. (2013). L'équilibre forêt-cervidés en question? Forêt Entreprise 210:6-10.
  • Chollet, S., Baltzinger, C., Le Saout, S., Martin, J.L. 2013. A better world for bryophytes? A rare and overlooked case of positive community-wide effects of browsing by overabundant deer. Ecoscience 20:352-360.
  • Chollet, S., Baltzinger, C., Ostermann, L., Saint Andre, F., Martin, J.L. 2013. Importance for forest plant communities of refuges protecting from deer browsing. Forest Ecology and Management 289:470-477.
  • Gautier, G., Ballon, P., Hamard, J.P., Redon, M. (2013). Un observatoire de l'équilibre sylvo-cynégétique dans le Parc National des Cévennes. Forêt Entreprise 212:50-53.
  • Klein, F., Ballon, P. (2013). Revue des modalités de gestion des populations d'ongulés sauvages en Europe. Forêt Entreprise 210:56-59.
  • Mårell, A., Hamard, J.P., Said, S. (2013). Diagnostics et suivis de l'impact des ongulés sur la régénération et la flore forestière. Forêt Entreprise 210:18-22.
  • Schwoerer, M.L., Hamard, J.P., Pellerin, M. (2013). L'expérience de l'observatoire de l'équilibre cerf-forêt du massif du Donon. Forêt Entreprise 210:38-42.


  • Ballon, P., Ginelli, L., Vollet, D. (2012). Les services rendus par la chasse en France : Regards croisés en écologie, économie et sociologie. Revue Forestière Française 64:305-318.
  • Ballon, P., Gosselin, F. (2012). Les indicateurs forestiers sur la voie d'une gestion durable? Revue Forestière Française 64:547-550.
  • Chevrier, T., Saïd, S., Widmer, O., Hamard, J.P., Saint Andrieux, C., Gaillard, J.M. 2012. The oak browsing index correlates linearly with roe deer density: a new indicator for deer management? European Journal of Wildlife Research 58:17-22.
  • Mårell, A., Ballon, P., Hamard, J.P., Boulanger, V. (2012). Les dispositifs de type enclos-exclos: des outils au service de la gestion et de la recherche. Revue Forestière Française 64:139-150.
  • Mårell, A., Pellerin, M., Rocquencourt, A. (2012). Mesure et suivi de l'empreinte écologique des ongulés sauvages sur la végétation forestière. Revue Forestière Française 64:711-721.
  • Peyron, J.L., Ballon, P. (2012). Evaluation et paiement des services écosystémiques. Compte-rendu de l'atelier 2. Revue Forestière Française 64:417-423.
  • Picard, M., Baltzinger, C. (2012). Hitch-hiking in the wild: should seeds rely on ungulates? Plant Ecology and Evolution 145:24-30.


  • Boulanger, V., Baltzinger, C. Saïd, S., Ballon, P., Ningre, F., Picard, J.-F., Dupouey, J.-L. (2011). Deer-mediated expansion of a rare plant species. Plant Ecology 212, 307-314.
  • Boulanger, V., C. Baltzinger, S. Saïd, and J. L. Dupouey. 2011. Relations cervidés - végétation forestière: Apports des suivis temporels. Forêt Wallonne 110:22-32.
  • Cassagne, N., Pimont, F., Dupuy, J.-L., Linn, R.R., Mårell, A., Oliveri, C., Rigolot, E. (2011). Using a fire propagation model to assess the efficiency of prescribed burning in reducing the fire hazard. Ecological Modelling 222:1502-1514.
  • Flament, C., Hamard, J.P., 2011. Observatoire du Donon: Diagnostic de l’impact des cervidés sur l’avenir des peuplements forestiers - Base de travail pour la gestion. Final report, 58 p. + annexes.
  • Hamard J.P., Ballon P. (2011) Appréciation de l’impact des cervidés sur l’avenir des peuplements forestiers: de nouvelles méthodes de diagnostic à la disposition des gestionnaires. Forêt entreprise no. 197, 60-64.


  • Ballon P, Hamard J.P. (2010) Effets passés et actuels des populations de cervidés sur les taillis avec réserves, apports de la photo-interprétation. Revue Forestière Française, 2, 107-123.
  • Boulanger V. (2010) Pression d'herbivorie et dynamique des communautés végétales: influence à court et moyen termes des populations de cervidés sur la diversité des communautés végétales en forêt. PhD Thesis, Henri Poincaré University, Nancy, 282 p.
  • Hamard J.P., Ballon P. (2010) - Guide pratique d’évaluation des dégâts en milieu forestier. 32 p + downloadable annexes from the MAAPRAT website:
  • Maillard D., Gaillard J.M., Hewison M., Ballon P., Duncan P., Loison A., Toîgo C., Baubet E., Bonenfant C., Garel M., Saint Andrieux C. (2010) Ungulates and their management in France, in European Ungulates and their management in the 21st Century / Edited by Marco Apollonio, Reidar Andersen and Rory Putman, Cambridge University Press, chapter 20, pp 441-474.
  • Morsdorf M., Mårell A., Koetz  A., Cassagne N., Pimont B., Rigolot E., Allgöwer C., (2010) Discrimination of vegetation strata in a multi-layered Mediterranean forest ecosystem using height and intensity information derived from airborne laser scanning. Remote Sensing of Environment, 114, 1403–1415.


