FRESHWATER BIOMES

1
FRESHWATER BIOMES

• Ecology
• Chapter 10

2
Aquatic Biomes

• Water covers more than 70 of the Earths
  surface
• Aquatic habitat one in which organisms live in
  or on water
• not grouped geographically
• difficult to show on a map
• often determined by depth rather than location

3
Land vs. Aquatic Biome

• Temperature and rainfall are important factors
  when distinguishing one land biome from another.
• Temperature in large bodies of water are
  relatively stable.
• Rainfall has less effect on aquatic biomes
  because organisms are already underwater.

4
Important Factors

• Salinity The amount of dissolved salts in a
  sample of water. Measured in parts per thousand
  ( units of salt in a thousand units of water)
• Aquatic biomes can be divided into two main
  groups
• Saltwater (30 parts/1000)
• Freshwater (0.5 parts/1000)
• Ocean water gt brackish water lt fresh water

5
Important Factors

• Depth directly related to the amount of
  sunlight that reaches the bottom of the body of
  water.
• Sunlight determines the types and amounts of
  plants that can grow. (Remember plants are
  producers, and the base of the food web)

6

• Photic zone top layer of sunlight that receives
  enough sunlight for photosynthesis to occur.
• Aphotic zone below the photic zone. Sunlight
  does not reach this zone.
• Benthic zone the floor of a body of water

7
Question Break

• What characteristic distinguishes the photic zone
  from the aphotic zone?
• Sunlight
• How is salinity measured?
• Parts per thousand ( units salt/1000 units of
  water)

8
Standing-water Ecosystems

• The most common types of standing-water
  ecosystems are lakes and ponds.
• Also includes wetlands (bogs, swamps, etc.)
• While there is no flow of water in and out of
  most standing-water ecosystems, there is a
  circulation of water throughout the system.
• Review question How does this circulation
  occur? What causes the circulation?

9
(No Transcript)
10
Standing-Water Organisms

• Several levels of habitat
• Plankton community
• Plankton microorganisms that float on the
  surface of the water
• Phytoplankton carry out photosynthesis. Main
  producers in most aquatic biomes
• Zooplankton do not carry out photosynthesis.
  Include microscopic animals and protozoans.
  Consumers feed on phytoplankton
• Big fish feed on little fish, little
  fish feed on
• plankton
• Benthic community
• Scavengers, depend upon a steady rain of organic
  material that drifts down from the top.
  Decomposers are also part of this community

11
Wetlands

• Ecosystems in which the roots of plants are
  submerged under water at least part of the year.
  Soils are soaked with water, and very low in
  dissolved oxygen.
• Marshes, swamps, bogs
• Act as filters, detoxifying chemicals that passes
  through them
• Can be used as part of a treatment system for
  waste water
• Important breeding, feeding, and resting grounds
  for waterfowl.

12
Endangered Wetlands

• Wetlands are being destroyed by human activity.
• Many do not find wetlands as attractive as other
  natural habitats
• Land (especially in coastal areas) is developed
  for resorts and homes
• Swamp Lands Act of 1849 encouraged the filling
  and draining of wetlands

13
Florida Everglades

• Once a swampy marsh that covered 160 km from Lake
  Okeechobee to the tip of Florida.
• Region has a wet season from May to October,
  followed by a dry season. Natural fires occur
  during the dry season, burning off dried plant
  material.
• Home to a large number of organisms, that are
  adapted to the annual cycle of growth, drought,
  and fire.

14

• In 1983, Save Our Everglades campaign was
  launched.
• 100,000 acres returned to wetland
• Flow of water adjusted to provide a more natural
  water supply

15
Flowing-Water Ecosystems

• Rivers, streams, creeks, brooks
• All water that flows over land - to a scientist
  they are all streams
• Water that flows underground is an aquifer
• Stream Organisms
• Adapted to the rate of the waters movement
• Hooks to grab hold of plants
• Suckers that anchor to rocks

16
Stream Stages
Youthful
Old

• ________
• Rapids
• Waterfalls
• Fast-moving water
• Steep slope

• _______
• Broad floodplain
• Meanders
• Oxbow lakes
• Meander Scars

17
Important Definitions
River System

• ____________ a stream and all its tributaries
• ________ a smaller stream that empties into a
  larger stream
• _________ the land area drained by a river
  system
• ______ a high point that separates river
  systems

Tributary
Watershed
Divide
18
(No Transcript)
19
________ the bends and curves of a stream
Meanders
20
(No Transcript)
21
Oxbow lake
deposition
erosion
22
(No Transcript)
23
(No Transcript)
24
____________ deposit formed when a stream
spreads out onto a less steep area
Alluvial Fan
25
_____ where a stream empties into a larger body
of water
Delta
26
Ganges River Delta
27
Nile River Delta
28
(No Transcript)
29
Human Impact on Streams

• Flow and course of streams has been changed by
  human activities
• Dams create reservoirs and are used for
  hydroelectric plants
• Dams and levees can be used to irrigate farmland
• Dams and levees affect farmland by preventing
  sediments from being deposited on floodplains
• Change of course damages or destroys the habitats
  of organisms
• Areas that were once streambeds become the
  bottoms of deep lakes

30
Chapter 10 Review

• To be considered fresh water, water must contain
  salt in a concentration
• More than 30 parts per thousand
• Less than 0.5 parts per million
• More than 40 parts per million
• Less than 0.5 parts per thousand

31

• Brackish water is common in
• Lakes
• Oceans
• Coastal marshes
• aquifers

32

• Sunlight reaches the benthic zone in
• Ponds
• Deep lakes
• Oceans
• Vents in the ocean floor

33

• Organisms that live in the benthic zone of deep
  lakes are often
• Producers
• Plants
• Scavengers
• plankton

34

• A type of standing-water habitat in which the
  soil is acidic and decay is slow is called a
• Bog
• Swamp
• Marsh
• pond

35

• Phytoplankton are
• Consumers
• Decomposers
• Producers
• scavengers

36

• Wetlands are
• Easy to define
• Have traditionally been protected by laws
• Are nonproductive areas that could be better used
  for other purposes
• Are important breeding grounds

37

• Sediments tend to accumulate
• In slow-moving parts of a stream
• On the outer edge of a curve in a stream
• In fast-moving parts of a stream
• Near the beginning of the stream

38

• Streams always flow
• South
• Toward the ocean
• Downhill
• Toward the poles of Earth

39

• Levees and dams are beneficial to farmlands
  because they
• Prevent stream sediments from being deposited on
  the fields
• Protect the fields from floods
• Provide a source of irrigation
• Help refill aquifers

40

• Levees and dams are harmful to farm lands because
  they
• Prevent stream sediments from being deposited on
  the fields
• Protect the fields from floods
• Provide a source of irrigation
• Help refill aquifers