Using Soil 13C to Detect the Historic Presence of Schizachyrium scoparium (Little Bluestem) Grasslands on Martha’s Vineyard

TitleUsing Soil 13C to Detect the Historic Presence of Schizachyrium scoparium (Little Bluestem) Grasslands on Martha’s Vineyard
Publication TypeJournal Article
Year of Publication2003
AuthorsG. Peterson, Gregory, and Neill Christopher
JournalRestoration Ecology
Pagination116 - 122
Date Published03/2003
KeywordsC-13, C-4 and C-3 vegetation, grassland restoration, landscape history, Schizachyrium scoparium, soil carbon

We used differences in soil carbon delta(13)C values between forested sites and grasslands dominated by the C-4 grass Schizachyrium scoparium (little bluestem) to detect the presence of former grasslands in the historical landscape of the coastal sand plain of Martha’s Vineyard, Massachusetts, U.S.A. Soil delta(13)C was measured at (1) sites with long-term forest or grassland vegetation and (2) sites with known histories where forest vegetation invaded grassland and where forest converted to grassland. The delta(13)C of soil under long-term grassland was -24.1parts per thousand at 0 to 2 cm depth and -23.4parts per thousand at 2 to 10 cm and was enriched by 3.4parts per thousand and 2.8parts per thousand compared with soil under long-term forest. In forests that invaded grasslands dominated by S. scoparium , soil delta(13)C decreased as C derived from trees replaced C from S. scoparium . This decline occurred faster in surface soils and in the light soil organic matter fraction than in the mineral soil. In forests that converted to grasslands, soil delta(13)C increased and the rate of increase was similar in surface and mineral soil and in the different soil organic matter fractions. Rates of change indicated that soil delta(13)C could be used to detect changes in vegetation involving the presence or absence of S. scoparium during the last 150 years. Application of this model to a potential grassland restoration site on Martha’s Vineyard where the landscape history was not known indicated that the site was previously unoccupied by S. scoparium during this time. The delta(13)C of surface mineral soil can be useful for detecting the presence of historic S. scoparium grasslands but only in the period well after European settlement of these coastal sand plain landscapes.