Common (Translated Scientific) Name: Western North American Ruderal Marsh, Wet Meadow & Shrubland Macrogroup

Colloquial Name: Western North American Ruderal Marsh, Wet Meadow & Shrubland

Hierarchy Level:  Macrogroup

Type Concept: This macrogroup contains disturbed natural habitats such as wet meadows, emergent marshes, coastal backwater dunes, and sloughs as well as waste areas that were once wetlands and are now dominated by non-native species. Dominant non-native species include Agrostis gigantea, Agrostis stolonifera, Alopecurus pratensis, Arundo donax, Cirsium arvense, Conyza canadensis, Schedonorus arundinaceus, Lactuca serriola, Phalaris arundinacea, Phragmites australis, Poa palustris, Poa pratensis, and Sonchus spp. Native species may be present but are so low in abundance that they are insufficient to identify the native macrogroup or lower units. This macrogroup occurs from sea level up to the subalpine throughout the western U.S. Due to disturbance, soils may be compacted, missing upper horizons, or unnaturally enriched or depleted. Disturbance can be from activities such as severe continuous heavy grazing, abandoned building sites, industry, and road beds, areas that have been logged, or chained and cleared that occur where wetlands once stood.

Diagnostic Characteristics: Strongly dominated by non-native and weedy or generalist native species that are primarily facultative wetland taxa in wet graminoid, forb or shrub meadow or marsh settings. These include grasses and forbs such as Agrostis gigantea, Agrostis stolonifera, Alopecurus pratensis, Cirsium arvense, Conyza canadensis, Schedonorus arundinaceus, Iris pseudacorus, Lepidium latifolium, Lactuca serriola, Phalaris arundinacea, Phragmites australis (non-native strains), Poa palustris, Poa pratensis, Rubus armeniacus, Sonchus spp., and Typha angustifolia, among others.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This macrogroup does not include actively managed irrigated hay meadows that have been historically seeded, whether with native or exotics grasses. These belong under 7. ~Agricultural & Developed Vegetation Cultural Class (CCL01)$$. If management (frequent mowing, seeding, fertilizing) is stopped (was abandoned) and they take on a more spontaneous composition and structure, they may be placed here in M301. Some native plant communities in other macrogroups may be converted to this macrogroup (M301) through disturbances, such as altered soil moisture or soil profile disturbance, introduction of exotics sometimes as a feedback mechanism stemming from the introduced vegetation itself. As long as those communities contain sufficient diagnostic species of the macrogroup, they may be considered as altered phases of that macrogroup, but they are placed here (M301) when the non-native or weedy natives component is overwhelmingly dominant. The decision should be based on the combination of both biotic and abiotic (site) factors, not just site factors. For example, if a site has 99% cover of Phragmites and has such high site disturbance that it is hard to know whether it was once a native woody-dominated swamp or was always a native, herbaceous-dominated marsh, then it is clearly in this macrogroup. But if a site with 98% Phragmites and 2% cover of a native shrub that seems to indicate that the site is a native Salix swamp that was disturbed, and that disturbance has now ended (was abandoned), and can still be identified as a native plant association (albeit very poor condition), then that may belong to the native swamp macrogroup (adapted from D. Meidinger pers. comm. 2014).

Similar NVC Types: No Data Available

note: No Data Available