G. Adam and H. Duncan, Development of a sensitive and rapid method for the measurement of total microbial activity using fluorescein diacetate (FDA) in a range of soils, Soil Biology and Biochemistry, vol.33, issue.7-8, pp.943-951, 2001.
DOI : 10.1016/S0038-0717(00)00244-3

P. B. Adler, D. G. Milchunas, W. K. Lauenroth, O. E. Sala, and I. C. Burke, Functional traits of graminoids in semi-arid steppes: a test of grazing histories, Journal of Applied Ecology, vol.33, issue.4, pp.653-663, 2004.
DOI : 10.1111/j.0021-8901.2004.00934.x

P. B. Adler, D. A. Raff, and W. K. Lauenroth, The effect of grazing on the spatial heterogeneity of vegetation, Oecologia, vol.128, pp.465-479, 2001.

R. Aerts and H. De-caluwe, Nutritional and Plant-Mediated Controls on Leaf Litter Decomposition of Carex Species, Ecology, vol.78, issue.1, pp.244-260, 1997.
DOI : 10.2307/2265993

B. Amiaud, Dynamique végétale d'un écosystème prairial soumis à différentes modalités de pâturage. Exemple des communaux du Marais Poitevin, Thèse de doctorat, 1998.

B. Amiaud, J. Bouzillé, F. Tournade, and A. Bonis, Spatial patterns of soil salinities in old embanked marshlands in western France, Wetlands, vol.28, issue.283, pp.482-494, 1998.
DOI : 10.1007/BF03161540

A. Minitab, S. Minitab, P. College, and P. Ansquer, Traits biologiques et réponses des plantes au pâturage: étude d'une prairie humide du Marais Poitevin, 1998.

E. S. Bakker, H. Olff, M. Boekhoff, J. M. Gleichman, and F. Berendse, Impact of herbivores on nitrogen cycling: contrasting effects of small and large species, Oecologia, vol.138, issue.1, pp.91-101, 2004.
DOI : 10.1007/s00442-003-1402-5

J. P. Bakker, The impact of grazing on plant communities Grazing and conservation management, pp.137-184, 1998.

S. Barbier, Quelques éléments sur la dynamique végétale en prairie naturelle humide pâturée (Marais Poitevin): répartition spatiale des fèces des grands herbivores, pâturage par les invertébrés et structure du mat racinaire, p.27, 2002.

R. D. Bardgett and A. Shine, Linkages between plant litter diversity, soil microbial biomass and ecosystem function in temperate grasslands, Soil Biology and Biochemistry, vol.31, issue.2, pp.317-321, 1999.
DOI : 10.1016/S0038-0717(98)00121-7

R. D. Bardgett, D. A. Wardle, and G. W. Yeates, Linking above-ground and below-ground interactions: how plant responses to foliar herbivory influence soil organisms, Soil Biology and Biochemistry, vol.30, issue.14, pp.1867-1878, 1998.
DOI : 10.1016/S0038-0717(98)00069-8

V. S. Baron, E. Mapfumo, A. C. Dick, M. A. Naeth, E. K. Okine et al., Grazing Intensity Impacts on Pasture Carbon and Nitrogen Flow, Journal of Range Management, vol.55, issue.6, pp.535-541, 2002.
DOI : 10.2307/4003996

J. E. Barrett and I. C. Burke, Potential nitrogen immobilization in grassland soils across a soil organic matter gradient, Soil Biology and Biochemistry, vol.32, issue.11-12, pp.1707-1716, 2000.
DOI : 10.1016/S0038-0717(00)00089-4

F. A. Bazzaz, The Response of Natural Ecosystems to the Rising Global CO2 Levels, Annual Review of Ecology and Systematics, vol.21, issue.1, pp.167-196, 1990.
DOI : 10.1146/annurev.es.21.110190.001123

A. J. Belsky, Does Herbivory Benefit Plants? A Review of the Evidence, The American Naturalist, vol.127, issue.6, pp.870-892, 1986.
DOI : 10.1086/284531

A. J. Belsky, W. P. Carson, C. L. Jensen, and G. A. Fox, Overcompensation by plants: Herbivore optimization or red herring?, Evolutionary Ecology, vol.42, issue.1, pp.109-121, 1993.
DOI : 10.1007/BF01237737

G. D. Bending, M. K. Turner, and I. G. Burns, Fate of nitrogen from crop residues as affected by biochemical quality and the microbial biomass, Soil Biology and Biochemistry, vol.30, issue.14, pp.2055-2065, 1998.
DOI : 10.1016/S0038-0717(98)00081-9

F. Berendse, Implications of increased litter production for plant biodiversity, Trends in Ecology & Evolution, vol.14, issue.1, pp.4-5, 1999.
DOI : 10.1016/S0169-5347(98)01451-7

F. Berendse, M. Schmitz, and W. De-visser, Experimental manipulation of succession in heathland ecosystems, Oecologia, vol.16, issue.1-2, pp.38-44, 1994.
DOI : 10.1007/BF00317128

T. P. Bolger, J. F. Angus, and M. B. Peoples, Comparison of nitrogen mineralisation patterns from root residues of Trifolium subterraneum and Medicago sativa, Biology and Fertility of Soils, vol.38, issue.5, pp.296-300, 2003.
DOI : 10.1007/s00374-003-0629-y

A. Bonis, J. Bouzillé, B. Amiaud, and G. Loucougaray, Plant community patterns in old embanked grasslands and the survival of halophytic flora, Flora - Morphology, Distribution, Functional Ecology of Plants, vol.200, issue.1, pp.74-87, 2005.
DOI : 10.1016/j.flora.2004.06.002

A. Bonis, J. Bouzillé, G. Loucougaray, N. Rossignol, P. Ansquer et al., Traits as synthetic response of species and communities to grazing?, Multi-function grasslands, pp.768-769, 2002.

J. Bouzillé, Structure et dynamique des paysages, des communautés et des populations végétales des marais de l'ouest. Thèse d'état, spécialité écologie, 1992.

