Aboveground Invertebrate Responses to Land Management Differences in a Central Kansas Grassland

Macroinvertebrate communities in a central Kansas grassland were examined to assess their responses to differences in landmanagement and explore their viability for biological assessment of grasslands. Canopy (drop-trap) and ground-dwelling (pitfall traps) communities were quantitatively sampled fromJuneÐSeptember 1998 and1999.The responsesof thewhole arthropodcommunity and two focal groups, Coleopteran families and Orthopteran species, to three land use types (brome Þelds, old Þelds, and native prairies) were examined. Vegetation analyses reßected clear differences among land use types.Bromus inermisLeyss, an exotic grass, andAndropogon gerardiiVitman, a native grass, dominated brome Þelds and native prairie sites, respectively. Old Þelds were composed of a mixture of native and exotic plant species. Coleopteran family richness anddiversitywere signiÞcantly greater in native prairies than brome Þelds (P 0.05), whereas orthopteran species richness and diversity peaked in brome Þelds. Diversity and richness of all arthropod groups examined were signiÞcantly, positively correlated with plant species diversity and richness in drop-trap samples (P 0.05). Coleopteran family diversity and richness in pitfall samples were positively correlated with abundance of native plants, but orthopteran species diversity and richness were negatively correlated with native plant abundance. Coleopteran and orthopteran responses to land use appeared linked to differences in management practices. Whereas coleopterans appeared most inßuenced by plant community composition, orthopterans showed sensitivity to mechanical disturbance associated with haying on native prairie. Plant and arthropod group diversities were not consistently correlated, demonstrating that arthropod groups can reßect differences in a landscape that may not be apparent from examining plant communities alone.