Carbon-Nitrogen-Water Cycles

I and T. Cronin have developed an improved version of our Terrestrial Ecosystems Model, TEM-Hydro, to allow for allocation of carbon and nitrogen to multiple vegetation pools, including leaves, roots, and stems, while developing a stomatal conductance model to allow for direct feedbacks between the carbon, nitrogen, and water cycles. Results show that nitrogen feedbacks and nitrogen limiting conditions can significantly affect the amount of future streamflow at specific sites (Felzer et al., 2009). The stomatal conductance also regulates the amount of ozone uptake, which adversely affects photosynthesis and plant growth.

Figure 1: New model structure.

Figure 2: Feedbacks and couplings in TEM-Hydro

Figure 3: Comparison of a) evapotranspiration (ET) in eastern forests and b) runoff in western forests, shrublands, and grasslands.

Felzer, B. S., Cronin, T. W., Melillo, J. M., Kicklighter, D. W., Schlosser, C. A. 2009. Importance of carbon-nitrogen interactions and ozone on ecosystem hydrology during the 21^st century. Journ. Geophys. Res. 114,doi:10.1029/2008JG000826.

Felzer, B. S., T. W. Cronin, J. M. Melillo, D. W. Kicklighter, C. A. Schlosser, and S. R. S. Dangal. 2011. Nitrogen effect on carbon-water coupling in forests, grasslands, and shrublands in the arid Western U.S. Journ. Geophys. Res. 116. G03023. doi:10.1029/2010JG001621.

Felzer, B. Carbon, 2012, Nitrogen, and Water Response to Climate and Land Use Changes in Pennsylvania during the 20^th and 21st Centuries, Ecological Modelling, 240: 49-63.[