State 1
Reference State (minimally-managed)

The marsh ecological site includes all open wetlands in MLRA 146. Current soil mapping does not distinguish between significant marsh types, and further research is required to define true wetland site concepts for the MLRA. Freshwater marsh sites occur in closed or open basins that are generally flat and shallow, they are associated with lakes, ponds, slow-moving streams, and/or impoundments or ditches. Surface water is non-tidal, persistent year-round (saturated to flooded), and ranges from several centimeters to several meters in depth. This ecological site provides a foraging, breeding, nesting habitat for many water-dependent animal populations. Several rare or endangered insects reptile, bird and amphibian species utilize these freshwater marsh habitats.

Characteristics and indicators. These sites are characterized by a variety of emergent , floating, and/or submergent aquatic vegetation species. Deciduous shrubs may be present and scattered, but trees are generally absent on these sites. The substrate is often a mixture of silty organic muck rather than peat.

Resilience management. The major threats to this ecological site are water quality degradation from excess nutrients in runoff and the spread of invasive aquatic plants. Maintaining appropriate wetland buffers can help ensure that adjacent land uses do not result in marsh degradation.

Community 1.1
Mixed Graminoid – Shrub Marsh

This site is very broadly defined and could be subdivided into shrub versus herbaceous types using additional site data and analyses.. This is a heterogeneous wetland type in which herbs and shrubs occur in various assemblages and proportions (herbs 25-95%, shrubs 0-70% cover). Many examples are transitional to other open wetland types and any of a variety of graminoids may be prominent at different sites. The more typical expression is dominated by herbs, with a mixture of graminoids making up at least 50% of the cover, often with a sparse shrub layer. Three-way sedge and yellow loosestrife are typical indicators of this site. Bryophytes are generally minor. Sites are typically on mineral soils (may have a thick organic layer of muck) with soil pH typically between 5.0-6.0. This site is typically flooded early in the growing season and remains saturated (or occasionally flooded) throughout the season. (Gawler and Cutko, 2010)

Resilience management. Maine Natural Areas Program State Rank: S5 Secure – At very low risk or extinction or elimination due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats. Maintaining appropriate wetland buffers can help ensure that adjacent land uses do not degrade the marshes. Beaver activity often affects these wetlands, and can cause dramatic (although sometimes temporary) changes in dominance. (Gawler and Cutko, 2010)

Community 1.2
Pickerelweed – Macrophyte Aquatic Bed

This ecological site occupies quiet waters along the shores of lakes, ponds, and streams. The substrate is usually mucky and the water ranges from acidic to circumneutral. This shallow water aquatic type is dominated by a mixture of emergent plants, floating plants, and submerged plants suspended in the water column. Pickerelweed, yellow water-lily, and bladderworts are almost always present, and one or more is typically dominant. A variety of pondweed species, bulrushes, bur-reed species, and other aquatics may be present. Total cover ranges from 30-100% and is typically >50%. (Gawler and Cutko, 2010)

Resilience management. Maine Natural Areas Program State Rank: S5 Secure – At very low risk or extinction or elimination due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats. This aquatic vegetation type is widespread and abundant in Maine. It can be found in the quieter portions of streams and rivers as well as in lakes and ponds. It provides habitat for a variety of water dependent animals. Many examples occur on public lands and private conservation lands; however, this common type is often not documented. The major threats to this community are water quality degradation from excess nutrients in runoff and the spread of invasive aquatic plants such as Eurasian water-milfoil and variable water-milfoil. (Gawler and Cutko, 2010)

Community 1.3
Bulrush Bed

These deepwater marshes have standing water over 15 cm deep all year, except during unusually prolonged low water levels. Bulrush beds are often near inlets and outlets of lakes or along slow moving portions of larger streams and rivers. Tall rushes and other non-persistent graminoids dominate this lakeshore or rivershore community. Aquatic macrophytes may be present, but are not usually abundant. Species richness is often low. (Gawler and Cutko, 2010)

Resilience management. Maine Natural Areas Program State Rank: S4 Apparently Secure – At fairly low risk of extinction or elimination due to an extensive range and/or many populations or occurrences, but with possible cause for some concern as a result of local recent declines, threats, or other factors. This type appears to be well distributed and secure in Maine. Anecdotal information indicates that the waters of numerous public lands and private conservation lands include these marshes. Maintaining appropriate wetland buffers can help ensure that adjacent land uses do not result in degradation. (Gawler and Cutko, 2010)

