Nematode Community Structure in Dogwood,Maple, and Peach Nurseries in Tennessee

Nursery blocks (48 dogwood, 27 maple, 17 peach) in 20 middle Tennessee nurseries were sampled for nematodes in March,July, and October 1981. Dogwoods and maples were grouped in three age classes: 1-2, 3-5, and 10+ years. Nematodes were extracted from soil samples, counted, and assigned to trophic groups as follows: plant parasites, microbivores, fungivores, predators, and omnivores (= Dorylaimida). Total nematode numbers per 200 cm s soil ranged from 52 to 9,166 (mean = 1,785 ± 1,420). Nematodes were more abundant in dogwood and maple than in peach blocks, and their numbers were significantly correlated with percentage of weed ground cover and number of weed species. Nematode numbers in dogwood sites were also correlated with dogwood age. Microbivores were the most abundant trophic group in all sites, followed by plant parasites, fungivores, omnivores, and predators. Nematode communities in nursery sites shared characteristics of both undisturbed and agricultural habitats. Degree and diversity of plant ground cover appeared to be the most important factors determining nematode community structure.