Vegetation changes with falling water levels in the Delta Marsh, Manitoba / Jennifer Walker.
Material type:
TextPublication details: Winnipeg, MB : 1965. University of Manitoba,Description: xii, 272 leaves : ill. ; 29 cmOnline resources: Dissertation note: Thesis (Ph.D.)--University of Manitoba, 1965. Abstract: This investigation was planned as a continuation and expansion of the study initiated in 1958 at Delta, Manitoba, to describe the vegetation of a freshwater marsh. At that time water levels in the marsh were falling. The expansion of vegetation on progressively drying areas was described by Walker (1959). In order to determine the effects of prolonged drying on seral succession in the marsh, the need to follow-up the original observations was emphasized. To do this it was necessary to estimate the overall composition of the vegetation and to study variation within the marsh complex. In an area of approximately 15,000 hectares sampling had to be restricted. Criticism has been levelled at the inaccuracy of subjective estimates of cover (e.g, Hope-Simpson,1940; Smith, 1944) and there is no doubt that criticism is valid if conclusions are drawn which are more detailed than the data justify. In this study analytical comparisons have been confined to differences in presence and frequency;
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Thesis (Ph.D.)--University of Manitoba, 1965.
Includes bibliographical references (leaves 240-256).
This investigation was planned as a continuation and expansion of the study initiated in 1958 at Delta, Manitoba, to describe the vegetation of a freshwater marsh. At that time water levels in the marsh were falling. The expansion of vegetation on progressively drying areas was described by Walker (1959). In order to determine the effects of prolonged drying on seral succession in the marsh, the need to follow-up the original observations was emphasized. To do this it was necessary to estimate the overall composition of the vegetation and to study variation within the marsh complex. In an area of approximately 15,000 hectares sampling had to be restricted. Criticism has been levelled at the inaccuracy of subjective estimates of cover (e.g, Hope-Simpson,1940; Smith, 1944) and there is no doubt that criticism is valid if conclusions are drawn which are more detailed than the data justify. In this study analytical comparisons have been confined to differences in presence and frequency;