Spatiotemporal changes of beetle communities across a tree diversity gradient

Abstract

Aim Plant and arthropod diversity are often related, but data on the role of mature tree diversity on canopy insect communities are fragmentary. We compare species richness of canopy beetles across a tree diversity gradient ranging from mono‐dominant beech to mixed stands within a deciduous forest, and analyse community composition changes across space and time.Location Germany’s largest exclusively deciduous forest, the Hainich National Park (Thuringia).Methods We used flight interception traps to assess the beetle fauna of various tree species, and applied additive partitioning to examine spatiotemporal patterns of diversity.Results Species richness of beetle communities increased across the tree diversity gradient from 99 to 181 species per forest stand. Intra‐ and interspecific spatial turnover among trees contributed more than temporal turnover among months to the total γ‐beetle diversity of the sampled stands. However, due to parallel increases in the number of habitat generalists and the number of species in each feeding guild (herbivores, predators and fungivores), no proportional changes in community composition could be observed. If only beech trees were analysed across the gradient, patterns were similar but temporal (monthly) species turnover was higher compared to spatial turnover among trees and not related to tree diversity.Main conclusions The changes in species richness and community composition across the gradient can be explained by habitat heterogeneity, which increased with the mix of tree species. We conclude that understanding temporal and spatial species turnover is the key to understanding biodiversity patterns. Mono‐dominant beech stands are insufficient to conserve fully the regional species richness of the remaining semi‐natural deciduous forest habitats in Central Europe, and analysing beech alone would have resulted in the misleading conclusion that temporal (monthly) turnover contributes more to beetle diversity than spatial turnover among different tree species or tree individuals.

Contrasting effects of sampling scale on insect herbivores distribution in response to canopy structure

“…However, Ribeiro & Basset (2007) showed that canopy gall-forming diversity and density were related to a restricted number of host tree species. Herbivore feeding guilds may thus respond differently to the same habitat conditions due to, mainly, level of specialization and life history constraints (Denno & Roderick 1991, Vehviläinen et al 2007, Sobek et al 2009). …”

“…Tree species richness was suggested as an important factor which may affect herbivorous insect species richness and distribution in the canopy (Novotny et al 2002, Sobek et al 2009). However, Ribeiro & Basset (2007) showed that canopy gall-forming diversity and density were related to a restricted number of host tree species.…”

Staphylinidae e Silphidae (Coleoptera) como Potenciais Famílias Bioindicadoras de Qualidade Ambiental

“…Marinoni e Dutra (1997) constataram que os coleópteros herbívoros predominam em áreas degradadas, em início de regeneração, enquanto os grupos detritívoros e fungívoros predominam em áreas conservadas. Diversos autores em seus estudos, citam diferenças entre áreas de borda, ambientes com diferentes níveis de fragmentação ou cobertura vegetal (Pohl et al 2007;Gardner et al 2008;Cagnolo et al 2009;Sobek et al 2009), nos quais a maior cobertura vegetal ou complexidade sustentam comunidades mais estáveis e/ou diversas (Eisenhauer et al 2008). Assim, os dados encontrados no presente estudo corroboram com estes autores, pois nos locais mais estáveis no fragmento estudados verifica-se maior incidências de Silphidae e Staphylinidae.…”

El ecosistema de dehesa como reservorio de diversidad de insectos saproxílicos (Coleoptera y Diptera: Syrphidae) y factores que determinan sus ensambles

“…En términos generales, la heterogeneidad del hábitat favorece una elevada diversidad de insectos saproxílicos (Tews et al, 2004;Sobek et al, 2009;Bouget et al, 2013) y en la dehesa, esta heterogeneidad ha permitido que, durante los 19 meses de muestreo se capturaron 9.603 individuos pertenecientes a 157 especies (40 familias) de coleópteros saproxílicos y 477 individuos de 18 especies de sírfidos saproxílicos explotando la amplia gama de microhábitats ofrecidos por la estructura de este ambiente (Ramírez-Hernández, 2014b) que ha sido resultado de la acción del hombre en el modelado de la estructura y dinámicas en la dehesa (Gómez-Gutiérrez, 1992;Sánchez-Martínez et al, 2012). Las características estructurales de este ecosistema, definidas como especie arbórea dominante y diferentes porcentajes de cobertura de matorral, han sido los principales factores que han afectado la diversidad y estructura de los ensambles de este grupo de insectos, aunque la respuesta de los ensambles ha sido distinta según el grupo evaluado (Ramírez-Hernández et al, 2014b).…”