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Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
MLRA notes
Major Land Resource Area (MLRA): 146X–Aroostook Area
This area is entirely in Maine and it makes up about 1,275 square miles (3,305 square kilometers). Presque Isle is the largest city in the area. Interstate 95 ends in the town of Houlton, at the border with New Brunswick, Canada. Aroostook State Park, Fort Kent Historic Site, and Loring Commerce Center are in this area. The Big Rock ski area is in the middle of this MLRA and is on the highest point, which is Mars Hill Mountain.
Ecological site concept
This site occurs on deep sandy and gravelly deposits associated with eskers, kames, outwash plains and outwash terraces. Soils range from excessively drained, which are sandy throughout, to well-drained which have a gravelly or sandy loam cap over a sandy subsoil. All of these soils formed in deposits of coarse sediment by fast-moving glacial meltwater. These landforms are dominated by softwoods, particularly red pine, white pine, hemlock and/or red spruce with sparse understory cover. However, hardwood and herbaceous species are more abundant where soils are loamier. Common hardwood species are red maple, white birch, bigtooth aspen, and black cherry.
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 pasture or hay land. Abandoned hay land may transition to pine, spruce-fir, or reference pine-dominated mixed-conifer forests.
When managed for timber production, several different ecological states are possible. The pine forest state, reference mixed conifer state, and spruce-fir state are managed to maintain dominance of their respective conifer 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.Associated sites
F146XY072ME Loamy Over Sandy
This site may grade into the Loamy over Sandy site as soil textures become finer. This results in increased hardwoods and decreased conifers.
Similar sites
F146XY072ME Loamy Over Sandy
The Loamy over Sandy site occurs on similar landforms as the Sandy site, but has finer soil textures, wetter drainage classes, and greater hardwood abundance.
Table 1. Dominant plant species
Tree (1) Pinus resinosa
(2) Pinus strobusShrub (1) Gaylussacia baccata
Herbaceous (1) Pteridium aquilinum
(2) Maianthemum canadensePhysiographic features
This site occurs on deep sandy deposits associated with eskers, kames, outwash plains and outwash terraces at elevations up to 2000 feet. Slopes are flat to very steep ranging from 0-45 percent. As glaciers receded, high-energy meltwater deposited coarse sediments, resulting in the sandy and gravelly landforms typical of this site.
Table 2. Representative physiographic features
Landforms (1) Esker
(2) Kame
(3) Outwash terrace
Runoff class Negligible to low Flooding frequency None Ponding frequency None Elevation 10 – 2000 ft Slope 0 – 45 % Water table depth 72 – 0 in Aspect Aspect is not a significant factor Climatic features
The climate of this site is characterized by cold, snowy winters, and cool summers. Precipitation is nearly equally distributed throughout the year, with slightly more moisture falling in June-October. During winter months, and sometimes fall and spring, cold winds from the north bring severe weather events. The effects of a relatively short growing season are somewhat mitigated by long summer days associated with the high latitudes of the region. Occasionally high winds, microbursts, or freezing rain events damage vegetation over small portions of the landscape.
Table 3 Representative climatic features
Frost-free period (characteristic range) 80-90 days Freeze-free period (characteristic range) 130-130 days Precipitation total (characteristic range) 40-40 in Frost-free period (actual range) 60-110 days Freeze-free period (actual range) 100-140 days Precipitation total (actual range) 40-40 in Frost-free period (average) 90 days Freeze-free period (average) 130 days Precipitation total (average) 40 in Characteristic rangeActual rangeBarLineFigure 1. Monthly precipitation range
Characteristic rangeActual rangeBarLineFigure 2. Monthly minimum temperature range
Characteristic rangeActual rangeBarLineFigure 3. Monthly maximum temperature range
BarLineFigure 4. Monthly average minimum and maximum temperature
Figure 5. Annual precipitation pattern
Figure 6 Annual average temperature pattern
Climate stations used
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(1) FT KENT [USC00172878], Fort Kent, ME
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(2) CARIBOU MUNI AP [USW00014607], Caribou, ME
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(3) ALLAGASH [USC00170200], Saint Francis, ME
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(4) BRIDGEWATER [USC00170833], Bridgewater, ME
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(5) HOULTON 5N [USC00173944], Houlton, ME
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(6) PRESQUE ISLE [USC00176937], Presque Isle, ME
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(7) HOULTON INTL AP [USW00014609], Houlton, ME
">Influencing water features
Due to its landscape position, this site is not influenced by streams or wetlands.
