PARENT SESSION
Poster Session #2: Carbon Storage.
Monday, August 5. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Bacterial and fungal diversity in a semiarid grassland.

Kaplan, Christopher¹, Spiker, Darci¹, Silhavy, Jennifer¹, Elwood, Susan¹, Kitts, Christopher^*,1, Ebinger, Michael², Brown, Joel³, Unkefer, Pat⁴, ¹ Dept. of Biology, San Luis Obispo, CA² Environmental Dynamics and Spatial Analysis Group, Los Alamos, NM³ USDA-NRCS Jornada Experimental Range, Las Cruces, NM⁴ Biosciences Division, Los Alamos, NM

ABSTRACT- The positive relationship between carbon substrates and soil microbial diversity has been established using such approaches as culture of microbe populations and substrate specificity screening. Unfortunately, these techniques are only able to address microbes that can be cultured, which are only a fraction of the total number of microbial species in soils. New DNA-sequence techniques, such as terminal restriction fragment (TRF) analysis, can be used to characterize soil microbes that cannot be cultured. We used TRF analysis to examine the overall diversity of bacteria and fungal populations in a semiarid grassland covered by native galletta (Hilaria jamesii) during a period of drought-induced plant dormancy. Primers that amplified the eubacterial 16S rRNA gene were used to create TRF patterns that reflected eubacterial diversity. Primers that amplified the intergenic transcribed spacer region between the large and small subunits of fungal rRNA were used to create TRF patterns that reflected fungal diversity. A grass edge-bare patch sampling structure was used in which soils were collected to a depth of 15 cm. Samples were taken across the west to east slope, and the grass patches were 8-10 feet in diameter. We will present results that include the diversity of microbes from grass and bare locations and the expected enrichment in soil for microbes in the decomposition food web.

KEY WORDS: microbes, carbon, soil, diverstity