Wenaha Breaks RNA

Wehana Breaks Research Natural Area (RNA) was established to represent mesic grand fir (Abies grandis) - forest of the Blue Mountains. The topopgraphy of the RNA consists of a gently sloping plateau. An abrupt drop into the canyon of the Wenaha River dissects the northern portion of the RNA. The RNA borders the Wenaha River where four tributaries enter from the north and west forming a significant intersection for fish migration. Lacustrine wetlands contain numerous small ponds scattered among the extensive grand fir forests. Common flora in these forests include big huckleberry (Vaccinium membranaceum), Oregon boxwood (Pachistima myrsinites), queen’s cup (Clintonia uniflora), and twinflower (Linnaea borealis) with scarce patches of Pacific yew (Taxus brevifolia). Douglas-fir-dominated stands are found in the northern portion of the RNA and accompanied by dense patches of mallow ninebark (Physocarpus malvaceus) and pine grass (Calamagrostis rubescens). There are also occasional patches of common snowberry (Symphoricarpos albus). Bladder sedge (Carex utriculata) is the dominant plant species in the lacustrine wetlands while tall mannagrass (Glyceria elata) and Scouler’s willow (Salix scouleriana) are also common. Mountain alder (Alnus viridis ssp. sinuata), black cottonwood (Populus balsamifera ssp. trichocarpa), and quaking aspen (Populus tremuloides) are present on the outer margins of these wetlands.