Ecosystem responses to a lack of water can manifest itself in different ways due physiological and structure differences in the ecosystem of interest. In addition, the nature of the physical aspect of the drought event can also be a determinant of the ecosystem response. In the north central region of the US, on-going drought studies are investigating factors determining how drought impacts various ecosystem services and challenge management decisions.
The effort reported here stems from research sponsored by the USGS North Central Climate Science Center, to deal with ecosystem response to drought with the goal to see if there indicators of drought emerging from the ecosystem interactions with various weather patterns, soil moisture dynamics, and the structural aspects of the ecosystem in question. The North Central domain includes various steppe, grassland, and forested ecosystem across a seven State region, including Colorado, Kansas, Wyoming, Nebraska, Montana, South Dakota, and North Dakota.
Using a mechanistic daily time-step ecosystem model, region wide simulation of ecosystem dynamics have been carried out over the domain using daily climate inputs derived from Daymet (Thornton et al). Simulations across these ecosystems and land use practices were made and output variables, net primary productivity, soil moisture content, evaporation, transpiration, and water use efficiency from 1980 through 2014 will be analyzed for different drought and non-drought events.
Results/Conclusions
Comparisons between satellite-derived ET and NPP of different Great Plains ecosystems related to simulated ET and NPP will be presented. These comparisons provide indications of the role that soil moisture recharge and rooting depth of different ecosystems have on determining the sensitivity to water stress due to seasonal warming and reduced precipitation across the region. In addition, indications that average annual rainfall levels over certain ecosystems may result in reduced production due to higher rates of water demand under the observed warmer temperatures and the prolonged warming in the spring and fall affecting soil moisture conditions.
These results are being used to inform managers in our region about recent climate trends regarding drought impacts and provide a basis for further co-design efforts of research to action strategies with resource managers and stakeholder s in our region.