PARENT SESSION
Contributed Oral Session 168: Invertebrate Ecology: Food Webs, Physiology, and Communities
Friday, August 12, 8:00 AM - 11:30 AM, Meeting Room 524 B, Level 5, Palais des congrès de Montréal

Arthropod diversity responds to nutrient enrichment and disturbance in a grassland experiment.

Karel, Irene^*,1, Foster, Bryan¹, Ramspott, Matthew ¹, Price, Kevin¹, ¹ University of Kansas, Lawrence, Kansas, USA

ABSTRACT- In grassland systems, nutrient enrichment and disturbance can influence the species composition and diversity of plant species. These factors may also affect communities of consumer species such as arthropods, but fewer studies have focused on these groups. We sampled arthropods in June and August in a Kansas grassland experiment in which treatments included fertilization, and disturbance by haying. In June, arthropod diversity was negatively affected by fertilization, but positively affected by haying (which had occurred in the previous year). In August, recently hayed subplots had not recovered their plant biomass, so sweep sampling was not conducted in these subplots. The August results from the non-hayed subplots showed that arthropod diversity was greatest in unfertilized plots. Athropod species richness was negatively correlated with NDVI (Normalized Difference Vegetation Index) values, which can be interpreted as an index of primary productivity. Arthropod species richness was positively correlated with plant species richness. This may indicate that the greater diversity of plant species in unfertilized plots was more important as a resource to arthropods than the higher tissue nutrient content and greater biomass of fertilized plots.

Key words: arthropod, insect, diversity, grassland