Gary M. Lovett
Institute of Ecosystem Studies

Collaborators:
Gary M. Lovett, Institute of Ecosystem Studies
Clive G. Jones, Institute of Ecosystem Studies
Lynn M. Christenson, Institute of Ecosystem Studies and SUNY-CESF
Peter M. Groffman, Institute of Ecosystem Studies
Julie E. Hart, Institute of Ecosystem Studies
Myron J. Mitchell, SUNY-CESF

The gypsy moth was introduced to North America from Europe in 1869 and has become a major defoliator of eastern hardwood forests. Gypsy moth outbreaks tend to occur on a roughly 10-year cycle, although in the last decade the outbreaks have been reduced because of a fungal disease that affects the caterpillars. When gypsy moths defoliate a forest canopy, the nitrogen in the foliage is turned into insect biomass, frass (insect feces), or is lost as bits of green litterfall, and is consequently unavailable for the trees to resorb in the autumn (Lovett et al 2002). We have found that much of the nitrogen in frass dropped to the forest floor is quickly taken up by soil microbes and perhaps directly incorporated into the soil, making it unavailable for plant uptake (Lovett and Ruesink 1995, Christenson et al 2002). This would suggest that there should also be little leaching of nitrogen after an outbreak, but some nitrogen leaching may occur in forests that have thin soils or an overabundance of nitrogen (Lovett et al 2002).

Publications on effects of gypsy moth on nitrogen cycling:

• Lovett, G.M. and P. Tobiessen. 1993. Carbon and nitrogen assimilation in red oaks (Quercus rubra L.) subject to defoliation and nitrogen stress. Tree Physiology 12:259-269.
• Lovett, G.M. and A.E. Ruesink. 1995. Carbon and nitrogen mineralization from decomposing gypsy moth frass. Oecologia 104:133-138.
• Lovett, G.M., J.E. Hart, L.M. Christenson, and C.G. Jones. 1998. Caterpillar guts and ammonia volatilization: Retention of nitrogen by gypsy moth larvae consuming oak foliage. Oecologia (Berlin) 117:513-516.
• Ostfeld, R.S., F. Keesing, C.G. Jones, C.D. Canham, and G.M. Lovett. 1998. Integrative ecology and the dynamics of species in oak forests. Integrative Biology 1:178-186.
• Christenson, L.M., G.M. Lovett, M.J. Mitchell, and P.M. Groffman. 2002.
• The fate of nitrogen in gypsy moth frass deposited to an oak forest floor. Oecologia 131: 444-452.
• Lovett G.M., L.M. Christenson, P.M. Groffman, C.G. Jones, J.E. Hart, and M.J. Mitchell. 2002. Insect defoliation and nitrogen cycling in forests. Bioscience 52:335-341.