Ground-dwelling ant diversity in Maliau Basin, Borneo: Evaluation of hand-sorting methods to estimate ant diversity

Abstract

The ground-dwelling ant fauna in tropical forests remains the final frontier in the study of Formicidae biodiversity. This is mainly due to a lack of convenient sampling methods for the inventory of ants in soil. In the present study, employing the hand-sorting of small soil cores, we carried out the first sur vey of ground-dwelling ants in Maliau BasinConser vation Area, in Sabah, Borneo, to compare disturbed and undisturbed forest ant communities and to evaluate the sampling method , s performance in assessing species richness and characterizing community structure of the ant fauna. For this purpose we set a 5 m long and 1 m wide transect, consisting of five 1-m 2 sections, in disturbed and undisturbed forest plots in the area, and compared the sampling results of hand-sorting between the two plots. A total of 50 ant species, in 28 genera and eight subfamilies, were collected in the two plots, of which 32 species in 20 genera were collected from the undisturbed plot and 24 species in 18 genera from the disturbed plot. According to estimates of expected species richness, the hand-sorting of soil cores allowed for the collection of 66.7 to 80.0% of the ant species expected in the undisturbed plot, and 83.3 to 88.9% in the disturbed plot. Besides lower species richness, the ant community in the disturbed plot had lower species evenness and a different species composition in comparison to undisturbed plot, which may be related with environmental changes in the plot, due to open canopy. These results indicate that hand-sorting of small soil cores is a method that could provide reliable information, not only to estimate species richness at a site, but also to evaluate differences in community structure between sites.

Effect of tropical forest disturbance on the competitive interactions within a diverse ant community

“…The change in community composition between the forest types in our study are consistent with previous studies showing lower ant diversity in logged forest 56 , 57 and genus-specific differences in tolerance to forest disturbance 38 , 54 , 93 , 94 . Differences in tolerance of ground-dwelling ants to disturbance may be mediated by microclimate variations and be contributing to variation in community composition alongside competition 67 , 79 , 95 – 98 , especially since ground temperatures have been reported to be higher in the logged versus primary forest areas we studied 99 .…”

Invasive ant (Hymenoptera: Formicidae) Paratrechina longicornis along elevational gradients on Mount Marapi, West Sumatera

“…The result from soil sampling technique was lower than what has been gained through the hand collection technique in sampling this invasive species. In a previous study in Sabah, Malaysian Borneo, the soil sampling technique showed the most optimal result [19]. The hand collection was deemed to be more proactive in searching and collecting ants within the study transects compared to the other three techniques, which seemed to be more passive.…”

“…Ant samples were processed at the Animal Taxonomy Laboratory, Department of Biology, Universitas Andalas, Padang. The identification process was guided with proper references [18,19,20,21]. This process was also assisted by comparing studied specimens with curated specimens stored in the lab.…”

Altitudinal gradients of ant species diversity (Hymenoptera: Formicidae) in Mount Talang, West Sumatra, Indonesia

“…Ant identification : Ant specimen was brought to the Laboratory of Animal Taxonomy at Universitas Andalas, where the identification was guided using proper references, such as Bolton (1994), Bolton (2016), andHashimoto (2003). Specimen collection in the Universitas Andalas Repository curated by the first author (Henny Herwina) was also used to assist the identification.…”