Ecosystem Services Ch 2.4
Ecosystem Services Def: benefits experienced by organisms, including humans, that are provided by sustainable ecosystems – –Natural result of all activities in biosphere Cycling of nutrients Pollination of crops Balance of growth/decomposition Contribution of beauty
Let’s examine a forest… HHow does it influence local climate? –C–Canopy traps humidity, keeps cool WWhat role do tree roots play? –R–Reduce erosion HHow many organisms do you see? How many are there? –P–Provide shelter and protection from predation
Desertification Trees extract massive quantities of water from soil On hot days, a lot of water escapes through the stomata, adding water vapour to the atmosphere – –This reduces temperature, forms rain clouds Did you know more than ½ the moisture above tropical forests comes from trees?
Desertification When forested areas are cleared, local precipitation drops – –The climate gets hotter and drier leading to desertification (change of non-desert land into a desert) Can also occur from climate change, over-farming, and excessive water use
Watersheds and Erosion A watershed is an area of land over which run-off drains into a body of water Trees benefit watersheds – –How??
Watersheds and Erosion Soil (without trees) cannot retain water as well as forested areas – –Erosion increases
Erosion Rock and soil are loosened from Earth's surface at one location and moved to another - Natural – –Wind and water break rock and soil into smaller pieces, and loosen them from the earth's surface. Changes landscape: – –Wears down mountains – –Fills in valleys – –Rivers appear and disappear Usually a slow and gradual process that occurs over thousands or millions of years. – –Can be sped up by such human activities as farming and mining.
Erosion
Another ecosystem service Cross-pollination: when pollen is transferred from one flower to a different flower Most plants rely on animals, insects to move pollen between flowers –Bees, beetles and bats are the busiest pollinators!
Cross-pollination What abiotic factor could also help cross- pollinate? –The wind
Did you know…? …that cross-pollination by insects contributes to 1/3 of world food production –Holy cripes! –$250 B per year
Homework Read “Case Study” on p What is colony collapse disorder? What 2 parasites are named as being potential factors in the decline of bees? How does pesticide use affect bees? How could your cell phone affect a poor bee?
Read section 3.1, “Measuring Biodiversity” Define these terms in the context of ecology: – –Biodiversity – –Protect – –Quadrat – –Transect – –biodiversity hotspot. Describe how each of these methods of measuring biodiversity works: – –canopy fogging – –quadrat sampling – –transect sampling – –netting