270 likes | 481 Vues
ECOSYSTEM is a natural unit consisting of plants, animals and micro-organisms in an area functioning together with all the non-living physical factors of the environment . What do Ecosystems do?. -Provide fundamental life-support services upon which human civilization depends
E N D
ECOSYSTEM is a natural unit consisting of plants, animals and micro-organisms in an area functioning together with all the non-living physical factors of the environment
What do Ecosystems do? -Provide fundamental life-support services upon which human civilization depends (pollination, various foods, wood, erosion prevention, clean water + air, etc)
Ecological Importance • Subcomponent of the Coastal Douglas Fir Ecosystem • More plant species than any other ecosystem in Canada • 118 plants, birds, mammals, reptiles, and butterflies
Plants: Flowers Blue Camas White Fawn Lily Shooting Star Chocolate Lily
Plants: Shrubs Snowberry Wild Rose or Nootka Rose Ocean Spray
Trees Garry Oak Arbutus Douglas fir
Birds Vesper Sparrow (Rare) Western Meadowlark (likely extirpated) Lewis’s Woodpecker (extirpated) Other Birds:Owls, Sparrows, Hummingbirds, Hawks,Warblers, Towhees, Swallows
Mammals, Reptiles & Amphibians Black-tailed Deer Alligator Lizard Sharp-tailed Snake “At Risk”
Species “At Risk” • “At Risk” means danger of disappearing from wild • approximately 100 species in G.O.E. • Numerous extirpated species Large Marbled Butterfly Sharp-Tailed Snake Western Bluebird
On the Decline • In BC today, Garry Oak meadows occupy only 1% to 5% of their former area
Why the Decline? #1 Threat: Development Other Threats: Invasive species Scotch Broom English Ivy Himalayan Blackberry
Why the Decline? Other Threats: Fire Suppression -Natural and Man-made fire has been restricted -Without natural fire bushes and then trees grow and out compete Garry Oaks and other pant species
Succession: the series of changes in an ecological community that occur over time after a disturbance
Cultural Importance: First Nations -Used fire to help maintain meadows -Encouraged bulb foods to grow -Encouraged deer to browse
Cultural Importance: Blue Camas -Main food source for Coast Salish peoples(pit-cooked to break down insulin into fructose)-Responded very well to fire -Main trade item with other First Nations-Taken on journeys and planted
Cultural Importance: First Nations • When Chief Factor James Douglas saw six square miles of open camas meadows surrounding Victoria (then called Camosack), the search for the site of the new Hudson’s Bay Company fort was over. • The verdant grasslands were a spectacular sight in spring. Millions of butterflies--at least 40 abundant species--filled the air. Native grasses and clover grew tall and lush. Colourful blue camas mixed with golden paintbrush, white fawn lilies, chocolate lilies, lupins, buttercups and violets. • “The place itself appears a perfect ‘Eden’ in the midst of the dreary wilderness of the North,” Douglas enthused to his friend James Hargrave. “One might be pardoned for supposing it had dropped from the clouds into its present position.” • British newcomers wrongly assumed the open meadows they “discovered” were “natural” and unused. They viewed unfenced, unploughed and unseeded land as “waste,” available for “civilized” use. • In fact, Coast Salish ancestors of the Songhees First Nation (Lekwungen) had cultivated and maintained the shrub-free grasslands for centuries. They worked to enhance the growth of camas, their staple root crop, and other edible native plants.
What can you do to help? -Volunteer for Broom clearing-Sign a conservation covenant or stewardship agreement with a land trust-Remove invasive species from your property and use native plants-Protect existing Garry Oak trees-Restrict the use of pesticides and herbicides-Treasure the natural and wild areas in our yards and parks