Vegetation Studies - 1994 Thunder Fire

Willows.

Final Reports (PDF) Thunder Fire Report, by G. Wooten, M. Poss, and M. Larsen (3 MB PDF file). Thunder Fire Project Appendices Links: Introduction Background and Highlights Ecology Wildlife Birds Amphibians Vegetation Threats Related pages: Boreal research Boreal Okanogan

Willows

The Long Swamp area appears to be the center of distribution of two population groups of willows, which can be, and often are, the ecosystem dominants in bottom lands and riparian areas in this area. This is the only area in the world where two distinctive population groups overlap. The first group includes willows representative of areas strictly to the north and east of Washington. These include Booth's willow, Drummond's willow, Farr's willow, and the sensitive Tweedy's willow. For the latter three, this area approximates their westernmost extent, and in the Cascades, their southernmost. The other group of willows extends from boreal zones down through the Coast Mountains through the Cascade-Sierran axis. Species include Salix planifolia, the plane-leaved willow, and S. commutata, which both occur here, as well as the common overstory tree, S. caudata (syn=S. lasiandra v. caudata). Specimens of S. commutata from this area differ in leaf shape and pubescence from typical Cascades material, and approach S. tweedyi. A number of other Cascade-Sierran species such as S. barclayi and S. sitchensis have their eastern range just west of here.

S. myrtillifolia also occurs here and resembles both S. boothii, which is taller and has smaller leaf stipules, and S. tweedyi, which is taller, and is an indicator of faster moving oxygenated lake and minerotrophic riparian environments. Willow experts still disagree about the status of S. myrtillifolia, and this area is important in having good material of that species and its close relatives, in addition to being a key site for forms of S. commutata. Other willows that occur here or immediately adjacent are the dwarf willows, S. nivalis and S. cascadensis, the upland S. scouleriana, S. prolixa (another contested entity), and S. melanocarpa (material from this area is also distinctive, and undercollected).

The year 1996 was a banner year for new discoveries of the glaucous willow, Salix glauca. After years of having only two known, small populations, a lucky break helped uncover many more, and pushed the plant's southern limit here as far as Roger Lake Research Natural Area. Apparently, an unusually late spring delayed maturation of the catkins until well into September, preserving them long enough for the plants to be identified by fair weather botanists surveying Long Swamp and Thunder areas.

Willow species are one of the drivers of ecosystem processes in the Long Swamp area. Truly, this area is a center of distribution, or at least a crossroads, for some willow species. There are some very special aspects of ecology, plant geography, and glaciology that make this so. In this and many northern and riparian ecosystems, it is the willow species that are the "drivers" of many ecosystem processes, and ecologists, foresters, botanists and wildlife biologists who are unaware of this are not well informed. Species such as great gray owls, lemmings, voles, moose, ptarmigan, etc. all depend on a highly integrated functional ecosystem involving these willow species. For example, one need only observe how often the commonest willow on the Okanogan, Scouler's willow, S. scouleriana, is used as a nest site. If tree species were recorded for our known hawk and owl sites, Scouler's willow would certainly rank as one of the most frequently used species. Willows, having had a long history of evolution from insect pollination to primarily wind pollination, have formed numerous relationships with other species along the way and are truely a cornerstone species for this ecosystem.

RARE PLANTS

Carex norvegica, Scandinavian sedge
R-6 Sensitive. This plant occurs in a dozen or so localities in upper Thirtymile Creek. It prefers edges of bog/fen habitats where it is associated with Carex disperma and mosses and where Carex scopulorum var. prionophylla and other agressive competitors are less dominant. Little is known about its biology here, but it does not occur south of Idaho. Suspected reasons for its rarity are habitat loss. It is currently undergoing development of a Conservation Strategy.

Salix tweedyi, Tweedy's willow
R-6 Sensitive. One male plant of Salix tweedyi was found on the Thirtymile side of the saddle between Twentymile Creek. Repeated searches found no more plants. Tweedy's willow prefers aerated, rapidly moving water, with open canopies, at elevations above 6000 ft., although it will tolerate slower-moving water or denser or more open habitats, or lower elevations. The characteristics of its preferred habitats are limited and declining in Thirtymile drainage, and its continued presence here is tenuous. It is an indicator for chemical water quality and stream gradient and changes in these two environments would be detrimental to it.

