Quantifying aboveground biomass and estimating net aboveground primary production for wetland macrophytes using a non-destructive phenometric technique

A non-destructive net aboveground primary production (NAPP) estimation technique which reduces the amount of labour required without sacrificing method accuracy was developed using phenometric models for nine species from freshwater Everglades wetlands. The predictive power of these models ranged from 90% to 97% and all were highly significant (p<0.0001). Five species' models were tested in other habitats. Three of these yielded non- destructively estimated biomass values that were not significantly different from harvested values. We also determined that a small sample of the total plot population could be measured and still yield accurate live standing crop (LSC) values using a technique similar to rarefaction - only 32% of the total number of individuals within any given plot must be regularly monitored. We tested the accuracy of our method by comparing NAPP rates computed using both estimated and destructively obtained LSC values. Calculated NAPP rates were not significantly different than those produced from the more traditional destructive technique. NAPP rates were also computed (1) using a variety of computation methods and (2) using different sampling frequencies. Both computation method and sampling frequency had an effect on NAPP rates and should be considered when conducting NAPP studies.