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AQUATIC ECOSYSTEMS LANDSCAPE ECOLOGY RESTORATION ECOLOGY ECOSYSTEM MANAGEMENT Chapters 8 and 10

Aquatic ecosystems

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Page 1: Aquatic ecosystems

AQUATIC ECOSYSTEMSLANDSCAPE ECOLOGY

RESTORATION ECOLOGYECOSYSTEM MANAGEMENT

Chapters 8 and 10

Page 2: Aquatic ecosystems

What are the basic needs of aquatic biota?

• CO2

• O2

• Sunlight• Nutrients- food &

minerals

Page 3: Aquatic ecosystems

What factors influence the 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.

Page 4: Aquatic ecosystems

Types of Aquatic Ecosystems

• 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

Page 5: Aquatic ecosystems

Freshwater Ecosystems

• Usually 0.005% 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

Page 6: Aquatic ecosystems

How is a lake 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.

Page 7: Aquatic ecosystems

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

Page 8: Aquatic ecosystems

Transitional Communities

• WETLANDS• Land saturated at least part of

the year• Swamps- have trees like bald

cypress; high productivity• Marshes- no trees; tall

grasses; high productivity• Bogs/Fens- may or may not

have trees; waterlogged soil with lots of peat; low productivity– Fens- fed by groundwater &

surface runoff– Bogs- fed by precipitation

Bog

Fen

Marsh

Swamp

Page 9: Aquatic ecosystems

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”

Page 10: Aquatic ecosystems

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

Page 11: Aquatic ecosystems

Marine Ecosystems

• BARRIER ISLANDS• Low, narrow offshore

islands• Protect inland shores

from storms• Beauty attracts

developers = developers destroy land

• New coastal zoning laws protect future development

Page 12: Aquatic ecosystems

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

Page 13: Aquatic ecosystems

What factors can alter 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

Page 14: Aquatic ecosystems

What factors can alter aquatic ecosystems?

• Humans!– Find food– Recreation– Waste disposal– Cooling of power

plants– Transportation– Dams, canals

Page 15: Aquatic ecosystems

Biomes

• Which biome has 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?

Page 16: Aquatic ecosystems

LANDSCAPE ECOLOGY

Page 17: Aquatic ecosystems

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”

Page 18: Aquatic ecosystems

LANDSCAPE ECOLOGY

• Uses geographical 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

Page 19: Aquatic ecosystems

LANDSCAPE ECOLOGY

• Focus on how neighboring communities of a landscape interact

Page 20: Aquatic ecosystems

RESTORATION ECOLOGY

Chapter 10

Page 21: Aquatic ecosystems

RESTORATION ECOLOGY

• Repair or reconstruct 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

Before

After

Page 22: Aquatic ecosystems

The 5 “R’s” of Restoration Ecology

1. Restoration- manipulation of nature to re-create species composition & ecosystem processes as close as possible to the state they were in before humans interfered.

Before

After

Page 23: Aquatic ecosystems

The 5 “R’s” of Restoration Ecology

2. Rehabilitation- to bring an area back to a useful state for human purposes rather than a truly natural state.

- reverse deterioration if can’t be restored fully

These people in Africa are trying to use rocks to create a sort of wind break to prevent wind erosion of their soil. The soil will never be like it was but it will hopefully be usable.

Page 24: Aquatic ecosystems

The 5 “R’s” of Restoration Ecology

3. 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

Page 25: Aquatic ecosystems

The 5 “R’s” of Restoration Ecology

4. Reclamation- techniques used to restore the shape, original contour and vegetation of a disturbed site- Surface Mining Control & Reclamation Act (SMCRA) requires mining operations to restore the open pit mines they create to natural state.

Before

After

Page 26: Aquatic ecosystems

The 5 “R’s” of Restoration Ecology

5. 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

Page 27: Aquatic ecosystems

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?

Page 28: Aquatic ecosystems

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

Page 29: Aquatic ecosystems

Restoration Ethics• If habitat was filled with diseased, ugly

organisms, should you return it to that state? Should you reintroduce mosquitoes, black flies, leeches, ticks, poisonous snakes?

• 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?

• Since humans are part of nature, whatever changes we make to landscape also are natural. Is that true?

• Can we use nature to solve human problems? Read story on page 121 about Arcata, California’s artificial wetland project.

Canal in China Before

Canal in China After

Notice plants used as filtering system

Page 30: Aquatic ecosystems

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.