The Effect of Land-Cover Typology on the Abundance of Macrofauna in Tropical Peatland Ecosystem

Abstract

Macrofauna is a group of organisms that are important in peatland ecosystems. Environmental factors (biotic and abiotic) including physical and chemical properties of the soil have an important influence on the presence and population density of soil macrofauna species. This study aims to analyze the types and abundance of soil macrofauna in 4 (four) typologies of peatland closure, namely: forests, shrubs, agroforestry gardens, and annual crops. A sampling of soil macrofauna was carried out by two methods. First, the pitfall traps are used for macrofauna that is active on the ground surface. Second, the hand sorting methods are used for macrofauna, which is in the soil. Individual soil macrofauna, which has been prepared in a collection bottle, is identified up to the order level, the family by using an insect identification key. The identified soil macrofauna are then counted (number of individuals and number of species). The total number of families or orders per sampling unit is used to calculate the Shannon diversity index and the Morisita community similarity index. The total number of individuals and biomass per sampling unit is used to calculate abundance. The diversity of soil fauna types was calculated using the Shannon diversity index. The similarity index of the Morisita community to soil macrofauna on forest land has the same or identical value as agroforestry land, with an index value of 0.96. Meanwhile, peat soils covered with plants and shrubs have identical types of macrofauna, with an index value of 0.84. The diversity of soil macrofauna in forest cover have a moderate level, with an index value of 1.84, whereas agroforestry and plant cover has moderate levels of soil macrofauna diversity, with index values ​​of 1.72 and 1.68, respectively. Peatlands with shrubs have the lowest level of soil macrofauna diversity, with an index value of 1.23. Different peatland cover results in different diversity, presence, and a number of different soil macrofauna. The difference in abundance of soil macrofauna is caused by land cover, peat structure, level of decomposition, soil moisture regime, nutrient content, chemical properties, soil temperature, light intensity, and air.