Seasonality overrides differences in butterfly species composition between natural and anthropogenic forest habitats

Abstract

Anthropogenic disturbances that alter habitat structures can lead to strong changes in species composition. The importance of certain habitat features for structuring species composition, however, may be determined by the availability of resources that can seasonally fluctuate. The Kenyan Arabuko Sokoke coastal forest consists of three pristine forest types and provides various anthropogenic forest-like habitats, such as plantations and transition zones between forest and agricultural land. In parallel, this region experiences pronounced climatic seasonality which causes differences in resource availability. To test for potential differences in butterfly communities between natural and anthropogenic forest habitats, and whether they vary seasonally, we assessed butterfly species along transects in all five habitat types during the rainy and the consecutive dry season. We compiled ecological characteristics for each transect and for each butterfly species. We found highest species richness and abundances in the three natural forest habitats during the rainy season. Our data show distinct species clusters for each habitat type during the rainy season. In contrast, butterfly species composition does not form distinct community groups during the dry season. During this time period, highest species richness and abundances are found in plantations. These temporal differences in species richness, abundance and species composition between the two seasons are assumed to be driven by limited nectar availability inside of the forest during the dry season. This situation might lead to increased mobility and the invasion of anthropogenic habitats, where nectar sources are still available during the dry season. Thus, plantations might represent a surrogate habitat for forest butterflies during their imaginal stage, but do not represent a suitable habitat providing all resources needed for successful larval development.

Insect diversity across an afro-tropical forest biodiversity hotspot

“…We also found comparatively high levels of relative abundance for representatives of the orders Lepidoptera and Diptera along the forest edge. This goes in line with previous studies on butterflies, which were observed inside and along forest edges of the Arabuko Sokoke forest (Habel et al 2018). The authors found that butterfly communities along the forest edges were comparatively diverse, consisting of both, typical forest specialist species intermixed with species occurring in open landscapes.…”

“…The forest consists of at least three forest types (Murithi and Kenyon 2002). The distribution of these forest types follows particular soil conditions, which subsequently impact species composition of plants, and thus shapes habitat structures and animal communities living therein (Lange and Mwinzi 2003;Habel et al 2018). The Cynometra forest is restricted to infertile laterite soils.…”

“…These forest types differ in plant species composition and diversity and soil conditions (Murithi and Kenyon 2002). Thus, 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).…”

Functional traits of carabid beetles reveal seasonal variation in community assembly in annual crops

“…For instance, the trait diversity within communities has been shown to increase with time after disturbance (Fukami et al, 2005). In addition, most organisms are characterized by seasonal dynamics which may have profound implications for the study of community assembly (Fitzgerald et al, 2017; Habel et al, 2018). How disturbance interacts with seasonal dynamics of organisms in real situation is however largely unknown although assembly time and disturbance regime are theoretically predicted to interact and determine the relative importance of stochastic vs. deterministic processes on community assembly (Mouquet et al, 2003).…”

Dinámica temporal de la riqueza de especies y la abundancia de mariposas frugívoras (Lepidoptera: Nymphalidae) en la sabana inundable del municipio de Arauca (Colombia)

“…Este patrón de respuesta de la comunidad de mariposas a la precipitación concuerda con lo reportado en múltiples estudios (DeVries, et al, 1997;Shahabuddin & Terborgh, 1999;Hilt, et al, 2007;Luna, et al, 2010;Hussain, et al, 2011;Vargas, et al, 2011;Grøtan, et al, 2012;Sorto, 2013;Brito. et al, 2014;Kishimoto-Yamada & Itioka, 2015;Franzen, et al, 2017;Habel, et al, 2018). El mecanismo que subyace a este patrón es que la disponibilidad del recurso hídrico tiene un efecto en la fenología, induciendo en la vegetación la producción de nuevos brotes de hojas y, posteriormente, de flores y frutos (Pollard, 1988).…”