This is a new file opened January 15, 2010, for the Summer 2010 issue of Kaatskill Life magazine BOREAL GROUND COVER PLANTS by Michael Kudish
Boreal means northern. A boreal forest is one of lower elevations at high latitudes, e.g. northern Canada, and of higher elevations at lower latitudes, e.g. southward along the mountains in the eastern United States. The characteristic trees are evergreen conifers - predominantly spruces and balsam fir - plus eastern larch, jack pine, and a small number of deciduous hardwoods such as paper birch, mountain ash, trembling aspen, balsam poplar, and red cherry.
Boreal forests in eastern North America have their own characteristic ground cover - small plants that grow on the forest floor under trees and shrubs. Here is a listing of fifteen of the more common ones, all of which occur in the Catskills:
Note that some plants have more than one common name, and even with scientific names there can be some synonymy.
All these boreal ground cover plants can tolerate from moderate to great amounts of shade, acid soils, and short growing seasons. Some have a wide tolerance to the availability of soil water, growing in wet places like bogs and swamps as well as in often water-stressed sites along exposed ledges and tops of boulders. Boreal forest in the Catskills
Not all the boreal forest tree species occur in the Catskills. White spruce and jack pine are absent. Black spruce and eastern larch are here but are very rare in the region, absent totally from the high peaks. Red spruce and balsam fir are present, but have somewhat limited and very puzzling distributions. The five hardwoods listed above are widespread.
The bulk of red spruce and/or balsam fir forests occur in the eastern Catskills at the higher elevations, generally above 3000 feet as most hikers will tell you. These two evergreens occur also at lower elevations in the southwestern part of our region (especially in the Willowemoc drainage and on into northern Sullivan County) and on the plateau in the Towns of Harpersfield, Jefferson, and Summit. Here, these conifers are at an average elevation of about 2000 feet and are often in, but not restricted to, swamps.
The fifteen species of boreal ground cover plants listed above are present in the Catskills under spruce and/or balsam fir forests just as they are present under the spruces and fir of northern Canada. These plants occur in other places where boreal forest exists: the Adirondacks, the mountains of northern New England, and in the high Appalachians to the south.
Ridgelines of the western Catskills
Something unexpected occurs along the high-elevation ridges and peaks of the western Catskills. Hikers who are familiar with the summits of Graham Mountain, the Beaverkill Range, Dry Brook Ridge, Mill Brook Ridge, Woodpecker Ridge, Belleayre Mountain, Halcott Mountain, Vly Mountain, Bearpen Mountain, Mount Pisgah, and Plattekill Mountain – all above 3300 feet (with Graham Mountain reaching 3868 feet) - know that these peaks are covered entirely with northern hardwood forests. There is no spruce and fir. Instead are yellow birch, black cherry, beech, red maple, mountain ash, and, in lesser abundance, sugar maple. The reasons for the lack of spruce and fir along the western high ridgelines is actively being studied; it is material for another Kaatskill Life article.
After hiking the spruce-fir peaks in the eastern Catskills, next time you visit these western all-hardwood peaks, look beneath your feet and examine the ground cover plants. You may be surprised. They are predominantly boreals. They are the same species that are found under the spruce and fir farther east at the same elevations! What this tells this forest historian is that these ground cover plants do not require the evergreen trees for their existence; they are not obligated to grow under them. They do just as well under northern hardwoods. In other words, these boreal ground cover plants, when they occur under spruce and fir, are there by coincidence - they require similar growing conditions of soil, light, and climate as do the spruce and fir, but not the spruce and fir themselves. The hardwoods above them provide an equally adequate site to grow.
Why aren’t there abundant boreal ground cover plants at the lower elevations of the Catskills, generally below about 2500 feet? Northern hardwood forests were removed in areas where the forest had been cleared for pasture or cropland. This occured mainly during the 19th century. Ground cover plants, including boreal species, were also removed. Forage grasses and agricultural crops replaced the forest. For those pastures and fields that have been abandoned, most boreal ground cover species have not readily returned. I’m not certain why, but I am certain that soil conditions have been greatly altered.
There are four exceptions, however. Canada mayflower, star flower, wild sarsaparilla, and intermediate woodfern seem to re-enter abandoned pastures, now with young white ash-red maple-sugar maple-black cherry forests, readily. They can also come in under pine plantations.
Boreal forest remnants exist on sites, often adjacent to pastures, where agriculture has never been practiced: in steep ravines and in swamps. Eastern hemlock is often mixed in with the northern hardwoods on these sites.
In the Hudson Valley, in the Shawangunks, and along the Catskills’ eastern escarpment, the forests are predominantly oaks, hickories, sprouts of American chestnut, mountain laurel, and often pitch pine. These forests exist because of several thousand years of repeated burning by Native Americans; all these forest fires apparently destroyed much of the boreal ground cover except for remnant populations in swamps and in other wetlands.
Biology of ground cover species
Each ground cover species, boreal or not, has its own strategies for survival and reproduction, its own ecological preferences, and its own relationships with other organisms. To tell the story of all of them would require a large volume, and a fascinating one at that.