Natural Resources
Conservation Service
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
Associated sites
R006XB011OR Meadow Knoll 14-26 PZ
The site is situated in the midst of wetter, meadow sites. It may also be associated with Meadow Knoll sites on remnant fans and terraces (from pre-Mazama materials). Complexes of Wet Pumice Terrace, Wet Pumice Meadow, and Meadow Swale are common, often with only micro-relief between sites.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous Not specified
Physiographic features
Alluvial fan and terrace remnants.
Table 2. Representative physiographic features
Landforms (1) Alluvial fan
(2) Stream terrace
Flooding duration Brief (2 to 7 days) to long (7 to 30 days) Flooding frequency Rare Elevation 4000 – 6000 ft Slope 0 – 1 % Ponding depth 0 in Water table depth 0 – 60 in Aspect Aspect is not a significant factor Climatic features
This site is characterized by relatively short, hot summers and cold, snowy winters. The site receives approximately 20 inches of precipitation per year, the bulk of which is snowfall. There are frequent thunderstorms in the summer months.
Table 3 Representative climatic features
Frost-free period (average) 20 days Freeze-free period (average) 50 days Precipitation total (average) 30 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
None (usually adjacent to seasonally ponded wetlands).
Soil features
Soils for this site typically have a thick organic layer, layers of coarse pumice over clay. There is an apparent water table present for most of the year that comes to within 30 inches of the surface early in the growing season. These moderately aged soils have been deposited over older, remnant fans and terraces. Variations and intergrades of soil characteristics are common.
Table 4. Representative soil features
Surface texture (1) Mucky loam
Family particle size (1) Clayey
Drainage class Somewhat poorly drained Permeability class Slow Soil depth 38 – 60 in Surface fragment cover <=3" 5 – 0 % Surface fragment cover >3" 5 – 0 % Available water capacity
(0-40in)5 – 6.5 in Calcium carbonate equivalent
(0-40in)1 % Electrical conductivity
(0-40in)0 – 2 mmhos/cm Sodium adsorption ratio
(0-40in)1 Soil reaction (1:1 water)
(0-40in)2 Subsurface fragment volume <=3"
(Depth not specified)5 – 0 % Subsurface fragment volume >3"
(Depth not specified)5 – 0 % Ecological dynamics
This site occurs on alluvial fans and terraces adjacent to deeper and lower marshy sites or stream channels. The water table is apparently below the effective rooting depth for the grass species present for a major protion of the growing season (depth to water table during the period of rapid growth appears to have a significant influence on the plant community). Wet Pumice Terraces are slightly elevated moist to wet sites eithin larger complexes of meadow and wetlands sites. The interpretative plant community for this site is the Historic Climax Plant Community (HCPC).
State and transition model
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 1
HCPC, POTR5/AGTR-POSE3Community 1.1
HCPC, POTR5/AGTR-POSE3Remnant Terrace (POTR5/AGTR-POSE): The site is characterized by the presence of Quaking Aspen and occasiaonally, Lodgepole Pine forming a sparse canopy over dense ground cover of various grasses, grass-likes, and forbs.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 2300 2950 3600 Forb 275 403 530 Tree 150 225 300 Shrub/Vine 45 58 70 Total 2770 3636 4500 Figure 4. Plant community growth curve (percent production by month). OR1841 , B6 Wet Pumice Terrace A. State A: RPC (POTR5/DECE-POSE3) B6 Wet Pumice Terrace .
