PARENT SESSION
Poster Session #5: Soil Ecology.
Monday, August 6, 2001. Presentation from 10:30 AM to 12:00 PM. Exhibition Hall

Spatial variation of microarthropods and soil fungi in a hardwood forest.

Dress, William¹, Frey, Serita¹, Boerner, Ralph¹, ¹

ABSTRACT- The abundance patterns of soil organisms typically exhibit highly aggregated distributions, yet we have little understanding of the factors that control these distributions. The goal of this study is to describe the spatial distribution of soil microarthropods and soil fungi in a southern Ohio hardwood forest, and to determine what factors control their distribution. The abundance of major microarthropod groups, fungal biomass, and litter biomass were measured on a 1 X 2 m grid in eight 27 m² plots. The degree and range of spatial autocorrelation was measured with semivariance analysis and point kriging. Overall, there was an average of 50,064 microarthropods/ m² and 220.9 g fungal biomass C/ g soil. The abundance of oribatid and mesostigmatid mites showed strong spatial structure, with 72 and 87 % of total variation in abundance attributed to spatial structure, respectively. The abundance of collembola and prostigmatid mites showed less spatial structure, with only 23 and 22% of total variation attributed to spatial structure. The abundance of collembola was more strongly related to litter biomass (r² = 0.336, p < 0.05). These results confirm that these soil organisms exhibit highly aggregated and spatially-structured distributions, and present the opportunity for subsequent analyses designed to determine which edaphic variables correlate with or control this structure.

KEY WORDS: microarthropods, fungal biomass, spatial scale, kriging