In certain areas mountain fir forests exhibit a distinctive pattern of disturbance and regrowth called "wave-regeneration." From a distance the forest appears patchy with large areas of green canopy interspersed with crescent-shaped bands of dead trees. These fir waves consist of "troughs" of standing and windthrown dead trees, grading downhill first into a zone of vigorous fir seedlings, then into a dense stand of fir saplings, and finally to a "crest" of mature fir trees that border another band of standing dead and windthrown trees. The only other place in the world where fir waves occur is in the mountains of Japan.
There are only 5 to 25 occurrences statewide. There are several large occurrences protected on state land. This community is restricted to the high-elevation slopes of mountainous areas generally above 4,000 feet, and includes several very large, high quality examples. The current trend of this community is probably declining slightly due to the combined effects of atmospheric deposition, recreational overuse, and logging. This community has probably declined moderately from historical numbers likely correlated with logging and development of the surrounding landscape.
The number and acreage of mountain fir forests in New York has probably remained stable in recent decades as a result conservation efforts at high elevation areas in the state.
The number and acreage of mountain fir forests in New York has probably declined moderately from historical numbers likely correlated with past logging and other development.
Communities that occur at higher elevations in the state (e.g., >3,000 feet) may be more vulnerable to the adverse effects of atmospheric deposition and climate change, especially acid rain and temperature increase. The primary threat to mountain fir forests is acid rain deposition. The ability of forest soils to resist, or buffer, acidity depends on the thickness and composition of the soil, as well as the type of bedrock beneath the forest floor. Places in the mountainous Northeast, like New York's Adirondack and Catskill Mountains, have thin soils with low buffering capacity. Forests in high mountain regions are often exposed to greater amounts of acid than other forests because they tend to be surrounded by acidic clouds and fog that are more acidic than rainfall. When leaves are frequently bathed in this acid fog, essential nutrients in their leaves and needles are stripped away. This loss of nutrients in their foliage makes trees more susceptible to damage by other environmental factors, particularly cold winter weather (US EPA 2005). Mountain fir forests may be threatened by development, excessive logging, and recreational overuse (e.g., ATV use, hiking trails, campgounds, ski slopes).Spruce budworm (Choristoneura fumiferana) may be considered a threat to occurrences of mountain fir forest that experience extreme outbreaks, especially if it coincides with other stresses and reduces tree regeneration. The spruce budworm is a native insect that creates canopy gaps in spruce and fir forests of the eastern United States and Canada. Since 1909 there have been waves of budworm outbreaks throughout the eastern United States and Canada. The states most often affected are Maine, New Hampshire, New York, Michigan, Minnesota, and Wisconsin (Kucera and Orr 1981). Balsam fir is the primary host tree for budworm in the eastern United States, although white, red, and black spruce are known to be suitable host trees. Spruce budworm may also feed on tamarack, pine, and hemlock. Spruce mixed with balsam fir is more likely to show signs of budworm infestation than spruce in pure stands (Kucera and Orr 1981).
Management should focus on activities that help maintain regeneration of the species associated with this community. Avoid cutting old-growth examples and encourage selective logging in areas that are under active forestry. Management activities should be consistent with recommendations presented in the High Peaks Wilderness Unit Management Plan (NYS DEC 1999).
Strive to minimize fragmentation of large forest blocks by focusing development on forest edges, minimizing the width of roads and road corridors extending into forests, and designing cluster developments that minimize the spatial extent of the development. Development projects with the least impact on large forests and all the plants and animals living within these forests are those built on brownfields or other previously developed land. These projects have the added benefit of matching sustainable development practices (for example, see: The President's Council on Sustainable Development 1999 final report, US Green Building Council's Leadership in Energy and Environmental Design certification process at http://www.usgbc.org/).
Survey for new occurrences in the Adirondack and Catskill Mountains in order to advance documentation and classification of mountain fir forests. A statewide review of alpine and high elevation (>3,000 feet) communities is desirable. Continue searching for large sites in good condition (A- to AB-ranked).