J. Bouzillé and F. Tournade, Blocage séculaire d'une succession végétale dans les marais de l'ouest de la France, Cr. Acad. Sc. III-vie 317, pp.571-574, 1994.

D. D. Briske, Strategies of plant survival in grazed systems: a functional interpretation The Ecology and management of Grazing Systems, CAB International, pp.37-68, 1996.

P. C. Brookes, A. Landman, G. Pruden, and D. S. Jenkinson, Chloroform fumigation and the release of soil nitrogen: A rapid direct extraction method to measure microbial biomass nitrogen in soil, Soil Biology and Biochemistry, vol.17, issue.6, pp.837-842, 1985.
DOI : 10.1016/0038-0717(85)90144-0

J. M. Bullock, J. Franklin, M. J. Stevenson, J. Silvertown, S. J. Coulson et al., A plant trait analysis of responses to grazing in a long-term experiment, Journal of Applied Ecology, vol.38, pp.253-267, 2001.

I. C. Burke, W. K. Lauenroth, M. A. Vinton, P. B. Hook, R. H. Kelly et al., Plant-Soil interactions in temperate grasslands, Biogeochemistry, vol.42, pp.121-143, 1998.
DOI : 10.1007/978-94-017-2691-7_7

C. A. Busso, D. D. Briske, and V. Olalde-portugal, Root traits associated with nutrient exploitation following defoliation in three coexisting perennial grasses in a semi-arid savanna, Oikos, vol.93, issue.2, 2001.
DOI : 10.1034/j.1600-0706.2001.930216.x

J. Cebrian, Patterns in the Fate of Production in Plant Communities, The American Naturalist, vol.154, issue.4, pp.449-468, 1999.
DOI : 10.1086/303244

F. S. Chapin, Integrated Responses of Plants to Stress, BioScience, vol.41, issue.1, pp.29-36, 1991.
DOI : 10.2307/1311538

M. Clarholm, Interactions of bacteria, protozoa and plants leading to mineralization of soil nitrogen, Soil Biology and Biochemistry, vol.17, issue.2, pp.181-187, 1985.
DOI : 10.1016/0038-0717(85)90113-0

R. T. Conant, Grazer-dominated Ecosystems, Encyclopedia of Life Sciences, 2002.
DOI : 10.1038/npg.els.0003195

R. T. Coupland, Approach and generalizations Natural grasslands: introduction and western helisphere, pp.1-6, 1993.

J. M. Craine, D. A. Wedin, and F. S. Chapin, Predominance of ecophysiological controls on soil CO2 flux in a Minnesota grassland, Plant and Soil, vol.207, issue.1, pp.77-86, 1999.
DOI : 10.1023/A:1004417419288

X. Dai, Impact of cattle dung deposition on the distribution pattern of plant species in an alvar limestone grassland, Journal of Vegetation Science, vol.50, issue.5, pp.715-724, 2000.
DOI : 10.2307/3236578

C. De-mazancourt and M. Loreau, Effect of Herbivory and Plant Species Replacement on Primary Production, The American Naturalist, vol.155, issue.6, pp.735-754, 2000.
DOI : 10.1086/303360

C. De-mazancourt, M. Loreau, and L. Abbadie, GRAZING OPTIMIZATION AND NUTRIENT CYCLING: WHEN DO HERBIVORES ENHANCE PLANT PRODUCTION?, Ecology, vol.79, issue.7, pp.2242-2252, 1998.
DOI : 10.1126/science.1273598

E. Del-val and M. J. Crawley, Are grazing increaser species better tolerators than decreasers? An experimental assessment of defoliation tolerance in eight British grassland species, Journal of Ecology, vol.48, issue.5, pp.1005-1016, 2005.
DOI : 10.1023/A:1009743130922

E. Del-val and M. J. Crawley, What limits herb biomass in grasslands: competition or herbivory?, Oecologia, vol.417, issue.2, pp.202-211, 2005.
DOI : 10.1007/s00442-004-1719-8

J. K. Detling and E. L. Painter, Defoliation responses of western wheatgrass populations with diverse histories of prairie dog grazing, Oecologia, vol.16, issue.1-2, pp.65-71, 1983.
DOI : 10.1007/BF00379563

S. Diaz, A. J. Symstad, F. S. Chapin, D. A. Wardle, and L. F. Huenneke, Functional diversity revealed by removal experiments, pp.140-146, 2003.

S. Diaz and M. Cabido, Vive la diff??rence: plant functional diversity matters to ecosystem processes, Trends in Ecology & Evolution, vol.16, issue.11, pp.646-655, 2001.
DOI : 10.1016/S0169-5347(01)02283-2

S. Diaz, I. Noy-meir, and M. Cabido, Can grazing response of herbaceous plants be predicted from simple vegetative traits?, Journal of Applied Ecology, vol.38, issue.3, pp.497-508, 2001.
DOI : 10.1046/j.1365-2664.2001.00635.x

S. Diaz, J. P. Grime, J. Harris, and E. Mcpherson, Evidence of a feedback mechanism limiting plant response to elevated carbon dioxide, Nature, vol.364, issue.6438, pp.616-617, 1993.
DOI : 10.1038/364616a0

M. I. Dyer, C. L. Turner, and T. R. Seastedt, Herbivory and Its Consequences, Ecological Applications, vol.3, issue.1, pp.10-16, 1993.
DOI : 10.2307/1941781

M. I. Dyer, D. L. Deangelis, and W. M. Post, A model of herbivore feedback on plant productivity, Mathematical Biosciences, vol.79, issue.2, pp.171-184, 1986.
DOI : 10.1016/0025-5564(86)90146-X

M. I. Dyer and U. G. Bokhari, Plant-Animal Interactions: Studies of the Effects of Grasshopper Grazing on Blue Grama Grass, Ecology, vol.57, issue.4, pp.762-772, 1976.
DOI : 10.2307/1936189

