การประชุมวิชาการระดับชาติ ครั้งที่ 16
มหาวิทยาลัยราชภัฏนครปฐม

Study of community structure and diversity change of benthic invertebrates in Bueng Sam Roi Yod, the main wetlands of Khao Sam Roi Yod National Park Wetlands, Prachuap Khiri Khan Province. The wetland was visited every month from October 2022 to October 2023, during which Thailand was affected by meteorological drought due to the El Niño. The accumulated precipitation from October 2023 to May 2024 (dry season) was 0 mm, and from June to October 2024 (wet season) was 271 mm. The study was carried out in 6 sampling sites across the wetland. Benthic invertebrates were collected using a D-shaped net. The 9 physical and chemical water parameters were measured. A total of 24,377 individuals representing 3 phylum, 4 classes, 13 orders, 60 families, and 94 taxa were recorded. Herein, the highest abundance was in Diptera (42.40%), followed by Mesogastropoda (24.47%), Hemiptera (14.07%) and Collembola displayed the lowest abundances (0.01%). The top 3 dominant taxa were Chironomids (Order Diptera, Family Chironomidae; 9,789 individuals), golden apple snail (Order Mesogastropoda, Pomacea canaliculate; 3,906 individuals), and water bugs (Order Hemiptera, Family Pleidae; 1,449 individuals). Based on analysis of biological indices, the Shannon - Wiener diversity index (H') in the dry season (2.03) was higher than in the rainy season (1.47). Whereas, Simpson's index (D) in the rainy season (0.32) was higher than in the dry season (0.16). Benthic invertebrate abundance was highest in January (10,664 individuals). It was found that the benthic invertebrate populations tended to decrease and the lowest was found in October 2023 (6,599 individuals).