State 1
Reference State (minimally-managed)

This site occurs in gently sloping areas near the bottom of watersheds where water saturates glaciolacustrine deposits for much of the growing season. Soils are poorly- and very poorly-drained with clayey textures and parent materials. The water table is seasonally high (within 12 inches of the surface) and typically dries out in late summer and fall. This site is typically drier than the Clay site (401) and may be ponded in depressions. Mixed hardwoods and softwoods dominate the reference community, including black and red spruce, red maple, brown ash, and balsam fir.

Resilience management. This site is dominated by mixed hardwood and softwood species including red and black spruce, balsam fir, larch, red maple and brown ash. It is often logged, which sets the stand through a series of phases, beginning with herbaceous colonizers, then dense spruce and balsam fir saplings, and eventually to mature spruce-fir forest. Within 100 years, any balsam fir dies out and longer-lived species dominate the mature forest. Similar community dynamics occur within stands on this site as blowdowns or spruce budworm open up small patches of mature overstory trees for establishment by herbs and conifer saplings.

Community 1.1
North Central Interior Wet Flatwoods

This system usually occurs on poorly drained uplands or in depressions associated with glacial features such as tillplains, lakeplains, or outwash plains. Soils often have an impermeable or nearly impermeable clay layer that impedes waterflow. This favors flooding or ponding in the spring or after heavy rains. It also restricts subsurface water movement into the system and slows the growth of roots through it. Both of these factors lead to water deficits for the vegetation in the late summer and fall. These fluctuating moisture levels can lead to complexes of forest upland and wetland species occurring within this system. Overall topographic relief is very flat in this system though small tip-up mounds and depressions can occur from windthrow and often create small pockets with vegetation more typical of upland or swamp forest, respectively. Quercus palustris and/or Quercus bicolor typically dominate the wetter portions and are often associated with Acer rubrum. Quercus alba, Quercus rubra, Fagus grandifolia, and Acer saccharum are common in the better-drained areas. Carya ovata is a characteristic tree in the Champlain Valley. Liquidambar styraciflua, Nyssa sylvatica, Fraxinus americana, and Fraxinus pennsylvanica are also common associates, though their occurrence varies somewhat by region. Understory herbaceous and shrub species present in examples of this system can vary. Stands with more dense tree cover have less shrub and herbaceous cover, while those with moderate tree canopy cover tend to have a dense understory. Some common species include Carex spp., Osmunda cinnamomea, Cephalanthus occidentalis, Alnus spp., and Ilex spp. In the clayplain forests of Vermont, characteristic herbs include Waldsteinia fragarioides and Moehringia lateriflora (= Arenaria lateriflora). The large seasonal change in local available moisture is key to the development and maintenance of this system. Plants must be able to tolerate the excessive available moisture (surface flooding or saturation) and drought conditions that occur in most growing seasons. Fire can occur after the system dries, typically late in the growing season. Fires rarely start in this system but under favorable conditions can spread from nearby fire-prone systems (typically prairies, oak savannas, or oak woodlands). With the often shallowly-rooted trees, strong winds can create canopy openings. Small-scale windthrow is a characteristic disturbance in flatwoods that influences composition and structure by creating canopy gaps that are suitable for the colonization and growth of light-dependent tree seedlings and saplings, shrubs, and herbs. Windthrow also tips and uproots trees, creating pit-and-mound topography that provides suitable microhabitats for a diversity of plants. NatureServe Element Code: CES202.700 (NatureServe, 2022)

Resilience management. Changes to the hydrologic regime and conversion to agricultural or urban uses are the most common threats to this system. Road building and urban development can cut off or increase waterflow; drainage systems for nearby agriculture can remove water from the system. Fraxinus spp. and Ulmus spp. can invade and become common if the flooding/drying regime is not maintained and fires do not move through the ground layer. Invasive shrubs are a problem in some areas. Very few examples remain as almost all have been converted to agriculture. Those sites that do remain typically occur as isolated woodlots in agricultural or urban landscapes, degraded by landscape-scale fragmentation and hydrologic alteration. Additional disturbances that have reduced viability of remnant flatwoods over the past century include the introduction of non-native pests and pathogens (e.g., elm blight and emerald ash borer), invasive plants, and excessive deer herbivory, which have significantly altered community structure, species composition, and successional trajectory. NatureServe Element Code: CES202.700 (NatureServe, 2022)

State 2
Semi-natural State

Shifts in ecological site composition, functionality, and dynamics driven by natural disturbances, processes, and pressures (may have some anthropogenic drivers). 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
Ponded

Increased annual/decadal precipitation or increase in significant flooding events

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 drivers). More research is needed to determine the extent of the cultural state associated with this ecological site.

Transition T1A
State 1 to 2

climate change, hydrological alteration, significant increase in flooding events and annual precipitation, introduction of invasive species, pests, and pathogens

Transition T1B
State 1 to 3

hydrologic alteration (barrier, obstruction, dam, diversion), landscape alteration, mechanical soil disturbance, landscape alteration, planting, seeding

Restoration pathway R2A
State 2 to 1

remediation of hydrologic alteration, management of invasive species, pests, and pathogens, restoration of key native plant species, restoration of terrestrial and aquatic habitat

Transition T2A
State 2 to 3

hydrologic alteration (barrier, obstruction, dam, diversion), landscape alteration, mechanical soil disturbance, landscape alteration, planting, seeding

Restoration pathway R3B
State 3 to 1

remediation of hydrologic alteration, seeding, planting, significant flooding events and increase in annual precipitation, compacted soil, establishment of key native plant species

Restoration pathway R3A
State 3 to 2

remediation of hydrologic alteration, seeding, planting, significant flooding events and increase in annual precipitation, compacted soil, establishment of key native plant species