Laserfiche WebLink
species outnumbered annual species by fourteen to six. Seasonality of 1987 <br />• Reclamation Area species was split between cool season, warm season, and deciduous <br />species. Graminoids were evenly split, six were cool season, and six were warm <br />season species. With the exception of Helianthus annuus, all fort species were <br />identified as cool season. The shrub species was deciduous. <br />Eight species (six grasses and two forts) represented greater than three percent relative <br />cover. These species included Calamotzlfa IongifoGa (48.96%), Bouteloua gracilis <br />(9.50%), Bromus marginatus (8.01 %), Agropyron cristatum (6.53%), Agropyron <br />smithii (4.45%), Andropogon hallii (3.26%), Helianthus annuus (3.26%), and Kochia <br />scoparium (3.26%). <br />COMPARISON OF RECLAIMED AREAS AND REFERENCE AREA <br />Evaluation of revegetation success was accomplished through comparisons of the 1985, <br />1986, and 1987 Reclamation Areas with the Osgood Sand Reference Area as required <br />by the approved CDMG permit. The reclaimed azeas and reference area were <br />quantitatively compared with regard to mean total vegetative cover. A standard was <br />established for species composition and there is no requirement for establishment of <br />woody plants in the 1985, 1986, and 1987 Reclamation Areas. <br />A Students-t test was used to compare equivalency of the 1985, 1986, and 1987 <br />• Reclamation Areas and the Osgood Sand Reference Area for the parameter of total <br />vegetation cover. The form of the Students-t parametric statistical test used is as <br />follows: <br />0.9X2 - Xt <br />t= <br />1-x2 <br />where: t =the Student's t distribution value <br />Xt =the sample mean from the reclaimed area <br />X2= the sample mean from the reference area <br />Sxt _xZ =the standard error of the difference between the means <br />If the t value calcu]ated from the sample information is less than the table t value, the <br />hypothesis that the sample means are equal is accepted. With regard to comparisons of <br />the reclamation areas and reference area, a calculated t value less than the table t value <br />indicates that there is no significant difference between the total vegetation cover on the <br />reference and the reclamation area. <br />U <br />-Ia <br />