Srivastava, Diane Sheila2012-11-142012-11-141993Thesis (M.Sc.) - University of Toronto. D.S. Srivastava: Theses Canada, 1993. (AMICUS No. 21557550)http://hdl.handle.net/10315/18774Masters Thesis completed in 1993 by D.S. Srivastava at the University of Toronto. Supervised by Dr. R.L. Jefferies.A positive feedback cycle between soil salinity and graminoid growth, triggered by intensive grazing and grubbing by geese, is proposed to account for the loss of graminoid vegetation in an arctic salt marsh (La Pérouse Bay, Manitoba, Canada) based on the results of experimental field studies. Decreases in above-ground biomass, caused by goose herbivory, increase soil salinity. High soil salinities further reduce graminoid growth, both in the salt marsh and under controlled conditions, causing additional decreases in above-ground biomass. Graminoid growth is also reduced by intraspecific competition. The implications of this positive feedback on vegetation dynamics and the size of the goose colony at La Perouse Bay are discussed.ensoil salinitygraminoid growthgrazingsalt marshManitobaLa Pérouse Bayabove-ground biomassintraspecific competitionvegetation dynamicspositive feedbackgrassGraminoidElectronic Thesis or Dissertation