C. Eno, Nitrate Production in the Field by Incubating the Soil in Polyethylene Bags1, Soil Science Society of America Journal, vol.24, issue.4, pp.277-279, 1960.
DOI : 10.2136/sssaj1960.03615995002400040019x

H. E. Epstein, I. C. Burke, and A. R. Mosier, Plant effects on nitrogen retention in shortgrass steppe 2??years after 15N addition, Oecologia, vol.128, issue.3, pp.422-430, 2001.
DOI : 10.1007/s004420100670

J. T. Fahnestock and J. K. Detling, Bison-prairie dog-plant interactions in a North American mixed-grass prairie, Oecologia, vol.132, issue.1, pp.86-95, 2002.
DOI : 10.1007/s00442-002-0930-8

D. O. Ferraro and M. Oesterheld, Effect of defoliation on grass growth. A quantitative review, Oikos, vol.74, issue.1, pp.125-133, 2002.
DOI : 10.1016/0169-5347(86)90048-0

A. C. Finzi and C. D. Canham, Non-additive effects of litter mixtures on net N mineralization in a southern New England forest, Forest Ecology and Management, vol.105, issue.1-3, pp.129-136, 1998.
DOI : 10.1016/S0378-1127(97)00277-6

G. Fleurance, P. Duncan, and B. Mallevaud, Daily intake and the selection of feeding sites by horses in heterogeneous wet grasslands, Animal Research, vol.50, issue.2, pp.149-156, 2001.
DOI : 10.1051/animres:2001123

URL : https://hal.archives-ouvertes.fr/hal-00889847

D. A. Frank, P. M. Groffman, R. D. Evans, and B. F. Tracy, Ungulate stimulation of nitrogen cycling and retention in Yellowstone Park grasslands, Oecologia, vol.123, issue.1, pp.116-121, 2000.
DOI : 10.1007/s004420050996

D. A. Frank and P. M. Groffman, UNGULATE VS. LANDSCAPE CONTROL OF SOIL C AND N PROCESSES IN GRASSLANDS OF YELLOWSTONE NATIONAL PARK, Ecology, vol.79, issue.7, pp.2229-2241, 1998.
DOI : 10.2307/1307227

D. A. Frank and R. D. Evans, EFFECTS OF NATIVE GRAZERS ON GRASSLAND N CYCLING IN YELLOWSTONE NATIONAL PARK, Ecology, vol.78, issue.7, pp.2238-2248, 1997.
DOI : 10.1007/BF00344913

A. Gallardo and W. H. Schlesinger, Factors determining soil microbial biomass and nutrient immobilization in desert soils, Biogeochemistry, vol.13, issue.1, pp.55-68, 1995.
DOI : 10.1007/BF02178061

F. Garcia, P. Carrère, J. Soussana, and R. Baumont, How do severity and frequency of grazing affect sward characteristics and the choices of sheep during the grazing season? Grass and Forage Science, pp.138-150, 2003.

N. J. Georgiadis, R. W. Ruess, S. J. Mcnaughton, and D. Western, Ecological conditions that determine when grazing stimulates grass production, Oecologia, vol.54, issue.3, pp.316-322, 1989.
DOI : 10.1007/BF00377077

M. J. Gibb and M. S. Ridout, Application of double normal frequency distributions fitted to measurements of sward height, Grass and Forage Science, vol.40, issue.2, pp.131-136, 1988.
DOI : 10.1111/j.1365-2494.1988.tb01880.x

M. J. Gibb and M. S. Ridout, The fitting of frequency distributions to height measurements on grazed swards, Grass and Forage Science, vol.38, issue.3, pp.247-249, 1986.
DOI : 10.1111/j.1365-2494.1986.tb01810.x

V. S. Green, D. E. Stott, and M. Diack, Assay for fluorescein diacetate hydrolytic activity: Optimization for soil samples, Soil Biology and Biochemistry, vol.38, issue.4, 2005.
DOI : 10.1016/j.soilbio.2005.06.020

R. A. Green and J. K. Detling, Defoliation-induced enhancement of total aboveground nitrogen yield of grasses, Oikos, vol.91, issue.2, pp.280-284, 2000.
DOI : 10.1034/j.1600-0706.2000.910208.x

J. P. Grime, Benefits of plant diversity to ecosystems: immediate, filter and founder effects, Journal of Ecology, vol.51, issue.6, pp.902-910, 1998.
DOI : 10.1016/0169-5347(92)90006-W

R. Guitian and R. D. Bardgett, Plant and soil microbial responses to defoliation in temperate semi-natural grassland, Plant and Soil, vol.220, issue.1/2, pp.271-277, 2000.
DOI : 10.1023/A:1004787710886

N. G. Hairston, F. E. Smith, and L. B. Slobodkin, Community Structure, Population Control, and Competition, The American Naturalist, vol.94, issue.879, pp.421-425, 1960.
DOI : 10.1086/282146

E. W. Hamilton and D. A. Frank, CAN PLANTS STIMULATE SOIL MICROBES AND THEIR OWN NUTRIENT SUPPLY? EVIDENCE FROM A GRAZING TOLERANT GRASS, Ecology, vol.82, issue.9, pp.2397-2402, 2001.
DOI : 10.2307/2446507

E. W. Hamilton, M. S. Giovannini, S. A. Moses, J. S. Coleman, and S. J. Mcnaughton, Biomass and mineral element responses of a Serengeti short-grass species to nitrogen supply and defoliation: compensation requires a critical [N], Oecologia, vol.116, issue.3, pp.407-418, 1998.
DOI : 10.1007/s004420050604

S. C. Hart, G. E. Nason, D. D. Myrold, and D. A. Perry, Dynamics of Gross Nitrogen Transformations in an Old-Growth Forest: The Carbon Connection, Ecology, vol.75, issue.4, pp.880-891, 1994.
DOI : 10.2307/1939413

D. C. Hartnett, Density- and growth stage-dependent responses to defoliation in two rhizomatous grasses, Oecologia, vol.228, issue.3, pp.414-420, 1989.
DOI : 10.1007/BF00379045

