Effect of calcium addition on litter decomposition; data from reciprocal litter transplant experiment at Hubbard Brook, NH

Cross-site syntheses of litter decomposition studies have shown that
litter calcium (Ca) concentration may have a role in controlling the
extent of decomposition of tree foliage. We used an ongoing watershed
CaSiO4 addition experiment at the Hubbard Brook Experimental Forest in
New Hampshire, USA, to test the hypotheses that increased Ca in litter
would have no effect on the initial rates of litter decay but would
increase the extent or completeness (limit value) of foliar litter
decomposition. We tested these hypotheses with a 6-year litter
decomposition experiment using foliar litter of four tree species that
are prominent at this site and in the Northern Hardwood forest type of
North America: sugar maple (Acer saccharum Marsh), American beech
(Fagus grandifolia Ehrh.) yellow birch (Betula alleghaniensis Britt.)
and white ash (Fraxinus americana L.). The experiment used a
reciprocal transplant design with the Ca-treated watershed and a
control site providing two sources of litter and two placement sites.
This dataset includes mass loss and changes in nutrient content of
litter over the six year period.