  • Archaux, F., Boulanger, V., Camaret, S., Corcket, E., Dupouey, J.-L., Forgeard, F., Heuzé, P., Lebret-Gallet, M., Mårell, A., Payet, K., Ulrich, E., Antonetti, P., Behr, P., Bourjot, L., Brêthes, A., Chevalier, R., Dobremez, J.-F., Dumas, Y., Dumé, G., Forêt, M., Kieffer, C., Mirlyaz, W., Picard, J.-F., Richard, F., Savoie, J.-M., Seytre, L., Timbal, J., Touffet, J. & Triesch, S. (2009) RENECOFOR - Dix ans de suivi de la végétation forestière: avancées méthodologiques et évolution temporelle de la flore (1994/95-2005), Office National des Forêts [National Forest Office], Direction Technique et Commerciale Bois [Wood Technical and Sales Department], Fontainebleau, France.
  • Ballon P., Hamard J.P., Pesme X (2009) A propos des fortes populations d’ongulés dans le massif forestier du Cosson. État des lieux et perspectives. Proceedings from the SFER symposium on Hunting, regions and sustainable development: analysis tools, issues and perspectives. March 25-26, 2009, ENITA, Clermont-Ferrand, 13 p.
  • Boulanger V., Baltzinger C., Saïd S., Ballon P., Picard J.F., Dupouey J.L. (2009) Ranking temperate woody species along a gradient of browsing by deer. Forest Ecology and Management 258 (2009), 1397-1406.
  • Dambrun S., Ballon P., Eymard D. (2009) La gestion de la faune sauvage peut-elle contribuer à une dynamique de développement territorial? Illustration à partir du Cerf sur le massif de la Pinatelle (Cantal). Revue d’Auvergne, Special edition: Développement, attractivité et ingénierie des territoires. Des enjeux de recherche pour l’action et la formation, pp 47-53.
  • Duncan P, Pellerin M, Gaillard J. M. Pettorelli N., Klein F., Saïd S., Delorme D., Van Laere G., Widmer O., Ballon P., Delcros P. (2009) Impact des tempêtes de 1999 sur les relations entre forêt et chevreuils et conséquences pour la gestion de ces ongulés. In La forêt face aux tempêtes, éditions Quae, chapter 9, pp 121-130.
  • Mårell A., Archaux F., Korboulewsky N. (2009) Floral herbivory of the wood anemone (Anemone nemorosa L.) by roe deer (Capreolus capreolus L.). Plant species Biology, 24, 209-214.  


  • Adrados C., Baltzinger C., Janeau G., Pepin D. (2008) Red deer resting places characteristics obtained from GPS data in a forest habitat. European Journal of Wildlife Research 54 (3), 487-494.
  • Ballon P., Hamard J.-P. (2008) Contributions pour obtenir un équilibre entre les populations de cervidés et le milieu forestier. Sinfotech – Les fiches savoir-faire. Irstea, 4p.
  • Hamard, J.P., (2008) Impact des abroutissements de cervidés sur les régénérations naturelles de chênes: Développement d'un outil de diagnostic et d'aide à la gestion sylvicole de ces peuplements. Dissertation for a Diploma from the Ecole Pratique des Hautes Études - Life and Earth Sciences Department. 112 p.
  • Klein F., Rocquencourt A., Ballon P. (2008) Pour un meilleur équilibre sylvo-cynégétique. Des pratiques sylvicoles favorables aux cervidés. ONCFS Brochure, Irstea, 54p.
  • Pépin, D., Adrados, C., Janeau, G., Joachim, J., & Mann, C. (2008) Individual variation in migratory and exploratory movements and habitat use by adult red deer (Cervus elaphus L.) in a mountainous temperate forest. Ecological Research, 23, 1005-1013.
  • Stroh N., Baltzinger C., Martin J.L. (2008) Deer prevent western red cedar (Thuya plicata) regeneration in old-growth forests of Haïda Gwaii: is there a potential for recovery? Forest Ecology and Management 255(12), 3973-3979.


  • Baltzinger, C. (2007) Les effets des cervidés et du sanglier sur la biodiversité: des recommandations de gestion des populations. Rendez-vous Techniques de l'ONF 16:48-51.
  • Morellet N., Gaillard J. M., Hewison A.J.M., Ballon P., Boscardin Y., Duncan P., Klein F., Maillard D. (2007) Indicators of ecological change: new tools for managing populations of large herbivores. Journal of applied ecology, 44, 634-643.