Effects of interannual climate variability on terrestrial carbon flux in the southern USA in concert with land-cover change

Spatial and temporary variability of carbon dynamics is increasingly important to understand the mechanisms responsible for terrestrial carbon budget.  This variability could be attributed to many factors including climate variability, land-use/land-cover change, and change in atmospheric carbon dioxide (CO₂).  In this study, we have used Terrestrial Ecosystem Model (TEM) to examine the effects of climate variability/change on terrestrial carbon dynamics of the southern US with or without land-use/land-cover change during 1894-2003.  Results of TEM simulation indicates that the interannual variability of average net carbon change (NCE) of terrestrial ecosystems is primarily controlled by climate interannual variability in the southern region.  However, the range of average NCE is reduced while land-use change was considered in the simulation.  Simulation results further indicate that climate variability responsible for average NCE variability is primarily caused by the interannual variability of precipitation in the southern USA.  The model simulation exercises show that climate variability is the dominant factor to control the interannual variability of NCE of terrestrial ecosystem in the south and the interannual variability could be changed when land-use/land cover change is considered.