SEARCH

SEARCH BY CITATION

References

  • Adamczewski, J., Boulanger, J., Croft, B., Cluff, D., Elkin, B., Nishi, J., Kelly, A., D'Hont, A. & Nicolson, C. (2009) Decline in the Bathurst Caribou Herd 2006–2009: A Technical Evaluation of Field Data and Modeling, pp. 105. Government of Northwest Territories, Yellowknife, NWT, Canada.
  • Akritas, M.G. (1990) The rank transform method in some 2 factor designs. Journal of the American Statistical Association, 85, 7378.
  • Andresen, L.C. & Michelsen, A. (2005) Off-season uptake of nitrogen in temperate heath vegetation. Oecologia, 144, 585597.
  • Augustine, D.J. & McNaughton, S.J. (1998) Ungulate effects on the functional species composition of plant communities: Herbivore selectivity and plant tolerance. Journal of Wildlife Management, 62, 11651183.
  • Baddeley, J.A., Woodin, S.J. & Alexander, I.J. (1994) Effects of increased nitrogen and phosphorus availability on the photosynthesis and nutrient relations of three Arctic dwarf shrubs from Svalbard. Functional Ecology, 8, 676685.
  • Bardgett, R.D., Wardle, D.A. & Yeates, G.W. (1998) Linking above-ground and below-ground interactions: how plant responses to foliar herbivory influence soil organisms. Soil Biology & Biochemistry, 30, 18671878.
  • Bärlocher, F. & Graça, M.A.S. (2005) Total Phenolics. Springer, Dordrecht, The Netherlands.
  • Bean, D. & Henry, G.H.R. (2003) CANTTEX Field Manual: Part A – Setting Up a Basic Monitoring Site Ecological Monitoring and Assessment Network. Environment Canada, Burlington.
  • Bergerud, A.T. (1972) Food habits of Newfoundland caribou. Journal of Wildlife Management, 36, 913923.
  • Bergerud, A.T., Luttich, S.N. & Camps, L. (2008) The Return of Caribou to UNGAVA. McGill-Queen's University Press, Montreal and Kingston.
  • Bergström, R. & Edenius, L. (2003) From twigs to landscapes: methods for studying ecological effects of forest ungulates. Journal for Nature Conservation (Jena), 10, 203211.
  • Boertje, R.D. (1984) Seasonal diets of the Denali caribou herd, Alaska. Arctic, 37, 161165.
  • Bråthen, K.A. & Oksanen, J. (2001) Reindeer reduce biomass of preferred plant species. Journal of Vegetation Science, 12, 473480.
  • Bråthen, K.A., Ims, R.A., Yoccoz, N.G., Fauchald, P., Tveraa, T. & Hausner, V.H. (2007) Induced shift in ecosystem productivity? Extensive scale effects of abundant large herbivores. Ecosystems, 10, 773789.
  • Bret-Harte, M.S., Shaver, G.R. & Chapin, F.S. (2002) Primary and secondary stem growth in Arctic shrubs: implications for community response to environmental change. Journal of Ecology, 90, 251267.
  • Bret-Harte, M.S., Shaver, G.R., Zoerner, J.P., Johnstone, J.F., Wagner, J.L., Chavez, A.S., Gunkelman, R.F., Lippert, S.C. & Laundre, J.A. (2001) Developmental plasticity allows Betula nana to dominate tundra subjected to an altered environment. Ecology, 82, 1832.
  • Bryant, J.P., Chapin, F.S. & Klein, D.R. (1983) Carbon/nutrient balance of boreal plants in relation to vertebrate herbivory. Oikos, 40, 357368.
  • Cargill, S.M. & Jefferies, R.L. (1984) The effects of grazing by lesser snow geese on the vegetation of a sub-Arctic salt marsh. Journal of Applied Ecology, 21, 669686.
  • CARMA (2008) Eastern NWT and Nunavut [herd] animation. CicumArctic Rangifer Monitoring and Assessment Network. Available at: http://www.caff.is/index.php?option=com_content&view=article&id=684&Itemid=1341 (accessed 1 November 2012).
  • CAVM (2003) Circumpolar Arctic Vegetation Map. U.S. Fish and Wildlife Service, Anchorage, Alaska.
  • Chapin, F.S. III (1980) The mineral nutrition of wild plants. Annual Review of Ecology and Systematics, 11, 233260.