Community 1.4
Cattail Marsh

Cattail marshes often occur in impounded, semi-permanently flooded, and/or nutrient-rich waters, they are generally associated with large basins and adjacent to open water. Standing water persists throughout all or most seasons and substrate is muck or mineral soil rather than peat. Tall marsh vegetation is dominated by cattails and mostly deciduous shrubs. The cattails may be patchy, locally dominant, and grow taller than the other plant species. The dense growth of shrubs and cattails leaves little room for other herbaceous species.. Bryophytes are usually sparse and occur on vegetation hummocks. (Gawler and Cutko, 2010)

Resilience management. Maine Natural Areas Program State Rank: S5 Secure – At very low risk or extinction or elimination due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats. This community is well distributed statewide and apparently well represented (although not well documented) on public lands and private conservation lands. Maintaining appropriate wetland buffers can help ensure that adjacent land uses do not result in degradation. (Gawler and Cutko, 2010)

Community 1.5
Water-lily – Macrophyte Aquatic Bed

This site is currently broadly defined and may be divisible into two or more types with additional data. These aquatic beds occur in quiet waters at depths mostly between 0.5 and 2.5 m. The substrate is typically a mixture of silty organic muck. Water-lilies or pondweeds are dominant in this floating aquatic vegetation type and submerged aquatic plants are also common and may include bladderworts and pipewort. (Gawler and Cutko, 2010)

Resilience management. Maine Natural Areas Program State Rank: S5 Secure – At very low risk or extinction or elimination due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats. The major threats to this natural community are water quality degradation from excess nutrients in runoff and the spread of invasive aquatic plants. (Gawler and Cutko, 2010)

State 2
Semi-natural State

Shifts in ecological site composition, functionality, and dynamics driven by natural disturbances, processes, and pressures (may have some anthropogenic influences). More research is needed to determine the extent of the Semi-natural state associated with this ecological site.

Community 2.1
Invasiveness and Biological Introductions

Introduction of invasive species, pathogens, and/or pests resulting in shifts in ecological site composition, functionality, and dynamics. More research is needed to determine the extent of these effects on the semi-natural state associated with this ecological site.

Community 2.2
Transitional Marsh

Hydrological alteration of sites that can include the removal or addition of dams, barriers, structures, or actions that temporarily or permanently alter watersheds or the fluvial geomorphology of rivers and streams. These actions strongly influence site functions, dynamics, and composition that promote a semi-natural state as opposed to either extremes of hydrological alteration within the reference state and cultural state.

Community 2.3
Ponded

Hydrologically-altered. Management of sites can include the addition of dams, barriers, structures, or actions that temporarily or permanently alter watersheds or the fluvial geomorphology of rivers and streams. These actions strongly influence site functions, dynamics, and composition promoting an intended cultural state.

Pathway 2.1a
Community 2.1 to 2.2

introduction of invasive species/pests/pathogens, soil disturbance, climate change, drought

Pathway 2.1b
Community 2.1 to 2.3

introduction of invasive species/pests/pathogens, soil disturbance, climate change, drought

Pathway 2.2a
Community 2.2 to 2.3

hydrologic alteration (obstruction or barrier), increase in annual precipitation (decadal) or increase in significant flooding events.

Pathway 2.3a
Community 2.3 to 2.2

remediation of hydrologic alteration (obstruction or barrier removed), increase in drought over several years, warmer annual temperatures (decadal)

State 3
Cultural State

Shifts in ecological site composition, functionality, and dynamics that are primary driven by anthropogenic disturbances and pressures (may have some associated natural influences). More research is needed to determine the extent of the cultural state associated with this ecological site.

Community 3.1
Drained

Cultural state used for plantations, cultivated cropland, pastures, or hayland primarily formed by hydrological alteration.

Transition T1A
State 1 to 2

hydrologic alteration (natural/anthropogenic), soil disturbance, increased flooding, drought, climate change

Transition T1B
State 1 to 3

hydrologic alteration (anthropogenic), mechanical soil disturbance

Restoration pathway R2A
State 2 to 1

restoration, seeding/planting, actively managed for invasiveness and biological introductions, remediation of hydrologic alteration

Transition T2A
State 2 to 3

hydrologic alteration, significant drought, potential for agricultural use

Restoration pathway R3A
State 3 to 1

remediation of hydrologic alteration, increased flooding frequency/duration, active restoration management

Restoration pathway R3B
State 3 to 2

remediation of hydrologic alteration, increased flooding frequency/duration, active restoration management