Litterfall at Harvard Forest HEM and LPH Towers since 2002

We measure the dry mass and estimated carbon content of leaves and fine twigs that abscise each year. These data are used to quantify one component of annual net primary productivity (ANPP), an important measure of ecosystem productivity and carbon cycling. Leaf area index (LAI) can also be estimated from these data, if area-to-mass ratios are calculated for leaves of each species. This was done for 2002 and 2003 leaf litterfall at the Little Prospect Hill (LPH) site. The fraction of total leaf mass or estimated total leaf area that is formed by leaves of each species also shows the species composition of the forest canopy. If repeated over many years, these data can indicate whether the forest canopy species composition is changing over time.