Soil and Water Sciences
Winter Seminar
Dr. Curtis Monger
Plant and Environmental Sciences
New Mexico State University
- Location: 1002 CHASS Interdisciplinary Building - North
- Time: Wednesday, January 21, 2009, 12:10-1:00 pm
- Campus Map CHASS (INTN)
"Carbon Sequestration in Desert Soils"
Abstract: Desert soils cover more of the Earth’s land surface than any other soil type. Although the amount of organic carbon in desert soils is small, the amount of total carbon is large because of soil carbonate. Globally, soil carbonate contains at least 800 x 1015 grams of carbon, which exceeds the amount of carbon in the atmosphere (ca. 750 x 1015 grams) or the amount in land plants (ca. 560 x 1015 grams). Although the chemistry of carbonate dissolution/precipitation has been understood for over a century, the role of carbonate in sequestering atmospheric carbon dioxide is deceptively complex. In particular, there is no classification system that organizes carbonate into categories that enable us to understand its origin in soil. This presentation discusses the role of soil carbonate in the global carbon cycle and how carbonate can be classified based on its source of Ca2+. The major categories of this system are in situ or ex situ pedogenic, non-pedogenic (i.e., geogenic), calcitic-pedogenic, and silicatic-pedogenic carbonate. This classification reveals that all soil carbonate contains sequestered atmospheric CO2 in a series of three generations.