Abstract
Tropical forests host a remarkable proportion of global arthropod diversity. Yet, arthropod communities living in tropical forests are still poorly studied, particularly for dry forests of Eastern Africa. The aim of this study was to analyse community structures, species richness and relative abundances of insects across a heterogeneous forest consisting of various forest types. We collected insects in the lower canopies with light traps across the Arabuko Sokoke forest, part of the East African coastal forest biodiversity hotspot in southeast Kenya. Sampling was conducted across three forest types and along the forest edge. In total we collected > 250,000 individuals. We grouped these individuals into orders, and beetles into (sub)families. Representatives of the taxonomically well-known beetle families Cerambycidae, Tenebrionidae and Scolytinae were further determined to species level. We subsequently classified these groups into guilds according to their ecological requirements and life-histories. Relative abundances of arthropods strongly differed among taxonomic groups and forest types. Evenness was highest in the heterogeneous natural Brachystegia forest type. The mixed forest type and the forest edges showed intermediate degrees of evenness, while the structurally homogenous Cynometra forest showed comparatively low degrees of evenness.Implications for insect conservationWe found that taxonomic and guild compositions strongly differed among the forest types. Our findings reveal that structural heterogeneity of a forest is the major driver of insect diversity, community composition, and relative abundance. Our study underlines that the preservation of all three forest types is crucial to maintain the complete diversity of arthropods across all taxonomic groups.
Highlights
Tropical forests contain a major proportion of earths biodiversity (Myers et al 1988)
Highest relative abundance was found in Brachystegia forest
Most taxa achieved highest relative abundances in Brachystegia forest, while relative abundances of most orders assessed in Cynometra forest was comparatively low (Fig. 2a)
Summary
Tropical forests contain a major proportion of earths biodiversity (Myers et al 1988). The East African dry coastal forest consists of at least three different forest types (Murithi and Kenyon 2002) These forest types differ in plant species composition and diversity and soil conditions (Murithi and Kenyon 2002). The East African dry coastal forest creates a mix of different forest types, which accelerates biodiversity, as shown for various taxa, such as snails (Lange and Mwinzi 2003) and butterflies (Habel et al 2018). In consequence, this forest is part of a global biodiversity hotspot (Myers et al 2000). Anthropogenic activities such as the transformation of forest into plantations of exotic trees and agricultural land produced multiple forest edges and caused severe disturbances inside the remaining forest patches (Habel et al 2017)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
