Evaluation of digital photography for estimating live and dead aboveground biomass in monospecific macrophyte stands

To reduce time and labor in the field, digital photographs were used to assess quantities of live and dead plant biomass in the Florida Everglades. Profile-oriented images were acquired of vegetation contained within an open-sided frame having a black backdrop of known area. Using imaging software, the pictures were transformed so that live, dead, and the absence of plant material were represented by the colors green, red, and black, respectively. Subsequent pixel counts within the boundaries of the backdrop, combined with average stand height values, gave estimate terms that were plotted against the dry weights of all aboveground materials harvested from within the frame. Regression analyses showed strong correlations (R-2 > 0.84) between estimated and actual dry weights, indicating that this technique is a rapid and accurate way to assess biomass in monospecific stands of these plants. (C) 2000 Elsevier Science B.V. All rights reserved.