Research the long-term combined effects that atmospheric deposition, climate change, and extreme budworm outbreaks may have on mountain fir forest occurrences. Further research on "fir waves" may be desirable. Precise temporal and spatial mapping of fir waves may add to our understanding of this ecological process.
This community is known from the high-elevation slopes of mountainous areas. It is essentially restricted to the higher peaks in the Adirondack and Catskill Mountains. In the Adirondacks it is represented by large patch to matrix examples.
This community is essentially restricted to high-elevation slopes of the northeastern U.S., but it is also found on the highest summits in the Catskill Peaks of New York and the Berkshire Mountains of Massachusetts. This range is estimated to span northwest to the Adirondack Mountains of New York, southwest to the Catskill Peaks of New York, and northeast to the peaks associated with Mount Katahdin, Maine.
Mountain fir forests have a closed canopy made up almost entirely of balsam fir (Abies balsamea), with occasional mountain paper birch (Betula cordifolia), red spruce (Picea rubens), and mountain ash (Sorbus americana). The shrub layer is dominated by balsam fir seedlings, and the ground layer has moderate herbaceous cover and a dense carpet of mosses. Along an the elevational gradient, they are often situated between mountain spruce-fir forest and alpine krummholz. This community is restricted to the high-elevation slopes of the Adirondack High Peaks and the Catskill Peaks.
This community is characteristically represented by a forest with a canopy made up almost entirely of balsam fir, located on the cool upper slopes of the Catskill and Adirondack Mountains.
Known examples of this community have been found at elevations between 1,932 feet and 4,856 feet.
Several wildflower species of mountain fir forests can be observed in bloom throughout the spring and summer. During the spring, flowers of bluebead lily (Clintonia borealis), and Canada mayflower (Maianthemum canadense) appear on the forest floor, followed by Labrador tea (Rhododendron groenlandicum), bunchberry (Cornus canadensis), goldthread (Coptis trifolia), and wood-sorrel (Oxalis montana). Later in the summer, flowers of mountain aster (Oclemena acuminata) and large-leaf goldenrod (Solidago macrophylla) appear.
This New York natural community encompasses all or part of the concept of the following International Vegetation Classification (IVC) natural community associations. These are often described at finer resolution than New York's natural communities. The IVC is developed and maintained by NatureServe.
This New York natural community falls into the following ecological system(s). Ecological systems are often described at a coarser resolution than New York's natural communities and tend to represent clusters of associations found in similar environments. The ecological systems project is developed and maintained by NatureServe.
Abies balsamea (balsam fir)
Betula alleghaniensis (yellow birch)
Betula cordifolia (mountain paper birch)
Picea rubens (red spruce)
Sorbus americana (American mountain-ash)
Alnus viridis ssp. crispa
Viburnum lantanoides (hobblebush)
Clintonia borealis (blue bead-lily)
Coptis trifolia (gold-thread)
Cornus canadensis (bunchberry)
Dryopteris campyloptera (mountain wood fern)
Dryopteris intermedia (evergreen wood fern, fancy wood fern, common wood fern)
Huperzia lucidula (shining firmoss)
Maianthemum canadense (Canada mayflower)
Oxalis montana (northern wood sorrel)
Solidago macrophylla (large-leaved goldenrod)
Streptopus lanceolatus (rose twisted stalk, rose mandarin)
This figure helps visualize the structure and "look" or "feel" of a typical Mountain Fir Forest. Each bar represents the amount of "coverage" for all the species growing at that height. Because layers overlap (shrubs may grow under trees, for example), the shaded regions can add up to more than 100%.
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This guide was authored by: Timothy G. Howard
Information for this guide was last updated on: March 7, 2017
Please cite this page as:
New York Natural Heritage Program. 2023. Online Conservation Guide for Mountain fir forest. Available from: https://guides.nynhp.org/mountain-fir-forest/. Accessed March 31, 2023.