D. J. Hatch, R. D. Lovell, R. S. Antil, S. C. Jarvis, and P. M. Owen, Nitrogen mineralization and microbial activity in permanent pastures amended with nitrogen fertilizer or dung, Biology and Fertility of Soils, vol.30, issue.4, pp.288-293, 2000.
DOI : 10.1007/s003740050005

G. F. Hayes and K. D. Holl, Cattle Grazing Impacts on Annual Forbs and Vegetation Composition of Mesic Grasslands in California, Conservation Biology, vol.48, issue.6, pp.1694-1702, 2003.
DOI : 10.1111/j.1523-1739.2003.00281.x

B. C. Hendon and D. D. Briske, Relative herbivory tolerance and competitive ability in two dominant : subordinate pairs of perennial grasses in a native grassland, Plant Ecology, vol.160, issue.1, pp.43-51, 2002.
DOI : 10.1023/A:1015841214866

T. M. Henriksen and T. A. Breland, Evaluation of criteria for describing crop residue degradability in a model of carbon and nitrogen turnover in soil, Soil Biology and Biochemistry, vol.31, issue.8, pp.1135-1149, 1999.
DOI : 10.1016/S0038-0717(99)00031-0

D. W. Hilbert, D. M. Swift, J. K. Detling, and M. I. Dyer, Relative growth rates and the grazing optimization hypothesis, Oecologia, vol.31, issue.1, pp.14-18, 1981.
DOI : 10.1007/BF00344645

S. E. Hobbie, Effects of plant species on nutrient cycling, Trends in Ecology & Evolution, vol.7, issue.10, pp.336-339, 1992.
DOI : 10.1016/0169-5347(92)90126-V

N. T. Hobbs, D. S. Schimel, C. E. Owensby, and D. S. Ojima, Fire and Grazing in the Tallgrass Prairie: Contingent Effects on Nitrogen Budgets, Ecology, vol.72, issue.4, pp.1374-1382, 1991.
DOI : 10.2307/1941109

A. Hodge, D. Robinson, and A. Fitter, Are microorganisms more effective than plants at competing for nitrogen?, Trends in Plant Science, vol.5, issue.7, pp.304-308, 2000.
DOI : 10.1016/S1360-1385(00)01656-3

E. A. Holland, W. J. Parton, J. K. Detling, and D. L. Coppock, Physiological Responses of Plant Populations to Herbivory and Their Consequences for Ecosystem Nutrient Flow, The American Naturalist, vol.140, issue.4, pp.685-706, 1992.
DOI : 10.1086/285435

E. A. Holland and J. K. Detling, Plant Response to Herbivory and Belowground Nitrogen Cycling, Ecology, vol.71, issue.3, pp.1040-1049, 1990.
DOI : 10.2307/1937372

J. N. Holland, W. Cheng, and D. A. Crossley, Herbivore-induced changes in plant carbon allocation: assessment of below-ground C fluxes using carbon-14, Oecologia, vol.95, issue.1, pp.87-94, 1996.
DOI : 10.1007/BF00582238

D. U. Hooper, F. S. Chapin, J. J. Ewel, A. Hector, P. Inchausti et al., EFFECTS OF BIODIVERSITY ON ECOSYSTEM FUNCTIONING: A CONSENSUS OF CURRENT KNOWLEDGE, Ecological Monographs, vol.75, issue.1, pp.3-35, 2005.
DOI : 10.1086/285824

URL : https://hal.archives-ouvertes.fr/hal-00188090

D. U. Hooper and J. S. Dukes, Overyielding among plant functional groups in a long-term experiment, Ecology Letters, vol.87, issue.2, pp.95-105, 2004.
DOI : 10.1046/j.1461-0248.2003.00555.x

D. U. Hooper and P. M. Vitousek, EFFECTS OF PLANT COMPOSITION AND DIVERSITY ON NUTRIENT CYCLING, Ecological Monographs, vol.68, issue.1, pp.121-149, 1998.
DOI : 10.2307/1940319

D. U. Hooper and P. M. Vitousek, The Effects of Plant Composition and Diversity on Ecosystem Processes, Science, vol.277, issue.5330, pp.1302-1305, 1997.
DOI : 10.1126/science.277.5330.1302

B. A. Hungate, F. S. Chapin, H. Zhong, E. A. Holland, and C. B. Field, Stimulation of grassland nitrogen cycling under carbon dioxide enrichment, Oecologia, vol.109, issue.1, pp.149-153, 1997.
DOI : 10.1007/s004420050069

N. Huntly, Herbivores and the Dynamics of Communities and Ecosystems, Annual Review of Ecology and Systematics, vol.22, issue.1, pp.477-503, 1991.
DOI : 10.1146/annurev.es.22.110191.002401

N. J. Huntly, Influence of Refuging Consumers (Pikas: Ochotona Princeps) on Subalpine Meadow Vegetation, Ecology, vol.68, issue.2, pp.274-283, 1987.
DOI : 10.2307/1939258

V. J. Jaramillo and J. K. Detling, Small-Scale Heterogeneity in a Semi-Arid North American Grassland. I. Tillering, N Uptake and Retranslocation in Simulated Urine Patches, The Journal of Applied Ecology, vol.29, issue.1, pp.1-8, 1992.
DOI : 10.2307/2404340

S. Jonasson, A. Michelsen, and I. K. Schmidt, Coupling of nutrient cycling and carbon dynamics in the Arctic, integration of soil microbial and plant processes, Applied Soil Ecology, vol.11, issue.2-3, pp.135-146, 1999.
DOI : 10.1016/S0929-1393(98)00145-0

C. G. Jones and J. H. Lawton, Linking species and ecosystems, 1995.
DOI : 10.1007/978-1-4615-1773-3

J. P. Kaye and S. C. Hart, Competition for nitrogen between plants and soil microorganisms, Trends in Ecology & Evolution, vol.12, issue.4, pp.139-142, 1997.
DOI : 10.1016/S0169-5347(97)01001-X

D. R. Keeney and D. W. Nelson, Nitrogen-inorganic forms Methods of soil analysis: Part 2: Chemical and Microbiological Properties, pp.676-682, 1982.

