SUMMARY
The vegetation of New Hampshire’s Presidential Range has been the subject of considerable study over the past 150 years. In contrast, alpine and subalpine summits elsewhere in the White Mountains have received relatively little attention from botanists, ecologists, and land managers, with a few notable exceptions. This report considers alpine and subalpine vegetation throughout the White Mountains, and is part of a broader systematic inventory of the floristics, plant communities, environmental attributes, and human factors associated with alpine vegetation in the northeastern United States. In addition, we seek to inform stewardship of alpine species and communities by identifying their locations, significance, and associated management issues.
We have documented 35 peaks outside the Presidential Range in New Hampshire with alpine or subalpine vegetation, all of which are at least one acre in size, and most of which are greater than five acres. Twenty-four of these peaks are over 4000' elevation, and 11 are lower but generally higher than 3500'. All contain heath/krummholz communities, and more than half have some dwarf shrub/sedgerush meadows or barrens typical of higher alpine areas. Some of these peaks have naturally rugged summits with essentially no soil. Franconia Ridge, Bondcliff, Guyot, Baldface Ridge, Moosilauke, Cannon Mountain, the Mahoosuc Range, and the Shelburne-Moriah vicinity contain the great majority of the acreage, with more than 600 acres total. Of these, only Franconia Ridge and South Twin exceed climatic treeline at 4900 feet. We have also documented numerous lower elevation cliffs, talus slopes, river gorges, and rocky ridges that have certain alpine or subalpine affinities. There are approximately 70 plant species in alpine areas of the White Mountains that are either rare in New Hampshire or restricted to alpine and subalpine habitats. There is a distinct decrease in the diversity of alpine-restricted species from larger and higher peaks to lower and smaller peaks. More than 200 other species of vascular plants are documented from alpine peaks and other habitats with alpine affinities. Many of these are found only in areas protected by latemelting snowpacks above treeline or on subalpine or lower elevation ledges. Overall plant composition relates well to elevation range, area, and range of soil moisture conditions.
Alpine zones typically consist of complex community mosaics in which patches of vegetation cover or grow among a matrix of bedrock, stone, talus, and/or gravel with or without thin organic soil layers. We have defined five major groups of alpine and subalpine plant communities from the data set, plus a sixth group of montane vegetation transitional to subalpine heath/krummholz found on lower ridges and ledges. Each of these major groups can be divided into two or more finer-scale communities for a total of 13 alpine/subalpine types (15 total with montane types). Some of these communities and constituent species are restricted to the higher peaks, while others are restricted to lower subalpine peaks.
Human use and impacts vary considerably among peaks. Most retain significant areas of largely natural vegetation with localized zones of trampled vegetation, soil erosion, and unofficial trail development. A few peaks are trail-less and remain intact, while several have been heavily trampled or reduced to gravel or bedrock with little hope of recovery at current recreational levels. Fires have certainly modified the extent of total open habitat on some subalpine peaks, although most were likely open to some extent prior to European settlement. At most summits, some combination of stewardship efforts will be needed to retain or stabilize existing natural vegetation, or in some cases to rehabilitate denuded areas.
