Isabel Jones

Habitat degradation through anthropogenic disturbance is one of the main drivers of global biodiversity loss. Resource extraction by the oil and gas industry is a large and growing component of this disturbance. This study quantifies the impacts of disturbance from oil and gas infrastructure on the semi-arid vegetation of the ecologically important Ustyurt Plateau, Uzbekistan. The footprint of oil and gas development on the Ustyurt is set to grow considerably in the future, so understanding the ecological consequences of infrastructure expansion will be vital, to mitigate negative impacts. The degree to which disturbed and undisturbed (control) sites differ in species abundance and vegetation cover, and how these metrics alter with distance from disturbance, were investigated using transects employing the line intercept method of data collection. Disturbed sites had significantly lower species abundance (p<0.001) and cover (p<0.001) compared to control sites, but this was only found at the site of disturbance itself (0 m), and not at further sampling points 25-500 m from disturbance; this indicates that the spatial extent of disturbance is limited. Other factors that could explain abundance and cover patterns, such as secondary disturbances and wind direction, were not significantly correlated to vegetation response variables. Disturbance was found to have a negative effect on species abundance and cover at the community, broad taxonomic group, and species levels; Alone among the vegetation groups, Poaceae showed an increase in species abundance at the site of the disturbance (P < 0.05). Because impacts can be seen at vegetation community level, impacts from infrastructure may affect other taxa and species relying upon this vegetation, such as the critically endangered saiga antelope. Future research should focus on the effects of disturbance on vegetation at finer spatial scales, and investigate disturbance effects on other taxa, completing the quantification of impacts from oil and gas development on the Ustyurt.