DIVERSITY AND SEASONAL SUCCESSION OF FRESHWATER OSTRACODA IN THE BAKER WETLANDS, DOUGLAS COUNTY, KANSAS: A BASELINE STUDY

The destruction of wetlands is one of the most significant environmental problems today. Because of their importance, wetlands require monitoring and protection, especially when new construction is proposed. An example of a wetland in this situation is the Baker Wetlands, a man-made, ephemeral wetland located on the southern edge of Lawrence, Kansas. The proposed construction of the South Lawrence Trafficway through the Baker Wetlands will alter the wetland environment, possibly affecting some elements of the flora and fauna. In this study we use ostracodes to establish a predisturbance baseline for monitoring the effects of the construction project on the wetland ecosystem. Ostracodes are used commonly as environmental indicators because of their narrow tolerance ranges, ease of colonization, and rapid replacement due to environmental changes. We determine species richness, species diversity, seasonal succession, and correlations with water chemistry at four sample sites in three ponds. Water temperature, conductivity, and reduction-oxidation (redox) potential were measured during 14 sampling periods in 2003; and pH was measured less frequently during the same interval. Correlation coefficients of the proportions of each species with temperature, conductivity, and redox potential show statistically significant relationships (p < 0.05) of Candona crogmaniana, Cypria ophtalmica, Cypria palustera, and Physocypria globula with some parameters of the water chemistry at three of the pond sample sites. This indicates that the ostracode species of the Baker Wetlands may be controlled to some extent by these environmental factors and may be used subsequently for monitoring both during and after construction of the trafficway.