Assessing the conservation and enhancement value of revegetated strips on arthropod assemblages in a pasture landscape

Abstract

Examining population dynamics of arthropod communities in habitats neighboring arable lands is essential to understanding how agroecosystems can be engineered to enhance ecosystem services and contribute to sustainable intensification. Arthropods comprise the bulk of faunal biomass on farms, are taxonomically diverse, and are the main drivers of many ecosystem functions. This study aimed to compare arthropod assemblages in revegetated strips of native plants and exotic pastures, and examine taxa of beneficial arthropods in revegetated strips and adjacent pasture in early spring (September 2009) and mid-summer (December 2009–January 2010) on two farms in southeastern Gippsland, Victoria, Australia. Arthropod community assemblages were distinctly different between revegetated strips and adjacent pasture with the exception of functional groups in early spring. Several taxa of beneficial arthropods including Carabidae (ground beetles) and Syrphidae (hoverflies) were of similar abundance in the two habitats. Only Formicidae (ants) were of higher abundances in revegetated strips compared to adjacent pasture in both seasons. Five of the 10 ant genera present, seven spider families and Dolichopodidae flies (long-legged flies) were found exclusively in revegetated strips. Apidae (bees) and Tachinidae (tachinid flies) had higher abundances in revegetated strips compared to 80 m into the adjacent pasture in mid-summer. Lycosidae (wolf spiders) were more abundant along the edge of revegetated strips and 20 m into adjacent pasture compared to the center (core) of revegetated strips and 80 m into pasture. These results illustrate that beneficial arthropods use revegetated strips as refugia and that revegetated strips clearly enhanced biological conservation of arthropods in pasturelands. Relevance of findings to enhanced biological control is also discussed.