limitations by reach

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