University of Wisconsin–Madison
Spatial Analysis For Conservation and Sustainability

Land use and climatic causes of environmental novelty in Wisconsin since 1890

Download Williams_etal_EcoApps_WI_Novelty_2019

Multiple global change drivers are increasing the present and future novelty of
environments and ecological communities. However, most assessments of environmental novelty have focused only on future climate and were conducted at scales too broad to be useful
for land management or conservation. Here, using historical county-level data sets of agricultural land use, forest composition, and climate, we conduct a regional-scale assessment of environmental novelty for Wisconsin landscapes from ca. 1890 to 2012. Agricultural land-use data
include six cropland types, livestock densities for four livestock species, and human populations. Forestry data comprise biomass-weighted relative abundances for 15 tree genera. Climate
data comprise seasonal means for temperature and precipitation. We found that forestry and
land use are the strongest cause of environmental novelty (NoveltyForest = 3.66,
NoveltyAg = 2.83, NoveltyClimate = 1.60, with Wisconsin’s forests transformed by early 20thcentury logging and its legacies and multiple waves of agricultural innovation and obsolescence. Climate change is the smallest contributor to contemporary novelty, with precipitation
signals stronger than temperature. Magnitudes and causes of environmental novelty are
strongly spatially patterned, with novelty in southern Wisconsin roughly twice that in northern
Wisconsin. Forestry is the most important cause of novelty in the north, land use and climate
change are jointly important in the southwestern Wisconsin, and land use and forest composition are most important in central and eastern Wisconsin. Areas of high regional novelty tend
also to be areas of high local change, but local change has not pushed all counties beyond
regional baselines. Seven counties serve as the best historical analogues for over one-half of
contemporary Wisconsin counties (40/72), and so can offer useful historical counterparts for
contemporary systems and help managers coordinate to tackle similar environmental challenges. Multi-dimensional environmental novelty analyses, like those presented here, can help
identify the best historical analogues for contemporary ecosystems, places where new management rules and practices may be needed because novelty is already high, and the main causes
of novelty. Separating regional novelty clearly from local change and measuring both across