Termite diversity and abundance across fire-induced habitat variability in a tropical moist savanna (Lamto, Central Côte d'Ivoire)

Record of New Termite (Blattodea, Termitidae) Species in Togo West Africa

In Africa, despite their economic and ecological importance, termites are still relatively unknown. Their systematic remains uncertain, the approximate number of species for many biogeographic areas is underestimated, and there is still confusion in the identification of the species for many genera. This study combined morphological traits with morphometric measurements to determine several species collected in Togo and provided head illustrations of soldiers. Termites were sampled within the frame of transects laid in several landscapes inside three different parks including: Fosse aux Lions, Galangashie, and Fazao Malfakassa. Samples were grouped by morphospecies and measurements of part of the body (length and/or width of head, mandible, pronotum, gula, and hind tibia) were conducted. Twelve termite species including Foraminitermescorniferus, Lepidotermes sp., Noditermes cristifrons, Noditermes sp. 1 and Noditermes sp. 2, Promirotermes holmgren infera, Promirotermes sp., Unguitermes sp., Amitermes evuncifer, A. guineensis, A. truncatus, and A. spinifer were separated and pictured. Ten new species were added to the check list of the country, including five unidentified ones. Further studies such as biomolecular analysis should be carried out in order to clarify the status of these unknown species.

Conservation management and termites: a case study from central Côte d’Ivoire (West Africa)

Termites are essential components of tropical ecosystems, in which they provide fundamental ecosystem services, such as decomposition of dead plant material, fostering of soil mineralization and provisioning of new microhabitats. We investigated the termite communities of four habitats in two protected areas in West Africa, which differ in management effectiveness: the strictly protected Lamto Reserve (LR) and the Marahoué National Park (MNP), which suffers from anthropogenic disturbance despite its protection status. We tested the effect of disturbance on species composition, richness and abundance as well as on functional (feeding type) composition. The effect of disturbance was clearly visible in the termite communities. Compared to the LR, the MNP had less termite species overall and in all habitats except the shrub savannah. Also the abundance of termites was generally reduced and a decrease of soil feeders recorded. The latter is well-known to be sensitive to anthropogenic disturbance in forests. Comparing our results with other studies, we were able to identify suitable bioindicators of ecosystem health for West-African savannahs. Furthermore, we discuss the potential consequences of anthropogenic disturbance on ecosystem services provided by termites.

Land use effects on termite assemblages in Kenya

Termites perform key ecological functions and they also cause crop damage. Land use change resulting from agricultural intensification can result in changes in termite species diversity and abundance. Termite species occurring in natural vegetation, maize monocrop and maize-beans intercrop macrohabitats were investigated in Embu and Machakos Counties, Kenya. Influence of soil properties and seasons was also evaluated. Across the two Counties, seven termite species were recorded with Machakos County having the highest number. Additive diversity partitioning of species richness and Simpson diversity showed that, α component contributed to 98.3% and 99.1% of the total diversity, respectively. Population densities of three termite species significantly varied between land use types in Machakos County but there were no differences in termite species abundance in Embu County. In addition, there were no significant differences in species richness between macrohabitats within each County. In Embu, season significantly influenced the abundance of Macrotermes subhyalinus, M. herus, and Coptotermes formosanus which occurred in greater numbers during the wet season. There was a significant influence of land use on Trinervitermes gratiosus and C. formosanus in Machakos with both species occurring in higher numbers in natural vegetation. Trinervitermes gratiosus was negatively associated with Mn and positively correlated to pH and sand. Macrotermes subhyalinus and M. herus showed a positive association with P and silt while C. formosanus was positively correlated to Ca and Mg. These findings provide an insight into the effects of land use change from natural vegetation to maize agro-ecosystems on termite diversity. It also provides a baseline for further studies on termite diversity in Kenya and their ecological significance.

