TY - JOUR
T1 - Leaf litter disappearance in earthworm-invaded northern hardwood forests : role of tree species and the chemistry and diversity of litter
AU - Holdsworth, Andrew R.
AU - Frelich, Lee E.
AU - Reich, Peter B.
PY - 2012
Y1 - 2012
N2 - Earthworm invasion in North American temperate forest reduces forest floor mass, yet the interactions between litter composition, invasive earthworm community composition, and forest floor structure and composition are not well understood. For 2 years, we compared disappearance of leaf litter in field mesocosms in which we manipulated litter composition (monocultures of Quercus rubra, Acer saccharum, and Tilia americana litter, and an equal mixture of all three) and thereby the initial litter chemistry (C, C fractions, N, Ca) in sites with and without the major litter-feeding invasive earthworm species. The disappearance of litter mass followed the same ranking at both the sites: T. americana > equal mixtures > A. saccharum ≥ Q. rubra. However, differences in disappearance rate between the sites depended on litter composition and time. The differences in mass loss among litters of different compositions were greatest at the site invaded by the large litter-feeding earthworm, Lumbricus terrestris, and especially for T. americana and the mixture. Similarly, observed disappearance of the litter mixture was faster than predicted by an additive model at the site with L. terrestris, especially for the higher quality litter component in early summer. Initial litter calcium content was the best predictor (R2 ≥ 0.90) of overall litter mass remaining each year, supporting the idea of the importance of calcium in forest floor dynamics, especially in the presence of calciferous, invasive earthworms.
AB - Earthworm invasion in North American temperate forest reduces forest floor mass, yet the interactions between litter composition, invasive earthworm community composition, and forest floor structure and composition are not well understood. For 2 years, we compared disappearance of leaf litter in field mesocosms in which we manipulated litter composition (monocultures of Quercus rubra, Acer saccharum, and Tilia americana litter, and an equal mixture of all three) and thereby the initial litter chemistry (C, C fractions, N, Ca) in sites with and without the major litter-feeding invasive earthworm species. The disappearance of litter mass followed the same ranking at both the sites: T. americana > equal mixtures > A. saccharum ≥ Q. rubra. However, differences in disappearance rate between the sites depended on litter composition and time. The differences in mass loss among litters of different compositions were greatest at the site invaded by the large litter-feeding earthworm, Lumbricus terrestris, and especially for T. americana and the mixture. Similarly, observed disappearance of the litter mixture was faster than predicted by an additive model at the site with L. terrestris, especially for the higher quality litter component in early summer. Initial litter calcium content was the best predictor (R2 ≥ 0.90) of overall litter mass remaining each year, supporting the idea of the importance of calcium in forest floor dynamics, especially in the presence of calciferous, invasive earthworms.
KW - calcium
KW - decomposition
KW - earthworm invasion
KW - hardwood forests
KW - lignin
KW - litter mesocosms
UR - http://handle.uws.edu.au:8081/1959.7/512732
M3 - Article
SN - 1432-9840
JO - Ecosystems
JF - Ecosystems
ER -