2010-08-30_REVISION - C1981008 (4)

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} r. www.bio-geo.com • Table 8, below, shows summary statistics for 2008 production measurements in the Dryland Pasture reference area and the Dryland Pasture reclaimed area, and the statistical data used to compare the reclaimed area means with the standard. Table 8. Summary and comparison of vegetation production data measured at Dryland Pasture reclaimed area and Dryland Pasture reference area, 2008. Production Ib/acre Dryland Pasture Reclaimed Area 2008 Dryland Pasture Reference Area, 2008 Noxious weeds* 5.3 0 Annual rasses* 54.7 0.6 Annual forbs* 10.2 109.1 Total annual lants* 53.0 109.7 Sub-shrub: broom snakeweed* 0 8.1 Shrubs* 0 4.3 Perennial grasses 423.2 11.0 Perennial forbs 18.4 45.2 Total mean production of desirable plants (:R) 441.7 56.2 Standard deviation of z 220.5 51.9 Q =90% of the standard 50.6 Number of samples 30 30 Sample adequacy demonstrated No No Comparison Statistics Standard Error SE = s/ n 40.26 9.48 SE Satterthwaite approximation) 41.15 Degrees of Freedom df Satterthwaite 32 Calculated t-statistic tj 9.505 Table t-statistic (tt), 1-tailed, P=0.20, df Satterthwaite 0.853 *Not counted toward total production of desirable plants Undesirable annual plants, mostly forbs, exceeded the total production of desirable plants in the reference area and equaled about 12% of total production of desirable plants in the reclaimed area. As in 2007, broom snakeweed was common in the reference area but absent in the reclaimed area. This sub-shrub is considered by the USDA Natural Resources Conservation Service (NRCS) to be unpalatable to livestock, and it was not included in total production of desirable plants. In 2008, production of perennial grasses in the reclaimed area exceeded the amount measured in 2007, and as in 2007 greatly exceeded production of perennial grasses in the reclaimed area, where the measurement was lower in 2008 than in 2007. Bunchgrasses in the reclaimed area did not appear to have declined in vigor since 2007; rather, the grasses are sparsely distributed and they seem to have fallen in 2008 sample plots with less frequency than in 2007, by chance. Production was again highly variable in both areas. Sampling in the reference area was terminated after 30 plots with estimated sample adequacy at 146 samples, and sampling the reclaimed area was terminated after 30 plots with estimated sample adequacy at 36 samples. 19