VOLUME 14 NUMBER 1 (January to June 2021)

Benjamin K. Valdez*¹, Julius A. Parcon² and Emmanuel Ryan C. de Chavez^1,2

¹Animal Biology Division, Institute of Biological Sciences
      University of the Philippines Los Baños, College,
      Laguna, Philippines, 4031;
²Museum of Natural History, University of the Philippines
      Los Baños, College, Laguna, Philippines, 4031

Many limestone ecosystems, particularly in tropical countries like the Philippines, still lack data regarding their malacofaunal diversity amidst extensive habitat destruction and modification, and uncontrolled tourism. To address this, the diversity and spatial distribution of land snails in the Masungi Georeserve in Rizal Province, Luzon Island were determined. A total of 120 5x5m quadrats were randomly set along six karst and six non-karst sites of the georeserve. Altitude, temperature, relative humidity, soil moisture, exchangeable soil calcium, number of trees, diameter of trees, canopy cover, and leaf litter depth were also determined per quadrat. A total of 1,283 land snails belonging to 45 species and 12 families were sampled. Three major land snail communities were distinguished by detrended correspondence analysis: the first group preferred cooler environments with high-calcium soil (karst), the second group dominated in warmer habitats with low-calcium soil (non-karst), and the third group was found in both habitat types. Species richness was highest (40 species/ H’=2.94) in the karst sites however non-karst sites had higher species evenness (J’=0.55). Species accumulation curve showed α-dominated community and efficient sampling (completeness ratio=0.97). Analysis of similarity further confirmed significant differences in land snail community assemblages between its karst and non-karst sites. These results suggest the rich malacofauna of the Masungi Georeserve needs to be protected as a refugia of land snail diversity.