Pond succession on the Kaibab Plateau, Arizona.

Quantitative data were obtained for a serai comparison of five sinkhole ponds on the Kaibab Plateau, Arizona. Species diversity, community metabolism, primary production, and relative serai rank were assayed. Information theory and non-information theory species diversity indices were used to compare the phyto- and zooplankton, benthos, and emergent vegetation both within and among ponds. Species diversity of these four pond features showed large fluctuations, hence diversity indices afford distinction only between early versus late serai stages. The ponds were divided into early versus late categories based on community metabolism estimates, as calculated by the diel oxygen curve method. Primary production values, derived from diel oxygen curve values, indicate that primary production increases during succession to a certain point, then decreases as the aquatic ecosystem approaches senescence. Methods of estimating serai stage based on measurements of individual characteristics were ineffective, so a systems analysis approach was developed. Species diversity, photosynthesis-respiration ratio, and mean depth wer*e related mathematically to produce a serai ranking value which varies directly with serai stage. Values calculated with this formula correspond well with presumed serai stages of the ponds.