Transposing Socioeconomic and Qualitative Research into a Historical, Landscape-scale Assessment of Carbon Stock in Agricultural-Forestland

Uncoordinated land use decisions by landowners play a key role in determining ecosystem production over time. While biophysical measurements and remote sensing have been used to quantify landscape-scale carbon production, contributions by land use and management remains evasive. We address this with 555 surveys of Michigan Centennial Farmers. The study area, a watershed in southwest Michigan, underwent land cover change after settlers cleared forestland for agriculture in the 1830s. Of the initial surveys, 79 stakeholders completed the survey and 49 agreed to interviews. Respondents own 15-430 acres, of which 20% own 15-98 acres, 15% own 98-181, and <5% own 181-430 acres. We compare findings to independent carbon equivalent production estimates from census records, remote sensing, and in situ eddy covariance carbon measurements. Initial examination of the National Agricultural Statistics Service census reports from 1950 through 2012 indicate decreased number of farms (from 30,269 to 10,562), increased average farm size (from 84.9 to 194 acres), increases owners leasing farmlands (from 131,310 to 261,942 acres). Likewise, stakeholders report a historic transition from sustenance and dairy farming to large crop rotations due to economic and labor hardships in 1960-1970, resulting in a loss of small farms (40-200 acres) and acreage sales to residential zoning. Increased wetlands and reforestation in areas with steep slopes is also reported. This corresponds to classification of Landsat data 1976-present that indicates rises in wetland (5.41% to 10.09%), and residential areas (3.54% to 14.18%) within the watershed. Many owners no longer farm but enroll in cropland reserve programs or rent to large-scale farms who manage the land; however, forestland remains preserved with no intention to sell or rent. Stakeholders also observed delayed season onset and cropping dates as well as to milder winters and colder, wetter springs since 1950. Initial comparisons of stakeholder interviews align with remote sensing and in situ observations, providing important socioeconomic context to historical landscape-scale carbon production.