Hardwood Seedling Survival Under Plantations of Scotch Pine and Red Pine in Central New York

Hardwood seeds germinate under both red pine and Scotch pine plantations, but few reach larger size classes under red pine. The environment of the plantation floor cannot explain this difference in hardwood survival. Differences were found in chlorophyll, nitrogen, and phosphorus content of leaves of hardwood seedlings growing under the two pine species, with the phosphorus content in the seedlings growing under red pines suggesting limitation of growth. Endomycorrhizal colonization was not found in 1st—yr hardwood seedlings growing under red pines, whereas it was found in all examined seedlings growing under Scotch pines. Laboratory experiments confirmed these findings. We suggest that this lack of endomycorrhizal colonization reduces the phosphorus uptake by the hardwood seedlings growing under the red pines to levels which limit their growth, eventually contributing to the observed seedling mortality.