A. P. Kinzig, S. W. Pacala, and D. Tilman, The functional consequences of biodiversity: empirical progress and theoretical extensions, 2001.

J. M. Knops, K. L. Bradley, and D. A. Wedin, Mechanisms of plant species impacts on ecosystem nitrogen cycling, Ecology Letters, vol.81, issue.3, pp.454-466, 2002.
DOI : 10.1126/science.274.5293.1720

S. Lavorel and E. Garnier, Predicting changes in community composition and ecosystem functioning from plant traits: revisiting the Holy Grail, Functional Ecology, vol.5, issue.5, pp.545-556, 2002.
DOI : 10.1016/0169-5347(92)90006-W

S. Lavorel, S. Mcintyre, J. Landsberg, and T. D. Forbes, Plant functional classifications: from general groups to specific groups based on response to disturbance, Trends in Ecology & Evolution, vol.12, issue.12, pp.474-478, 1997.
DOI : 10.1016/S0169-5347(97)01219-6

S. F. Ledgard, S. C. Jarvis, and D. J. Hatch, Short-term nitrogen fluxes in grassland soils under different long-term nitrogen management regimes, Soil Biology and Biochemistry, vol.30, issue.10-11, pp.1233-1241, 1998.
DOI : 10.1016/S0038-0717(98)00022-4

P. Loiseau, F. Louault, X. Le-roux, and M. Bardy, Does extensification of rich grasslands alter the C and N cycles, directly or via species composition?, Basic and Applied Ecology, vol.6, issue.3, pp.275-287, 2005.
DOI : 10.1016/j.baae.2004.07.006

URL : https://hal.archives-ouvertes.fr/halsde-00354255

M. Loreau, Biodiversity and ecosystem functioning: recent theoretical advances, Oikos, vol.91, issue.1, pp.3-17, 2000.
DOI : 10.1034/j.1600-0706.2000.910101.x

M. Loreau, Consumers as Maximizers of Matter and Energy Flow in Ecosystems, The American Naturalist, vol.145, issue.1, pp.22-42, 1995.
DOI : 10.1086/285726

M. Loreau, S. Naeem, and P. Inchausti, Biodiversity and ecosystem functioning: synthesis and perspectives, 2002.

G. Loucougaray, Régimes de pâturage et hétérogénéité de la structure et du fonctionnement de la végétation prairiale (Marais Poitevin), Thèse de doctorat, 2003.

G. Loucougaray, A. Bonis, and J. Bouzillé, Effects of grazing by horses and/or cattle on the diversity of coastal grasslands in western France, Biological Conservation, vol.116, issue.1, pp.59-71, 2004.
DOI : 10.1016/S0006-3207(03)00177-0

C. A. Marriot, G. R. Bolton, J. M. Fisher, and K. Hood, Short-term changes in soil nutrients and vegetation biomass and nutrient content following the introduction of extensive management in upland sown swards in Scotland, UK, Agriculture, Ecosystems & Environment, vol.106, issue.4, pp.331-344, 2005.
DOI : 10.1016/j.agee.2004.09.004

E. J. Mcintire and D. S. Hik, Influences of chronic and current season grazing by collared pikas on above-ground biomass and species richness in subarctic alpine meadows, Oecologia, vol.93, issue.2, pp.288-297, 2005.
DOI : 10.1007/s00442-005-0127-z

E. J. Mcintire and D. S. Hik, Grazing history versus current grazing: leaf demography and compensatory growth of three alpine plants in response to a native herbivore (Ochotona collaris), Journal of Ecology, vol.6, issue.2, pp.348-359, 2002.
DOI : 10.1086/285309

S. Mcintyre, S. Lavorel, and R. M. Tremont, Plant Life-History Attributes: Their Relationship to Disturbance Response in Herbaceous Vegetation, The Journal of Ecology, vol.83, issue.1, pp.31-44, 1995.
DOI : 10.2307/2261148

S. J. Mcnaughton, F. F. Banyikwa, and M. M. Mcnaughton, Promotion of the Cycling of Diet-Enhancing Nutrients by African Grazers, Science, vol.278, issue.5344, pp.1798-1800, 1997.
DOI : 10.1126/science.278.5344.1798

S. J. Mcnaughton, D. G. Milchunas, and D. A. Frank, How can net Primary Productivity be Measured in Grazing Ecosystems?, Ecology, vol.77, issue.3, pp.974-977, 1996.
DOI : 10.2307/2265518

S. J. Mcnaughton, Ecology of a Grazing Ecosystem: The Serengeti, Ecological Monographs, vol.55, issue.3, pp.259-294, 1985.
DOI : 10.2307/1942578

J. M. Melillo, J. D. Aber, and J. F. Muratore, Nitrogen and Lignin Control of Hardwood Leaf Litter Decomposition Dynamics, Ecology, vol.63, issue.3, pp.621-626, 1982.
DOI : 10.2307/1936780

C. Ménard, Etude comparée du comportement alimentaire des chevaux et des bovins en pâturage extensif, 1999.

C. Ménard, P. Duncan, G. Fleurance, J. Georges, and M. Lila, Comparative foraging and nutrition of horses and cattle in European wetlands, Journal of Applied Ecology, vol.39, issue.1, pp.120-133, 2002.
DOI : 10.1046/j.1365-2664.2002.00693.x

J. Mikola, G. M. Barker, and D. A. Wardle, Linking above-ground and below-ground effects in autotrophic microcosms: effects of shading and defoliation on plant and soil properties, Oikos, vol.89, issue.3, pp.577-587, 2000.
DOI : 10.1034/j.1600-0706.2000.890318.x

D. G. Milchunas, A. R. Mosier, J. A. Morgan, D. R. Lecain, J. Y. King et al., Elevated CO2 and defoliation effects on a shortgrass steppe: Forage quality versus quantity for ruminants, Agriculture, Ecosystems & Environment, vol.111, issue.1-4, pp.166-184, 2005.
DOI : 10.1016/j.agee.2005.06.014

