Mountain Loam STM T2 Diverse Understory T2R Wheatgrass Shrubland T1 T1R T3 Dense or Eroding Mt. Big Sagebrush- Shrubland Diverse Understory 1934 lbs/acre Species richness: 41.4 Invasives: 0% Erosiveness: 5.2 Sage Grouse habitat:.67 Mule Deer habitat:.61 T2 T2R Wheatgrass 1215 lbs/acre Species richness: 43.4 Invasives: 0.6% Erosiveness: 7.1 Sage Grouse habitat:.75 Mule Deer habitat:.64 T1 T1R Dense Understory 807 lbs/acre Species richness: 38.2 Invasives: 2.2% Erosiveness: 6.6 Sage Grouse habitat:.53 Mule Deer habitat:.51 T3 1
Mountain Loam TransiQons T1: ReducQon of the herbaceous understory, caused by heavy (above NRCS- recommended) grazing and/or drought, combined with lack of disturbance that reduces shrub cover (fire, herbicide) T1R: Disturbance that reduces shrub cover (fire, herbicide) combined with recovery of the herbaceous understory, under lower grazing pressure and/or more precipitaqon T2: Moderate (NRCS recommended) grazing in we\er years allows western wheatgrass to become dominant T2: Moderate (NRCS recommended) grazing in we\er years allows western wheatgrass to become dominant T2R: Low grazing pressure combined with drought decrease wheatgrass cover; also occurs under heavy (above NRCS- recommended) grazing pressure T3: Heavy grazing (above NRCS recommended rates) causes conqnued reducqon in wheatgrass cover and an increase in shrub cover 3
Claypan STM T3 NaQve Alkali Sagebrush Steppe T3R Alkali Sagebrush- Western Wheatgrass Shrubland T2 T1 T1R T4 T4R T2R Eroding Alkali Sagebrush Shrubland NaQve Grassland Na@ve Alkali Sagebrush Steppe 1192 lbs/acre Species richness: 36.6 Invasives: 0.7% Erosiveness: 8.5 Sage Grouse habitat:.47 Mule Deer habitat:.26 T1 T3 T3R T2 T1R 1039 lbs/acre Species richness: 29.3 Invasives: 0.8% Erosiveness: 4.6 Sage Grouse habitat:.41 Mule Deer habitat:.27 T4 Na@ve Grassland 960 lbs/acre Species richness: 28.3 Invasives: 0.5% Erosiveness: 8.0 Sage Grouse habitat:.24 Mule Deer habitat:.11 Alkali Sagebrush- Western Wheatgrass Shrubland T2R T4R Eroding Alkali Sagebrush Shrubland 268 lbs/acre Species richness: 34.7 Invasives: 2.8% Erosiveness: 15.2 Sage Grouse habitat:.32 Mule Deer habitat:.1 2
Claypan TransiQons T1: T1R: T2: T2R: T3: T3R: T4: T4R: Fire and/or spraying reduces shrub cover, which causes the transiqon to naqve grassland Shrubs re- colonize over Qme (but this takes a long Qme, especially for alkali sagebrush) A combinaqon of high grazing pressure, drought, and/or fire reduce herbaceous plant cover, which triggers erosion on the site A combinaqon of lower grazing pressure, favorable precipitaqon, and/or lack of fire increase herbaceous plant cover, reducing erosion on the site Moderate (NRCS recommended) grazing in we\er years allows western wheatgrass to become dominant Low grazing pressure combined with drought decrease wheatgrass cover; also occurs under heavy (above NRCS- recommended) grazing pressure A combinaqon of high grazing pressure, drought, and/or fire reduce wheatgrass cover, which triggers erosion A combinaqon of lower grazing pressure, average precipitaqon, and/or lack of fire increase wheatgrass cover, reducing erosion 4
Appendix 1. Vegetation characteristics of potential states of the Claypan (CP) and Mountain Loam (ML) ecological sites, Elkhead Watershed, NW Colorado. Foliar and basal plant cover were measured using the line-point intercept method (five 50 m transects, 250 points). Species richness was derived from a whole-plot search of each 20 x 50 m plot. Means ± standard errors are reported. Foliar Cover Basal Cover States N Total Shrub Grass Forb Plant Bare Ground Litter Species Richness CP Diverse 3 73 ± 10 27.4 ± 9.5 23.4 ± 7.6 22.2 ± 12.6 5.6 ± 2.6 26 ± 5.8 68.4 ± 7.3 38.3 ± 0.3 Claypan CP Wheatgrass 11 58.4 ± 3.9 7.4 ± 1.4 27.6 ± 4.4 23.4 ± 4.4 13.5 ± 2.5 36.3 ± 6.5 49.4 ± 4.5 29.3 ± 1.2 CP Native Grassland 10 61.2 ± 1.6 4.1 ± 2.4 41 ± 2.6 16.1 ± 1.9 14.7 ± 2 24 24.9 ± 1.3 58.4 ± 2.6 28.3 ± 1.3 CP Eroding 6 47 ± 5.2 30.6 ± 3 9.8 ± 2.1 6.6 ± 1.6 10 ± 3.2 39.7 ± 6.1 51.4 ± 5.4 34.7 ± 2.5 Mountain Loam ML Diverse 7 75.3 ± 3.9 26.6 ± 4.2 22.7 ± 4.9 25.9 ± 4.5 11.1 ± 5 16.4 ± 4.5 72.4 ± 4.6 41.4 ± 2.5 ML Dense 5 73.1 ± 3.3 41.8 ± 4.9 19.1 ± 2.5 12.2 ± 3.8 4.5 ± 1.7 20.5 ± 5 75 ± 3.6 38.2 ± 1.6 ML Wheatgrass 12 74.3 ± 3.3 20.3 ± 2.9 22.3 ± 3.7 31.7 ± 3.3 8.4 ± 2.6 24.1 ± 5.2 65.9 ± 4.6 43.4 ± 2.3 From: Kachergis, E. 2011. An alternate state approach to range management in the sagebrush steppe. PhD dissertation, Colorado State University. 202 p.