Botrychium lunaria, moonwort
R-6 Sensitive. Five plants were found in the saddle of Thirtymile and Twentymile Creeks. It was growing in the only grass dominated site on a small island in the middle of the fen/bog in the saddle. This is expected, since Botrychiums often occur at the edges of wetlands, where some seasonal drying can occur. This habitat occurs in Thirtymile Meadows, and more plants undoubtedly exist there. Plants often occur with Fragaria spp., Potentilla spp., and other Botrychium spp.

Botrychium pinnatum, pinnate moonwort
R-6 Sensitive. Five plants were found with Botrychium lunaria, above. See the discussion under Botrychium lunaria.

Botrychium minganense, Victorin's moonwort
R-6 Sensitive. One plant was found in a large dry meadow, 1 mi. ENE of Thirtymile Meadows, apparently in association with mountain sagebrush, Artemisia tridentata var. vaseyana. This same association was found for another single plant of Botrychium minganense associated with mountain sagebrush on DNR land nearby, in nearly identical habitats. This plant was growing 2" from the base of a live sagebrush. Relationship may be mycorrhizal, as sagebrush forms mycorrhizal associations with a number of species, for instance, Orobanche, and Comandra. The fire in the big meadow burned approximately one half of the sagebrush plants, however its affect on other species in this plant community is not apparent. Threats are loss of mountain sagebrush, and invasion by Poa pratensis, Kentucky bluegrass, which can change fire and mycorrhizal characteristics with the flora.

Carex scopulorum var. prionophylla
R-6 Sensitive. This plant occurs throughout the area, wherever wet. It is an ecosystem dominant in wetlands, and indicates forested fens. This plant is more common than previously thought.

Potentilla diversifolia var. perdissecta
R-6 Sensitive. In wet habitats, this variety of Potentilla diversifolia can be predominant. Identification is complicated by the presence of the similar Potentilla drummondii, and tendencies of aquatic habitats to produce plants with elongate leaf lobes. Relatively distinct populations occur at the bend in the final headwaters of Twentymile Creek, and in the small bog 1.5 mi ENE of Thirtymile Meadows in a small unburned tributary. Populations have not been mapped or recorded with Washington Natural Heritage Program due to the difficulties in distinguishing intergradient forms between this plant and with Potentilla diversifolia var. diversifolia.

Dodecatheon pulchellum var. watsonii
WNHP Monitor. Known from Thirtymile Meadows and Dog Creek Meadows. This plant appears to be completely intergradient with D. pulchellum var. pulchellum, which led to its recent delisting by WNHP.

Saxifraga apetala.
WNHP Monitor. Forms of this species apparently occur in this area, however more taxonomic work needs to be done to establish its status.

Geum triflorum var. campanulatum
Subalpine populations of Geum triflorum are partly cleistogamous (selfers) and this condition has been classified as an Olympic Mountain ecotype (plants of the same genome with different habits in differing environments--they are not technically varieties). Although our plants may be the same entity, no systematic study has been to demonstrate whether or not the plant is an ecotype or indeed, a variety, and whether our plants are the same as those on the Olympic. Status unknown.

Penstemon washingtonensis
WNHP Monitor. This plant is a narrow endemic, which however, is common in its two localities, the Chelan-Sawtooth Range, and here in the Okanogan Range, where it ranges from Thirtymile Peak, to Rock Mountain, north to Thunder Mountain. Although the plant is apparently very similar to Penstemon procerus, no apparent hybrids are known, however in a big surprise to botanists, a freely intergradient hybrid population of Penstemon washingtonensis X Penstemon confertus occurs in Twentymile Creek. Flower color is pink to lavendar, and glandular pubescence is scant to present, reflecting contributions from both parents.

Agoseris lackschewitzii, "pink agoseris"
Unconfirmed in Washington. Numerous sightings of what appear to be this plant occur in the Meadows area, from Beaver Meadows to the Canadian border. The species was only recently monographed (Henderson et. al., 1990), and it is intermediate between Agoseris elata and Agoseris aurantiaca. However, initial reports are that our "pink agoseris" do not match those of Henderson et. al., leaving the identity of these plants to fall to one of the parents, and in support of the intermediate nature of this plant. Tony Basabe, a plant surveyor for the ONF from WSU found a single plant with both colored flowers connected by a single root. In investigations of the distinctness of the pink agoseris, it might be noted that even though all three species occur together here, the pink agoseris prefers muddy trails, is weedier overall, has earlier blooms and smaller, possibly sterils seeds. These observations would be consistent with its identity as a hybrid.