Intra-annual analysis and prediction of a benthic macroinvertebrate community

Benthic macroinvertebrates have become popular for use in biological monitoring programs. Many of these organism’s life cycles are variable due to environmental conditions. Therefore it is important to understand how seasonal variability influences biological measurements of macroinvertebrate community structures. The reference stream Burris Fork in Moniteau county Missouri was sampled for benthic macroinvertebrates, water quality, and habitat parameters, monthly from December, 2002 to December, 2003 for the purpose of constructing predictive models. This period of time is referred to as the Model Development Period (MDP). Three test samples were taken the following year to reflect different seasons for the purpose of validating models constructed from the MDP. A suite of 98 community measures, known as ecological metrics, were screened for variation and redundancy during the MDP. Multiple regression models were constructed for nine selected metrics based on physico-chemical-temporal variables and evaluated by the mean square prediction error of the three test dates. Cluster analysis of stepwise reduced macroinvertebrate abundance data was used to biologically classify the sample dates of the MDP into seasons. Physico- temporal variables were used to create discriminant functions for these seasonal classifications. Test dates were evaluated for probability of group membership to each season and the observed community was compared to the expected community. Short term temporal changes within a single community offer challenging perspectives in benthic macroinvertebrate research. Definite patterns exist that can be observed and at times predicted.