In urban systems, ecosystem function is highly influenced by human decisions (regarding vegetation composition and management), and people benefit directly from many ecosystem services provided by urban ecosystems. Ultimately, the further an urban system is from the “natural” state, the more resources and management are required to maintain it. Thus, these systems may be vulnerable to system changes, when climate variability or other events limit resource availability or funding to undertake management activities. As one of the geographically largest cities in the US, Oklahoma City has a range of land cover and microclimates. Here we bring together ground based vegetation surveys, remotely sensed land cover and vegetation function (e.g. greenness, productivity and water loss), and assessments of household water use in order to better understand 1) the response of different types of urban landscapes to climate drivers, and 2) the relative importance of human versus climate drivers.
Over the past three decades, vegetation greenness in low-density urban areas has been comparable to that of surrounding grasslands, with a similar sensitivity to precipitation. Urban areas were less green and more responsive to precipitation than surrounding deciduous forests. This is likely due to the overwhelming signal of lawns in the urban landscape. We expect that on a local scale, vegetation greenness will be less sensitive to climate (e.g. temperature and precipitation) than household water use, due to the buffering impact of irrigation. Such work allows us to better understand relationships between urban land use and ecosystem function, how decision-making responds to environmental cues, and has implications for cities dealing with limited water supplies.