ICOM1 Abstract

CONN, CHRISTINE & DIGHTON, JOHN. Rutgers Pinelands Field Station, P.O. Box 206,New Lisbon, NJ, 08064. - The influence of litter quality on mycorrhizal communities. The influence of litter quality on root growth, mycorrhizal communities and decay processes was investigated through a litterbag experiment. Litterbags containing either pine needles, oak leaves or oak/pine mix were placed within the O horizon of a lowland pitch pine (Pinus rigida) forest in the New Jersey Pinelands. Upon retrieval, ingrown pine roots were removed and quantified for total length and percent mycorrhizal colonization by morphotype. Ergosterol content (fungal biomass indicator) and phosphatase activity was determined for dominant morphotypes. In addition, litter decay rates, hyphal colonization of litter and N and P litter content were measured. Preliminary data show mixed litter (oak + pine) had highest total pine root ingrowth. Pine and mixed litters had greater mycorrhizal morphotype diversity than oak. Dominant mycorrhizal morphotype differed in response to litter type. A tuberculate form dominated (35%) in pine litters while distinctly different nontuberculate morphotypes dominated in oak and mixed litters. Mixed litters generally had greater hyphal length colonization than pure litters. Pine needle decay was slower in the presence of oak leaves (mixed litter) than when alone.