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Shiro TSUYUZAKI
Plant community ecology / Environmental conservation

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

(Update on Jan. 26 2010)

Alpine zone

Elevational zones above treeline

Alpine plants (高山植物)

Plants of which major habitats are alpine. Global warming and ozone depletion have strongly struck this zone. In particular, skislpes may be damaged and closed. The pohot shown in right side is one of the alpine plants, Viola kitamiana.

Timberline and alpine vegetation in WA

This vegetation may be divided into two broad types: subalpine meadow complexes occur due to heavy snow pack and topographic features, often mixed with tree vegetation. Above this zone is a truly alpine vegetation in which the growing season is everywhere too short for tree growth. All such vegetation requires high elevation. How high depends upon the vegetation is lower than what would be expected on the basis of current climate. In the Olympics, the heavy snow pack acts to limit tree growth; on Mount St. Helens, the youth of the cone (and occasional set backs) precludes a climatic tree line. All the Washington volcanoes, the Olympics, and most of the Cascades have subalpine or alpine meadow vegetation.
Elevation: First subalpine meadows begin as low as 1340 m on Mount St. Helens and 1400 m on Mt. Baker and true alpine conditions usually begin above 2100 m or higher.
Climate: Short growing season with extensive snow accumulates in western Washington.

A. Subalpine Meadows

1. Phyllodoce-Cassiope-Vaccinium (Heath scrub) association: Dominance is by one or more of these ericaceous shrubs; typical associations that occur broadly in western Washington include:
1. Phyllodoce empetriformis-Vaccinium deliciosum association. This association also usually contains Cassiope mertensiana, Leutekea pectinata, and Antennaria lanata. Usually on moist, well drained sites with limited snow accumulation and relatively long growing season. Soils are usually Cryorthods (podzols).
2. Lush Herb: These meadows are floristically rich and have dominance shared by many species in different locales.
1. Valeriana sitchensis-Veratrum viride association has a rich group of associates including Lupinus latifolius, Castilleja parvi-flora, and Heracleum lanatum. Occurs on steep, well-watered slopes, especially where avalanches are common.
2. Carex spectabilis association that occurs primarily in late snow melt areas, with Lupinus latifolius and Polygonum bistortoides always present. c. Rubus parviflorus-Epilobium angustifolium association occurs mainly in the North Cascades on steep exposed slopes with a long snow-free season. It is a low elevation type controlled more by soil conditions that by climatic conditions.
3. Carex nigricans association: These associations always occur in wet sites with a short growing season due to late snow melt. They are usually surrounded by associations requiring longer growing periods (e.g., heather associations).
4. Rawmark associations: These are associations that pioneer rocky or extremely disturbed conditions. They vary greatly from place to place. The more important include these:
1. Saxifraga tolmiei association, common on exposed sands and gravels.
2. Luetkea pectinata associations that often colonize talus slopes. Luetkea may be found in many conditions, including stable associations.
3. Antennaria lanata association found on flat, shallow soil conditions drier than conditions dominated by Carex nigricans.
4. Phlox diffusa dominates subalpine early snow melt communities in many places, growing with species such as Allium crenulatum and Lomatium martindalei
5. Festuca associations: Grassy, dry meadows dominated by Festuca viridula are common on Mt. Rainier; in the Olympics, Festuca idahoensis appears to be the functional equivalent. The fescues have broad moisture tolerances and will occur with a variety of herbs depending on location and moisture status.

B. Alpine communities

The true alpine zone is limited in Washington due to heavy snow packs. Much of it less on recent volcanoes where the substrates are young. These vegetation types are generally found above 2300 m. Snow accumulation and wind, combined with soil factors do much to control distributional patterns. Soil instability is a major feature of alpine vegetation, leading to solifluction terraces and stone stripes, among others. Major studies have been conducted in the North Cascades, Olympics, Mt. Rainier, and the Enchantment Lakes. Typical assemblages include the following from Mt. Rainier, but there are many variants.

1. Empetrum nigrum-Lupinus lepidus association, a rich, mesic community with relatively high cover.
2. Arctostaphylos uva-uris-Solidago spathulata association is a rich, warm site association with strong dominance by scrubby species, including Juniperus communis and Potentilla fruticosa.
3. Arenaria obtusiloba-Lupinus lepidus association is a very rich, xerophytic association of typically cushion plants. Phlox diffusa and Silene acaulis are common
4. Phyllodoce gladuliflora-Aster alpigenus association is low in richness, high in cover. The heather dominates cool, moist habitats in which this association occurs. Soils are stable, acid.
5. Pedicularis-Carex spectabilis association from a mesic turf association.
6. Erigeron aureus-Lupinus lepidus association is a dry, open herb community on well-drained soils.

In other areas, homologous associations and additional associations have been described. Associations vary clinally from north to south and from east to west.

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Lab-study. High elevation vegetation

Species are listed below by major habitat types. Study the species demonstrated to learn their identifying traits and to learn some of the common associations to be found in Washington. For each dominant species, try to associate several usual subordinates and to determine the kind of habitat you would find these species.

Subalpine Meadow Vegetation

Occurs at elevations that might support trees, but do not due to topographic or historical factors. May occur below 1500 m (unusual circumstances), typically around 1750 m.
Distribution: throughout high-elevation habitats of western Washington, with five major types of vegetation, defined by growth-from of the dominant species: Heath Scrub (HS), Lush Herb (LH), Dwarf Sedge (DS), Rawmark (RM) and Grassland (GL).

Typical associations: (Heath Scrub) Phyllodoce empetriformis-Vaccinium deliciosum; Cassiope meertensiana-Phde; Vade; Phem/Lupinus latifolius; (Lush Herb) Valeriana sitchensis-Veratrum viride; Vasi-Lula; Lula-Polygonum bistortoides; Carex spectabilis; (Dwarf Sedge) Carex nigricans; (Rawmark) Luetkea pectinata; Saxifraga tolmiei; (Grassland) Festuca viridula-Lula; Fevi-Aster ledophyllus; Festuca idahoensis-Lupinus lepidus (Olympics).

Alpine Meadows

Occur at high elevations, beyond the climatic limit of tree growth, at least 2000 m or more.
Distribution: poorly developed in Washington, due in part to heavy snow pack in and rarity of high elevation habitats. The alpine zone is steep, rugged and often covered in ice or glaciers. Most of true alpine is on volcanoes, hence soils are poorly developed and disturbance is chronic. Seven typical associations have been recognized on Mount Rainier: Lush Fellfield (LF), Dry Fellfield (DF), Pioneer Cushion Plant (PC), Wet Alpine (WA), Turf Sedge (TS), Forb Stripes (FS), and Pioneer Turf (PT).

Alpine Association in the Mount Stuart Area: Arenaria obtusiloba-Phlox diffusa; Lule-Carex proposita-Penstemon davidsonii; Phlox diffusa-Eriogonum pyrolifolium (widespread); Carex spectabilis-Lule; Casp-Juncus parryi; Carex nigricans-Lupinus latifolius (and others).

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References

• Flora on Mount Koma

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