William H. Schlesinger

William H. Schlesinger (April 30, 1950 – Present) is a biogeochemist and the president of the Cary Institute of Ecosystem Studies, a private environmental research organization in Millbrook, NY. He assumed this position after 27 years on the faculty of Duke University, where he served as the Dean of the Nicholas School of the Environment and Earth Sciences and James B. Duke Professor of Biogeochemistry.

Education, career, and honors

Schlesinger began his college education at Dartmouth College where he received his A.B. in biology in 1972. He earned his Ph.D. at Cornell University in Ecology and Systematics in 1976.Schlesinger’s teaching career began at the University of California, Santa Barbara where he was an assistant professor of biology for four years. Afterwards, he transferred to Duke University becoming a full professor and teaching for over 20 years. In 2001, Schlesinger was promoted as the Dean of the Nicholas School of Environment and Earth Sciences at Duke University. Schlesinger retired as the dean on June 1, 2007 and became the president of the Cary Institute of Ecosystem Studies where he currently works.

Schlesinger was elected a member of the National Academy of Sciences in 2003, and was President of the Ecological Society of America from 2003 - 2004. He is also a fellow in the American Academy of Arts and Sciences, the American Geophysical Union, and the Soil Science Society of America.

Contributions to biogeochemistry

Schlesigner is the author or coauthor of over 180 scientific papers on subjects of environmental chemistry and global change and the widely-adopted textbook [http://www.cplbookshop.com/contents/C357.htm Biogeochemistry: An analysis of global change] (Academic Press, 2nd ed. 1997). He was among the first to quantify the amount of carbon held in soil organic matter globally, providing subsequent estimates of the role of soils and human impacts on forests and soils in global climate change. He is a proponent of sound environmental policies and has testified before U.S. House and Senate committees. Environmental issues that he has advocated for include: preserving desert habitats, addressing global climate change, and carbon sequestration. His efforts have influenced tangible legislation such as the Clean Air Act, and California Desert Protection Act.

Work with desert ecosystems, 1991-2006

Schlesinger served as the co-principal investigator for the Jornada Basin Long Term Ecological Research (LTER) located in the Chihuahuan Desert in southern New Mexico. Research projects mainly focus on inorganic fluxes, including studies of ammonia volatilization from soils, hydrology natural runoff plots and transect soil water content. He has also worked extensively in arid ecosystems and landscapes, studying responses to resource redistribution and global change, which can lead to soil degradation and regional desertification.

Forest-atmosphere carbon transfer and storage, 1996-1999

Schlesinger is the co-principal investigator for the Free Air CO₂ Enrichment (FACE) Experiment simulated in the Duke Forest. The object of the study was to investigate the efficacy of carbon sequestration in forest ecosystems (vegetation and soil) in reponse to elevated atmospheric CO₂ concentration, as a means to mitigate the potential for global warming.

Organic material in soil samples was divided into particulate organic matters (coarse >0.5mm, fine (53 µm-0.5mm) and mineral-associated fractions (<53 µm), with the smaller components having greater stability and higher chance to cause long-term carbon sequestration in soils. Study of variation of δ13C in soil during the three-year experimental period shows fresh plant debris input at 15-30cm depth but minimal production or downward movement of dissolved organic carbon compounds with its stable concentration in the mineral-associated fraction.

Mean residence time (MRT) for carbon in the forest floor under non-steady-state conditions was 2.86yr (k=0.35) estimated from C_t = C₀e^-kt + (I/K)(1-e^-kt), which is in good agreement with the value 3.23yr (k=0.31) derived from depleted δ13C of fresh litter.

Given the absence of significant changes of carbon content in deeper mineral soil layers, forest soils are unlikely to be in account for the long-term net carbon sequestration.

References

Schlesinger, W. H., Better Living Through Biogeochemistry, "Ecology", 85(9), 2004, pp.2402-2407
Schlesinger, W. H., Biogeochemistry, An Analysis of Global change, Academic Press, 1997, pp. 159-163
Schlesinger, W. H., Lichter, J., 2001. Limited carbon storage in soil and litter of experimental forest plots under increased atmospheric CO₂. "Nature" 411, 466-469.
Finzi, A.C., Norby, R.J., Calfapietra, c., Gallet-Budynek, A., Gielen, B., Holmes, W.E., Hoosbeek, M.R., Iversen, C.M., Jackson, R.B., Kubiske M.E., Ledford, J., Liberloo, M., Oren, R., Polle, A., Pritchard, S., Zak, D.R., Schlesinger W.H., ceulemans, R., 2007. Increase in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO₂. "PNAS" 104 (35) 14014-14019.