chapter 35: the biosphere - weebly

35-1

Aquatic Communities

Aquatic communities can be classified as freshwater or saltwater.

The two sets of communities interact and are joined by the water cycle.

Gravity eventually returns all fresh water to the sea, but meanwhile, it is contained as standing water in lakes and ponds, or as flowing water within streams and rivers.

35-2

Freshwater and saltwater

communities

35-3

LakesLakes are bodies of freshwater often

classified by their nutrient status.

Oligotrophic lakes are nutrient-poor and have low productivity.

Eutrophic lakes are nutrient-rich and have high productivity.

Through the activities of both nature and humans, oligotrophic lakes become eutrophic through large inputs of nutrients; this is called eutrophication.

35-4

Types of lakes

35-5

Standing-Water EcosystemsMicroscopic floating organisms in lakes

are called plankton; phytoplankton are photosynthesizing algae, and zooplankton are the tiny animals that eat them.

35-6

Freshwater Wetlands• A wetland is an ecosystem in which

water either covers the soil or is near the surface

• The three main types of freshwater wetlands are bogs (depressions where water collects), marshes (at river edge has grasses), and swamps (has trees and shrubs)

35-7

Estuaries

An estuary is a partially enclosed body of water where fresh water and salt water mix.

Organisms living there must be able to tolerate brackish water (mix of salt and fresh water).

Estuaries trap nutrients delivered by rivers and act as nurseries for larval fish.

Estuaries are the feeding grounds for man, birds, fish, and shellfish.

35-8

Estuaries

Near the mouth of a river, a salt marsh in

the temperate zone or a mangrove

swamp in the subtropical and tropical

zones is likely to develop.

35-9

Estuary structure and function

35-10

Types of estuaries

35-11

Photic Zone: region of the ocean that

light penetrates

Aphotic Zone: permanently dark

In addition to the division between photic

and aphotic zones, marine biologists

divide the ocean into zones based on the

depth and distance from shore:

• the intertidal zone

• the coastal ocean

• the open ocean

Marine Ecosystems

Copyright Pearson Prentice Hall

Marine Ecosystems

200 m

1,000 m

Aphotic

zone

Photic

zone

Abyssal

plain

Continental

slope

and continental

rise

Continental

shelf

Open

ocean

Coastal

ocean

Land

Ocean

trench

4,000 m

6,000 m

10,000 m

Marine Ecosystems

Intertidal Zone

Organisms that live in the intertidal zone are

exposed to regular and extreme changes in

their surroundings.

Competition among organisms in the rocky

intertidal zone often leads to zonation, the

prominent arrangement of organisms in a

particular habitat in horizontal bands.


Marine Ecosystems

Coastal Ocean

The coastal ocean extends from

the low-tide mark to the outer

edge of the continental shelf.

It falls within the photic zone,

and photosynthesis occurs

throughout its depth.

The coastal ocean is often rich

in plankton and many other

organisms.


Marine Ecosystems

Kelp forests are

named for their

dominant

organism, a giant

brown alga. Kelp

forests are one of

the most

productive coastal

ocean

communities.

Kelp forests

support a complex

food web.

35-17

Coral reefs are areas of biological

abundance found in shallow, warm

tropical waters.

Their chief constituents are stony corals

with a limestone exoskeleton, and red

and green algae.

.


Marine Ecosystems

Open Ocean

The open ocean, the oceanic zone, extends from the

edge of the continental shelf outward.

It is the largest marine zone.

Most of the photosynthetic activity on Earth occurs in

the photic zone of the open ocean by the smallest

producers.

35-19

Benthic ZoneThe benthic zone includes

organisms living on or in the ocean floor

Organisms of the benthic zone (benthos) depend on the debris that floats down from above.

35-20

Ocean inhabitants

35-21

Chapter Summary

The spherical earth causes different

amounts of sunlight to be received at

different latitudes, resulting in

differences in temperature from the

equator to the poles.

The tilt and rotation of the earth cause the

four seasons.

Rising and falling air currents trigger moist

or dry areas across the globe.

35-22

Topography also influences rainfall patterns.

Terrestrial biomes are distributed according to climate; moisture and temperature determine major types of vegetation.

Terrestrial biomes include tundra, coniferous forest (taiga), temperate deciduous forest, tropical rain forest, shrublands, grasslands, savanna, and deserts.

Each biome has characteristic organisms.

35-23

Streams, rivers, lakes, ponds, and

wetlands are different freshwater

communities.


4-4

The photic zone is

• A. Found in the intertidal zone

• B. Where light penetrates

• C. contains plankton

• D. all of the above


4-4

Coastal wetlands that are widespread in

tropical regions such as southern Florida

and Hawaii are known as

• detritus.

• bogs.

• mangrove swamps.

• benthos.


4-4

Coral animals cannot grow in water that

• contains salt.

• contains oxygen.

• is cold.

• receives sunlight.


4-4

The zone that covers the ocean floor is the

• benthic zone.

• abyssal plain.

• continental shelf.

• continental rise.

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