Habitat quality and edge area of fragments determine insect diversity in a heavily used landscape: Implications for forest landscape restoration

Abstract

Worldwide, forest fragmentation and degradation have affected the flora and fauna, and are threatening the livelihood of people depending upon forest resources. It is essential to understand the underlying ecological processes to better manage such landscapes. In ecological assessments, insects are useful tools to assess the effects of human interventions such as restoration, as insects are vital for several ecosystem processes. Therefore, we studied the ecological processes that determined the distributions of the epigeic insect communities among the degraded forest fragments of the Attappady Hills (Western Ghats, India), which are being restored. Our objectives were to determine the spatial variations in the epigeic insect communities and their responses to habitat quantity and quality of the forest fragments, along with an assessment of the invasive ants' responses to fragmentation and degradation, and their effects on the native insect communities. We used pitfall traps in several forest fragments representing varying disturbance levels along an east-west gradient. The diversity of various insect taxonomic groups and functional feeding guilds were higher in smaller fragments than compared to larger fragments due to edge effects. The variations in the distributions of insect communities were explained by the habitat features that were spatially correlated. Invasive ants, Anoplolepis gracilipes, infested the smaller fragments where the vegetation quality had degraded. We conclude that an understanding of the effects of fragmentation and degradation on insect communities is vital to restoration managers as ecological restoration becomes an important strategy to reverse degradation and to revive ecological processes of fragmented forests.

Colonization and coexistence of non‐native ants on a model Atlantic island

“…Habitat quality is often poorer in close proximity to settlements (Ahrends et al, 2010; Xiong et al, 2020) and on Ascension this manifested in dominance of invasive vegetation, mostly comprising Mexican thorn ( Prosopis juliflora ; Ascension Island Government, 2015). Invasive ants are known to establish more readily on barren and disturbed habitats (Bernal & Espadaler, 2013; Ramalingam & Dharma, 2022), and so restoring such habitat may create an ecological barrier to ant establishment outside of settlements. Such habitat restoration effort to meaningful buffer widths would be costly, but undoubtedly cheaper than the comparative cost of managing continual invasive ant colonization in the future.…”

Ecological Assessment and Ecological Space Optimization of Landform Landscape in the Middle and Lower Reaches of the Yellow River

“…To manage forest landscape patterns, Ramalingam et al proposed the process of analyzing ecosystems using insect community distribution as well as carrying out the relevant analysis. The results indicate that changes in the distribution of insect communities can be explained by spatially relevant habitat characteristics, which has certain feasibility [9]. To quantify the driving force of evapotranspiration dynamics, Yu et al proposed using a surface energy balance system to construct a spatiotemporal dynamic analysis model of evapotranspiration and conducted empirical analysis on this model.…”

Biodiversity of India: Evolution, biogeography, and conservation

“…Krishnan et al (2022) shows higher seed predation by mammals in fragmented forests but no difference in seed predation by insects between contiguous forests and fragmented forests. Ramalingam and Dharma Rajan (2021) showcases the higher diversity of insect taxonomic groups and functional feeding guilds in smaller fragments and the presence of invasive ants in fragments with low quality vegetation, suggesting a possibility of using insect community data as a tool to assess effectiveness of forest restoration.…”