

@mastersthesis {7011,
	title = {External drivers of lakes in forested watersheds: {Aeolian} organic carbon inputs and ice phenology},
	year = {2009},
	note = {3384445},
	school = {The University of Wisconsin - Madison},
	type = {phdPh.{D}.},
	address = {Ann Arbor},
	abstract = {Carbon, climate, and water are intertwined with global environmental changes attributable to human activities. Expanding our understanding of the biogeochemical pathways of carbon will help determine how these changes are propagated among ecosystems. Meanwhile, long-term records provide a reference point for the impacts of climate change on ecosystems. This dissertation focuses on two related topics: the movement of carbon among ecosystems and the influence of climatic variability on aquatic organisms. Aquatic ecosystems present a potential pathway for carbon to the atmosphere. Many lakes respire more carbon than they produce. This suggests they are subsidized by external carbon inputs, thereby coupling the biogeochemical cycle in lakes to both local and remote ecosystems. Chapter 1 describes the drivers of inputs of particulate organic carbon to a remote, forested lake. The flux of these inputs was significantly influenced by episodic storm events, conditions that are expected to increase as a consequence of global warming. Chapter 2 expands the study of carbon subsidies to lakes to the landscape level. Small lakes were expected to receive proportionately more carbon than larger lakes, due to the proximity of the lake surface to shoreline sources of carbon. While smaller lakes did receive higher inputs of carbon, nearshore deposition was higher in larger lakes. This was attributed to differences in shoreline vegetation. Particulate carbon deposition was constant across the entire lake surface, which suggests a link between the carbon pool in lakes and atmospheric carbon sources. The long-term reduction in ice cover on lakes is a readily observable change attributable to climate. Ice-off is occurring sooner and advancing the onset of spring. High inter-annual variability in ice-off can be used to explore historic responses to climate by aquatic organisms. Zooplankton density increased significantly during years with early ice-off in five northern temperate lakes. The correlation was most pronounced for large-bodied herbivorous zooplankton that can capitalize on favorable vernal conditions for growth. This pattern could not be generalized to other sites in the Laurentian Great Lakes region.},
	keywords = {0329:Ecology, 0425:Biogeochemistry, 0793:Limnology, Aeolian organic carbon, Biogeochemistry, Biological sciences, Earth sciences, Ecology, Forested watersheds, Ice cover, Limnology, Zooplankton},
	url = {http://search.proquest.com/docview/305034747?accountid=14270},
	author = {Preston, Nicholas D.}
}