  • Chapin, F.S. III, Johnson, D.A. & McKendrick, J.D. (1980) Seasonal movement of nutrients in plants of differing growth form in an Alaskan tundra ecosystem: implications for herbivory. Journal of Ecology, 68, 189210.
  • Chapin III, F.S.., Shaver, G.R., Giblin, A.E., Nadelhoffer, K.J. & Laundre, J.A. (1995) Responses of Arctic tundra to experimental and observed changes in climate. Ecology, 76, 694711.
  • Chu, H. & Grogan, P. (2010) Soil microbial biomass, nutrient availability and nitrogen mineralization potential among vegetation-types in a low Arctic tundra landscape. Plant and Soil, 329, 411420.
  • Cooper, E.J. (2006) Reindeer grazing reduces seed and propagule bank in the High Arctic. Canadian Journal of Botany-Revue Canadienne De Botanique, 84, 17401752.
  • Crête, M. & Doucet, G.J. (1998) Persistent suppression in dwarf birth after release from heavy summer browsing by caribou. Arctic and Alpine Research, 30, 126132.
  • Crête, M., Huot, J. & Gauthier, L. (1990) Food selection during early lactation by caribou calving on the tundra in Quebec. Arctic, 43, 6065.
  • Elmendorf, S.C., Henry, G.H.R., Hollister, R.D., Björk, R.G., Boulanger-Lapointe, N., Cooper, E.J. et al. (2012) Plot-scale evidence of tundra vegetation change and links to recent summer warming. Nature Climate Change, 2, 453457.
  • Epstein, H.E., Raynolds, M.K., Walker, D.A., Bhatt, U.S., Tucker, C.J. & Pinzon, J.E. (2012) Dynamics of aboveground phytomass of the circumpolar Arctic tundra during the past three decades. Environmental Research Letters, 7, 112.
  • Eskelinen, A. & Oksanen, J. (2006) Changes in the abundance, composition and species richness of mountain vegetation in relation to summer grazing by reindeer. Journal of Vegetation Science, 17, 245254.
  • Festa-Bianchet, M., Ray, J.C., Boutin, S., Côté, S. & Gunn, A. (2011) Conservation of caribou (Rangifer tarandus) in Canada: an uncertain future. Canadian Journal of Zoology-Revue Canadienne De Zoologie, 89, 419434.
  • Folin, O. & Ciocalteu, V. (1927) On tyrosine and tryptophane determination in proteins. Journal of Biological Chemistry, 27, 239343.
  • Forbes, B.C., Fauria, M.M. & Zetterberg, P. (2009) Russian Arctic warming and ‘greening’ are closely tracked by tundra shrub willows. Global Change Biology, 16, 15421554.
  • Fourier, B. & Gunn, A. (1998) Muskox Numbers and Distribution in the Northwest Territories, 1997. Department of Resources, Wildlife and Economic Development, Government of the Northwest Territories, Yellowknife, NWT.
  • Frank, D.A. & Groffman, P.M. (1998) Ungulate vs. landscape control of soil C and N processes in grasslands of Yellowstone National Park. Ecology, 79, 22292241.
  • Giblin, A.E., Nadelhoffer, K.J., Shaver, G.R., Laundre, J.A. & McKerrow, A.J. (1991) Biogeochemical diversity along a riverside toposequence in Arctic Alaska. Ecological Monographs, 61, 415435.
  • Goetz, S.J., Bunn, A.G., Fiske, G.J. & Houghton, R.A. (2005) Satellite-observed photosynthetic trends across boreal North America associated with climate and fire disturbance. Proceedings of the National Academy of Sciences of the United States of America, 102, 1352113525.
  • Gough, L., Wookey, P.A. & Shaver, G.R. (2002) Dry heath Arctic tundra responses to long-term nutrient and light manipulation. Arctic Antarctic and Alpine Research, 34, 211218.
  • Gough, L., Shrestha, K., Johnson, D.R. & Moon, B. (2008) Long-term mammalian herbivory and nutrient addition alter lichen community structure in Alaskan dry heath tundra. Arctic Antarctic and Alpine Research, 40, 6573.
  • Grellmann, D. (2002) Plant responses to fertilization and exclusion of grazers on an Arctic tundra heath. Oikos, 98, 190204.
  • Gunn, A. (2003) Voles, lemmings and caribou – population cycles revisited? Rangifer, 23, 105111.
  • Haag, R.W. (1974) Nutrient limitations to plant production in two tundra communities. Canadian Journal of Botany-Revue Canadienne De Botanique, 52, 103116.
