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Aquatic ecosystems
- 1. AQUATIC ECOSYSTEMS LANDSCAPE ECOLOGY RESTORATION ECOLOGY ECOSYSTEM MANAGEMENT Chapters 8 and 10
- 2. What are thebasic needs of aquatic biota? • CO2 • O2 • Sunlight • Nutrients- food & minerals
- 3. What factors influencethe availability of those basic needs? • Substances dissolved in water- Nitrates, phosphates, potassium, O2 • Suspended matter- (silt, algae) can affect light penetration • Depth • Temperature • Rate of flow • Bottom characteristics (muddy, sandy, or rocky) • Internal convection currents • Connection to or isolation from other aquatic ecosystems.
- 4. Types of AquaticEcosystems • Freshwater Ecosystems – Standing Water- lakes & ponds – Moving Water- rivers & streams • Transitional Communities – Estuaries – Wetlands- bogs/fens, swamps, marshes • Marine Ecosystems – Shorelines – Barrier Islands – Coral Reefs – Open Ocean
- 5. Freshwater Ecosystems • Usually0.005% salt – Some exceptions: • Great Salt Lakes- 5-27% salt • Dead Sea- 30% salt • Moving water- high elevations; cold; high O2; trout; streamlined plants • Standing water- lower elevations; warmer; less O2; bass, amphibians; cattails, rushes
- 6. How is alake stratified and what lives in each level? • Epilimnion- upper layer of warm water; high light & O2; ex: water striders, phyto- & zooplankton, fish • Thermocline (mesolimnion); middle layer; medium light & O2; ex: phyto- & zooplankton, fish • Hypolimnion- lower layer of cold water; lower light & O2; ex: fish • Benthos- bottom level; no light & little O2; ex: anaerobic bacteria, leeches; insect larvae • Littoral- near the shoreline; cattails, rushes, amphibians, etc.
- 7. Transitional Communities • ESTUARIES •Where freshwater dumps into ocean • Brackish (less salty than seawater) • Has rich sediments that often form deltas • Productive & biodiverse • Organisms adapted to varying levels of salinity as tide ebbs & flows • “Nursery” for larval forms of many aquatic species of commercial fish & shellfish
- 8. Transitional Communities • WETLANDS • Land saturated at least part of the year Swamp • Swamps- have trees like bald cypress; high productivity • Marshes- no trees; tall grasses; high productivity • Bogs/Fens- may or may not Marsh have trees; waterlogged soil with lots of peat; low productivity – Fens- fed by groundwater & surface runoff – Bogs- fed by precipitation Bog Fen
- 9. Importance of Wetlands • Highly productive- get lots of sunlight, ↑ plants = ↑ animals • Nesting, breeding ground for migratory birds • Slows flooding by absorbing runoff • Silt settles, making water clearer & nutrient rich • Trap & filter water • Natural chemical rxns neutralize and detoxify pollutants • Gives H2O time to percolate thru soil & replenish underground aquifers. • Threats- artificial eutrophication (see slide 13), draining, sedimentation via construction • “Nature’s Septic Tank”
- 10. Marine Ecosystems • SHORELINES • Rocky coasts- great density & diversity attached to solid rock surface • Sandy beaches- burrowing animals • Threats- due to hotels, restaurants, homes on beach, more plant life destroyed, destabilizing soil, susceptible to wind & water erosion • Insurance high; danger of hurricanes, erosion • Build sea walls to protect people but changes & endangers shoreline habitat
- 11. Marine Ecosystems • BARRIERISLANDS • Low, narrow offshore islands • Protect inland shores from storms • Beauty attracts developers = developers destroy land • New coastal zoning laws protect future development
- 12. MARINE ECOSYSTEMS • CORAL REEFS • Clear, warm shallow seas • Made up of accumulated calcareous (made of calcium) skeletons of coral animals • Formation depends on light penetration. • Have a symbiotic relationship with algae • Very diverse, abundant (rainforests of sea) • Threats- destructive fishing (cyanide & dynamite to stun fish), pet trade; about 3/4ths have been destroyed
- 13. What factors canalter aquatic ecosystems? • Natural Succession- normal cycle of pond becoming forest • Artificial Succession- humans add N & P to water via fertilizer & sewage causing succession to happen faster = EUTROPHICATION
- 14. What factors canalter aquatic ecosystems? • Humans! – Find food – Recreation – Waste disposal – Cooling of power plants – Transportation – Dams, canals
- 15. Biomes • Which biomehas the largest total area? The smallest total area? • Which biome has the highest % of undisturbed habitat? • Which biome has the lowest % of undisturbed habitat? • Which biome has the highest % human dominated habitat? • Which biome has the lowest % human dominated habitat?
