Ecology of a Northeastern Outlying Stand of Pinus Flexilis

Abstract

A small stand (208 acres) of limber pine (Pinus flexilis) occurs in association with Juniperus scopulorum in southwestern North Dakota, about 12 miles north of Marmarth, and at an average elevation of 2,850 feet in typical "Badlands" terrain. Both P. flexilis and J. scopulorum are reproducing well, although the pine shows greater relative density and a higher frequency index in the larger size classes, indicating site dominance. The total foliage cover of the shrub stratum was only 7.6% however, the dominance of one shrub, Rhus trilobata is of particular importance. From increment borings of 50 Pinus flexilis trees the oldest tree was 238 years old at breast height. The greatest diameter was 17.2 in. at breast height, and the greatest height was 26 ft. The average diameter growth was .11 in. per year. The trees growing on the knolls showed the greatest growth rate. Sectioned trunks showed a definite pattern of radial eccentricity, with growth the least on the south side and increasing toward the northeast side. This small stand of Pinus fexilis may have been seeded, either accidentally or purposely, by Indians camping in the area before settlement by the white man.