The goal of this project was the measure changes in woody vegetation cover over time, in riparian and non-riparian locations. The study was retrospective, using high resolution aerial imagery to identify areas dominated by grasslands, shrubs, trees, and woody plant that could not be differentiated as shrubs or trees (referred to as “unk” or “unknown”). These data help us understand rates of woody plant cover over time and how these changes might affect other populations (e.g., avifauna) and processes (e.g. hydrology). These data show and increase in woody plant cover across all three watersheds up until 2010, but with less woody plants expansion in the non-riparian zone of watershed and N1B. Through 2020, woody plant expansion continued in watersheds N1B and N4D. In N2B, tree cover decreased sharply in 2011 and remained low through 2020. This was expected due to the tree removal treatment. However, shrub cover increased rapidly over this same time frame, resulting in little net change in total woody cover (tree plus shrub cover). These results suggest that even an extreme intervention of repeated tree removal is not enough to return the riparian zone to a grassland state.
In three watersheds, we established a series of permanent plots with a 20-meter radius. Two users used photo interpretation to draw polygons around each vegetation type (performed by Brynn Ritchey and Zak Ratajczak). These shapefiles were used to tabulate the total cover of each vegetation type, which is reported in this data-set. Measurements were taken for riparian and non-riparian locations in three watersheds:
-N1B (with data for 1978, 2002, 2010, 2012, 2019, and 2020)
-N2B (with data available for 1978, 2002, 2003, 2010, 2012, 2014, 2016, 2018, 2019, and 2020),
-N4D (with data for 1978, 2002, 2010, 2012, 2019, and 2020)
For further details, see Keen RM, Nippert JB, Sullivan PL, Ratajczak Z, Ritchey B, O’Keefe K, Dodds WK. Impacts of Riparian and Non-riparian Woody Encroachment on Tallgrass Prairie Ecohydrology. Ecosystems. 2022 Apr 13:1-2. https://doi.org/10.1007/s10021-022-00756-7