PREDICTING CRUSTACEAN ZOOPLANKTON SPECIES RICHNESS

Data from 66 North American lakes were collected to construct a model for predicting the number of crustacean zooplankton species expected in a lake. The chosen lakes have a range from 4 m2 to 80 x 10(9) m2 surface area, range from ultra-oligotrophic to hypereutrophic, and have zooplankton species lists based on several years of observation. The number of crustacean zooplankton species in a lake is significantly correlated with lake size, average rate of photosynthesis (parabolic function), and the number of lakes within 20 km. A multiple linear regression model, using these three independent variables, explains approximately 75% of the variation in log species richness. Prediction of species richness was not enhanced by knowledge of lake depth, salinity, elevation, latitude, longitude, or distance to the nearest lake. The North American species-area curve is statistically different from and steeper than the corresponding European curve.