  • Hansen, B.B., Henriksen, S., Aanes, R. & Saether, B.-E. (2007) Ungulate impact on vegetation in a two-level trophic system. Polar Biology, 30, 549558.
  • Henry, G.H.R. & Gunn, A. (1991) Recovery of tundra vegetation after overgrazing by caribou in Arctic Canada. Arctic, 44, 3842.
  • den Herder, M., Virtanen, R. & Roininen, H. (2004) Effects of reindeer browsing on tundra willow and its associated insect herbivores. Journal of Applied Ecology, 41, 870879.
  • den Herder, M., Virtanen, R. & Roininen, H. (2008) Reindeer herbivory reduces willow growth and grouse forage in a forest-tundra ecotone. Basic and Applied Ecology, 9, 324331.
  • Herms, D.A. & Mattson, W.J. (1992) The dilemma of plants – to grow or defend. Quarterly Review of Biology, 67, 283335.
  • Hjálten, J., Danell, K. & Ericson, L. (1993) Effects of simulated herbivory and intraspecific competition on the compensatory ability of birches. Ecology, 74, 11361142.
  • Hobbie, S.E. (1992) Effects of plant-species on nutrient cycling. Trends in Ecology & Evolution, 7, 336339.
  • Hobbs, N.T. (1996) Modification of ecosystems by ungulates. Journal of Wildlife Management, 60, 695713.
  • Holland, J.N., Cheng, W.X. & Crossley, D.A. (1996) Herbivore-induced changes in plant carbon allocation: assessment of below-ground C fluxes using carbon-14. Oecologia, 107, 8794.
  • Hudson, J.M.G. & Henry, G.H.R. (2009) Increased plant biomass in a high Arctic heath community from 1981 to 2008. Ecology, 90, 26572663.
  • Jia, G.J., Epstein, H.E. & Walker, D.A. (2009) Vegetation greening in the Canadian Arctic related to decadal warming. Journal of Environmental Monitoring, 11, 22312238.
  • Johnstone, J., Russell, D.E. & Griffith, B. (2002) Variations in plant forage quality in the range of the Porcupine caribou herd. Rangifer, 22, 8391.
  • Jonasson, S. (1988) Evaluation of the point intercept method for the estimation of plant biomass. Oikos, 52, 101106.
  • Jonasson, S., Michelsen, A., Schmidt, I.K. & Nielsen, E.V. (1999) Responses in microbes and plants to changed temperature, nutrient, and light regimes in the Arctic. Ecology, 80, 18281843.
  • Jones, C.G. & Hartley, S.E. (1999) A protein competition model of phenolic allocation. Oikos, 86, 2744.
  • Kitti, H., Forbes, B.C. & Oksanen, J. (2009) Long- and short-term effects of reindeer grazing on tundra wetland vegetation. Polar Biology, 32, 253261.
  • Klein, D.R. (1987) Vegetation recovery patterns following overgrazing by reindeer on St. Matthew Island. Journal of Range Management, 40, 336338.
  • Manseau, M. (1996) Relation réciproque entre les caribous et la végétation des aires d'estivage: le cas du troupeau de caribous de la rivière George. PhD thesis, Université Laval.
  • Manseau, M., Huot, J. & Crete, M. (1996) Effects of summer grazing by caribou on composition and productivity of vegetation: community and landscape level. Journal of Ecology, 84, 503513.
  • Mårell, A., Ball, J.P. & Hofgaard, A. (2002) Foraging and movement paths of female reindeer: insights from fractal analysis, correlated random walks, and Levy flights. Canadian Journal of Zoology-Revue Canadienne De Zoologie, 80, 854865.
  • McNaughton, S.J. (1979) Grazing as an optimization process: grass-ungulate relationships in the Serengeti. American Naturalist, 113, 691703.
  • Mulvaney, R.L. (1996) Nitrogen–Inorganic Forms. Soil Science Society of America and American Society of Agronomy, Madison, WI.
  • Nadelhoffer, K.J., Giblin, A.E., Shaver, G.R. & Laundre, J.A. (1991) Effects of temperature and substrate quality on element mineralization in 6 Arctic soils. Ecology, 72, 242253.
  • Nelson, D.W. & Sommers, L.E. (1996) Total Carbon, Organic Carbon and Organic Matter. Soil Science Society of America and American Society of Agronomy, Madison, WI.
