Tamaracks are very cold tolerant, able to survive temperatures down to at least , and commonly occurs at the
Arctic tree line at the edge of the
tundra. Trees in these severe climatic conditions are smaller than farther south, often only tall. They can tolerate a wide range of soil conditions but grow most commonly in
swamps,
bogs, or
muskegs, in wet to moist organic soils such as
sphagnum,
peat, and woody peat. The central
Alaskan population, separated from the eastern
Yukon populations by a gap of about , is treated as a distinct variety
Larix laricina var.
alaskensis by some botanists, though others argue that it is not sufficiently distinct to be distinguished. Rust is the only common foliage disease amongst Tamaracks, and causes minimal damage to the trees. The needle-cast fungus
(Hypodermella laricis) is also a cause for concern in Tamaracks.
Associated forest cover Tamarack forms extensive pure stands in the
boreal region of
Canada and in northern
Minnesota. In the rest of its United States range and in the
Maritime Provinces, tamarack is found locally in both pure and mixed stands.
Black spruce (
Picea mariana) is usually tamarack's main associate in mixed stands on all sites. Other commonly associated overgrowth species include
balsam fir (
Abies balsamea),
white spruce (
Picea glauca), and
quaking aspen (
Populus tremuloides) in the boreal region. In the better organic soil sites in the northern forest region, the most common associates are the
northern white-cedar (
Thuja occidentalis), balsam fir,
black ash (
Fraxinus nigra), and
red maple (
Acer rubrum). In
Alaska, quaking aspen and tamarack are almost never found together. Additional common associates are
American elm (
Ulmus americana),
balsam poplar (
Populus balsamifera),
jack pine (
Pinus banksiana),
paper birch (
Betula papyrifera),
Kenai birch (
B. papyrifera var.
kenaica), and
yellow birch (
B. alleghaniensis). There are a vast number of shrubs associated with Tamarack due to their range, some of the common ones are
dwarf and
swamp birch (
Betula glandulosa and
Betula pumila),
willows (
Salix spp.),
speckled alder (
Alnus rugosa), and
red-osier dogwood (
Cornus stolonifera)
bog Labrador tea (
Ledum groenlandicum),
bog-rosemary (
Andromeda glaucophylla),
leather leaf (
Chamaedaphne calyculata), blueberries and huckleberries (
Vaccinium spp.) and
small cranberry (
Vaccinium oxycoccos). Characteristically the herbaceous cover includes
sedges (Carex spp.),
cottongrass (Eriophorum spp.),
three-leaved false Solomonseal (
Maianthemum trifolium),
marsh cinquefoil (
Potentilla palustris),
marsh-marigold (
Caltha palustris), and
bogbean (
Menyanthes trifoliata). == Uses ==