Soil Macrofaunal Diversity and Biomass Across Different Land Use Systems in Wondo Genet, Ethiopia

Abstract

One of the most important roles of soil organisms is breaking up the complex substances in decaying plants and animals so that they can be used again by living plants. The objective of this research work was to assess the biomass, diversity, and abundance of soil macrofauna in four different land use systems: natural forest, mixed stand plantation, agricultural and grazing lands in Wondo Genet, Ethiopia. Moreover, soil carbon and nitrogen were analyzed. In each land use system, three transect lines of 20m by 2m were laid out at 8 meters distance from each other, three quadrants of 1m² were randomly excavated. Hand-sorting of soil was used to extract all fauna greater than 2 mm body length from soils under the four land use systems during the dry season (April to May 2014). Triplicates of soil samples were also collected from 0-30 cm depth for soil physico-chemical analysis. The highest abundance of soil macrofauna was recorded from the natural forest (64.6), while the lowest figure was from plantation forest (45.7).  Likewise, the highest biomass and diversity of soil macrofauna was found in the natural forest (6.3857 gm/m²and H' = 2.041, respectively) where it is characterized by higher diversity of plant species whereas the lowest biomass and diversity of soil macrofauna was observed from agricultural land (2.7863 gm/m² and H' =1.033, respectively). Generally, the highest biomass and diversity of soil macrofauna in soil under the natural forest was due to the highest diversity of floral composition and high leaf litterfall.

Keywords: land use, soil macrofauna, diversity, biomass, abundance