Productivity of Florida Springs: first semi-annual report to Biology Division, Office of Naval Research, progress from June 1, 1952 to January 31, 1953

Abstract

Work has begun on studying the factors responsible for productivity in the Florida springs, which are nearly constant temperature, constant chemical, steady state giant laboratories. Progress has been made on five aspects: qualitative description, quantitative description, completion of knowledge of chemical factors, measurement of productivity , development of productivity theory. Measurement of the primary productivity in Silver Springs and Green Cove Springs by two new methods: the raising of organisms in cages, and the measurement of night & day differences in oxygen downstream agree roughly. Production in these springs is greater than previous production figures reported for marine, fresh water, and land areas. Instantaneous measures of production show large variations with season, time of day, cloud cover. Production estimates range from 11,000 lbs per acre per year to 70,000 lbs. glucose per acre per year during daylight hours. Essential stability of the springs environment has been shown with respect to temperature, phosphorus, and plant cover. A correlation of species number with lack of stability has been shown with insects. Quantitative studies have shown very large plant base to pyramids of mass. Correlation of marine invasion with chlorinity has been shown. The essential aspects of pH regulated phosphorus geochemistry in Florida have been outlined. Some theoretical ideas on productivity have been evolved. Mapping of sessile organisms in springs and taxonomic identification of dominants are half completed. Plans for second six months include measurement of herbivore and carnivore production rates and completion of food chain efficiency determinations in Silver Springs as a preparation for subsequent comparisons between springs. (34pp.