Project Title
The Biology and Ecology of
Macroinvertebrates and Aquatic Plants in Rice Field.

The studies were carried out in Sawah Sempadan rice field, Tanjung Karang, Selangor, Malaysia. Samples of weeds, water, sediment and macrofauna were collected at 40 sampling stations weekly for seventeen weeks.

The number of weed species were lesser than the previous reports. The species present were Echinochloa cruss-gulli, E. colona, Rotala rosea, Sagittaria guayanensis, Jussiaea linifolia, Limnocharis flava, Blyxa auberti, Nymphoides indica, Marsilea crenata and Croton hirtus. E. cruss-gulli was a dominant species. Range of the water physicochemical factors were as the following: water temperature (24.5-42.0 ^oC), pH values (3.76-7.93), oxygen (1.2-8.8 mg/l), conductivity (20-270 mhos/cm), NO₃ (0.4-2.0 mh/l), NH₃ (0.02-2.32 mg/l) and PO₄ (0.04-2.62 mg/l). Range of the soil physicochemicals were as follows: organic matter (39.3-54.6%), pH (3.20-4.73) and water content (9-12%). The macrofauna present were Culex sp., Chironomidae, Ceratopogonidae, Caenidae, Ephemerellidae, Trichoptera and Oligochaeta. Each of weed species showed a different trend of weekly succession and spatial distribution. Benthic macrofauna, water and soil physicochemical factors fluctuated.

The data are being prepared for multivariate and time-series analyses to obtain a dynamic visual simulation of the aquatic component interaction.