Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass
Dissertation (Ph.D.) University of Alaska Fairbanks, 1996 I examined effects of herbivory by black brant geese (Branta bernicla nigricans) on the small herbaceous perennial Triglochin palustris (arrowgrass) in a subarctic saltmarsh in SW Alaska. I investigated effects of biomass removal, and indirec...
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1996
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ftunivalaska:oai:scholarworks.alaska.edu:11122/9495 2023-05-15T15:46:08+02:00 Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass Mulder, Christa Pauliene Hilda 1996 http://hdl.handle.net/11122/9495 unknown http://hdl.handle.net/11122/9495 Ecology Dissertation phd 1996 ftunivalaska 2023-02-23T21:37:17Z Dissertation (Ph.D.) University of Alaska Fairbanks, 1996 I examined effects of herbivory by black brant geese (Branta bernicla nigricans) on the small herbaceous perennial Triglochin palustris (arrowgrass) in a subarctic saltmarsh in SW Alaska. I investigated effects of biomass removal, and indirect effects of geese (changes in resource availability and competition) to compare the role of selective herbivory in this mixed-species environment with that of herbivory in monospecific saltmarsh communities. I manipulated nutrient availability, light availability, and salinity in a transplant experiment, and manipulated size of arrowgrass, and neighbor size and feces deposition in exclosure experiments. Additional experiments examined relationships between size, biomass allocation, survival and reproduction, and explanations for low rates of sexual reproduction in arrowgrass. A cellular automata model was used to investigate potential long-term effects of changes in grazing intensity. Direct effects of geese were smaller than indirect effects: biomass removal had little effect on rates of population growth or plant size, and resulting changes in biomass allocation did not affect survival or reproduction. For unclipped arrowgrass, feces deposition resulted in increased competition for light, which was ameliorated by consumption of neighboring plants, but some species may provide protection from grazing. Expansion into neighboring communities is limited by physical factors on the sea-side end of the distribution, and by competition for light and high selectivity on the inland end. Overall effects of changes in grazing pressure will depend on changes in goose foraging behavior and selectivity. Trade-offs exist between sexual reproduction and all other functions, and sexual reproduction may increase risk of herbivory. Goose effects occur at several spatial and temporal scales: immediately (through biomass removal), within a growing season (through changes in competition and resource availability), over several growing ... Doctoral or Postdoctoral Thesis Branta bernicla Kuskokwim Subarctic Alaska Yukon University of Alaska: ScholarWorks@UA Brant ENVELOPE(7.105,7.105,62.917,62.917) Fairbanks Yukon |
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University of Alaska: ScholarWorks@UA |
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unknown |
topic |
Ecology |
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Ecology Mulder, Christa Pauliene Hilda Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass |
topic_facet |
Ecology |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 1996 I examined effects of herbivory by black brant geese (Branta bernicla nigricans) on the small herbaceous perennial Triglochin palustris (arrowgrass) in a subarctic saltmarsh in SW Alaska. I investigated effects of biomass removal, and indirect effects of geese (changes in resource availability and competition) to compare the role of selective herbivory in this mixed-species environment with that of herbivory in monospecific saltmarsh communities. I manipulated nutrient availability, light availability, and salinity in a transplant experiment, and manipulated size of arrowgrass, and neighbor size and feces deposition in exclosure experiments. Additional experiments examined relationships between size, biomass allocation, survival and reproduction, and explanations for low rates of sexual reproduction in arrowgrass. A cellular automata model was used to investigate potential long-term effects of changes in grazing intensity. Direct effects of geese were smaller than indirect effects: biomass removal had little effect on rates of population growth or plant size, and resulting changes in biomass allocation did not affect survival or reproduction. For unclipped arrowgrass, feces deposition resulted in increased competition for light, which was ameliorated by consumption of neighboring plants, but some species may provide protection from grazing. Expansion into neighboring communities is limited by physical factors on the sea-side end of the distribution, and by competition for light and high selectivity on the inland end. Overall effects of changes in grazing pressure will depend on changes in goose foraging behavior and selectivity. Trade-offs exist between sexual reproduction and all other functions, and sexual reproduction may increase risk of herbivory. Goose effects occur at several spatial and temporal scales: immediately (through biomass removal), within a growing season (through changes in competition and resource availability), over several growing ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Mulder, Christa Pauliene Hilda |
author_facet |
Mulder, Christa Pauliene Hilda |
author_sort |
Mulder, Christa Pauliene Hilda |
title |
Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass |
title_short |
Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass |
title_full |
Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass |
title_fullStr |
Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass |
title_full_unstemmed |
Plant-herbivore interactions on the Yukon-Kuskokwim Delta: The effect of goose herbivory on arrowgrass |
title_sort |
plant-herbivore interactions on the yukon-kuskokwim delta: the effect of goose herbivory on arrowgrass |
publishDate |
1996 |
url |
http://hdl.handle.net/11122/9495 |
long_lat |
ENVELOPE(7.105,7.105,62.917,62.917) |
geographic |
Brant Fairbanks Yukon |
geographic_facet |
Brant Fairbanks Yukon |
genre |
Branta bernicla Kuskokwim Subarctic Alaska Yukon |
genre_facet |
Branta bernicla Kuskokwim Subarctic Alaska Yukon |
op_relation |
http://hdl.handle.net/11122/9495 |
_version_ |
1766380820372652032 |