PARENT SESSION
Oral Session #59: Soil Ecology: Microbial and Invertebrate.
Presiding: M. Rillig
Wednesday, August 7. 8:00 AM to 11:30 AM. Palo Verde Room, Radisson.
Differences in soil microbial community composition among forest, pasture, and Koa plantation in Hawaii.
NIELSEN, CAROLINE*,1, MATSON, PAMELA1, 1 Stanford University, Stanford, CA
ABSTRACT- Different land uses often influence ecosystem process rates. However, little is known about the effects of land use on microbial communities, nor their specific role in regulating differences in processes among land use types. We characterized soil microbial communities across sites with differing land-uses on the island of Hawaii. The sites included forest, pasture, and 1-, 10-, 13-, 17-, and 24-year-old plantations of Acacia koa, an N-fixing tree. Principal components analysis of data from phospholipid fatty acid (PLFA) analyses suggest that soil microbial communities differed significantly among pasture, forest, 1-year-old tree plantation, and the older plantations; the 10- through 24-year-old tree plantations were indistinguishable. Microbial biomass was lowest in the 1-year-old plantation, but similar among the other treatments. Fungal:bacterial ratios were highest in the forest, lowest in the 1-year-old plantation, and intermediate in the pasture and the older plantations. Preliminary results suggest that both disturbance and parent material may influence microbial community composition, but vegetation type is the most crucial control.
KEY WORDS: Acacia koa, microbial community, PLFA, Hawaii