PARENT SESSION
Oral Session #43: Soil Ecology: Mycorrhizae and Roots. Presiding: W. Stock.
Wednesday, August 8, 2001. 8:00 AM to 12:15 PM. Hall of Ideas F.

Temporal and spatial variation in arbuscular mycorrhizal communities in a temperate forest.

ANDERSEN, KELLY¹, LOVELOCK, CATHERINE¹, ¹

ABSTRACT- Arbuscular mycorrhizal fungi (AMF) are symbiotic fungi associated with plant roots. Here we investigated AMF spore community composition and their distribution in a temperate forest in Maryland dominated by tulip poplar (Liriodendron tulipfera) to determine the temporal and spatial variation in AMF spore community composition. AMF spores were isolated from soil cores using standard wet sieving/decanting procedures and identified using the taxonomic guidelines provided by INVAM (http://invam.caf.edu). Approximately twenty AMF species in four genera were recovered from field soils. AMF spores were more abundant in the fall than in the summer and the species composition was significantly different in the two seasons. Acaulospora lacunosa was the most abundant species in the summer and A. koskei in the fall. AMF spore communities were significantly different in different forest patches, but no significant differences in AMF communities were detected among 50 and 100-year-old forests. Similarities in species composition were greatest among communities at 10cm distance, rapidly decreasing in similarity to a distance of 50cm. At greater distances the similarity between the communities fluctuated but gradually continued to decrease with distance. The AMF communities sampled varied seasonally in species composition and were patchily distributed through out the forest on several scales, indicating possible differences in the functional importance of AMF species.

KEY WORDS: arbuscular mycorrhizal fungi, community composition, temperate forest, temporal and spatial variation