GRAND TETON NATURE NOTES

TREES OF THE GRAND TETON NATIONAL PARK

by Willis Smith
Ranger-Naturalist

The Grand Teton National Park embraces the most spectacular portion of the Teton mountains. The northern border of this park is just eleven miles south of Yellowstone National Park. To the east lies the valley of the Snake River (Jackson Hole) at an elevation of about 7,000 feet. The peaks rise with precipitous east faces to elevations of from ten to fourteen thousand feet. The lower slopes of the range and the glacial moraines that encircle the shores of some six or more beautiful lakes of the park, are densely populated with the trees that are characteristic of any other similar area of the Rocky Mountains.

The Lodgepole Pine (Pinus contorta) forms dense black stands in the more arid and lower areas of the park. This friendly tree grows under soil and water conditions that no other tree would tolerate and in doing so serves as a protection to the water sheds of the arid plateaus of the region. In Grand Teton National Park this forest gives way to the Engelmann Spruce (Picea engelmanni), Alpine Fir (Abies lasiocarpa), Whitebark Pine (Pinus albicaulis) association as one travels up the more moist, shaded canyons or up the slopes of the range.

The Douglas Fir (Pseudotsuga taxifolia) is found on the east face of Mount Teewinot up to about 8,000 feet. This tree with its fir-like leaves, its pendant cones that suggest the Spruce, its thick furrowed bark like that of the Western Yellow Pine (Pinus scopulorum) and a name that refers one to the Hemlock (Tsuga) leaves the amateur naturalist somewhat confused, but the common name Douglas or Oregon Fir identifies it as the most valuable lumber tree in America. It reaches its highest development in the rain-soaked forest of Western Oregon.

At timberline, about 10,500 feet, the matted, decumbent, Alpine Fir sprawls across the rocky slopes appearing in the distance like closely-cropped blue grass lawn. The Whitebark Pine, broken and gnarled from countless battles with the elements, stands guard on the wind swept ridges. In the upper reaches of south fork of Cascade Canyon stands one of these veterans of the ages. It is seven feet in diameter and is as far as is now known, the largest diameter in the park. Hundreds of hikers who have walked up the switchbacks to the top of Hidden Falls have marveled at a dwarfed and contorted specimen of Whitebark Pine growing from a crevice in an immense granite boulder. No doubt but that this tree is hundreds of years old.

A few Limber Pine (Pinus flexilis) are found in arid and exposed places at lower elevations. The flexible whip-like branches act as a special adaptation to wind-swept slopes.

For sheer beauty of form and color the Alpine Fir stands supreme, although the Engelmann Spruce is a worthy rival to it. The Alpine Fir is tall and tapers to an extremely narrow spire-like top. The silvery gray bark vividly contrasts with the dark blue-green of the leaves. The cones, always borne at the top, are erect and of velvety texture. They are dark purple in color, and with the sunlight reflecting from the pitch that has beaded itself on the cone, one can compare them with nothing other than lighted Christmas candles. However, this beautiful cone seldom comes to one's hand. On ripening, which takes place in the fall of the year following its origin in the spring, the cone disintegrates, scattering seeds and scales to the wind. The fact that a large fir is oftimes surrounded by a cluster of small ones, much as a mother hen with her chicks, tends to indicate that the seeds mostly fall to the foot of the parent tree.

Another interesting characteristic of this tree is the rooting, much as a strawberry does, of the lower branches as they touch the ground due to squirrels making caches under them or the snow pressing them down. This rooting results in the tip of the rooted branch turning up and becoming a tree. As time goes on this process is successively repeated. It is not uncommon to see mature snow mats, as these are called, with the old parent tree dead and disintegrated with the live mat forming a truncated cone a quarter of an acre or more in extent.

In the short glacial canyons that extend to the east face of the range and along the west shores of the lakes the Engelmann Spruce is found at its best. Mature specimens four to five feet in diameter, 100 feet high are found. The tree is pyramidal but not as spire-like as the Alpine Fir. The lower branches droop as do all the branchlets. This gives the tree a dense, black aspect. The foliage is dark blue-green, and contrasts vividly with the reddish brown flakey bark that is found on the young as well as on the mature trees. The pendant cones are narrowly cylindrical and borne on the ends of the branchlets, mostly near the top of the tree. This tree never produces a snow mat.

The Colorado Blue Spruce (Picea pungens) is found only along the Snake River bottoms. Here the tree is typical of the species, and no confusion between it and the Engelmann Spruce could arise in the mind of an observer. The tree is wider in proportion to its height than the Engelmann. The bark is tough and furrowed, being of gray color. The cones are large, oftimes five inches in length. The pungent, four-angled leaves are usually covered with a light blue bloom from which it takes its common name.

LEPIDOPTERA COLLECTION - A fine addition to the museum exhibit, as well as a valuable addition to the scientific collection of the park was made this summer in the way of a collection of butterflies native to the region. The collection includes about 130 mounted specimens, and makes an exhibit second only to the fresh flower display in color and attractiveness. The work was done by John W. McSwain. The following genera are represented: Papilio (3 species), Parnassius (2 species), Danaus, Pieris (2 species) Anthocharis, Eurymus (3 species), Oeneis, Cereyonis, Coenympha, Epibea, Vanessa (2 species), Argynnis (9 species), Phyciodes (2 species) Brenthis, Euphydryas (3 species), Basilarchia, Miletea, Euptieta, Plebius (6 species), Glaucophysche, Heodes (8 species), and Thecla (2 species). - Allan D. Cameron.