Ecological dynamics
[Caveat: The vegetation information contained in this section and is only provisional, based on concepts, and future projects support validation through field work. *] The vegetation groupings described in this section are based on the terrestrial ecological system classification and vegetation associations developed by NatureServe (Comer 2003) and localized associations provided by the Maine Natural Areas Program (Gawler and Cutko, 2010).
Much of this site is considered prime farmland for growing crops. Where native vegetation is present, hardwood species predominate, with some conifers in the overstory a diverse and productive understory. Common hardwood species are red maple, sugar maple, yellow birch, white birch, bigtooth aspen, and black cherry.
Abandoned cropland may transition to pine, spruce-fir, or reference hardwood-dominated mixedwood forests.
This site is subject to logging, wind, insects and disease, and other natural and human disturbances resulting in a variety of alternative states.
When managed for timber production, several different ecological states are possible. The pine forest state, reference hardwood-dominated mixedwood state, and spruce-fir state are managed to maintain dominance of their respective timber species, and to facilitate profitable harvests along predictable timelines. Hemlock forests may also result from logging practices, though these are typically less-desirable and may result from selective harvest of more valuable species, leaving the hemlock behind. As hemlock increases on the site, it inhibits the establishment of other species by shading, reducing soil moisture availability to other plants, and especially by acidifying the soil.
With sufficient economic inputs, any of the states that occur on this site may transition from one to another, however, due to cost limitations, forests are typically managed for whatever timber species are currently present on the site.
State 1
Reference State (minimally managed)
The forest canopy typically exceeds 65%, with red pine dominant or co-dominant (at least 33% cover) with other conifers; the shrub layer is usually sparse (<15%).
Dominant resource concerns
-
Plant productivity and health
-
Plant structure and composition
-
Plant pest pressure
-
Terrestrial habitat for wildlife and invertebrates
Community 1.1
Red Pine - White Pine Forest
These ecological sites are usually on flats, slopes of <25% or low ridges (<1000’), on dry-mesic to xeric soils that are somewhat to very shallow (10-50 cm to obstruction, usually bedrock). Soils are coarse (sandy loams to sands) and acidic (pH 4.8-5.2).
These are upland forests with red pine as the dominant tree. The canopy may be somewhat open but is more typically >70%. Especially in post-fire sites, the canopy may include deciduous trees, while lower layers are generally sparse (<25% cover) and contain few species Graminoids are virtually absent. The ground is typically covered with conifer litter and patches of bryophytes, or less commonly, lichens. (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.
Red pine has been widely planted in the past, but natural occurrences of this type are fairly rare outside of eastern Maine. Under natural conditions, these forests apparently require fire for persistence or regeneration, but community dynamics are not well documented, and at some known sites clearcut harvesting has perpetuated the type. Most known sites are small, lack formal protection, and could be maintained within a forested matrix. (Gawler and Cutko, 2010)
Dominant resource concerns
-
Sheet and rill erosion
-
Wind erosion
-
Plant productivity and health
-
Plant structure and composition
-
Plant pest pressure
-
Wildfire hazard from biomass accumulation
-
Terrestrial habitat for wildlife and invertebrates
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.
Dominant resource concerns
-
Plant productivity and health
-
Plant structure and composition
-
Plant pest pressure
-
Terrestrial habitat for wildlife and invertebrates
-
Aquatic habitat for fish and other organisms
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.
Dominant resource concerns
-
Plant productivity and health
-
Plant structure and composition
-
Plant pest pressure
-
Terrestrial habitat for wildlife and invertebrates
-
Aquatic habitat for fish and other organisms
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
Alteration of landscapes for timber or crop production and harvesting
Dominant resource concerns
-
Compaction
-
Pesticides transported to surface water
-
Pesticides transported to ground water
-
Plant productivity and health
-
Plant structure and composition
Transition T1A
State 1 to 2
Introduction of invasive species, pests, and/or pathogens; alteration of ecological dynamics, functions, and composition, etc.
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
Mechanical, biological, or chemical management of invasive species, pests, and/or pathogens; establishment of native plants through seeding and/or planting
| Vegetated Treatment Area |
|
| Restoration and Management of Rare and Declining Habitats |
|
| Early Successional Habitat Development/Management |
|
| Invasive Plant Species Control |
|
| Invasive Species Pest Management |
|
| Precision Pest Control Application |
|
| Restoration and Management of Rare or Declining Habitats |
|
| Monitoring and Evaluation |
|
Transition T2A
State 2 to 3
Timber management and harvesting, landscape clearing, mechanical landscape alteration, mechanical soil disturbance, planting, seeding, cultivation
| Cover Crop |
|
| Land Clearing |
|
| High residue cover crop or mixtures of high residue cover crops for weed suppression and soil health |
|
| Intensive no-till (Organic or Non-organic systems) |
|
| Crop management system on crop land acres recently converted |
|
Restoration pathway R3A
State 3 to 1
Restoration of native plant communities, planting, seeding, removal of obstructions or barriers
| Critical Area Planting |
|
| Obstruction Removal |
|
| Vegetated Treatment Area |
|
| Early Successional Habitat Development/Management |
|
| Restoration and Management of Natural Ecosystems |
|
| Native Plant Community Restoration and Management |
|
| Forest stand improvement for habitat and soil quality |
|
| Multi-species Native Perennials for Biomass/Wildlife Habitat |
|
| Monitoring and Evaluation |
|
Restoration pathway R3B
State 3 to 2
Restoration of native plant communities, planting, seeding, removal of obstructions or barriers
| Early Successional Habitat Development/Management |
|
| Restoration and Management of Natural Ecosystems |
|
| Native Plant Community Restoration and Management |
|
| Monitoring and Evaluation |
|
