Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Dec. 16, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Psychology, University of Alberta." Includes bibliographical references.

Carbon dioxide is one of the major greenhouse gases being cycled by forests. Mature boreal forests are often carbon sinks, however, following disturbance, forests can become carbon sources. Three forest sites in central Saskatchewan burned in 1977 (F77 site), 1989 (F89 site), and 1998 (F98 site) were studied using eddy covariance to obtain measurements of the energy, carbon, and water budgets. Latent heat flux density increased gradually over time at F98 but remained lower than F77 and F89. Weekly net ecosystem production was lower at F98 than at F77 and F89. F77 lost 40 g C m-2 and 79 g C m-2 in 2004 and 2005, respectively. F89 gained 177 g C m-2, 113 g C m-2, and 88 g C m-2 in 2003, 2004, and 2005, respectively. F98 lost 5 g C m-2, 17 g C m-2, and 52 g C m-2 during these three years, respectively. / May 2007

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No description available.

Carbon dioxide is one of the major greenhouse gases being cycled by forests. Mature boreal forests are often carbon sinks, however, following disturbance, forests can become carbon sources. Three forest sites in central Saskatchewan burned in 1977 (F77 site), 1989 (F89 site), and 1998 (F98 site) were studied using eddy covariance to obtain measurements of the energy, carbon, and water budgets. Latent heat flux density increased gradually over time at F98 but remained lower than F77 and F89. Weekly net ecosystem production was lower at F98 than at F77 and F89. F77 lost 40 g C m-2 and 79 g C m-2 in 2004 and 2005, respectively. F89 gained 177 g C m-2, 113 g C m-2, and 88 g C m-2 in 2003, 2004, and 2005, respectively. F98 lost 5 g C m-2, 17 g C m-2, and 52 g C m-2 during these three years, respectively.

Carbon dioxide is one of the major greenhouse gases being cycled by forests. Mature boreal forests are often carbon sinks, however, following disturbance, forests can become carbon sources. Three forest sites in central Saskatchewan burned in 1977 (F77 site), 1989 (F89 site), and 1998 (F98 site) were studied using eddy covariance to obtain measurements of the energy, carbon, and water budgets. Latent heat flux density increased gradually over time at F98 but remained lower than F77 and F89. Weekly net ecosystem production was lower at F98 than at F77 and F89. F77 lost 40 g C m-2 and 79 g C m-2 in 2004 and 2005, respectively. F89 gained 177 g C m-2, 113 g C m-2, and 88 g C m-2 in 2003, 2004, and 2005, respectively. F98 lost 5 g C m-2, 17 g C m-2, and 52 g C m-2 during these three years, respectively.

The Western Boreal Forest exhibits complex hydrogeology juxtaposed with rapid resource development. Predicting surface water chemistry to assess the influence of landuse and climate change is needed. The research purpose was to test if a global model (Gibbs), used to assess water chemistry relative to precipitation, geologic and evaporative processes can be applied to mid-continental locations; and test if regional to local scale controls of surface-groundwater interactions can be used to refine predictions where geologic processes dominate water chemistry. The global model applied to many ponds, but failed in dilute and saline ponds. Caution is necessary, as the model assumes chloride-dominated precipitation, and continental to regional scale groundwater systems influence water chemistry, independent of evaporative processes. Bedrock geology influenced ion composition, TDS and pH via mineral dissolution and scale of flow. Surficial geology influenced TDP, TDN, DOC, pH and TDS, and wetland connection influenced TDP, TDN and DOC via flowpath. To assess water chemistry and the influence of landuse and climate change, regional to local controls of surface-groundwater interactions prove valuable over the global assessment of chemistry in heterogeneous and complex landscapes. / Ecology

Terrestrial gastropods are important decomposers, herbivores, and prey items in forest systems and constitute a poorly understood element of forest biodiversity in Canada. I studied gastropod assemblages in relation to forest cover type and in response to variable retention harvesting in the mixedwood boreal forest of northwestern Alberta. Gastropods were sampled using two methods: board traps and collection of litter samples. Gastropod assemblages were influenced by canopy composition, with most gastropods of the mixedwood showing a strong affinity for broadleaf dominated forests. Tree species mixture influenced gastropod distribution; basal tree area of either conifer or broadleaf trees was generally associated with gastropod distribution within a stand. Harvesting was clearly associated with increased abundance of many species 9 years post-harvest, however, abundance declined for other species. Harvesting with retention helps to maintain pre-harvest boreal gastropod assemblages and will likely conserve boreal gastropod assemblages if used as a tool for biodiversity management. / Conservation Biology

Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2001. / Härtill 4 uppsatser.