Theses
Science Quality and Integrity
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse more than 100 theses authored by our scientists going back to 1959 and refine search by topic, location, year, and advanced search.
Filter Total Items: 157
Ground-water age and atmospheric tracers: Simulation studies and analysis of field data from the Mirror Lake site, New Hampshire Ground-water age and atmospheric tracers: Simulation studies and analysis of field data from the Mirror Lake site, New Hampshire
The use of environmental tracers in characterization of ground-water systems is investigated through mathematical modeling of ground-water age and atmospheric tracer transport, and by a field study at the Mirror Lake site, New Hampshire. Theory is presented for modeling ground-water age using the advective-dispersive transport equation. The transport equation includes a zero-order source...
Authors
Daniel J. Goode
Ecological, morphological, genetic and life history characteristics of two sockeye salmon populations, Tustumena Lake, Alaska Ecological, morphological, genetic and life history characteristics of two sockeye salmon populations, Tustumena Lake, Alaska
Populations can differ in both phenotypic and molecular genetic traits. Phenotypic differences likely result from differential selection pressures in the environment, whereas differences in neutral molecular markers result from genetic drift associated with some degree of reproductive isolation. Two sockeye salmon, Oncorhynchus nerka, populations were compared using both phenotypic and...
Authors
Carol Ann Woody
Ecology of a biological invasion: alien annual plants in the Mojave Desert Ecology of a biological invasion: alien annual plants in the Mojave Desert
No abstract available at this time
Authors
M.L. Brooks
Modelling root reinforcement in shallow forest soils Modelling root reinforcement in shallow forest soils
A hypothesis used to explain the relationship between timber harvesting and landslides is that tree roots add mechanical support to soil, thus increasing soil strength. Upon harvest, the tree roots decay which reduces soil strength and increases the risk of management -induced landslides. The technical literature does not adequately support this hypothesis. Soil strength values...
Authors
Arne E. Skaugset
A Multi-Scale Conservation Assessment of Plant Communities in Southern California A Multi-Scale Conservation Assessment of Plant Communities in Southern California
No abstract available at this time
Authors
P.A. Stine
Birds of large floodplain forests: Local and regional habitat associations on the upper Mississippi River Birds of large floodplain forests: Local and regional habitat associations on the upper Mississippi River
Abstract not submitted to date
Authors
M. G. Knutson
Habitat use and movements of Northern Pintails wintering in the Suisun Marsh, California Habitat use and movements of Northern Pintails wintering in the Suisun Marsh, California
No abstract available at this time
Authors
Michael L. Casazza
Influence of cryptobiotic soil crusts on annual plants and foraging movements of the desert tortoise in the northeast Mojave Desert Influence of cryptobiotic soil crusts on annual plants and foraging movements of the desert tortoise in the northeast Mojave Desert
No abstract available at this time
Authors
L.A. DeFalco