Tuesday, November 14, 2006

Topo and Chrono-Sequence Effects of Native and Reconstructed Prairies on Soil Physical and Biological Activities.

Mahdi Al-Kaisi, Jose Guzman, Beth Larabee, and Mark Licht. Iowa State Univ, 2104 Agronomy Hall, Ames, IA 50011-1010

Slope position and time of establishment of prairie species can significantly influence soil physical properties (i.e., infiltration rate, etc.), soil carbon distribution, soil microbial population, sediment movement and a whole suite of other related properties. One native prairie, three restored prairies and one agricultural site of the same soil association were selected for this study. The experimental design of each location was a completely randomized block design along the slope of each site. The plots of each location were summit, midslope and toeslope with 3 replications for each slope location. The sampling protocol for each site included: soil water infiltration rates, soil carbon and bulk density in depth increments of 0-7.5, 7.5-15, 15-30, 30-45 and 45-60 cm, soil microbial biomass, soil incubation, soil aggregate stability and root biomass for the top 6 inches. Preliminary data show a strong correlation between prairie establishment time and aggregate stability. Root biomass, microbial biomass increased with prairie restoration while soil carbon dioxide evolution was more strongly influenced by nitrogen availability. Infiltration rates were influenced by both landscape position and time for prairie restoration.