C and N Cycles

Leaf litter and fine root turnover enter the litter and soil pools via decomposition as shown below. Detritus production is the source for input into the litter pool. The nitrogen (green) and carbon (black) are tightly coupled via the chemical (N and lignin) concentration for each litter type.

The nitrogen budget is sensitive to the N pool sizes and decomposition rates of N in the litter and soil. The rate leaf litter is incorporated into the soil pool is proportional to the leaf lignin concentration and the balance goes to the litter compartment. The decomposition rates of the soil and litter pools are calculated as a function of the integrated daily average water fraction and a daily temperature degree day summation, both provided from the climate data. This allows more realistic modeling of the forest carbon cycles.