2011-11-02_REVISION - M2003019 (5)

Home Browse Search

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 0 0 0 5 15 35 25 15 5 0 0 0 to Type: Rangeland Limestone Breaks MLRA: 69 - Upper Arkansas Valley Rolling Plains R069XY058CO • Prescribed grazing that allows for adequate recovery opportunity following each grazing event and proper stocking will maintain the Sideoats Grama, Little Bluestem, New Mexico feathergrass, Bigelow Sagebrush Plant Community (HCPC). Increased Blue Grama with Decreased Mid Grasses and Shrubs Plant Community This plant community developed with continuous grazing without adequate recovery periods during the growing season. The dominant grass is typically blue grama with increased amounts of galleta. New Mexico feathergrass can increase under spring deferment or continuous summer grazing. Sideoats grama and little bluestem are still present as secondary grasses in the community. Big bluestem, Indiangrass, switchgrass, needleandthread and western wheatgrass have been significantly reduced. Forbs and shrubs that have increased are mat loco, sessile nailwort, Hood's phlox, hairy goldaster, western ragweed, slimflower scurfpea, small soapweed and broom snakeweed. Purple prairie clover, American vetch, winterfat, fourwing saltbush, currants and skunkbush sumac have been significantly reduced. Oneseed juniper and pinyon has increased above the amount that existed in the HPCP. Plant frequency, production and litter levels are lower compared to the HCPC. Soil erosion may be a concern at this point especially on high travel or impact areas. Some flow paths may be connected and minor rilling evident. Water cycle and nutrient cycle are beginning to be affected by the reduction of key warm /cool season species, forbs and shrubs. Desertification is becoming apparent. Total annual production can vary from 200 to 500 pounds of air -dry vegetation per acre and will average 300 pounds during an average year. The following is the growth curve of this plant community expected during a normal year: Growth curve number: C06903 Growth curve name: Warm season dominant, cool season sub - dominant; MLRA -69; upland fine textured soils. (monthly percentages of total annual growth) Transitions or pathways leading to other plant communities are as follows: • Continuous grazing without adequate recovery opportunities between grazing events will shift this plant community across an ecological threshold toward the Blue Grama with or without Remnant Mid Grasses and Shrubs Plant Community. • Prescribed grazing that allows for adequate recovery periods between grazing events and proper stocking will move this plant community toward the Sideoats Grama, Little Bluestem New Mexico Feathergrass, Bigelow Sagebrush Plant Community (HCPC). Low Plant Density, Decadent Plant Community This plant community developed under many years of non -use (rest) and lack of fire. Plant species resemble the HCPC however, species frequency and production will be reduced. Eventually, litter levels can become high enough to cause stagnation and mortality of various species such as little bluestem, sideoats grama, big bluestem, Indiangrass, switchgrass and blue grama. Bunchgrasses typically develop dead centers and rhizomatous grasses form small communities because of a lack of stimulation by grazing animals. Initially, high surface litter levels will minimize erosion. Advanced stages of non -use (rest) or lack of fire can result in lower vigor plants, causing an increase in bare areas. These areas can be susceptible to water erosion, especially on steeper slopes. Total annual production can vary from 250 to 950 pounds of air -dry vegetation per acre. Technical Guide Section IIE 8 USDA NRCS Rev. 3/04