Today's schedule is CDAB
C & D Blocks Social and Environmental Sciences - Today we start in room 115, where you'll have the morning to work on your Towhee Creek Watershed map from your field work. You are representing data in a graphic format (encoding rather than decoding). Remember Towhee Creek is important due to superior capacity for nutrient spiraling and fish habitat (particularly Coho and trout) providing winter habitat for Tsolum River salmon populations in the watershed. The headwaters of Towhee Creek is a rare 5.53 hectare Garry oak woodland behind G.P. Vanier Secondary School. This protected Garry oak woodland is a remnant of the most northern ecosystem of its kind in Canada. It also hosts a variety of unusual vegetation species. Your objective is to explain your views on the health of Towhee Creek graphically. First you'll need to determine what it is that makes a stream healthy. To that end check out:
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| From the Chesapeake Bay Foundation |
Some factors that have an impact on streams include:
When it comes to stream health, land use and protection matter
A New Way of Understanding What Makes a River Healthy
Stream (National Geographic explanation)
How do I recognize a healthy stream?
You should also consider
Stream bed - Many aquatic animals rely on stony stream beds, where they live on and in-between the stones. Sediment from soil erosion (eg, as a result of deforestation, earthworks or storms) in the catchment can cover the stones and degrade the habitat for fish and aquatic invertebrates.
Algae - Algae grow on the stones in the stream bed. Some invertebrates feed on algae as their main food source and are adapted to eat short algae. When nutrient levels are high (from agricultural runoff) or when there is too much sunlight (lack of stream shading), algae grows longer and thicker and invertebrates can no longer eat it.
Pool/riffle/run - A healthy stream will have pools, riffles and runs as these provide a variety of habitat for aquatic animals.
• A pool is an area of slow flowing, deep water, often on the outside bend of a stream
• A riffle is an area of fast flowing, shallow water where the surface of the water is broken from flowing over stones
• A run is a smooth, unbroken flow of water that connects pools and riffles
Stream shading - Trees provide shading that has several benefits:
• reduces temperature extremes
• limits light and keeps water cooler to help limit algal growth
• keeps water cooler to hold more dissolved oxygen (invertebrates and fish need oxygen to survive)
• provides falling leaves and insects as a year round supply of food for aquatic animals
Bank stability - Bank stability is provided naturally by trees and plants. Root systems hold the banks together and are particularly effective when they grow right down to the water’s edge. Bare banks, erosion and bank slumping show instability. Tree roots help stream ecosystems by:
• preventing sediment (soil) from coating the stream bed and covering the gaps between the rocks where invertebrates live
• keeping sediment out of the water and maintaining water clarity. (This is important for stream dwelling creatures who need good visibility to hunt prey and need their gills clear for taking in oxygen)
• creating habitat for fish and freshwater crayfish in amongst their roots
Human impacts - Some human actions have a direct effect on the stream and the animals within it. Examples include:
• storm water pipes that may discharge polluted water
• grazing animals (eg, cows) that pollute the water
• culverts and weirs that stop the migration of native fish
• straightening of streams that reduce pool or riffle habitat
• concreted stream beds with no stony habitat available for aquatic animals
So...what can you show visually / graphically on your map to support these assessment pieces?
Also don't forget the headwaters are in our Garry Oak ecosystem. In Canada, Garry Oak Ecosystems are found only on the east side of Vancouver Island, the Gulf Islands, and a few isolated patches on the mainland. They are restricted to this limited geographic area because of the unique climatic conditions found here. Once common in coastal areas of southwestern BC, less than 5% of these ecosystems now remain in a near-natural condition. They are of cultural significance to First Nations and also provide many unrecognized benefits such as habitat for insects that act as pollinators or eat aphids, or homes for Sharp-tailed Snakes that eat garden slugs. Garry Oak and associated ecosystems are high in biodiversity – in fact, they are the richest land-based ecosystems in coastal BC. They are also some of Canada’s most endangered ecosystems, and are home to more than 100 species of plants, mosses, lichens, animals, and invertebrates at risk. The endangered status of Garry Oak ecosystems in Canada results from three main causes:
Habitat loss due to conversion of land for urban, industrial, and agricultural purposes. These losses are largely irreversible.
Habitat fragmentation, whereby once-connected habitat patches have become isolated and reduced in size. This partitioning has negative impacts on species persistence and ecosystem integrity. Fragmentation of habitats prevents dispersal and genetic interchange among populations of plants and animals, and reduces the size of habitat patches so much that they can no longer support the full complement of Garry Oak ecosystem species.
Habitat degradation results mostly from the spread of invasive species and the loss of natural disturbance regimes, such as fire. Consequently, even the small remnants of Garry Oak ecosystems are compromised and continue to be degraded by a variety of human activities.
What Are Garry Oak & Associated Ecosystems?
A Block Criminology - To start the class we'll watch the first half hour or so of a really cool video on the roots of violence from NOVA called Inside the Mind of a Rampage Killer...
What makes a person walk into a theater or a church or a classroom full of students and open fire? What combination of circumstances compels a human being to commit the most inhuman of crimes? Can science in any way help us understand these horrific events and provide any clues as to how to prevent them in the future? As the nation tries to understand the tragic events at Newtown, NOVA correspondent Miles O’Brien separates fact from fiction, investigating new theories that the most destructive rampage killers are driven most of all, not by the urge to kill, but the wish to die. Could suicide–and the desire to go out in a media-fueled blaze of glory–be the main motivation? How much can science tell us about the violent brain? Most importantly, can we recognize dangerous minds in time—and stop the next Newtown?
After we discuss what we've seen with the nature/nurture concept in terms of criminality
B Block Physical Geography - Today we'll quickly review systems and then we'll move on to geographic spheres within the Earth system (the Lithosphere, the Atmosphere, the Biosphere and the Hydrosphere).
After a few notes, you'll need to look at figure 1.8 (p.13) and figure 1.9 (p.14) in the Geosystems book and try to interpret the relationships among the four spheres as a result of humans burning fossil fuels. If you're having trouble with this consider the carbon cycle (pages 634-5 in text) or look at Earth Observatory Carbon Cycle from NASA. You could also look at Annenberg Media's "The Habitable Planet" Carbon Cycling website. For more help with positive and negative feedback loops take a look at Chapter 2 of Gerry Martin's on line Human Ecology textbook.
The Carbon Cycling Game
For more on Spheres check out:
Earth System Science in a Nutshell @SERC
Earth Systems Interactions
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