Montana Field Guide

This group includes wet meadows and marshy habitats found in the montane and subalpine zones. Sites occur on both sides of the Continental Divide in open, wet depressions, basins and flats with still or low-velocity surface and subsurface flows. They occur as large meadows in montane and subalpine valleys, or 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 subirrigated sites with slopes up to 10%. Sites are usually seasonally wet, often drying by late summer, and many occur in a zone between perennial wetlands and uplands, where water tables fluctuate. They may have surface water for part of the year, but depths rarely exceed a few centimeters. Snowmelt is important for many of these sites. Soils are mostly mineral and show typical hydric soil characteristics such as low chroma and redoximorphic features; some areas may have high organic content as inclusions or pockets. Vegetation of this group can manifest as a mosaic of several plant associations, or be a monotypic stand of a single association which is dominated by graminoids or forbs. Dominant species include graminoids such as Sedges (Carex spp), Rushes (Juncus spp), Spikerushes (Eleocharis spp), Water Horsetail (Equisetum fluviatile), Tufted Hairgrass (Deschampsia cespitosa), and Blue-joint Reedgrass (Calamagrostis canadensis). Common forbs include Arrow-leaf Groundsel (Senecio triangularis) and Lewis' Monkeyflower (Mimulus lewisii).

This Group includes portions of the Alpine-Montane Wet Meadow, Emergent Marsh and the Rocky Mountain Wooded Vernal Pool Ecological Systems.

Wetlands; Marsh and Wet Meadow; Herbaceous Dominated; Rocky Mountain Region; Montane and Subalpine Zones; Seasonally, Vernally or Permanently Saturated; Hydric Soils

Typical Dominants: Sedges (Carex spp), Rushes (Juncus spp), Spikerushes (Eleocharis spp), Water Horsetail (Equisetum fluviatile), Tufted Hairgrass (Deschampsia cespitosa), Blue-joint Reedgrass (Calamagrostis canadensis), Mannagrass (Glyceria spp), Arrow-leaf Groundsel (Senecio triangularis), Lewis' Monkeyflower (Mimulus lewisii)

This wetland group occurs in the montane and subalpine zones of all the major mountain ranges of the state on both sides of the Continental Divide. East of the divide, this group occurs in all of the higher elevation island ranges.

In MT, G521 occurs within these Level III Ecoregions: 15 (Northern Rockies), 16 (Idaho Batholith), 17 (Middle Rockies), and 41 (Canadian Rockies).

In Montana, G521 occurs primarily within these Major Land Resource Areas: 43A - Northern Rocky Mountains, 43B - Central Rocky Mountains, and in limited extent within 44A - Northern Rocky Mountain Valleys, 44B - Central Rocky Mountain Valleys, and 46 - Northern and Central Rocky Mountain Foothills.

Small Patch

Wet meadows are typically found on flat areas or gentle slopes but may occur on subirrigated sites with slopes up to 10%. Sites are usually seasonally wet, often drying by late summer, and many occur in a zone between perennial wetlands and uplands, where water tables fluctuate. They may have surface water for part of the year, but depths rarely exceed a few centimeters. Wet meadows can be tightly associated with snowmelt and typically are not subjected to high velocity disturbance but can be flooded by slow-moving waters. Moisture for these wet meadow community types is acquired from groundwater, stream discharge, overland flow, overbank flow, and on-site precipitation. Salinity and alkalinity are generally low due to the frequent flushing of moisture through the meadow. Depending on the slope, topography, hydrology, soils and substrate, intermittent, ephemeral, or permanent pools may be present.

These areas may support species more representative of purely aquatic environments. Standing water may be present during some or all of the growing season, with water tables typically remaining at or near the soil surface. Fluctuations of the water table throughout the growing season are not uncommon, however. On drier sites supporting the less mesic types, the late-season water table may be 1 m or more below the surface.