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- 17. LANDSCAPE ECOLOGY • Landscape-geographic unit with a history that shapes the features of the land and organisms in it. • Landscape ecology- the study of how landscape structure affects the abundance and distribution of organisms. • Does not just focus on “untouched nature”
- 18. LANDSCAPE ECOLOGY • Usesgeographical information systems (GIS) to map patch size, type and configuration to create 3-D maps • These maps assist land planners in analyzing land use patterns
- 19. LANDSCAPE ECOLOGY • Focuson how neighboring communities of a landscape interact
- 20. RESTORATION ECOLOGY Chapter 10
- 21. RESTORATION ECOLOGY • Repairor reconstruct Before ecosystems damaged by humans or natural forces • Growing field of science • People are now being held responsible for their actions- restoring wetlands & habitat for endangered species After
- 22. The 5 “R’s”of Restoration Ecology • Restoration- Before manipulation of nature to re-create species composition & ecosystem processes as close as possible to the state they were in before humans interfered. After
- 23. The 5 “R’s”of Restoration Ecology • Rehabilitation- to bring an area back to a useful state for human purposes rather than a truly natural state. - reverse These people in Africa are trying to deterioration if can’t use rocks to create a sort of wind be restored fully break to prevent wind erosion of their soil. The soil will never be like it was but it will hopefully be usable.
- 24. The 5 “R’s”of Restoration Ecology • Remediation- process of cleaning chemical contamination from a polluted area by physical or biological methods to protect human & ecosystem health - Incinerate soil contaminated with oil - use special bacteria to clean up oil spills in water (bioremediation) This is like an artificial wetland- wastewater comes in, settles, roots cleanse the water
- 25. The 5 “R’s”of Restoration Ecology • Reclamation- techniques used to Before restore the shape, original contour and vegetation of a disturbed site - Surface Mining Control & Reclamation Act (SMCRA) requires mining operations to After restore the open pit mines they create to natural state.
- 26. The 5 “R’s”of Restoration Ecology • Re-creation- attempts to construct a new biological community on a site so severely disturbed that there is virtually nothing left to restore. - often must build a wetland elsewhere to make up for the one destroyed by developer - Read story of Army Corp of Engineers & Florida Everglades restoration
- 27. Preservationists vs. Restorationists • Preservationist- don’t start destructive projects in the first place. Preserve nature- “you can’t always fix what you broke” • Restorationists- you are never going to be able to save every bit of land. Who says changes we make in restoring ecosystems is unnatural? • Are we members of the community or separate from it? • Should we use our creative energies to try to improve nature, or should we leave well enough alone?
- 28. Tools of Restoration •Prairies- collect native prairie grasses from graveyards and plant in abandoned farm fields to reestablish native grasslands • Remove alien species- like privet @ nature center; hunting goats on Galapagos • Walk away from ecosystem & let recover naturally- N. & S. Korea after the Korean War
- 29. Restoration Ethics • If habitat was filled with diseased, ugly organisms, should you return it to that Canal state? Should you reintroduce in mosquitoes, black flies, leeches, ticks, China poisonous snakes? Before • Should you improve on nature? • Where do you find plants for restoration? Do you take from small population nearby or find larger population farther away? • Is there more than one natural state? What is the history of the area? Canal • Since humans are part of nature, in whatever changes we make to China landscape also are natural. Is that After true? • Can we use nature to solve human Notice problems? Read story on page 121 plants about Arcata, California’s artificial wetland project. used as filtering system
- 30. Ecosystem Management • How can we have progress and still maintain the environment? • Aldo Leopold was one of the pioneers on his Sand County farm • US Forest Services, Bureau of Land Management, National Park Service all adopted versions of ecosystem management • Previously, these agencies used their lands for commercial or recreational uses & did not focus on wildlife habitats, endangered species, etc.