  • Olofsson, J. (2006) Short- and long-term effects of changes in reindeer grazing pressure on tundra heath vegetation. Journal of Ecology, 94, 431440.
  • Olofsson, J. (2009) Effects of simulated Reindeer Grazing, trampling, and waste products on nitrogen mineralization and primary production. Arctic Antarctic and Alpine Research, 41, 330338.
  • Olofsson, J., Moen, J. & Oksanen, J. (2002) Effects of herbivory on competition intensity in two Arctic-alpine tundra communities with different productivity. Oikos, 96, 265272.
  • Olofsson, J., Moen, J. & Ostlund, L. (2010) Effects of reindeer on boreal forest floor vegetation: does grazing cause vegetation state transitions? Basic and Applied Ecology, 11, 550557.
  • Olofsson, J. & Oksanen, L. (2005) Effects of reindeer density on vascular plant diversity on North Scandinavian mountains. Rangifer, 25, 518.
  • Olofsson, J., Stark, S. & Oksanen, L. (2004b) Reindeer influence on ecosystem processes in the tundra. Oikos, 105, 386396.
  • Olofsson, J., Kitti, H., Rautiainen, P., Stark, S. & Oksanen, L. (2001) Effects of summer grazing by reindeer on composition of vegetation, productivity and nitrogen cycling. Ecography, 24, 1324.
  • Olofsson, J., Hulme, P.E., Oksanen, L. & Suominen, O. (2004a) Importance of large and small mammalian herbivores for the plant community structure in the forest tundra ecotone. Oikos, 106, 324334.
  • Olofsson, J., Oksanen, L., Callaghan, T., Hulme, P.E., Oksanen, T. & Suominen, O. (2009) Herbivores inhibit climate-driven shrub expansion on the tundra. Global Change Biology, 15, 26812693.
  • Pajunen, A., Virtanen, R. & Roininen, H. (2008) The effects of reindeer grazing on the composition and species richness of vegetation in forest-tundra ecotone. Polar Biology, 31, 12331244.
  • Pajunen, A., Virtanen, R. & Roininen, H. (2012) Browsing-mediated shrub canopy changes drive composition and species richness in forest-tundra ecosystems. Oikos, 121, 15441552.
  • Pastor, J., Cohen, Y. & Hobbs, N.T. (2006) The role of large herbivores in ecosystem nutrient cycles. Large Herbivore Ecology, Ecosystem Dynamics and Conservation (eds K. Danell, R. Bergström & P. Duncan), pp. 289325. Cambridge University Press, Cambridge.
  • Pastor, J., Dewey, B., Naiman, R.J., McInnes, P.F. & Cohen, Y. (1993) Moose browsing and soil fertility in the boreal forest of Isle Royale National Park. Ecology, 74, 467480.
  • Payette, S., Boudreau, S., Morneau, C. & Pitre, N. (2004) Long-term interactions between migratory caribou, wildfires and nunavik hunters inferred from tree rings. Ambio, 33, 482486.
  • Post, E.S. & Klein, D.R. (1996) Relationships between graminoid growth form and levels of grazing by caribou (Rangifer tarandus) in Alaska. Oecologia, 107, 364372.
  • Post, E. & Pedersen, C. (2008) Opposing plant community responses to warming with and without herbivores. Proceedings of the National Academy of Sciences of the United States of America, 105, 1235312358.
  • R Core Team (2012) R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria.
  • Ravolainen, V.T., Yoccoz, N.G., Brathen, K.A., Ims, R.A., Iversen, M. & Gonzalez, V.T. (2010) Additive partitioning of diversity reveals no scale-dependent impacts of large ungulates on the structure of tundra plant communities. Ecosystems, 13, 157170.
  • Ravolainen, V.T., Brathen, K.A., Ims, R.A., Yoccoz, N.G., Henden, J.-A. & Killengreen, S.T. (2011) Rapid, landscape scale responses in riparian tundra vegetation to exclusion of small and large mammalian herbivores. Basic and Applied Ecology, 12, 643653.
  • Russell, D.E. & Ulvevadet, B. (2004) Conclusion. Family-Based Reindeer Herding and Hunting Economies, and the Status and Management of Wild Reindeer/Caribou Populations (eds B. Ulvevadet & K. Klokov), pp. 147158. Centre for Saami Studies, University of Tromsø, Tromsø, Norway.
  • Sharma, S., Couturier, S. & Côté, S.D. (2009) Impacts of climate change on the seasonal distribution of migratory caribou. Global Change Biology, 15, 25492562.
