Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 13 of 13 for “"Arid Ecosystems"”.
-
Advancing Vegetation Monitoring Strategies in Arid Ecosystems Using Unmanned Aircraft Systems
Arid ecosystems present unique challenges for environmental monitoring using remotely sensed data because vegetation communities in drylands are often sparsely distributed and have heterogeneous species and soil composition. Unmanned Aircraft Systems (UAS) offer centimeter-scale spatial resolution …
-
Structure, distribution and phenology of perennial plant species in the Worcester Veld Reserve, in the arid winter rainfall region of the Southwestern Cape
… diversity amongst plant species in the arid winter rainfall region of southern Africa is common to other arid regions of the world. Details of the range and combinations of structural attributes in species, and within plant communities, are not widely known for southern African arid …
-
Sources And Controls Of Reactive Nitrogen Gas Emissions From A Mojave Desert Ecosystem
… of gaseous nitrogen (N) loss dynamics in arid ecosystems, a process that directly affects longterm N bioavailability and the release of chemically important gas species into the atmosphere. Chapter one focuses on identifying controls over biological sources of reactive N gas emissions, …
-
Ecosystem Consequences of Post-Fire Invasive Species in the Great Basin Desert
… storage of ecosystem resources in these arid ecosystems. Understanding the disruption of carbon and water cycling in invaded ecosystems provides insight into controls on ecosystem function and provides a foundation for predicting future impacts of global change on arid ecosystems.
-
The effects of neighbor, distance, and organic fertilizer on the establishment and early performance of three woody species in a restoration trial in the Kunene region, Namibia
Land degradation poses a significant challenge in arid ecosystems across Africa, adversely affecting the livelihoods of many who depend on the environment. It has become an urgent priority to restore these ecosystems. While various restoration approaches have been studied globally, few have …
-
Bacterial Diversity of the Atacama Desert, Chile: The Challenges of Characterizing the Community Dynamics of Extreme Oligotrophic Ecosystems
… examines the bacterial diversity of hyperarid and arid regions of the Atacama Desert, Chile, as a first step towards understanding the global biogeochemical significance of arid-land microbial communities. The specific objectives were to characterize bacterial diversity and infer the …
-
Can sociality buffer the impacts of climate change on a cooperatively-breeding bird, the southern pied babbler Turdoides bicolor?
… in characteristically harsh and unpredictable arid and semi-arid ecosystems are useful models for studying impacts of climate variability and change because these ecosystems are experiencing rapid increases in both average and maximum temperatures, as well as increased interannual rainfall …
-
Water balance and productivity of a Mediterranean oak woodland : Quantifying understory vegetation impacts by development of a stable oxygen isotope partitioning approach
Semi-arid ecosystems cover large areas world-wide and contribute about 40% to global gross primary production (GPP). The major driving factor of GPP in these ecosystems is water availability; since annual precipitation pattern show periodical summer droughts and evapotranspiration losses are high. …
-
An integrated modelling approach for sustainable management of semi-arid and arid rangelands
… resource management strategies for semi-arid and arid rangelands is acute as non-adapted grazing strategies lead to irreversible environmental problems such as desertification and associated loss of economic support to society. In such vulnerable ecosystems, successful implementation of …
-
Restoring semi-arid lands with superabsorbent polymers under reduced precipitation and threat of Bromus tectorum invasion
Restoration of arid ecosystems in the western United States (US) is often constrained by low and variable moisture and invasion by exotic species. After disturbance, variability in resources as well as inherent soil moisture and temperature regimes may influence the susceptibility of an ecosystem …
-
Mojave Desert restoration: drought and facilitation influences on plant communities and soil seed banks in annual grass invaded shrublands
… like Bromus rubens, have become widespread in arid ecosystems across the western United States, including the Mojave Desert. Their prolific seed production and rapid spread pose significant threats to native flora and wildlife habitats. These invasive grasses alter fire cycles, degrade …
-
Sustainable management of semi-arid African savannas under environmental and political change
… of the global human population. Worldwide, these ecosystems are prone to heavy degradation. Increasing levels of dryland degradation result a strong decline of ecosystem services. In addition, in highly variable semi-arid environments changing future environmental conditions will potentially have …
-
The Effect of Prescribed Burning on Soil Microbial Communities, Nutrients, and Carbon Dioxide Fluxes Under and Between Sagebrush Canopies in the Semi-Arid Rangelands of Northern Nevada
… an immediate reduction in soil microbes in semi-arid ecosystems, especially in soils under shrub canopies. Our results demonstrated that fire has a direct effect on soil CO2 respiration in cold desert sagebrush ecosystems in both the short and long term. Although burning did not immediately lead …