Soil features
The soils of this site are deep and sandy, often with gravels that occur in patches or throughout the soil profile. This site includes both excessively drained soils which are sandy throughout, and well drained to somewhat excessively well drained soils which have a gravelly or sandy loam cap over a sandy subsoil. All of these soils formed in deposits of relatively coarse sediment deposited by fast-moving glacial meltwater. Water holding capacity is low and pH ranges from 3.6 to 6.5. The soil temperature regime is frigid and the soil moisture regime is udic.
Table 4. Representative soil features
Parent material (1) Glaciofluvial deposits – granite
Surface texture (1) Gravelly sandy loam
(2) Gravelly loam
(3) Extremely gravelly coarse sand
Family particle size (1) Sandy
Drainage class Well drained to excessively drained Permeability class Moderately slow to moderate Soil depth 60 – 0 in Surface fragment cover <=3" 0 – 5 % Surface fragment cover >3" 0 – 1 % Available water capacity
(0-40in)1.4 – 6.3 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)3.6 – 6.5 Subsurface fragment volume <=3"
(Depth not specified)25 – 62 % Subsurface fragment volume >3"
(Depth not specified)5 – 9 % 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).
The reference plant communities on this site are red pine, white pine, hemlock and/or red spruce with sparse understory cover. However, hardwood and herbaceous species are more abundant where soils become finer. Common hardwood species are red maple, white birch, bigtooth aspen, and black cherry.
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 pasture or hay land. Abandoned hay land may transition to pine, spruce-fir, or reference pine-dominated mixed-conifer forests.
When managed for timber production, several different ecological states are possible. The pine forest state, reference mixed conifer state, and spruce-fir state are managed to maintain dominance of their respective conifer 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 and transition model
Custom diagramStandard diagram
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textState 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
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 (
Dominant resource concerns
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Plant productivity and health
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Plant structure and composition
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Plant pest pressure
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Terrestrial habitat for wildlife and invertebrates
Community 1.1
Red Pine - White Pine ForestThese ecological sites re usually on flats, slopes of
Resilience management. Maine Natural Areas Program State Rank: 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 plant species
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bigtooth aspen (Populus grandidentata), tree
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red pine (Pinus resinosa), tree
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red spruce (Picea rubens), tree
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eastern white pine (Pinus strobus), tree
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eastern hemlock (Tsuga canadensis), tree
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black huckleberry (Gaylussacia baccata), shrub
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brackenfern (Pteridium), other herbaceous
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Canada mayflower (Maianthemum canadense), other herbaceous
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starflower (Trientalis borealis), other herbaceous
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American wintergreen (Pyrola americana), other herbaceous
Dominant resource concerns
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Sheet and rill erosion
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Wind erosion
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Plant productivity and health
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Plant structure and composition
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Plant pest pressure
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Wildfire hazard from biomass accumulation
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Terrestrial habitat for wildlife and invertebrates
State 2
Semi-natural StateShifts 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
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Plant productivity and health
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Plant structure and composition
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Plant pest pressure
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Terrestrial habitat for wildlife and invertebrates
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Aquatic habitat for fish and other organisms
Community 2.1
Invasiveness and Biological IntroductionsIntroduction of invasive species, pests, and pathogens
Dominant resource concerns
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Plant productivity and health
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Plant structure and composition
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Plant pest pressure
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Terrestrial habitat for wildlife and invertebrates
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Aquatic habitat for fish and other organisms
State 3
Cultural StateShifts 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
PlantationAlteration of landscapes for timber or crop production and harvesting
Dominant resource concerns
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Compaction
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Pesticides transported to surface water
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Pesticides transported to ground water
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Plant productivity and health
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Plant structure and composition
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Terrestrial habitat for wildlife and invertebrates
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Aquatic habitat for fish and other organisms
Transition T1A
State 1 to 2Introduction of invasive species, pests, and/or pathogens; alteration of ecological dynamics, functions, and composition, etc.
