The dynamics of benthic invertebrates in different part of peat swamp forests converted to rice fields

Abstract

The Indonesian government plans to turn Central Kalimantan province into a national food barn by planting rice paddies in several places, including in shallow peatlands. Tropical peatlands have limited potential to be used as agricultural land since the growing media in some cases, is not conducive to root development, saturated-water soil that poissons the plants. Aquatic invertebrates can be used as indicators to determine whether water quality in a field is safe for plants or not. The objective of this study is to evaluate the dynamics of benthic in different part of aquatic ecosystems on peat swamp forests. This study was conducted in Peat Techno Park (PTP) of the University of Palangka Raya, Central Kalimantan. Samples were collected from 9 stations with different forms of land use for agricultural activities, namely unplowed paddy fields, plowed fields, swamps, connecting ditches, beje, natural peat swamp forests, breeding ponds, and irrigation ponds. Data were collected over 6 months and coincided with the peak of dry and wet seasons. The abundance and species of aquatic invertebrates were then analyzed some related physic-chemical parameters, such as depth, water temperature, pH, and dissolved oxygen (DO). The results showed that the macrozoobenthos species found on this study was slightly rare. There was identified merely 3 genera, include in the two benthic groups, e.i. Annelida and insect. As to the insect, the dominant species was from the order of Diptera and family of Chironomidae, especially Chironomus. Spatially, stations 1 (unplowed rice fields), 2 (ploughed rice fields), 3 (peat swamp forest), 7 (cultivated ponds), and 9 (new beje) were particularly abundant. In this case, the conversion of peat swamp forests to rice fields and fish culture ponds will possibly promote greater diversity and abundance of macroinvertebrate communities.