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Appendix D. A table (Table D1) showing distance-from-water classes at each study site defines by absolute distance from water (km), and figures showing (Fig. D1) the relationship between consumption, estimated by direct harvest and distance from water; (Fig. D2) the relationship between distance from water and utilization (proportion of forage consumed); (Fig. D3) perennial grass basal cover and standard errors as a function of distance from water class at (A) SGBR arid, (B) semiarid, and (C) subhumid, and (D) PAT arid, (E) semiarid, and (F) subhumid study areas; (Fig. D4) repeated measures (2 years) test of the effect of distance from water on shrub production at (A) arid SGBR, (B) semiarid SGBR, and (C) arid PAT study areas; (Fig. D5) nonnative species per site as a function of (A) distance from water, averaging across precipitation and region and (B) precipitation, averaging across distance from water; and (Fig. D6) concentration of C and N in soils under (g) grasses, (s) shrubs, and (b) bare ground at (A) SGBR arid, (B) semiarid, and (C) subhumid, and (D) PAT arid, (E) semiarid, and (F) subhumid study areas.

Table  D1. Distance-from-water classes at each study site defined by absolute distance from water (km). “Exclosures” are sites that have not been grazed by livestock for at least 20 years; the number of sites in each study area meeting this criterion is shown in parentheses.

FIG. D1. The relationship between consumption, estimated by direct harvest, and distance from water. On the top row are (A) SGBR arid, (B) semiarid, and (C) subhumid study areas, with (D) PAT arid, (E) semiarid, and (F) subhumid study areas on the bottom row. Error bars show +1 SE. Within each panel, least squares means sharing lowercase letters are not significantly different ( = 0.05). Negative values of observed consumption occured when forage biomass in the grazed area was higher than in the temporary exclosure, a result of spatial heterogeneity. The dotted lines show expected consumption, based on stocking rates (calculation explained in Table 2 legend). In contrast to the field measures (vertical bars), these expected consumption estimates do not take into account heterogeneity in animal distributions and forage production.

FIG. D2. The relationship between distance from water and utilization (proportion of forage consumed). On the top row are (A) SGBR arid, (B) semiarid, and (C) subhumid study areas, with (D) PAT arid, (E) semiarid, and (F) subhumid study areas on the bottom row. Forage is defined as all annuals, forbs, and perennial grasses. Negative values of utilization occur when forage biomass in the grazed area is higher than in the temporary exclosure. Different symbols denote different transects within each study area. Vertical dotted lines show how sites within each study area were grouped into distance-from-water classes 1, 2, and 3.

FIG. D3. Perennial grass basal cover and standard errors as a function of distance from water class at (A) SGBR arid, (B) semiarid, and (C) subhumid, and (D) PAT arid, (E) semiarid, and (F) subhumid study areas. Within each panel, least square means sharing lowercase letters are not significantly different ( = 0.05). “Excl” refers to long-term ungrazed sites, and “nd” indicates no data.

FIG. D4. Repeated measures (2 years) test of the effect of distance from water on shrub production at (A) arid SGBR, (B) semiarid SGBR, and (C) arid PAT study areas. Least square means sharing the same letter within each panel are not significantly different ( = 0.05). Bars show +1 SE.

FIG. D5. Nonnative species per site as a function of (A) distance from water, averaging across precipitation and region and (B) precipitation, averaging across distance from water. Bars show +1 SE.

FIG. D6. Concentration of C and N in soils under (g) grasses, (s) shrubs, and (b) bare ground at (A) SGBR arid, (B) semiarid, and (C) subhumid, and (D) PAT arid, (E) semiarid, and (F) subhumid study areas. Values shown are means and standard errors, aggregating sites across distance from water classes within each study area.