Woody shrub encroachment into grasslands ecosystems is rapidly altering site biogeochemistry as well as ecosystem structure and function. The mechanisms responsible for woody shrub encroachment in North American grasslands are often site-specific and confounded with varying local environmental conditions. To assess differences in leaf-level carbon and water exchange as a function of land history and site demography, we are measuring the δ¹³C and δ¹⁵N in leaves of roughleaf dogwood (Cornus drummondii) growing in mesic grassland. This research occurs at Konza Prairie, which has complex topoedaphic gradients on site and is divided into replicated watersheds with varying management history of burning (1, 2, 4, 10, and 20 year intervals) and grazing (with bison and no grazing). Roughleaf dogwood leaves are collected from 70 discrete islands distributed along topoedaphic gradients and across and all burning and grazing regimes at KPBS. Mature, new leaves were sampled from each dogwood island in late June, July and early September, 2008 and every 3 weeks from late May to early September, 2009. Site demography including burn frequency, grazing, elevation, aspect, slope and soil type are being used as predictors of leaf carbon and nitrogen isotopic signature during summer growth. Using this data, we are creating δ¹³C and δ¹⁵N isoscapes to better understand how similar site-level environmental conditions (air temperature, precipitation, relative humidity) and may help explain non-uniform patterns physiological functioning and interpret the mechanisms responsible for woody encroachment into grasslands.