State 1
Reference State (minimally-managed)

This site occurs in glacial till deposits on hill slopes, till plains, drumlins and ridges. Soils formed in lodgement till, which consists of 10-34 inches of loamy soil over a highly compacted layer of gravelly loam subsoil. This dense layer was compacted by the weight of overlying glaciers and impedes plant roots and water movement on the site. Drainage ranges from somewhat poorly to well drained. Slopes are typically moderate, but may be as high as 30 percent or higher. This site has a seasonally high water table between 16 and 41 inches in the winter and spring. During the summer and fall the water table is usually deeper, except following heavy rain events. Soil pH ranges from 3.5 to 6.5 and tends to be more acidic near the soil surface and less acidic in the dense subsoil.

Characteristics and indicators. Hardwoods are dominant on much of this ecological site, including yellow birch, sugar maple, red maple, American beech, and white ash. Softwood abundance tends to be higher where bedrock is within 40 inches of the soil, near drainageways, and on steeper slopes. Common understory species are intermediate woodfern, wild sarsasparilla, starflower, Canada mayflower, and striped maple.

Resilience management. This site is subject to logging, wind, insects and disease, and other natural and human disturbances resulting in a variety of alternative states. Cultivated sites occur on flatter slopes, and are mostly cropland, pasture or hay land. Abandoned farmland may transition to pine, spruce-fir, or reference hardwood-dominated forests, often with an intermediate early seral forest phase.

Community 1.1
Hardwood Seepage Forest

This reference state occurs on slight slopes (<15%) and adjacent bottoms where an impervious soil layer (~30 cm deep), such as marine clay or packed till, forces seepage water near the surface. Sites often occur at breaks in slope – either at the base of a slope, or on a slope bench. Soils are loamy, or grading to silty in flats, and moderately acidic to neutral (pH 5.2-7.0). Soils place this as a wetland type, but some sites may grade from wetland to upland as one moves upslope. Small sites, or ‘forest seeps’ (i.e., less than one acre) are frequent and are typically considered as inclusions within the broader forest rather than distinct natural communities. These closed canopy to partial canopy forests support a mixture of mostly deciduous overstory trees with occasionally patchy local dense conifers. The understory is usually open, with few shrubs and patches of tree regeneration. The herb layer is typically patchy, and reflects the underlying seepage gradients between species inhabiting the wettest areas and species less restricted by soil moisture. Bryoids are sparse. (Gawler and Cutko, 2010)

Resilience management. Maine Natural Areas Program State Rank: S3 Vulnerable – At moderate risk of extinction or elimination due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors. Many sites are on land with a long settlement history and have been either cleared or harvested in the past. Because these tend to occur as small forest patches, their conservation depends in part on maintaining some surrounding forest cover (both upslope and downslope) as a buffer. Like vernal pools, recognition of this type is more difficult in the winter, when snow cover and plant senescence may make it difficult to distinguish these sites from upland forest. Seeps may remain unfrozen through the winter, making it difficult to operate logging equipment. (Gawler and Cutko, 2010)

Community 1.2
Spruce - Northern Hardwoods Forest

These forests occur on cooler microsites from near sea level to 2200’. They are usually on hillslopes, ranging from lower to upper slopes and from gentle to steep (up to 50%). The soils are typically well drained, sometimes somewhat excessively drained, sandy to loamy in texture, with pH 5.0-5.4. This mixed forest type is characterized by hardwoods with occasional scattered large supercanopy species. The sapling/shrub layer may be fairly well developed (20-40% cover), with saplings of canopy species; shrub species vary among sites. The herb layer ranges from sparse to dense but is usually >15% cover, divided between forbs, ferns, and regenerating trees, with dwarf shrubs virtually absent. The bryoid layer is patchy and locally well developed, with bryophytes far more abundant than lichens. (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. Nearly all forests of this type have been harvested in the past, and at many sites the spruce has been selectively removed. As a result, the canopies of such sites are more often indicative of Beech - Birch - Maple Forests, with spruce and fir more common in the understory than in the canopy. Sites with relatively little human disturbance are rare but are moderately well represented on conservation lands. (Gawler and Cutko, 2010)

