Montana Field Guide

These upper subalpine and alpine herbaceous and dwarf-shrub communities are found on wet sites in the higher mountains of northwestern, southwest and south-central Montana. The elevations range from as low as 6,000 feet in northwestern Montana to 10,500 feet in southwestern Montana. The climate is very cold, with heavy snow accumulation and a very short growing season (60 to 90 days). These types occur as wet meadows, as narrow strips bordering ponds, lakes and streams, and along toeslope seeps. These communities may be dominated by a variety of wet site herbaceous communities as well as wetland sites dominated by dwarf-shrublands. These sometimes take the form of rings of different plant communities around a late-melting snowbed with drier turf species on the outside edges, wetland species near the middle and sometimes a sparsely vegetated center as a result of the extremely short growing season. These sites are tightly associated with snowmelt and typically not subjected to high disturbance events such as flooding.

This group includes the higher elevation communities included in the Alpine-Montane Wet Meadow Ecological System.

Upper Subalpine and Alpine Zones; Wet sites, Wetland Communities, Snowbed Communities; Vegetation Cover >15%; Herbaceous Vegetation, Dwarf Shrubs, Subshrubs; Short Growing Season.

This group occurs in many of the higher elevation mountain ranges in northwestern, southwest and south-central Montana that have significant, vegetated, alpine areas above treeline. This includes many areas along and west of the Continental Divide and the higher ranges east of the Continental Divide such as the East Pioneers, Tobacco Root Mtns, the Crazy Mtns and mountainous areas south of these ranges.

In Montana, G520 is confined to areas within or immediately adjacent to Level IV Ecoregions 15h (High Northern Rockies), 16h (High Idaho Batholith), 17h (Middle Rockies Alpine Zone) and 41b Canadian Rockies Crestal Alpine-Subalpine Zone.

In Montana, G520 occurs within these Major Land Resource Areas: 43A-Northern Rocky Mountains and 43B-Central Rocky Mountains.

Small Patch

This group occurs in the upper subalpine and alpine zones. The elevation ranges from as low as 6,000 feet in northwestern Montana to 10,500 feet in southwestern Montana. The climate is very cold, with heavy snow accumulation and a very short growing season (60 to 90 days). These types occur as meadows, as narrow strips bordering ponds, lakes and streams, and along toeslope seeps. They are typically found on flat areas or gentle slopes but may also occur on sub-irrigated sites with slopes up to 10%. In alpine regions, sites typically are small depressions located below late-melting snow patches or on snowbeds. Moisture for these wet meadow community types is acquired from groundwater, stream discharge, overland flow, overbank flow, and on-site precipitation. Depending on the slope, topography, hydrology, soils and substrate, intermittent, ephemeral or permanent pools may be present. Water tables typically remain at or near the soil surface though fluctuations of the water table throughout the growing season are not uncommon.

Soils of this group are mineral often with a thin (<40 cm) organic layer over the mineral layers. As a result, they are not classified as peatlands. Soils show hydric soil characteristics, often including high organic content and/or low chroma and redoximorphic features including gleying and/or mottling throughout the profile. Soils typically possess a high proportion of organic matter, but this may vary considerably depending on the frequency and magnitude of alluvial deposition (Kittel et. al. 1999b). Organic composition of the soil may include a thin layer near the soil surface or accumulations of highly sapric (mucky) material. Environmental information was compiled from Willard (1963), Komarkova (1976, 1986), Nachlinger (1985), Cooper (1986b), Kovalchik (1987, 1993), Padgett et al. (1988a), Reed (1988), Meidinger and Pojar (1991), Shiflet (1994), Manning and Padgett (1995), Sanderson and Kettler (1996), Zwinger and Willard (1996), Cooper et al. (1997), Crowe and Clausnitzer (1997), and Kittel et al. (1999b).

This group includes open to dense, graminoid- and forb-dominated, wet herbaceous communities as well as wetland sites dominated by dwarf-shrublands. These sometimes take the form of rings of different plant communities around a late-melting snowbed with drier turf species on the outside edges, wetland species near the middle and sometimes a sparsely vegetated center as a result of the extremely short growing season.

This group often occurs as a mosaic of several plant associations, often dominated by graminoids including Carex illota, Carex lachenalii, Carex nigricans, Deschampsia cespitosa, Phippsia algida, Juncus drummondii, Juncus mertensianus, and the forbs Caltha leptosepala, Trollius laxus, Parnassia fimbriata, Polygonum bistortoides, Sibbaldia procumbens, and Trifolium parryi. Scattered to moderately dense dwarf or low shrubs are occasionally present, including Shrubby Cinquefoil (Dasiphora fruticosa), Alpine Bog Laurel (Kalmia microphylla), or Bog Blueberry (Vaccinium uliginosum). Willow species such as Salix glauca, Salix planifolia, and Salix reticulata may also be present. Floristic information was compiled from Willard (1963), Komarkova (1976, 1986), Nachlinger (1985), Cooper (1986b), Kovalchik (1987, 1993), Padgett et al. (1988a), Reed (1988), Meidinger and Pojar (1991), Shiflet (1994), Manning and Padgett (1995), Sanderson and Kettler (1996), Zwinger and Willard (1996), Cooper et al. (1997), Crowe and Clausnitzer (1997), and Kittel et al. (1999b).

In Montana, this group is represented by 8 Associations grouped into 4 Alliances within the National Vegetation Classification, though 1 Alliance has no Associations attributed for the state. Additional work is needed to clarify the Alliances and Associations that occur in Montana.

These sites are tightly associated with snowmelt and typically not subjected to high disturbance events such as flooding. Due to the mesic setting of these communities along with the patchiness of the vegetation, fires are not an important process.

Depending on the particular setting and scope of the wetland plant community, critical functions may include water filtration, flow attenuation, and wildlife habitat functions. These communities are fragile due to the very limited growing season and limited soil development. Species that occur in these systems are generally slow growing and decrease in cover and vigor in areas of trampling.

K.A. Schulz 2015

S. Mincemoyer, L. Vance, C. McIntyre, T. Luna

11/25/2024