Consequences of shade management on the taxonomic patterns and functional diversity of termites (Blattodea: Termitidae) in cocoa agroforestry systems

Abstract

Termites have gained importance as major pests in cocoa agroforests. Proper identification of termite species and knowledge on their functional diversity are the first steps in developing environmentally compatible management strategies. We tested the hypothesis that patterns of termite species richness in different cocoa agroforests is related to responses by termite functional groups to changes in shade management. We compared termite assemblages under five cocoa agroforestry systems in Cameroon to assess the impact of shade on termite taxonomic and functional group diversity. Sampling was done using a modified standardized transect method. Two 30 × 30 m quadrates each divided into three transects were laid in four farms at each site. Termites sampled were identified and grouped according to habitats, functional groups, and feeding habits. Sixty‐nine termite species in 33 genera and five subfamilies under two families were sampled. Termitidae was the most dominant family and Rhinotermitidae the least dominant with few species. Termite species richness decreased significantly from the heavy shaded cocoa agroforests (44 species) to the full sun (11 species). Functional group pattern differed significantly in all the cocoa agroforests and within each agroforestry system and dominated by wood and litter feeder species. Many species belonging to this group were responsible to most damages on cocoa trees. Both the richness of termite pests and marketable yield followed a quadratic curve and were found to be lowest and highest in plots with shade cover above 40%. The simulated optimal shade levels for low termite infestations and marketable yield overlapped between 45% and 65% indicating that cocoa agroforestry systems with around 55% shade cover may be optimal to balance termite infestations and marketable yield. Shade maintenance in cocoa agroforests is valuable in reducing termite pest species and conserving soil feeding termites which provide beneficial ecosystem services.

Diversity of termites (Isoptera) on industrial forest plantation of Eucalyptus pellita stands of tropical ecosystem in Riau, Indonesia

“…Moist soil and canopy cover can protect termites and microclimate soils (Jamil et al 2017). Canopy cover was positively correlated with diversity and termite abundance (Felicitas et al 2018). As the age of the holder increases, the diversity of termite soils increases.…”

Termite diversity is resilient to land‐use change along a forest‐cocoa intensification gradient in Ghana, West Africa

“…These studies suggest natural forests in West African have lower termite species compared with natural forests in Central Africa, and also South America and Asia where termite species richness tends to be higher. For example, in Ecuador Dahlsjö et al (2020) This is consistent with a decline in species numbers due to forest disturbance (Felicitas et al, 2018;Gathorne-Hardy et al, 2001).…”

“…Nevertheless, possibly because the forest community appears somewhat depauperate, termite species richness, abundance, and ies have shown that termite abundance declines with disturbance (Dawes, 2010;Dosso et al, 2013;Felicitas et al, 2018;Vasconcellos et al, 2010), shade trees clearly add some buffering capacity as there was only weak evidence that richness and abundance declined. Deep forest and non-pest termite species were, by in large, maintained under shade trees which provide a relatively conducive environment for termites to survive, especially, the soil-feeding termites (Davies, Eggleton, et al, 2003a;Palin et al, 2011).…”

“…They have been reported to tolerate semiarid and arid environmental conditions such as full-sun cocoa plantations (Felicitas et al, 2018).…”

“…For example, in a study that surveyed an assemblage of migratory birds, the cocoa plantation had the most similar migrant assemblage to natural forest (Greenberg, 2004). Shaded cocoa agroforestry systems can also maintain beneficial ecosystem services and minimize potential ecosystem disservices through trophic and non‐trophic interactions (Felicitas et al, 2018). Thus, cocoa farms maintaining substantial proportions of shade trees are seen as following a sustainable land‐use practice with comparable ecosystem services to that provided by a primary or secondary forest (Vanhove et al, 2016).…”