Termites’ diversity in a protected park of the northern Sudanian savanna of Togo (West Africa)

Termites occur in many ecosystems throughout tropical and subtropical areas. Their distribution is driven by several factors, including landscape and some soil characteristics. This study aims to determine soil organic matter’s role on termites’ diversity in a shrubby savanna park. Termites were sampled across transects in 3 sites of Galangashi park (northern part of Togo). The soil in which termites were harvested was analyzed to check organic matter’s influence on termites’ species richness. A total of 28 termite species belonging to 14 genera and 6 subfamilies were identified. Feeding group II (all fungus-growing termites, grass feeders, and wood feeders) was the most important among the three identified groups. Nine species (with two potentially new species for sciences: Amitermes sp and Eremotermes sp) were recorded for the first time in the country. A strong correlation was found between species richness, total organic matter, and total organic carbon, suggesting the influence of soil richness on termite distribution. The occurrence of the unique member of the feeding group I, Coptotermes intermedius Silvestri, 1912, as well as the occurrence of Fulleritermes tenebricus Silvestri, 1914 (both wood-dwelling termites), was certainly due to the vegetation. The relatively higher species richness as well as the correlation between the species richness and the organic matter of shrub savanna, suggest a better conservation of this landscape.

Termite Communities along A Disturbance Gradient in a West African Savanna

(1) Background: Termites are important ecosystem engineers, crucial for the maintenance of tropical biodiversity and ecosystem functioning. But they are also pests which cause billions of dollars in damage annually to humans. Currently, our understanding of the mechanisms influencing species occurrences is limited and we do not know what distinguishes pest from non-pest species. (2) Method: We analyzed how anthropogenic disturbance (agriculture) affects species occurrences. We tested the hypothesis that strong disturbance functions as a habitat filter and selects for a subset of species which are major pests of crop. Using a cross-sectional approach, we studied termite assemblage composition along a disturbance gradient from fields to 12-year-old fallows in a West African savanna. (3) Results: We reliably identified 19 species using genetic markers with a mean of about 10 species-many of them from the same feeding type-co-occurring locally. Supporting our hypothesis, disturbance was associated with environmental filtering of termites from the regional species pool, maybe via its effect on vegetation type. The most heavily disturbed sites were characterized by a subset of termite species which are well-known pests of crop. (4) Conclusion: These results are in line with the idea that strong anthropogenic disturbance selects for termite pest species.

Determinants of Termite Assemblages' Characteristics within Natural Habitats of a Sudano-Guinean Savanna (Comoe National Park, Côte d'Ivoire)

Termites are one of the major components of tropical ecosystems. However, the ecological and biological variables determining the structure of their communities within natural habitats are less documented in general and especially in the Comoe National Park, a Sudano-Guinean savanna zone located in the north-eastern part of Côte d’Ivoire (West Africa). Using a standardized method of belt transects, the structure of termite’s communities was estimated within habitats differing in the structure of their vegetation, soil characteristics, and the disturbance level caused by annual occurrences of bushfires. The effect of a set of environmental variables (habitat type, occurrence of annual bushfire, woody plant density, woody plant species richness, and soil physicochemical parameters) was tested on the habitat-specific recorded termite species. Sixty species of termites belonging to 19 genera, seven subfamilies and two families, namely Rhinotermitidae (Coptotermitinae and Rhinotermitinae) and Termitidae (Apicotermitinae, Cubitermitinae, Macrotermitinae, Nasutitermitinae, and Termitinae) were sampled. These species were assigned to the four feeding groups of termites: fungus growers (18 species), wood feeders (17 species), soil feeders (19 species) and the grass feeders (6 species). The highest diversity of termites was encountered in forest habitats, with 37 and 34, respectively, for the gallery forest and the forest island. Among savanna habitats, the woodland savanna was identified as the most diversified habitat with 32 recorded species, followed by the tree savanna (28 species) and the grassy savanna (17 species). The distribution of termite species and their respective feedings groups was determined by the habitat type and a set of environmental variables such as Woody Plant Diversity (WPD), Woody plant Families Diversity (WPFD), and Organic Carbon (OC). The annual Fire Occurrence (FO) was found to indirectly impact the characteristics of termite assemblages within natural habitats via their respective Herbaceous Species Richness (HSR) and Woody Plant Species Richness (WPSR). In summary, the spatial heterogeneity of the Comoe National Park, modeled by the uncontrolled annual bushfire, offers a diversified natural habitat with an important variety of termite-habitat-specific species, probably due to the food preference of these organisms and its relatively good conservation status.

