EVALUATION OF PROCEDURES TO ESTIMATE BIOMASS ON SURFACE COAL-MINE LANDS RECLAIMED UNDER THE SURFACE-MINING-CONTROL-AND-RECLAMATION-ACT-OF-1977

Current surface mine regulations as ascribed under the Surface Mining Control and Reclamation Act of 1977 require that mine lands be returne d to the approximate original contours (AOC) with an area coverage of at least 70% and to biological productivity equal to or greater than t hat which existed prior to mining. Six different procedures were evalu ated on nine mine sites in northwestern Pennsylvania as to their suita bility to estimate aboveground biomass on mines reclaimed as hayland a nd pastures. Biomass estimates determined by different procedures were compared to those obtained by random clip plots and with landowner es timates of the annual yield from each site. Biomass estimates determin ed from a disk meter and landowner interviews Varied approximately +/- 10% from those obtained from random clip plots compared to a Variation of +/-8%-37% for the other procedures. The number of samples required to obtain reliable estimates within +/-10% of the mean at 95% confide nce intervals varied among the different sampling procedures according to the variance in biomass on the site. Although all procedures may b e used either singly or in combination to estimate above ground biomas s on reclaimed mine lands, the combination of the disk meter, profile board, and vegetation height is recommended because of their ease of m easurement compared to the other procedures.