Lack of vesicular-arbuscular mycorrhizal inoculum in a ponderosa pine forest.

Abstract

Comparison of live and mountain pine beetle Dendroctonus ponderosae, killed Pinus ponderosa pine stands revealed that understory biomass was higher under beetle-killed pines. Carex heliophila, a nonmycorrhizal plant, was virtually the only species present beneath live ponderosa pines. The authors examined the extent to which vesicular-arbuscular mycorrhizae (VAM) colonized understory plants on both live and beetle-killed pine sites; the availability of live- and killed-pine soil VAM inoculum in situ and in the laboratory; the abundance of VAM spores in field soils; and the possible inhibition of VAM formation by forest floor decomposition products in live-pine soils. -from Authors