An Integrated Climate-Ecological Modeling Framework for Simulating Vegetation Changes due to Climate Change in the Prairie Pothole Region of the United States

Abstract:

The quality of habitat for species in the Prairie Pothole Region (PPR) of the northern Great Plains is dependent on the existence of wetland vegetation. Historically, prairie wetlands have been sensitive to the temporally and spatially variable climate of the PPR which portends a similar response to climate change. The projected rise in PPR precipitation is not expected to offset the projected rise in temperature which could have detrimental effects to the ecosystem. Other studies have found spatial shifts of vegetation types in the PPR due to climate change. To enable the projection of vegetation conditioned on climate, we developed an integrated, novel climate-ecological modeling framework. The climate component of this framework consists of a stochastic weather generator (SWG) which has the capability to generate a wide variety of daily weather sequences and extremes at the desired resolution based on the station data. Further, the SWG can simulate weather scenarios conditioned on large-scale climate information such as seasonal climate forecasts or future projections from climate models. Thus, the SWG translates large-scale climate information to local weather sequences by generating realizations of maximum and minimum temperature (T_max, T_min) and precipitation occurrence and amount (P_occ, P_amt). Vegetation dynamics for chosen species are simulated by the DayCent ecosystem model based on T_max, T_min, and P_amt. The SWG and DayCent will be calibrated and validated using historical data before using the coupled framework to generate projections of PPR vegetation net primary productivity (NPP) at select locations based on climate change scenarios RCP2.6 and RCP8.5. We expect model results to show a decrease in NPP indicating a negative impact to vegetation in the PPR – this would ultimately negatively affect numerous wildlife species that depend on this important habitat. Analyzing the outputs from the framework – climate, hydrology, and vegetation – will offer insights into the dynamics of the coupling that will be of immense use to ecosystem managers and for local communities in making developmental decisions. Lastly, this framework can be adapted to sites across the world and to other processes such as watershed hydrology.