D. G. Milchunas, A. S. Varnamkhasti, W. K. Lauenroth, and H. Goetz, Forage quality in relation to long-term grazing history, current-year defoliation, and water resource, Oecologia, vol.128, issue.3, pp.366-374, 1995.
DOI : 10.1007/BF00328824

D. G. Milchunas and W. K. Lauenroth, Quantitative Effects of Grazing on Vegetation and Soils Over a Global Range of Environments, Ecological Monographs, vol.63, issue.4, pp.327-366, 1993.
DOI : 10.2307/2937150

S. Mishra, H. J. Di, K. C. Cameron, R. Monaghan, and A. Carran, Gross nitrogen mineralisation rates in pastural soils and their relationships with organic nitrogen fractions, microbial biomass and protease activity under glasshouse conditions, Biology and Fertility of Soils, vol.28, issue.1, pp.45-53, 2005.
DOI : 10.1007/s00374-005-0863-6

A. S. Moretto, R. A. Distel, and N. G. Didoné, Decomposition and nutrient dynamic of leaf litter and roots from palatable and unpalatable grasses in a semi-arid grassland, Applied Soil Ecology, vol.18, issue.1, pp.31-37, 2001.
DOI : 10.1016/S0929-1393(01)00151-2

S. Naeem, L. J. Thompson, S. P. Lawler, J. H. Lawton, and R. M. Woodfin, Declining biodiversity can alter the performance of ecosystems, Nature, vol.368, issue.6473, pp.734-736, 1994.
DOI : 10.1038/368734a0

B. Nicolardot, S. Recous, and B. Mary, Simulation of C and N mineralisation during crop residue decomposition: A simple dynamic model based on the C:N ratio of the residues, Plant and Soil, vol.228, issue.1, pp.83-103, 2001.
DOI : 10.1023/A:1004813801728

I. Noy-meir, M. Gutman, and Y. Kaplan, Responses of Mediterranean Grassland Plants to Grazing and Protection, The Journal of Ecology, vol.77, issue.1, pp.290-310, 1989.
DOI : 10.2307/2260930

M. Oesterheld, Effect of defoliation intensity on aboveground and belowground relative growth rates, Oecologia, vol.4, issue.3, pp.313-316, 1992.
DOI : 10.1007/BF00317456

M. Oesterheld and S. J. Mcnaughton, Effect of stress and time for recovery on the amount of compensatory growth after grazing, Oecologia, vol.42, issue.3, pp.305-313, 1991.
DOI : 10.1007/BF00320604

L. Oksanen, Predation, herbivory, and plant strategies along gradients of primary productivity Perspective on plant competition, pp.445-474, 1990.

L. Oksanen, S. D. Fretwell, J. Aruda, and P. Niemela, Exploitation Ecosystems in Gradients of Primary Productivity, The American Naturalist, vol.118, issue.2, pp.424-444, 1981.
DOI : 10.1086/283817

H. Olff and M. E. Ritchie, Effects of herbivores on grassland plant diversity, Trends in Ecology & Evolution, vol.13, issue.7, pp.261-265, 1998.
DOI : 10.1016/S0169-5347(98)01364-0

J. Olofsson and L. Oksanen, Role of litter decomposition for the increased primary production in areas heavily grazed by reindeer: a litterbag experiment, Oikos, vol.146, issue.3, pp.507-515, 2002.
DOI : 10.1034/j.1600-0706.2002.960312.x

J. Olofsson, H. Kitti, P. Rautiainen, S. Stark, and L. Oksanen, Effects of summer grazing by reindeer on composition of vegetation, productivity and nitrogen cycling, Ecography, vol.24, issue.1, pp.13-24, 2001.
DOI : 10.1034/j.1600-0587.2001.240103.x

Y. Osem, A. Perevolotsky, and J. Kigel, Site productivity and plant size explain the response of annual species to grazing exclusion in a Mediterranean semi-arid rangeland, Journal of Ecology, vol.74, issue.2, pp.297-309, 2004.
DOI : 10.1046/j.1365-2664.2001.00646.x

E. L. Painter and A. J. Belsky, Application of Herbivore Optimization Theory to Rangelands of the Western United States, Ecological Applications, vol.3, issue.1, pp.2-9, 1993.
DOI : 10.2307/1941780

R. J. Pakeman, Consistency of plant species and trait responses to grazing along a productivity gradient: a multi-site analysis, Journal of Ecology, vol.10, issue.5, pp.893-905, 2004.
DOI : 10.1046/j.1469-8137.1999.00427.x

J. Pastor and Y. Cohen, Herbivores, the Functional Diversity of Plants Species, and the Cycling of Nutrients in Ecosystems, Theoretical Population Biology, vol.51, issue.3, 1997.
DOI : 10.1006/tpbi.1997.1327

J. Pastor, B. Dewy, R. J. Naiman, P. F. Mcinnes, and Y. Cohen, Moose Browsing and Soil Fertility in the Boreal Forests of Isle Royale National Park, Ecology, vol.74, issue.2, pp.467-480, 1993.
DOI : 10.2307/1939308

E. Paterson, B. Thornton, A. Sim, and S. Pratt, Effects of defoliation and atmospheric CO2 depletion on nitrate acquisition, and exudation of organic compounds by roots of Festuca rubra, Plant and Soil, vol.250, issue.2, pp.293-305, 2003.
DOI : 10.1023/A:1022819219947

V. Pavlù, M. Hejcman, L. Pavlù, J. Gaisler, and . Ne?erková, Effect of continuous grazing on forage quality, quantity and animal performance, Agriculture, Ecosystems & Environment, vol.113, issue.1-4, pp.349-355, 2006.
DOI : 10.1016/j.agee.2005.10.010

H. W. Polley and J. K. Detling, Defoliation, Nitrofen, and Competition: Effects on Plant Growth and Nitrogen Nutrition, Ecology, vol.70, issue.3, pp.721-727, 1989.
DOI : 10.2307/1940222

