Soil-litter ant (Hymenoptera: Formicidae) community response to reforested lands of Gishwati tropical montane forest, northern-western part of Rwanda

Abstract

Recently, human activities have impacted biodiversity-rich forest in western Rwanda, creating a need to enhance restoration activities of degraded lands in the region. To evaluate the effects of reforestation activities on the community composition of soil-litter ants, research was conducted in Gishwati tropical montane forest, located in northern-western part of Rwanda. The ant fauna was studied in reforested lands dominated by regenerated native species and exotic tree species. Further, a primary forest made of native trees served as a reference. In each forest type, nine sampling points were used to sample ants. Ant specimens were collected using pitfalls, hand sampling and Winkler extractor. They were identified to subfamilies, genus and species levels using dichotomous keys, and also statistically analysed for species richness, diversity, evenness and community composition. We collected a total of 2,481 individuals from 5 subfamilies, 18 genera and 35 species. Higher abundance, diversity and species richness were found in soil-litter under natural primary and secondary forests dominated by regenerated native plant species compared to exotic tree forest. The ant community composition analysis indicated higher similarities in ant species sampled under primary native forest and secondary forest dominated by regenerated native species. Reforestation by regenerating native species may be given priority in restoration of degraded lands due to their importance in species richness and species diversity.

First Record of Five Ant Species (Hymenoptera: Formicidae) from Rwanda

“…Since Rwanda is a region rich in biodiversity, more ant species might be recorded either for the first time or being new to science. In addition, only a small area has been studied so far (Nsengimana et al ., 2018; Nsengimana et al ., 2021; Nsengimana & Dekoninck, 2021; Nsengimana et al ., 2023), hence a big part of the country remains unexplored. Furthermore, the studied areas have been sampled only once using rapid sampling.…”

“…In Rwanda there is limited information on the diversity and distribution of the species in genera Camponotus, Odontomachus and Tetramorium. Only Odontomachus troglodytes Santschi, 1914(Nsengimana et al, 2018Nsengimana & Dekoninck, 2020) has been reported in Rwanda. However, a recent review of the ant species collected from Rwanda and housed at the Royal Belgium Institute of Natural Science (IG 33.894) has indicated that this is a misidentification, and all the available specimens from Rwanda are Odontomachus assiniensis (Kiko Gómez.…”

“…Only eight species of Camponotus i.e. Camponotus fulvopilosus (De Geer, 1778), Camponotus cinctellus (Gerstäcker, 1859), Camponotus flavomarginatus Mayr, 1862, Camponotus rufoglaucus syphax Wheeler, 1922, Camponotus zimmermanni Forel, 1894, Camponotus caesar Forel, 1886, Camponotus maculatus (Fabricius, 1782 (Nsengimana & Dekoninck, 2020) and Camponotus orinobates Santschi, 1919(Nsengimana et al, 2023, are known from Rwanda.…”

“…In Rwanda ants count for more than 50% of all studied individual specimens of arthropods from different land uses such as pasture (Nsengimana et al, 2022), coffee, banana (Nsengimana et al, 2023), and different planted tree species (Nsengimana et al, 2021b). There is no doubt that more ant species new to science or new to the country will be recorded in Rwanda and that the real number of ant species is much higher compared to what is reported in the checklist of ants from Rwanda (Nsengimana & Dekoninck, 2020) and a current publication on ant species from Nyungwe tropical rain forest, Western Rwanda (Nsengimana et al, 2023). This motivated us for a continuous ant sampling since 2017.…”

“…Only a few studies focused on species level, namely Odonata (Uyizeye et al ., 2021), Lepidoptera (Uwizelimana et al ., 2022b, 2022a) and ants [Hymenoptera: Formicidae] (Nsengimana et al ., 2018; Nsengimana & Dekoninck, 2021; Nsengimana et al ., 2021; Nsengimana et al ., 2023). A recent study on ants has indicated that 105 ant species are known so far from Rwanda and highlighted that this number is an underestimation because Rwanda is in a biodiversity hotspot region for many other taxonomical groups too (Nsengimana et al ., 2023).…”