matter, energy, and ecosystem cycles env115/lec14_aquatic ecosystems.pdf•surface water –1% of...
TRANSCRIPT
Aquatic Systems
Preview
1. Freshwater
2. Oceans
Freshwater
• Water seems abundant
• Freshwater is relatively rare (<3%)
1.
Figure 12.2
Freshwater
• Recall that water cycles through ecosystems
–Precipitation
–Runoff/Percolation
–Evaporation
1.
Freshwater
• Human modifications
–Dams
–Levees
–Runoff
1.
raredelights.com
Disney World Parking Lot
Freshwater
• Groundwater
–20% of Earth’s fresh water
–Aquifer: sponge-like
reservoir of water
1.
1.
Figure 12.4
Figure 12.21
1.
Figure 12.20
Overexploited water resources: 15-35% Uses: • Agriculture • Industry • Domestic
Freshwater
• Surface Water
–1% of Earth’s fresh water
–Watershed: land drained by a river and its tributaries
–Floodplain: land periodically flooded by river
1.
1.
www.wikipedia.org
Watersheds of the World
1.
1993
2002
The Great Flood of 1993 Images: explorestlouis.com; www.wikipedia.org
Freshwater
• Water bodies
–Lakes
–Rivers and streams
–Wetlands
1.
Freshwater
Great Lakes contain ~20% of world’s surface freshwater
1.
www.wikipedia.org
Freshwater
• Rivers and streams
–Water carries sediment and nutrients to oceans
–Important ecologically and economically
1.
Freshwater
• Columbia River
–Annual flow of goods ~$18 billion
– Biodiversity ~700 spp. of vertebrates
1.
www.wikipedia.org
Freshwater
• Wetlands
–Important for groundwater filtration and nutrient retention
–Bogs and fens
–Source of peat
1.
Sphagnum (peat) moss
Amending sandy soil
Images: Reece et al. 2011; www.homedepot.com; www.wikipedia.org
1.
Oceans
• Largest reservoir of water on Earth
• Changes in temperature and water currents influence climate
2.
Images: www.wikipedia.org
Oceans
• Upper waters –Lots of light and oxygen
–Warmer temperature
• Deeper waters –Less light
–Cooler temperature
–Lots of organic matter (snow)
2.
~10m depth ~50-60m depth
Approximately 80% of solar energy striking the ocean is absorbed in first 10m
2.
Images: Molles and Cahill 2011
Oceans
• Thermohaline circulation
–Worldwide oceanic current
–Downwelling: Warmer, oxygen-rich water sinks to deeper water
–Upwelling: Deeper, cooler, nutrient-rich water rises to surface
2.
2.
Figure 12.10
Oceans • Thermohaline circulation cont’d
–1992: 28,800 toy ducks spilled into Pacific Ocean
2.
Images: www.wikipedia.org “Friendly Floatees”
Oceans
• Ocean ecosystems
–Kelp forests/coral reefs
–Intertidal zones
–Salt marshes/estuaries
2.
Oceans
• Kelp forests
–Relatively high biodiversity
–Cooler waters
–Rocky shores
2.
www.wikipedia.org
Oceans
• Coral reefs
–Occur in warmer waters
–Sandy shores
–Change over time
2.
Figure 12.16
Oceans
• Intertidal zones
–Occurs where ocean meets land
–High vs. low tide
2.
Rocky intertidal zone on the Oregon coast
Reece et al. 2011
Oceans
• Salt Marshes/Estuaries
–Shallow zones of fresh and saltwater
–Important habitats
2.
Figure 12.12 Reece et al. 2011
Resources Publications
Molles, M. C. and J. F. Cahill. 2011. Ecology: Concepts and Applications, 2nd Canadian Edition. McGraw-Hill Ryerson, Whitby.
Reece, J.B., Urry, L.A., Cain, M.L., Wasserman, S.A., Minorsky, P.V., and R.B. Jackson. 2011. Campbell Biology, 9th edition. Pearson, New York.
Withgott, J. and M. Laposata. 2012. Essential Environment: The Science behind the Stories, 4th Edition. Pearson, New York.