Hubbard Brook Experimental Forest: Leaf Area Index (LAI) Watershed 1

Leaf area index (LAI) of the mature deciduous forest on WS1 at Hubbard Brook Experimental Forest is estimated on the basis of leaf litterfall collections; the raw data for litterfall are posted in the EDI data package – Fine Litterfall Data at the Hubbard Brook Experimental Forest, 1992 – present (https://portal.edirepository.org/nis/mapbrowse?scope=knb-lter-hbr&identifier=49). This watershed was treated with a calcium silicate mineral (wollastonite) in 1999 to gradually replace Ca lost as a result of acid deposition. Leaf litterfall is collected in 0.097 m2 litter traps raised 1.5 m above ground level and is sorted by species. The number of leaves of each species is counted. The counts are multiplied by the average area per leaf for each species in each plot to estimate LAI. Litter traps are located randomly within each of three plots that are arranged along the elevation gradient within the deciduous forest zone.