SPATIAL DISTRIBUTION OF EASTERN MISTLETOE (PHORADENDRON LEUCARPUM, VISCACEAE) IN AN URBAN ENVIRONMENT.

Gougherty, Andrew V.

Understanding the spatial patterns of plant parasites can provide important ecological information about the host-parasite relationship and can elucidate the factors affecting parasite distribution. Phoradendron leucarpum, Viscaceae (eastern mistletoe) is a bird-dispersed, evergreen, obligate, hemi-parasitic plant of many native tree species in the southeastern United States. The objectives of this study were to (i) determine the effect of tree size on mistletoe infestation severity (number of mistletoe clusters per tree) and (ii) assess the spatial distribution of mistletoe-infested trees in an urban environment. All trees in an approximately 35 hectare area in Auburn, Alabama were surveyed for mistletoe infestation. Spatial location of all trees was recorded, as were the number of mistletoe clusters, and DBH of infested trees. Pearson's correlation was used to assess the relationship between mistletoe severity and tree size while Moran's Index and Ripley's L function were used to assess the distribution of mistletoe-infested trees. In total, 42 of 333 (12.6%) trees surveyed were found to be infested with mistletoe. A positive relationship was detected between DBH and the natural log (In) of mistletoe severity. Mistletoe-infested trees and infestation severity were both found to be weakly spatially aggregated, and further, mistletoe-infested trees were found to be clustered over distances of 8 to 200 m. Results indicate that tree size plays a significant role in mistletoe severity and that the distribution of mistletoe-infested trees has a weak aggregated pattern.

UNITED States; PHORADENDRON; MISTLETOES; URBAN ecology (Sociology); TREES; SPATIAL distribution (Quantum optics)

Journal of the Alabama Academy of Science, 2013, Vol 84, Issue 3/4, p155

0002-4112

Academic Journal