2008-04-25_REVISION - M1992113 - Laserfiche WebLink

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Site Type: Rangeland Gravel Breaks MLRA: 69 -Upper Arkansas Valley Rolling Plains R069XY064CO Plant Community Narratives Following are the narratives for each of the described plant communities. These plant communities may not represent every possibility, but they probably are the most prevalent and repeatable plant communities. The plant composition tables shown above have been developed from the best available knowledge at the time of this revision. As more data is collected, some of these plant communities may be revised or removed, and new ones may be added. None of these plant communities should necessarily be thought of as "Desired Plant Communities". According to the USDA NRCS National Range and Pasture Handbook, Desired Plant Communities will be determined by the decision-makers and will meet minimum quality criteria established by the NRCS. The main purpose for including any description of a plant community here is to capture the current knowledge and experience at the time of this revision. Sideoats Grams, Little Bluestem, Blue Grama Plant Community This plant community is the interpretive plant community for this site and is considered to be the Historic Climax Plant Community (HCPC). This community evolved with grazing by large herbivores and is suited to grazing by domestic livestock. Historically, fires likely occurred infrequently. This plant community can be found on areas that are grazed and where the grazed plants receive adequate recovery periods during the growing season. The potential vegetation is about 75-85% grasses and grass-likes, 10-15% forbs and 5-10% woody plants. The principal mid grasses are little Bluestem and sideoats grams. Secondary grasses include blue grams, galleta, big Bluestem, prairie sandreed, switchgrass, needleandthread, hairy grams and western wheatgrass. Threadleaf and sun sedge are common.. Dominant forbs are purple prairie clover, dotted gayfeather and upright prairie coneflower. Winterfat, Bigelow sagebrush and skunkbush sumac are some of the major shrubs found on this plant community. This is a sustainable plant community in terms of soil stability, watershed function and biological integrity. Litter is properly distributed where vegetative cover is continuous. Some litter movement may occur on steeper slopes. Decadence and natural plant mortality is very low. Community dynamics, nutrient cycle, water cycle and energy flow are functioning properly. This community is resistant to many disturbances except continuous grazing, tillage and/or development into urban or other uses. Areas having lost all vegetation, such as livestock and vehicle trails are subject to high erosion rates and extreme runoff. Total annual production, during an average year, ranges from 350 to 1200 pounds of air-dry weight and will average 750 pounds. The following is the growth curve of this plant community expected during a normal year: Growth curve number: CO6905 Growth curve name: Warm season dominant, cool season sub-dominant; MLRA-69; upland coarse textured soils. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 0 5 10 22 35 15 10 3 0 0 0 (monthly percentages of total annual growth) Transitions or pathways leading to other plant communities are as follows: • Continuous grazing without adequate recovery periods between grazing events will shift this plant community toward the Increased Blue Grams with Decreased Mid and Tall Grass Plant Community. • Long-term non-use (rest) and no fire will move this plant community toward the Bare Ground, Annuals, Cryptogams Plant Community. This transition may take 40 years or more to achieve. Technical Guide USDA NRCS Section IIE 6 Rev. 3/04 ~/