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec J F M A M J J A S O N D 0 0 0 15 20 30 20 5 5 5 0 0 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 1667–2655 slender wheatgrass ELTRT Elymus trachycaulus ssp. trachycaulus 450–675 – Sierra rush JUNE Juncus nevadensis 315–450 – Kentucky bluegrass POPR Poa pratensis 225–450 – Sandberg bluegrass POSE Poa secunda 225–450 – Maui reedgrass CAEX Calamagrostis expansa 46–90 – Tracy's bluegrass POTR Poa tracyi 46–90 – 2 363–720 Kentucky bluegrass POPR Poa pratensis 225–450 – Tracy's bluegrass POTR Poa tracyi 46–90 – Maui reedgrass CAEX Calamagrostis expansa 46–90 – Nebraska sedge CANE2 Carex nebrascensis 46–90 – needle spikerush ELAC Eleocharis acicularis 46–90 – meadow barley HOBR2 Hordeum brachyantherum 46–90 – prairie Junegrass KOMA Koeleria macrantha 46–90 – mat muhly MURI Muhlenbergia richardsonis 46–90 – 3 46–90 Nebraska sedge CANE2 Carex nebrascensis 46–90 – 4 406–765 Sierra rush JUNE Juncus nevadensis 315–450 – needle spikerush ELAC Eleocharis acicularis 46–90 – Forb3 275–530 slender cinquefoil POGR9 Potentilla gracilis 135–225 – Chamisso arnica ARCHI4 Arnica chamissonis ssp. foliosa var. incana 45–90 – 4 6–360 common yarrow ACMI2 Achillea millefolium 6–90 – Tatarian aster ASTA Aster tataricus 6–90 – fleabane ERIGE2 Erigeron 6–90 – Virginia strawberry FRVI Fragaria virginiana 6–90 – Rainier pleated gentian GECA Gentiana calycosa 6–90 – bigleaf lupine LUPO2 Lupinus polyphyllus 6–90 – buttercup RANUN Ranunculus 6–90 – 5 180–315 cinquefoil POTEN Potentilla 135–225 – arnica ARNIC Arnica 45–90 – 6 6–360 common yarrow ACMI2 Achillea millefolium 6–90 – aster ASTER Aster 6–90 – erigenia ERIGE Erigenia 6–90 – Virginia strawberry FRVI Fragaria virginiana 6–90 – old man's whiskers GETR Geum triflorum 6–90 – bigleaf lupine LUPO2 Lupinus polyphyllus 6–90 – buttercup RANUN Ranunculus 6–90 – Shrub/Vine5 45–70 golden currant RIAU Ribes aureum 45–90 – 7 45–70 golden currant RIAU Ribes aureum 45–90 – Tree6 150–300 quaking aspen POTR5 Populus tremuloides 90–225 – willow SALIX Salix 45–135 – lodgepole pine PICO Pinus contorta 45–90 – 8 150–300 quaking aspen POTR5 Populus tremuloides 90–225 – coastal blacksnakeroot SALA7 Sanicula laciniata 45–135 – lodgepole pine PICO Pinus contorta 45–90 – Interpretations
Animal community
The site is an important source of forage for grazing animals. Mule deer, elk, anelope, and nesting birds use the site seasonally. The site is usually associated with stream channels which provide additional wildlife habitat, particularly for birds. The site usually has a slightly higher elevation than adjacent wetter sites making it slightly drier. The presence of a tree canopy gives a measure of shade that is not found on adjacent sites.
Hydrological functions
The site has a moderate potential in low seral condition to produce run-off to receiving waters. In some years, the site may be flooded with water backed up in the adjacent wetter sites. There are usually fingers of wetter and lower sites threading throughout the site providing extra ground water that may move laterally through the Wet Pumice Terrace site. In good condition, the site provides stability to adjacent streambanks and floodplains; vegetation is usually resistant to flows. Woody materials add to the stability of stream systems and provide habitat for aquatic insects not found on adjacent, wetter meadow sites.
Recreational uses
There is little recreation use on this site other than big game hunting and bird watching.
Wood products
Generally not productive enough for harvest of wood products.
Other products
None
Other information
Grazing-The site is frequently used for grazing by domestic livestock and wildlife (mule deer, elk, and antelope). There are several species that are preferred that are available for most of the growing season. Forages stay green (and presumable high in protein and digestible organic matter) well into the fall each year. The site can be heavily used because the slightly higher elevation and convex shape of this site makes it drier than adjacent meadow sites and therefore more attractive for resting, ruminating, and grazing. Livestock may seek out the shade and cover from the woody plants on this site (adjacent wetter sites are treeless).
Wildlife- The site provides important habitat for grazing animals, shorebirds, raptors, and waterfowl. Lesser Sandhill Cranes may use the site in their search for food. The cranes scratch or till the ground to find and consume invertebrates. Larger grazing animals use the site for resting and shade. Raptors made use of the larger woody plants for perches and nests.Supporting information
Contributors
Jeffrey P. Repp
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Contact for lead author Date Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
Number and extent of rills:
-
Presence of water flow patterns:
-
Number and height of erosional pedestals or terracettes:
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
-
Number of gullies and erosion associated with gullies:
-
Extent of wind scoured, blowouts and/or depositional areas:
-
Amount of litter movement (describe size and distance expected to travel):
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
-
Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
-
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
-
Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
-
Perennial plant reproductive capability:
Print Options
Sections
Font
AAAAOther
PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Accessibility statement
