Abstract:
The species diversity of ground ants in mixed deciduous and dipterocarp forests, Sri Nan National Park, Nan Province, northern Thailand was investigated by using hand collecting, leaf litter sifting, and pitfall traps. Ants were collected each two months period from December 2005 to December 2006. the total of 73 species 48 morphospecies belonging to 41 genera in 7 subfamilies was recorded. Fourteen species were new record for the north of Thailand. Using pitfall traps, the means of ant species diversity indices in mixed deciduous forest were significantly higher than in dipterocarp forest (p ≤ 0.05) in both winter and summer. In summer and rainy seasons, the means from leaf litter sifting were higher in mixed deciduous forest than in dipterocarp forest (p ≤ 0.05). Among the three seasons, the ant species diversity index in rainy season was statistically lower than in winter and summer (p ≤ 0.05). the means of dominance indices of ants caught by pitfall traps were not significantly different between the mixed deciduous and dipterocarp forests in summer and rainy seasons (p ≤ 0.05). In contrast, the mean of dominance indices in the dipterocarp forest in winter was significantly higher than in the mixed deciduous forest (p ≤ 0.05). In addition, Anoplolepsis gracilipes and Odontoponera denticulata were common ant species found in both forest areas. Using pitfall technique in the summer , the populations of these two kinds of ants were found to be significantly higher in mixed deciduous forest than in dipterocarp forest (p ≤ 0.05) but in the winter, populations of Anoplolepsis gracilipes was not statistically different between the two forest.