Soils are mostly mineral and show typical hydric soil characteristics such as low chroma and redoximorphic features; some areas may have high organic content as inclusions or pockets. Soils may have organic soils inclusions. The presence and amount of organic matter 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 material of up to 120 cm thick. Soils may exhibit gleying and/or mottling throughout the profile. Wet meadows provide important water filtration, flow attenuation, and wildlife habitat functions. Environmental information is compiled from Komarkova (1976, 1986), Nachlinger (1985), Kovalchik (1987, 1993), Barbour and Major (1988), Meidinger et al. (1988), Padgett et al. (1988a), Lloyd et al. (1990), Banner et al. (1993), DeLong et al. (1993), Manning and Padgett (1995), Sawyer and Keeler-Wolf (1995), Sanderson and Kettler (1996), Crowe and Clausnitzer (1997), Steen and Coupe (1997), Kittel et al. (1999b), and MacKenzie and Moran (2004).

This group is most common in the montane and lower subalpine and may be dominated by a variety of herbaceous communities. Vegetation communities within this group can manifest as a mosaic of several plant associations within an individual wetland, or as a monotypic stand of a single association which is dominated by graminoids or forbs. Most commonly, communities are dominated by Sedges (Carex spp), Rushes (Juncus spp), Spikerushes (Eleocharis spp), Water Horsetail (Equisetum fluviatile), Tufted Hairgrass (Deschampsia cespitosa), and Blue-Joint Reedgrass (Calamagrostis canadensis). Common sedge communities include the Carex aquatilis Wet Meadow, Carex utriculata Marsh, Carex vesicaria Wet Meadow, Carex microptera Wet Meadow and the Carex scopulorum Wet Meadow. In areas that have received moderate to heavy grazing pressure, conversion to a Carex nebrascensis Wet Meadow is commonplace within specific habitat within this group. In the Seeley Lake area and the Swan Valley, the Equisetum fluviatile Marsh plant association is common in some wetlands with standing water or within particular zones within a wetland. Spikerush communities classified as Eleocharis palustris Marsh in shallow, standing water are common though often localized in some wetlands. Grass dominated types are also common, including the Deschampsia cespitosa Wet Meadow, the Calamagrostis canadensis Wet Meadow and in more localized settings within a wetland the Glyceria grandis Wet Meadow.

Streamside communities dominated by Senecio triangularis, Saxifraga spp or Mimulus lewisii occur as narrow zones, particularly within the Northern Rocky Mountains. Wet meadow communities are generally 1 to 3ft in height. They may be large and occupy an entire valley floor, or they can be very small patches or narrow linear strips. They also occur in complex mosaics of meadows intermixed with patches shrublands and more continuous areas of dense, coniferous forest. Bryophytes are abundant in some of these wetland communities, while lichens are mostly absent or occur only within microsites. Non-native species are rare in many of these wetlands though some habitats within this group may have non-natives represented, esp around the margins or in drier settings. Within some marshy sites, Reed Canarygrass (Phalaris arundinaceous) is a problematic species that can spread and outcompete the native communities.

In Montana, this group is represented by 4 Alliances and 21 Associations within the National Vegetation Classification. The range of variation in vegetation types found within Montana within this group is mostly covered by the described types, though some additional associations likely should be attributed to the state. A4427 - Heracleum maximum - Carex scopulorum var. bracteosa - Veratrum viride Wet Meadow Alliance and its 2 Associations are probably better placed in G271.

Communities associated with this group are adapted to soils that may be flooded or saturated throughout the growing season. They may also occur in areas with soils that are only saturated early in the growing season, or intermittently during heavy convective storms in the summer. Most appear to be relatively stable types, although in some areas these may be impacted by intensive livestock grazing.

Non-native species are uncommon in many of these wetlands though some habitats within this group may have non-native species such as Kentucky Bluegrass (Poa pratensis), and Fowl Bluegrass (Poa palustris) represented, esp around the margins or in drier settings. Within some marshy sites, Reed Canarygrass, Creeping Foxtail (Alopecurus arundinaceus) or Meadow Foxtail (Alopecurus pratensis) are problematic species that can spread and outcompete the native communities. Some montane sedge meadows within this group that have a moderate to extensive grazing history may have been converted to a Carex nebrascensis Wet Meadow.

Small scale restoration projects may occur in areas of heavy recreational use or areas of past intensive grazing. Efforts may include removing foot traffic or grazing through fencing or other means. Weed control efforts may be necessary in areas where Reed Canarygrass or Creeping Foxtail (Alopecurus arundinaceus) have established.

P. Comer, G. Kittel and C. Chappell (2015)

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

12/6/2024