Wrangell - St Elias National Park and Preserve Wildflowers

FLORISTIC COMPOSITION

The most common flower in Alaska appears to be the fireweed, occurring in vibrant purple rows along the highways. Yet, in the Wrangell's alone, there are 887 vascular plant taxa documented by vouchers within the park. This represents 54% of the Alaskan flora (which has approximately 1535 species) and 69% of the Yukon Territory flora. The biogeographic composition of the vascular flora is: 32.2% North American, 25.8% circumpolar, 23.2% amphiberingian, 10.8% incompletely circumpolar and 7.1 % Alaska-Yukon endemic. The ecological distribution of the flora is 29.45% boreal-montane, 25.37% arctic-alpine, 20.05% widespread, 12.23% Pacific coastal, 10.99% Cordilleran, 1.02% disjunct from temperate zones and 0.91% introduced. An additional 191 native vascular plant species are expected to occur in the park based on the distributions of adjacent floras, hence an estimated 81% of flora has been documented. Sixty-one of the species expected to occur in the park (35%) have a strictly coastal distribution.

RARE PLANTS

There are 76 vascular plant species in the park's flora which have an Alaska Natural Heritage state rank of three or less (known from fewer than 100 localities) and are treated as rare species by the National Park Service. None of the rare species are considered threatened or endangered by the U.S. Fish and Wildlife Service. However, three species are listed as Species of Concern by the U.S. Fish and Wildlife Service ( Cryptantha shacklettenana, Carex laxa and Taraxacum carneocoloratum ). The biogeographic composition of the rare flora is 38.9% North American, 26.4% Alaska-Yukon endemic, 11.1% North American, 9.7% incompletely circumpolar, 8.3% circumpolar and 1.4% amphiatlantic. The rare flora is distributed somewhat evenly throughout the mountain ranges of the park, but there is a predominance of rare plants in the Chitina River basin. There is a trend for rare plants to occur in the alpine zone, above 1200 m elevation, in xeric sites, in the alpine-herb talus slope plant community, on southerly aspects and on slopes of 20 - 40 degrees. We are lacking sufficient knowledge about the distribution, life history and population ecology of rare plants to adequately protect them. Inventories focusing on the rare flora, status surveys of the USFWS Species of Concern and the development of predictive models for the distribution of rare plants are priorities for management of this resource. Rare plant populations are often at the edges of their geographic and ecological ranges and may be good indicators of environmental changes for ecological monitoring.