Community 1.3
Red Oak - Northern Hardwoods - White Pine Forest

This reference state occurs on gently to somewhat steeply sloping (15-35%) mid- and lower slopes, occasionally upper slopes, but usually not highly exposed sites. Known sites are at low elevations (<1200’) on moderately well drained mineral soils, often rocky but not extremely shallow (typically 25-50 cm) and loamy, with pH 5.0-5.4. This is a mixed upland forest type with red oak and northern hardwoods in the canopy. Some stands are almost entirely deciduous (typically oak - beech), while others are mixed with white pine, red spruce, hemlock, or (especially along the coast) northern white cedar. Large red oak trees are prominent. Red maple is frequent. The shrub/sapling layer is usually sparse (<25%, but occasionally up to 50% cover). The herb layer is likewise spotty (usually <10% cover, sometimes 20-50% cover), with very few dwarf shrubs and with typical forest herbs and tree regeneration. Few bryoids are found on the leaf litter covered forest floor. (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. Most sites in Maine are on lands with a long settlement history, and have apparently been timbered, pastured, or burned in the past. Several sites occur on public lands but are not necessarily designated as areas to be set aside from timber harvest. Small and isolated protected stands (on the order of 25 acres or less) may not be viable in the long run; though larger stands, or naturally small stands protected within a managed forest matrix, could be viable. (Gawler and Cutko, 2010)

Community 1.4
Hemlock Forest

Hemlock forests are usually on slopes (typically 5-50%) and ravines, with well drained loamy soil. On lower slopes and flats, soils may grade to imperfectly drained. Soils tend to be shallow (<50 cm) and acidic (pH 4.8-5.6). Sites are from sea level to 1200’ and often in cool microsites, although aspect varies. This closed canopy forest type is dominated by hemlock (>50% cover). The conifer canopy allows little light to reach below, and the shrub, herb, and bryoid layers are sparse (each usually <25%, and sometimes absent altogether). Small conifers are present in the herb layer, as well as scattered individuals of typical upland conifer forest plants. Graminoids are rarely very apparent. The ground layer is mostly conifer litter, with spotty bryophyte cover. (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. Demand in the 1700s -1800s for hemlock considerably reduced mature, undisturbed examples of this type, yet poor market conditions more recently have caused hemlock to be left in partial harvests; many of these legacy trees are quite old. Some evidence suggests that hemlock is less successful at maintaining itself in the face of human-caused disturbance than are northern hardwoods. Most sites known to be of high ecological quality are in southern and central Maine and lack formal protection. Maintaining the surrounding lands as forest is important in conserving particular stands of this type, particularly given that many known examples are small (<50 acres). (Gawler and Cutko, 2010)

Pathway 1.2a
Community 1.2 to 1.3

Presence of red oak, red oak dominated forest

Pathway 1.3a
Community 1.3 to 1.2

Absence of red oak and spruce dominated forest

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.

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
Plantation

Crop or hayland cultivation, timber management and harvesting

Transition T1A
State 1 to 2

Introduction of invasive species, pests, and/or pathogens that alter ecological site functions, dynamics, and properties

Transition T1B
State 1 to 3

Timber management and harvesting, landscape clearing, mechanical landscape alteration, mechanical soil disturbance, planting, seeding, cultivation

Restoration pathway R2A
State 2 to 1

Removal, remediation, or control of invasive species, pests, and/or pathogens through mechanical, biological, or chemical management; establishment of native plants through seeding and/or planting

Transition T2A
State 2 to 3

Timber management and harvesting, landscape clearing, mechanical landscape alteration, mechanical soil disturbance, planting, seeding, cultivation

Restoration pathway R3B
State 3 to 1

Restoration of native plant communities, planting, seeding, removal of obstructions or barriers

Restoration pathway R3A
State 3 to 2

Restoration of native plant communities, planting, seeding, removal of obstructions or barriers