and-atmosphere interactions are an important component of climate, especially in semi-arid regions such as the Southern Great Plains. Interactions between soil moisture and vegetation modulate land-atmosphere coupling and thus represent a crucial, but not well understood climate factor. This study examines soil moisture-vegetation health interactions using both in situ observations and land surface model simulations. For the observational study, soil moisture is taken from 20 in situ Oklahoma Mesonet soil moisture observation sites, and vegetation health is represented by MODIS-derived normalized difference vegetation index (NDVI). For the modeling study, the variable infiltration capacity (VIC) hydrologic model is employed with two different vegetation parameterizations. The first is the model default vegetation parameter which is interannually-invariant leaf area index (LAI). This parameter is referred to as the control parameter. The second is MODIS-derived LAI, which captures interannual differences in vegetation health. Soil moisture simulations from both vegetation parameterizations are compared and the VIC-simulated soil moisture’s sensitivity to the vegetation parameters is also examined. Correlation results from the observation study suggest that soil moisture-vegetation interactions in Oklahoma are inconsistent, varying both in space and time. The modeling results show that using a vegetation parameterization that does not capture interannual vegetation health variability could potentially result in dry or wet biased soil moisture simulations.

>Magister Scientiae - MSc / Groundwater dependent vegetation (GDV) communities are increasingly threatened by the transformation of the natural environment to different land use/land cover, over-exploitation of groundwater resources and the proliferation of invasive species within the Cape Floristic Region (CFR). These changes affect the groundwater regime, level, and quality, which supports GDV. Natural resource managers often lack an understanding at appropriate scales of the nature of dependency of GDV to make informed sustainable decisions. This work thus assesses the spatial distribution of GDV and their responses to groundwater variability within the Cape floristic region from June 2017 to July 2018. To achieve this aim, firstly a literature review on the background of GDV, threats and the impact of climate change was assessed.

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Forests can be considered as one of the most important Earth's ecosystems not only because of oxygen production and carbon sequestration via photosynthesis, but also as a source of many natural resources (such as wood) and as a habitat of many specific plants and animals. Monitoring of forest health status is thus crucial activity for keeping all production and ecosystem functions of forests. The main aim of the thesis is development of an alternative approach for forest health status based on airborne hyperspectral data (HyMap) analysis supported by field sampling. The proposed approach tries to use similar vegetation parameters which are used in case of the current methods of forest health status assessment based on field inspections. It is believed that importance of such new methods will significantly increase in the time when the planned satellite hyperspectral missions (e.g. EnMap) will move into operational phase. The developed forest health monitoring approach is practically demonstrated on mature Norway spruce (Picea abies L. Karst) forests of the Sokolov lignite basin which were affected by long-term coal mining and heavy industry and therefore high variability of forest health status was assumed in this case. Two leaf level radiative transfer models were used for simulating spectral...