Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Entire DC Network
Above- And Belowground Responses To Environmental Change In The Northern Chihuahuan Desert, Renée F. Brown
Above- And Belowground Responses To Environmental Change In The Northern Chihuahuan Desert, Renée F. Brown
Biology ETDs
Drylands cover 45% of the terrestrial surface and are expanding rapidly due to anthropogenic drivers. Altered precipitation regimes, atmospheric nitrogen deposition, and wildfire will likely have significant consequences in these regions where ecological processes are limited by water and nitrogen. In this dissertation, I explored temporal dynamics of net primary production (NPP) and related above- and belowground processes under several environmental change drivers in the Sevilleta National Wildlife Refuge, central New Mexico, USA. Located in the northern Chihuahuan Desert, this region experiences strong seasonal precipitation patterns driven by the North American Monsoon, historically characterized by frequent small rain events hypothesized …
Sex- And Age - Specific Migratory Strategies Of Blue Whales In The Northeast Pacific, Christina Blevins
Sex- And Age - Specific Migratory Strategies Of Blue Whales In The Northeast Pacific, Christina Blevins
Biology ETDs
Sequential subsampling of blue whale baleen plates can yield information of individual migratory plasticity of this endangered species in the northeast Pacific Ocean. We measured δ13C and δ15N isotope values along baleen from thirteen whales of different age and sex. Results showed sex/age-specific migratory strategies. Adult females exhibited relatively stable cyclical movements between temperate and subtropical regions. Adult males exhibited two strategies, most remained within temperate latitudes, whereas two migrated to subtropical latitudes. Movement patterns in juveniles were erratic. These patterns are potentially driven by energetic requirements of females, intraspecific competitions among adult males, and inexperience in locating prey in …
Ecophysiology Of Ponderosa Pine Seedlings After Severe Fire: The Effect Of Tree Canopy, Lauren M. Bansbach
Ecophysiology Of Ponderosa Pine Seedlings After Severe Fire: The Effect Of Tree Canopy, Lauren M. Bansbach
Biology ETDs
Ponderosa pine forests evolved with low-severity surface fires to maintain forest structure and process. However, increasingly common high-severity fires often result in complete overstory canopy loss and a shift from forest to shrub- and grass-dominated vegetation that may persist as an alternate stable state due to limited rates of ponderosa seedling regeneration in severely burned areas. Though overstory tree canopy is an important driver of understory plant response, little is known about how the absence of tree canopy following severe fires interacts with changes in year-to-year climate to affect the physiological function of ponderosa pine seedlings. This field study tested …