  • Shaver, G.R. & Chapin, F.S. III (1980) Response to fertilization by various plant growth forms in an Alaskan tundra: nutrient accumulation and growth. Ecology, 61, 662675.
  • Shaver, G.R. & Chapin, F.S. (1991) Production: biomass relationships and element cycling in contrasting Arctic vegetation types. Ecological Monographs, 61, 131.
  • Shaver, G.R. & Jonasson, S. (1999) Response of Arctic ecosystems to climate change: results of long-term field experiments in Sweden and Alaska. Polar Research, 18, 245252.
  • Skarin, A., Danell, O., Bergstrom, R. & Moen, J. (2008) Summer habitat preferences of GPS-collared reindeer Rangifer tarandus tarandus. Wildlife Biology, 14, 115.
  • Stark, S. & Grellmann, D. (2002) Soil microbial responses to herbivory in an Arctic tundra heath at two levels of nutrient availability. Ecology, 83, 27362744.
  • Stark, S., Mannisto, M.K. & Smolander, A. (2010) Multiple effects of reindeer grazing on the soil processes in nutrient-poor northern boreal forests. Soil Biology & Biochemistry, 42, 20682077.
  • Stark, S., Tuomi, J., Strommer, R. & Helle, T. (2003) Non-parallel changes in soil microbial carbon and nitrogen dynamics due to reindeer grazing in northern boreal forests. Ecography, 26, 5159.
  • Suominen, O. & Olofsson, J. (2000) Impacts of semi-domesticated reindeer on structure of tundra and forest communities in Fennoscandia: a review. Annales Zoologici Fennici, 37, 233249.
  • Tape, K., Sturm, M. & Racine, C. (2006) The evidence for shrub expansion in Northern Alaska and the Pan-Arctic. Global Change Biology, 12, 686702.
  • Ter Braak, C.J.F. & Šmilauer, P. (2002) CANOCO for Windows 4.5. Microcomputer Power, Ithaca, NY, USA.
  • Vankoughnett, M. (2010) Shrub expansion in the low Arctic: the influence of snow and vegetation feedbacks on nitrogen cycling. MSc thesis, Queen's University, Kingston ON.
  • Väre, H., Ohtonen, R. & Mikkola, K. (1996) The effect and extent of heavy grazing by reindeer in oligotrophic pine heaths in northeastern Fennoscandia. Ecography, 19, 245253.
  • Vors, L.S. & Boyce, M.S. (2009) Global declines of caribou and reindeer. Global Change Biology, 15, 26262633.
  • van der Wal, R. (2006) Do herbivores cause habitat degradation or vegetation state transition? Evidence from the tundra. Oikos, 114, 177186.
  • van der Wal, R. & Brooker, R.W. (2004) Mosses mediate grazer impacts on grass abundance in Arctic ecosystems. Functional Ecology, 18, 7786.
  • Wegener, C. & Odasz-Albrigtsen, A.M. (1998) Do Svalbard reindeer regulate standing crop in the absence of predators? A test of the “exploitation ecosystems” model. Oecologia, 116, 202206.
  • White, R.G. & Trudell, J. (1980) Habitat preference and forage consumption by reindeer and caribou near Atkasook, Alaska. Arctic and Alpine Research, 12, 511529.
  • van Wijk, M.T., Clemmensen, K.E., Shaver, G.R., Williams, M., Callaghan, T.V., Chapin, F.S. et al. (2004) Long-term ecosystem level experiments at Toolik Lake, Alaska, and at Abisko, Northern Sweden: generalizations and differences in ecosystem and plant type responses to global change. Global Change Biology, 10, 105123.
  • Yu, Q., Epstein, H.E., Walker, D.A., Frost, G.V. & Forbes, B.C. (2011) Modeling dynamics of tundra plant communities on the Yamal Peninsula, Russia, in response to climate change and grazing pressure. Environmental Research Letters, 6, 112.
  • Zalatan, R., Gunn, A. & Henry, G.H.R. (2006) Long-term abundance patterns of barren-ground caribou using trampling scars on roots of Picea mariana in the Northwest Territories, Canada. Arctic Antarctic and Alpine Research, 38, 624630.
  • Zamin, T.J. & Grogan, P. (2012) Birch shrub growth in the low Arctic: the relative importance of experimental warming, enhanced nutrient availability, snow depth and caribou exclusion. Environmental Research Letters, 7, 19.