Limitations by Reach
Table 1. Scoring ranges for bioindicator variables in the SPRNCA.
Score
1 1.5 2.5 3
No. of 10-cm Fremont cottonwood and Goodding’s willow size classes ≤ 3 ≥ 4
Fremont cottonwood and Goodding’s willow basal area (m2 ha-1) ≤ 4.7 ≥ 4.8
Fremont cottonwood and Goodding’s willow relative basal area (%) ≤ 21 ≥ 22
Maximum vegetation height (m) ≤ 15 ≥ 16
Shrublands (%) ≥ 35 ≤ 34
Absolute cover of streamside hydric perennial herbs (%) ≤ 5 ≥ 6
Relative cover of streamside hydric perennial herbs (%) ≤ 14 ≥ 15
Absolute cover of streamside hydric herbs (%) ≤ 29 ≥ 30
Relative cover of streamside hydric herbs (%) ≤ 24 ≥ 25
Functioning Condition Site Scores
• Scores of 1 to 1.5 indicate reduced water availability or stressors producing similar effects (Condition Class 1).
• Scores of 1.5 to 2.5 indicate intermediate conditions of water availability (Condition Class 2).
• Scores of 2.5 to 3.0 indicate no apparent water stress (Condition Class 3).
Hydrologic Thresholds for Riparian Condition Classes
Riparian Condition Class
Persistence of Streamflow
Maximum Depth to Ground Water
Annual Fluctuation in Ground-water
Levels
Wet >99 % of time <2.5 meters < 0.5 meters
Intermediate 60-99 % of time 2.5 to 3.5 meters 0.5 to 1.0 meters
Dry <60 % of time >3.5 meters >1.0 meters
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