Response of Terrestrial Invertebrates to High- and Low-Diversity Grassland Restorations in South-Central Nebraska

Successful grassland restorations are influenced by the diversity of seed mixes initially sowed in the restoration. Two common seed mixes used in grassland restorations are high- and low-diversity mixes. The type of seed mixture used in restorations may affect invertebrate diversity and abundances that occur in restorations. We compared terrestrial invertebrate diversity and abundances between high- and low-diversity restorations in south-central Nebraska. Pitfall trap and sweep net sampling were used to assess invertebrate communities from six low- and six high-diversity plantings. Our results did not clearly demonstrate that terrestrial invertebrate assemblages respond better to high-diversity plantings than low-diversity plantings. There was no difference in total abundance, family richness, or diversity of invertebrates between the plantings. Composition of invertebrate communities was similar between plantings. Araneae and Acrididae were the only major taxa that differed in abundances between plantings. Similarity of invertebrate communities in plantings is likely attributed to lack of plant architectural complexity, absence of host-plants, and time-lag effects in high-diversity plantings. Because recovery time of high-diversity plantings lagged considerably behind low-diversity plantings, invertebrate communities in high-diversity plantings were likely to be in early stages of development, but will likely become more diverse and abundant as the planting matures. Consequently, our results emphasize the need for long-term monitoring of invertebrate and plant communities in grassland restorations. Additionally, discrepancies in types and abundances of captured invertebrates between pitfall trapping and sweep netting emphasizes the need to use more than one sampling method when using invertebrates to monitor and assess restoration success.