Presentation on theme: "Alpine Vegetation reference: Körner, Ch. 1999. Alpine Plant Life. Springer Verlag, Berlin Some slides courtesy of Bill Bowman Mountain Research Station,"— Presentation transcript:
Alpine Vegetation reference: Körner, Ch Alpine Plant Life. Springer Verlag, Berlin Some slides courtesy of Bill Bowman Mountain Research Station, INSTAAR
MOUNTAINS Have the highest plant species diversity High mountain environments have a high percentage of endemic plants Alpine areas have a much high plant diversity than forested areas
Boulder County: 1550 species (50% of flora of Colorado) Weld County: ~600 species Regional scale plant diversity in S. Rockies; the influence of mountains:
Nival Alpine treeline Subalpine Montane
Mixed Aspen - Lodgepole Pine Forest : 8,500 to 10,000 feet yellow - green color foliage dense trees straight, pole-like Used by humans since prehistoric times light construction, finishing lumber, poles
Lodgepole pine needles attached to twigs in bunches paired, twisted long, green
Aspen only deciduous tree at this altitude grow in a variety of soil conditions from wet to dry
Subalpine Forest: 10, ,000 ft spruce and fir dominate. narrow crowns dark green color cool,dark, humid E.g. Engelmann Spruce Humans have seldom used these forest due to their remoteness
Engelmann Spruce short needles attached to twigs rounded, spiky Spruce bark is reddish and outer layer flakes off
Rocky Mtn. Douglas Fir short needles attached to twigs; flat needles smooth bark
Forest- Tundra Transition: CLIMATE Situated between timberline and treeline (lower) (upper) Windier and colder mean annual soil temps ~ 0 deg. Snow covered
Alpine environment summarized: Cold + windy snowy! short growing season low nutrient availability High UV radiation How do plants survive in these conditions?
Plant adaptation to alpine environment (1) evolutionary adaptation (2) ontogenetic modifications, which are non-reversible during the life of an individual (3) reversible adjustment, often termed “acclimation”
4 things plants need: Liquid water nutrients warmth light Limiting factors in alpine and arctic tundra Limiting factor in arctic tundra only
Adaptations to cold 1) Cushion plants: grow in small, rounded humps –conserve heat –reduce wind chill
Adaptations to cold 2) Develop a blanket of white hairs –protect them from cold at night –White to reflect radiation during the day –e.g. Giant Lobelia, in Kenya
Adaptations to cold 3) Keep dead leaves on the stem –prevents ground from freezing –e.g. Groundsel
Adaptations to cold 4) Grow short and small –to avoid harsh winds and crushing snow –the air temperature is warmer 10-15cm above the soil.
Adaptations to cold 5) Grow in balls that roll around w/frost heave, eg. Kenya moss deal w/expansion and contraction of soil due to freezing and thawing. Stone circles
Adaptations to cold 6) Rosette plants cabbage-like leaves surround a central bud winter: central bud is protected by the remaining vegetation.
More adaptations to cold high investment into belowground biomass (high root:shoot ratio) tolerance to low temperatures (= intolerance of high temperatures)
Cold-tolerant species examples Heaths: hard evergreen leaves that can withstand drying winds and cold temperatures. Common heaths: cranberries, blueberries, and rhododendrons
II. Adaptations to dry conditions Many high mountains plants are succulents, with water stored in thick leaves; minimize evaporation E.g. cactus
Adaptations to High UV irradiance Cover their leaves with white hairs (reflect the suns rays). Some plants contain a red pigment called anthocyanin which absorbs UV sunlight before it has a chance to damage the leaves.
Short growing season Cold nights short daylight hours 180 days/year The Fireweed's seeds are plume- shaped. This allows them to ride on the wind before falling to the ground where they can take root. Adaptation: start to grow as soon as the snows melts store food during the summer months pollination strategies?
Summary Cold- grow short, close to ground - grow horizontally -cushion trees wind- grow in clumps (island trees) low nutrients-carnivorous UV-white hairs; antocyanin low growing seasons - grow fast; store nutrients; -pollination strategies dry-wax leaves LIMITATIONSADAPTATION