SOIL INOCULUM POTENTIAL AND ARBUSCULAR YCORRHIZAL COLONIZATION OF ACER RUBRUM IN FORESTED AND DEVELOPED LANDSCAPES
P. Eric Wiseman and Christina Wells
Abstract: Arbuscular mycorrhizal fungi (AMF) form a symbiotic relationship with numerous landscape tree species and can improve tree growth and environmental stress tolerance. Construction-related soil disturbance is thought to diminish AMF colonization of transplanted trees in newly developed landscapes. We gathered root, soil, and foliar data from red maples (Acer rubrum) growing in newly developed landscape sites and adjacent native forest sites to test two independent hypotheses: (1) landscape trees show lower levels of AMF colonization than forest trees, and (2) the AMF inoculum potential of landscape soils is lower than that of forest soils. Fine roots sampled from landscape maples had significantly lower AMF colonization than maples from adjacent forest sites (3% versus 22%). However, soilsand mixtures made from landscape soils possessed greater AMF inoculum potential than those made from forest soils (10% versus 4%). Forest soils were more acidic and possessed less extractable P than landscape soils, and differences in AMF colonization between field and landscape maples appeared to reflect differences in soil chemical properties rather than in inoculum potential. The results of this study suggest that not all disturbed landscape soils are deficient in AMF propagules.
Keywords: Acer rubrum; arbuscular mycorrhizal fungi; mycorrhizae; red maple; soil acidity; soil disturbance