Mt. Hagan Block RNA

Hagan Research Natural Area (RNA) was established to represent forested watersheds in the western hemlock zone containing first to third order streams. The terrain is generally steep with streams originating from two small valleys. Douglas-fir (Pseudotsuga menziesii) is common throughout the RNA. Several stands of chinkapin (Castanopsis chrysophylla), sugar pine (Pinus lambertiana), Pacific yew (Taxus brevifolia), and bigleaf maple (Acer macrophyllum) are also present with a few patches of western redcedar (Thuja plicata). Common understory shrubs include salal (Gaultheria shallon), dwarf Oregon grape (Berberis nervosa), Pacific rhododendron (Rhododendron macrophyllum), vine maple (Acer circinatum) and red huckleberry (Vaccinium parvifolium). Sword fern (Nephrolepis), Oregon oxalis (Oxalis oregana), beargrass (Xerophyllum tenax) and bracken fern (Pteridium aquilinum) are common herbs. The riparian vegetation zone is dominated by red alder (Alnus rubra) and black cottonwood (Populus balsamifera ssp. trichocarpa). The riparian understory has a shrub layer of stink currant (Ribes bracteosum), salmonberry (Rubus spectabilis) and devil's club (Oplopanax horridus) and a rich herbaceous layer including many fern species.   Hagan RNA became part of the regional Permanent Sampling Plot Network in 1981 and the growth, death, and recruitment of trees within permanent plots are measured at 5-year intervals.