Short-term changes in the structure of ant assemblages in a Guinean savanna under differing fire regimes at Lamto Scientific Reserve, Côte d'Ivoire

To maintain savanna vegetation, mid-seasonal fire has been applied since 1961 in the Lamto Savanna (Côte d'Ivoire). However, this prescribed fire has not impeded tree encroachment during recent years, nor have its effects on insect assemblages been documented. Also the impact of tree intrusion on insect assemblages is poorly studied in savanna. To prevent tree density increasing, a change in fire regime might be a solution. In this study, we examined the effect of different fire regimes (early, mid-seasonal and late fires) on leaf-litter ant assemblages in order to suggest appropriate measures for preventing tree invasion without having an effect on insect communities. Sampling was implemented by combining pitfall trapping and leaf-litter sampling before and after three different fire regimes, early, mid-seasonal and late fires. While the ant species richness declined after the passage of early and mid-seasonal fires, significantly more species were found in the burnt savanna after the late fire. However, the losses or gains of species due to different fire regimes did not cause severe changes in the ant species composition. Of the functional groups identified, only the generalists and specialist predators were respectively strongly affected by the early and mid-seasonal fires, certainly due to micro-habitat modification. Based on the trends observed in the present study, we suggest sampling other invertebrate fauna in similar savanna plots to find out if other insect groups have similar reactions to the applied fire regimes.

Response of Termite (Blattodea: Termitoidae) Assemblages to Lower Subtropical Forest Succession: A Case Study in Dinghushan Biosphere Reserve, China

Termite (Blattodea: Termitoidae) assemblages have important ecological functions and vary in structure between habitats, but have not been studied in lower subtropical forests. To examine whether differences in the richness and relative abundance of termite species and functional groups occur in lower subtropical regions, termite assemblages were sampled in Dinghushan Biosphere Reserve, China, among pine forest, pine and broad-leaved mixed forest (mixed forest), and monsoon evergreen broad-leaved forest (monsoon forest). The dominant functional group was wood-feeding termites (family Termitidae), and the mixed forest hosted the greatest richness and relative abundance. Soil-feeding termites were absent from the lower subtropical system, while humus-feeding termites were sporadically distributed in mixed forest and monsoon forest. The species richness and functional group abundance of termites in our site may be linked to the forest succession. Altitude, soil temperature, air temperature, surface air relative humidity, and litter depth were significant influences on species and functional group diversity.

Importance of protected areas for biodiversity conservation in central Côte D'ivoire: comparison of termite assemblages between two neighboring areas under differing levels of disturbance

To highlight human impact on biodiversity in the Lamto region, termites were studied with regard to their use as bio-indicators of habitat change in the tropics. Using a standardized method, termites were sampled in the three most common habitat types, i.e., in semi-deciduous forest, savanna woodland, and annually burned savanna, all inside Lamto Reserve and its surrounding rural domain. Termite species richness fell from 25 species in the Lamto forest to 13 species in the rural area, involving strong modification in the species composition (species turnover = 59 %). In contrast, no significant change in diversity was found between the Lamto savannas and the rural ones. In addition, the relative abundance of termites showed a significantly greater decline in the rural domain, even in the species Ancistrotermes cavithorax (Sjöstedt) (Isoptera: Termitidae), which is known to be ecologically especially versatile. Overall, the findings of this study suggest further investigation around Lamto Reserve on the impact of human activities on biodiversity, focusing on forest conversion to land uses (e.g. agricultural and silvicultural systems).