Key drivers
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Fire
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Climate
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Mechanical soil disturbance
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Nonnative pest presence and/or establishment
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Nonnative disease presence and/or establishment
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Timber management
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Nonnative plant species presence and/or establishment
Key ecosystem services affected
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Erosion control
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Pollination
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Nutrient cycling
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Primary production
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Climate regulation: carbon cycling and storage
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Wildlife habitat
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Soil formation
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Animal biodiversity
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Plant biodiversity
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Climate regulation
Transition T1B
State 1 to 3Timber management and harvesting, landscape clearing, mechanical landscape alteration, mechanical soil disturbance, planting, seeding, cultivation
Key drivers
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Mechanical soil disturbance
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Timber management
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Seeding
Key ecosystem services affected
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Pollination
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Aesthetic values
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Nutrient cycling
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Recreation
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Wildlife forage
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Climate regulation: carbon cycling and storage
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Wildlife habitat
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Soil formation
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Animal biodiversity
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Plant biodiversity
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Climate regulation
Restoration pathway R2A
State 2 to 1Mechanical, biological, or chemical management of invasive species, pests, and/or pathogens; establishment of native plants through seeding and/or planting
Conservation practices
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 3Timber management and harvesting, landscape clearing, mechanical landscape alteration, mechanical soil disturbance, planting, seeding, cultivation
Conservation practices
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 Key drivers
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Mechanical soil disturbance
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Timber management
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Seeding
Restoration pathway R3A
State 3 to 1Restoration of native plant communities, planting, seeding, removal of obstructions or barriers
Conservation practices
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 2Restoration of native plant communities, planting, seeding, removal of obstructions or barriers
Conservation practices
Early Successional Habitat Development/Management Restoration and Management of Natural Ecosystems Native Plant Community Restoration and Management Monitoring and Evaluation Additional community tables
Table 5. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 6. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 7. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Supporting information
Inventory data references
Future work is needed, as described in a future project plan, to validate the information presented in this provisional ecological site description. Future work includes field sampling, data collection and analysis by qualified vegetation ecologists and soil scientists. As warranted, annual reviews of the project plan can be conducted by the Ecological Site Technical Team. A final field review, peer review, quality control, and quality assurance reviews of the ESD are necessary to approve a final document.
Other references
Comer, P., D. Faber-Langendoen, R. Evans, S. Grawler, C. Josse, G. Kittel, S. Menard, M. Pyne, M. Reid, K. Schultz, K. Snow, and J. Teague. 2003. Ecological Systems of the United States: A Working Classification of U.S. Terrestrial Systems. NatureServe, Arlington, Virginia
Gawler, S. and A. Cutko. 2010. Natural Landscapes of Maine: A Guide to Natural Communities and Ecosystems. Maine Natural Areas Program, Maine Department of Conservation, Augusta, Maine.
NatureServe. 2018. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. NatureServe Explorer (accessed 10 July. 2021).
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. 2006. Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin. Agricultural Handbook 296
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Official Soil Series Descriptions. Available online. (accessed 11 Aug. 2021).
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Soil Climate Research Station Data. Available online. (accessed 23 June. 2021).
Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Soil Survey Geographic (SSURGO) Database for [MLRA 146, Maine]. Available online. (accessed 14 Oct. 2021).
USNVC [United States National Vegetation Classification]. 2017. United States National Vegetation Classification Database V2.01. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. Available The U.S. National Vegetation Classification (usnvc.org) (accessed 2 March. 2021).Contributors
Christopher Mann
Jamin JohansonApproval
Greg Schmidt, 5/20/2025
Acknowledgments
Nels Barrett, Nick Butler, and Carl Bickford provided considerable review of this ecological site concept.
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Contact for lead author Date 05/06/2025 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
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Perennial plant reproductive capability:
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