Introduction The distribution of sclerotium grains, the resting bodies formed by fungal species, and soil fauna diversity was studied in three altitudes of Akita Fagus Forest soils. Both sclerotium grains and soil fauna are considered to play major roles and contribution in soil genesis and soil ecosystem. Thus there is still lack of information of the interaction between the two. This study aims to describe the soil ecosystem structure and interaction between the grains and the fauna among different altitudes.
Materials and Methods Investigated area was located in a fagus forest in Senhoku city, Akita prefecture. Soil samples were collected at the altitudes of 0, 20, and 60 meters, with a triple repeat on each sampling site. The three sites were then named as the B (bottom), S (slope), and T (top) site respectively. L, F, H, and A horizons of each repeat were collected within a 50 x 50 cm plot. Soil fauna found in the L horizon were collected manually, while fauna in the rest of the layers were collected using Berlese-Tullgren method. Collected fauna were further identified, with each individual of each species counted, to obtain the speciess richness and abundance of each site. A description of soil fauna diversity will then be obtained by using the Shannon-Wiener diversity index (H’), whereas the proportion of each species in a community is taken into account. Sclerotium grains in the A horizon were manually collected. Water content, soil pH and Total Nitrogen and Carbon content are also analysed.
Results and Discussion The average moisture content of the B, S, and T sites were 0.452, 0.387, and 0.437v/v respectively. A weight ratio of the L:F:H horizons roughly measured in the field are 1 : 1.42 : 2.46 for the B site, 1 : 2.6 : 2.78 for the S site, and 1 : 2.22 : 2.57 for the T site.
Soil fauna such as mites (Acari) and springtails (Collembola) are considered to feed on mycorrhiza fungi (Coleman,
et al., 2004). Results show that the number of mites and springtail reduce as the number of sclerotium grains found rises. There were no sclerotium grains found at the B1 site, but the most grains were found at the T1. Larger soil fauna found such as nematodes feed on smaller arthropods and are said to fragment plant residues, alter nutrient turnover, promote humification, and stimulate microbial activity in the nutrient cycling (Gobat,
et al., 2003). These nematodes were found at the T site and were not found at the B site. There were also less mites and springtails on this site. A food chain of mycorrhizal fungus feeding mites and springtail feeding nematodes is assumed to be responsible for the existing community structure within the sample sites.
ReferencesColeman, DC, DA Crossley, and PF Hendrix. 2004. Fundamentals of Soil Ecology. Second edition. Elsevier Academic Press.
Gobat, J, M Aragno, and W Matthey. 2003. The Living Soil: Fundamentals of Soil Science and Soil Biology. Science Publishers, Inc.
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