LTREB Renewal: Long-term Interactions among Biodiversity, CO2, and N in a Perennial Grassland Ecosystem

Rapid human-caused increases in atmospheric carbon dioxide (CO2) concentrations during the next 50 years will contribute to global warming and will likely shift precipitation patterns and/or amounts, influencing the growth and performance of vegetation worldwide. Plants and their ecosystems absorb roughly one-fourth of the CO2 emitted from fossil fuel combustion each year, and it is critical to understand whether plants can continue this important function as CO2 levels continue to rise. There are fewer than five realistic long-term field experiments that test whether vegetation will continue to absorb extra carbon, and whether such carbon capture may be constrained by infertile soils, lack of soil moisture, climate warming, or loss of diversity. The BioCON experiment is one of these, where plants are exposed to CO2 levels expected to occur late in the 21st century. Since 1998 BioCON has examined interactions among biodiversity, atmospheric CO2, and soil N supply in a temperate perennial grassland in Minnesota. BioCON includes precipitation manipulation (begun in 2007) and warming treatments (begun in 2012). This project will support this experiment from 2012-2017, including measures of plants and soils relevant to both ecosystem science and atmospheric change.

This research will address issues of major importance to society, in particular the potential impacts of human activities on environmental processes at local to global scales. The degrees to which loss of diversity, climate warming, soil nitrogen, and soil moisture constrain the long-term ability of ecosystems to capture and sequester carbon will also be examined. In addition, because it is a unique facility open to and encouraging new initiatives, BioCON will enhance research and education and promote teaching, training, and learning for students, teachers, journalists and others.