Climate, land cover and topography: essential ingredients in predicting wetland permanence

[摘要] Wetlands in the Prairie Pothole Region (PPR) are forecastto retract in their ranges due to climate change, and potholes that typicallycontain ponded water year-round, which support a larger proportion ofbiological communities, are most sensitive to climate change. In addition toclimate, land use activities and topography also influence ponded wateramounts in PPR wetlands. However, topography is not typically included inmodels forecasting the impacts of climate change on PPR wetlands. Using acombination of variables representing climate, land cover/land use andtopography, we predicted wetland permanence class in the southern Boreal Forest,Parkland and Grassland natural regions of the Alberta PPR ( N   =  40 000 wetlands). We showthat while climate and land cover/land use were strong predictors of wetlandpermanence class, topography was as important, especially in the southernBoreal Forest and Parkland natural regions. Our misclassification error rates forthe gradient boosting models for each natural region were relatively high(43–60) though our learning rates were low (  0.1) and our maximumtree depths shallow (5–7) to balance bias and overfitting. Clearly, factorsin addition to climate, topography and land cover/land use influencewetland permanence class (i.e., basin size, depth, ground waterconnectivity, etc.). Despite classification errors, our results indicatethat climate was the strongest predictor of wetland permanence class in theParkland and Grassland natural regions, whereas topography was mostimportant in the southern Boreal Forest Natural Region among the three domains we considered.

[学科分类] 大气科学