H. W. Polley and J. K. Detling, Herbivory tolerance of Agropyron smithii populations with different grazing histories, Oecologia, vol.10, issue.2, pp.261-267, 1988.
DOI : 10.1007/BF00379196

E. Pucheta, M. Cabido, S. Diaz, and G. Funes, Floristic composition, biomass, and aboveground net plant production in grazed and protected sites in a mountain grassland of central Argentina, Acta Oecologica, vol.19, issue.2, pp.97-105, 1998.
DOI : 10.1016/S1146-609X(98)80013-1

M. E. Ritchie, D. Tilman, and J. M. Knops, HERBIVORE EFFECTS ON PLANT AND NITROGEN DYNAMICS IN OAK SAVANNA, Ecology, vol.79, issue.1, pp.165-177, 1998.
DOI : 10.1007/BF00320810

A. J. Rook, B. Dumont, J. Isselstein, K. Osoro, M. F. Wallisdevries et al., Matching type of livestock to desired biodiversity outcomes in pastures ??? a review, Biological Conservation, vol.119, issue.2, pp.137-150, 2004.
DOI : 10.1016/j.biocon.2003.11.010

N. Rossignol, A. Bonis, and J. Bouzillé, Consequence of grazing pattern and vegetation structure on the spatial variations of net N mineralisation in a wet grassland, Applied Soil Ecology, vol.31, issue.1-2, pp.62-72, 2006.
DOI : 10.1016/j.apsoil.2005.04.004

URL : https://hal.archives-ouvertes.fr/hal-00015027

R. W. Ruess and S. J. Mcnaughton, Grazing and the Dynamics of Nutrient and Energy Regulated Microbial Processes in the Serengeti grasslands, Oikos, vol.49, issue.1, pp.101-110, 1987.
DOI : 10.2307/3565559

G. M. Rusch and M. Oesterheld, Relationship between Productivity, and Species and Functional Group Diversity in Grazed and Non-Grazed Pampas Grassland, Oikos, vol.78, issue.3, pp.519-526, 1997.
DOI : 10.2307/3545613

T. Sariyildiz and J. M. Anderson, Interactions between litter quality, decomposition and soil fertility: a laboratory study, Soil Biology and Biochemistry, vol.35, issue.3, pp.391-399, 2003.
DOI : 10.1016/S0038-0717(02)00290-0

S. M. Schaeffer, S. A. Billings, and R. D. Evans, Responses of soil nitrogen dynamics in a Mojave Desert ecosystem to manipulations in soil carbon and nitrogen availability, Oecologia, vol.81, issue.4, pp.547-553, 2003.
DOI : 10.1007/s00442-002-1130-2

D. S. Schimel, D. C. Coleman, and K. A. Horton, Soil organic matter dynamics in paired rangeland and cropland toposequences in North Dakota, Geoderma, vol.36, issue.3-4, pp.201-214, 1985.
DOI : 10.1016/0016-7061(85)90002-3

J. Schnürer and T. Rosswall, Fluorescein diacetate hydrolysis as a measure of total microbial activity in soil and litter, Applied and Environmental Microbiology, vol.6, pp.1256-1261, 1982.

N. A. Scott and D. Binkley, Foliage litter quality and annual net N mineralization: comparison across North American forest sites, Oecologia, vol.111, issue.2, pp.151-159, 1997.
DOI : 10.1007/s004420050219

S. W. Seagle, S. J. Mcnaughton, and R. W. Ruess, Simulated Effects of Grazing on Soil Nitrogen and Mineralization in Contrasting Serengeti Grasslands, Ecology, vol.73, issue.3, pp.1105-1123, 1992.
DOI : 10.2307/1940184

M. Semmartin, M. R. Aguiar, R. A. Distel, A. S. Moretto, and C. M. Ghersa, Litter quality and nutrient cycling affected by grazing-induced species replacements along a precipitation gradient, Oikos, vol.63, issue.1, pp.148-160, 2004.
DOI : 10.1111/j.0030-1299.2004.13153.x

M. Semmartin and M. Oesterheld, Effects of grazing pattern and nitrogen availability on primary productivity, Oecologia, vol.126, issue.2, pp.225-230, 2001.
DOI : 10.1007/s004420000508

M. Shiyomi, S. Takahashi, and H. Kirita, Roles of plant biomass and vegetational heterogeneity, and energy-matter cycling in grassland sustainability, Ecological Modelling, vol.132, issue.1-2, pp.135-149, 2000.
DOI : 10.1016/S0304-3800(00)00311-2

M. Shiyomi, M. Okada, S. Takahashi, and Y. Tang, Spatial pattern changes in aboveground plant biomass in a grazing pasture, Ecological Research, vol.109, issue.3, pp.313-322, 1998.
DOI : 10.1046/j.1440-1703.1998.00266.x

J. C. Simon, A. Jacquet, M. L. Decau, E. Goulas, L. Dily et al., Influence of cutting frequency on the morphology and the C and N reserve status of two cultivars of white clover (Trifolium repens L.), European Journal of Agronomy, vol.20, issue.4, pp.341-350, 2004.
DOI : 10.1016/S1161-0301(03)00042-X

F. J. Singer and K. A. Schoenecker, Do ungulates accelerate or decelerate nitrogen cycling? Forest Ecology and Management 181, pp.189-204, 2003.
DOI : 10.1016/s0378-1127(03)00133-6

J. M. Sirotnak and N. J. Huntly, DIRECT AND INDIRECT EFFECTS OF HERBIVORES ON NITROGEN DYNAMICS: VOLES IN RIPARIAN AREAS, Ecology, vol.81, issue.1, pp.78-87, 2000.
DOI : 10.2307/3546100

S. Stark and D. Grellmann, SOIL MICROBIAL RESPONSES TO HERBIVORY IN AN ARCTIC TUNDRA HEATH AT TWO LEVELS OF NUTRIENT AVAILABILITY, Ecology, vol.83, issue.10, pp.2736-2744, 2002.
DOI : 10.1080/00103629509369283

S. Stark, R. Strömmer, and J. Tuomi, Reeinder grazing and soil microbial processes in two suboceanic and two subcontinental tundra heaths, pp.69-78, 2002.

