Spatial Water Quality Assessment and Mapping of Lahan Swamp, Chaiyaphum, Thailand

AbstractLahan Swamp is important as a national wetland of Thailand, providing water for nearby agriculture, fisheries and even people in Chaiyaphum municipality. Water samples from eight monitoring sites in Lahan Swamp were collected in November 2009, January, March, May and August, 2010 and analyzed for temperature, pH, salinity, Dissolved Oxygen (DO), turbidity, transparency, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), ammonia-nitrogen (NH3-N), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), Total Phosphorus (TP), Coliform bacteria and E. coli. Then all data were used to produce water quality maps with the ArcGIS program. The results classified water quality of Lahan Swamp at class 2, as described by The Pollution Control Department of Thailand, suitable for consumption but requiring special water treatment. However, the water can be used for fishing, swimming, and water sports. Yet, in some months, water qualities at Lam Kunchoo, Klong Sansab, Shrine-pump station, and Don Lanam village were poor with BOD values at 6.1, 6.6, 7.0, and 7.8mg/L, respectively. They were categorized as class 5 thus should only be used for navigation. Since the human community and industrial areas are growing around Lahan swamp, wastewater treatment regulation and fishery restriction will be needed to protect water quality in this swamp

Diversity and abundance of earthworms across an agricultural land-use intensity gradient

Understanding how communities of important soil invertebrates vary with land use may lead to the development of more sustainable land-use strategies. We assessed the abundance and species composition of earthworm communities across six replicated long-term experimental ecosystems that span a gradient in agricultural land-use intensity. The experimental systems include a conventional row-crop agricultural system, two lower-intensity row-crop systems (no-till and tilled organic input), an early successional old-field system, a 40–60 years old coniferous forest plantation, and an old-growth deciduous forest system. Earthworm populations varied among systems; they were lowest in the most intensively managed row-crop system (107 m−2) and coniferous forest (160 m−2); intermediate in the old-field (273 m−2), no-till (328 m−2) and tilled organic (344 m−2) cropping systems; and highest in the old-growth deciduous forest system (701 m−2). Juvenile Aporrectodea species were the most common earthworms encountered in intensively managed systems; other species made up a larger proportion of the community in less intensively managed systems. Earthworm community biomass and species richness also varied and were lowest in the conventional row-crop system and greatest in the old-growth forest system. These results suggest that both land-use intensity and land-use type are strong drivers of the abundance and composition of earthworm communities in agricultural ecosystems