M. J. Swift, O. Andren, L. Brussaard, M. Briones, M. Couteaux et al., Global change, soil biodiversity, and nitrogen cycling in terrestrial ecosystems: three case studies, Global Change Biology, vol.112, issue.1, pp.729-743, 1998.
DOI : 10.1016/0038-0717(75)90038-3

B. R. Taylor, D. Parkinson, and W. F. Parsons, Nitrogen and Lignin Content as Predictors of Litter Decay Rates: A Microcosm Test, Ecology, vol.70, issue.1, pp.97-104, 1989.
DOI : 10.2307/1938416

J. P. Taylor, B. Wilson, M. S. Mills, and R. G. Burns, Comparison of microbial numbers and enzymatic activities in surface soils and subsoils using various techniques, Soil Biology and Biochemistry, vol.34, issue.3, pp.387-401, 2002.
DOI : 10.1016/S0038-0717(01)00199-7

D. Tilman, ECOLOGY:Diversity and Production in European Grasslands, Science, vol.286, issue.5442, pp.1099-1100, 1999.
DOI : 10.1126/science.286.5442.1099

F. Tournade, Les prairies naturelles humides communales du Marais Poitevin. Organisation, fonctionnement & génèse d'un agro-écosystème, Thèse de l'Ecole Nationale Supérieure d'Agronomie de Rennes (ENSAR), 1993.

B. F. Tracy and D. A. Frank, Herbivore influence on soil microbial biomass and nitrogen mineralization in a northern grassland ecosystem: Yellowstone National Park, Oecologia, vol.114, issue.4, pp.556-562, 1998.
DOI : 10.1007/s004420050480

C. L. Turner, T. R. Seastedt, and M. I. Dyer, Maximization of Aboveground Grassland Production: The Role of Defoliation Frequency, Intensity, and History, Ecological Applications, vol.3, issue.1, pp.175-186, 1993.
DOI : 10.2307/1941800

T. Van-der-krift and F. Berendse, The effect of plant species on soil nitrogen mineralization, Journal of Ecology, vol.84, issue.4, pp.555-561, 2001.
DOI : 10.1007/s100219900042

H. J. Van-wijnen, R. Wal, and J. P. Bakker, The impact of herbivores on nitrogen mineralization rate: consequences for salt-marsh succession, Oecologia, vol.118, issue.2, pp.225-231, 1999.
DOI : 10.1007/s004420050722

P. A. Vesk and M. Westoby, Predicting plant species??? responses to grazing, Journal of Applied Ecology, vol.18, issue.5, pp.897-909, 2001.
DOI : 10.1046/j.1365-2664.2001.00646.x

P. M. Vitousek, Nutrient Cycling and Nutrient Use Efficiency, The American Naturalist, vol.119, issue.4, pp.553-572, 1982.
DOI : 10.1086/283931

P. M. Vitousek and R. W. Howarth, Nitrogen limitation on land and in the sea: How can it occur?, Biogeochemistry, vol.13, issue.2, pp.87-115, 1991.
DOI : 10.1007/BF00002772

L. L. Wallace, Effects of clipping and soil compaction on growth, morphology and mycorrhizal colonization of Schizachyrium scoparium, a C4 bunchgrass, Oecologia, vol.72, issue.3, pp.423-428, 1987.
DOI : 10.1007/BF00377574

M. F. Wallisdevries, J. P. Bakker, and S. E. Van-wieren, Grazing and conservation management, 1998.
DOI : 10.1007/978-94-011-4391-2

D. A. Wardle, K. I. Bonner, and G. M. Barker, Linkages between plant litter decomposition, litter quality, and vegetation responses to herbivores, Functional Ecology, vol.71, issue.5, pp.585-595, 2002.
DOI : 10.1046/j.1365-2745.1998.00268.x

D. A. Wardle, D. J. Barker, K. I. Bonner, and K. S. Nicholson, Can comparative approaches based on plant ecophysiological traits predict the nature of biotic interactions and individual plant species effects in ecosystems?, Journal of Ecology, vol.84, issue.3, pp.405-420, 1998.
DOI : 10.1016/0167-7012(86)90012-6

M. W. Weatherburn, Phenol-hypochlorite reaction for determination of ammonia, Analytical Chemistry, vol.39, issue.8, pp.971-974, 1967.
DOI : 10.1021/ac60252a045

D. A. Wedin, Species, Nitrogen, and Grassland Dynamics: The Constraints of Stuff, Linking species and ecosystems, pp.253-262, 1995.
DOI : 10.1007/978-1-4615-1773-3_24

B. L. Williams, L. A. Dawson, S. J. Grayston, and C. A. Shand, Impact of defoliation on the distribution of 15N-labelled synthetic sheep urine between shoots and roots of Agrostis capillaris and soil N pools, Plant and Soil, vol.251, issue.2, pp.269-278, 2003.
DOI : 10.1023/A:1023082709033

A. Zacheis, R. W. Ruess, and J. W. Hupp, Nitrogen dynamics in an Alaskan salt marsh following spring use by geese, Oecologia, vol.130, issue.4, pp.600-608, 2002.
DOI : 10.1007/s00442-001-0837-9

D. R. Zak, D. Tilman, R. R. Parmenter, C. W. Rice, F. M. Fisher et al., Plant Production and Soil Microorganisms in Late-Successional Ecosystems: A Continental-Scale Study, Ecology, vol.75, issue.8, pp.2333-2347, 1994.
DOI : 10.2307/1940888

D. R. Zak, K. S. Pregitzer, P. Curtis, J. A. Teeri, R. Fogel et al., Elevated atmospheric CO2 and feedback between carbon and nitrogen cycles, Plant and Soil, vol.88, issue.1, pp.105-117, 1993.
DOI : 10.1007/BF00010791