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Ecosystems & Communities:Organisms and their Environments

Chapter 15

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Ecosystems have living and non-living components

15.1 What are ecosystems?

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15.1 What is an Ecosystem?• A community of biological organisms plus the non-

living components with which the organisms interact.• Living organisms are not self-sufficient. They need

energy and raw materials.

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15.1Communities• The biotic environment consists of all the living

organisms within an area and is often referred to as a community.

• Communities can be any size and diversity – bacteria• - single celled organisms• - insects• - other larger sized creatures

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Habitat• The abiotic (aka non-living or physical) environment,

often referred to as the organisms’ habitat, consists of:• the chemical resources of the soil, water, and air,

such as carbon, nitrogen, and phosphorus• the physical conditions, such as the temperature,

salinity (salt level), moisture, humidity, and energy sources

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Examples of ecosystems1. Different species interacting together at the same

place and time2. Different species interacting with each other at the

same time in a desert3. A smaller species living on a larger species in a

mutually beneficial relationship

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Ecosystem• An ecosystem is all of the living organisms in a habitat

as well as the physical environment. Ecosystems are found not just in obvious places such as ponds, deserts, and tropical rainforests but also in some unexpected places, like the digestive tracts of organisms or the shell of a beetle.

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Ecosystem• An ecosystem is made of two components: • the biotic environment, or community, consisting of the

living organisms within an area,• the physical environment, or the habitat in which these

organisms live. A habitat consists of its chemical resources of the soil, water, and air as well as its physical conditions.

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Ecosystems have living and non-living components

15.2 A variety of biomes occur around the world, each determined by temperature and rainfall.

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15.2 A variety of biomes occur around the world, each determined by temperature and rainfall.• What is the average temperature?• What is the average rainfall (or other precipitation)?• Is the temperature constant or does it vary seasonally?• Is the rainfall constant or does it vary seasonally?

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Tropical Rain Forest

• forest of tall trees in a region of year-round warmth• ~ 125 to 660 cm yearly rainfall• temperature ranges from 20 °C - 34 °C• average humidity 77 - 88%• rainfall > 250 cm/year (may be a brief dry season) • almost all rain forests lie near the equator

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Tropical Rain Forest

• 6% of Earth's land surface• 50% of all the world's plant and animal species live in

tropical rain forests• Produce 40% of Earth's oxygen• 70% of the plants in the rainforest are trees• 25% of all the medicines we use come from rainforest

plants

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Tropical Rain Forest

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Indicator Species

• any biological species that defines a trait or characteristic of the environment• may delineate an ecoregion • could indicate an environmental condition such as

a disease outbreak, pollution, species competition or climate change

• can be among most sensitive species in a region; sometimes act as early warning to monitoring biologists

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Tropical Rain Forest – Indicator Plant Species

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Tropical Rain Forest – Indicator Animal SpeciesGorilla 

Gorilla gorilla

Orangutan (Pongo pygmaeus)

Spider MonkeyAteles geoffreyi

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Tropical Rain Forest – Indicator Animal Species2-toed sloth

Cholepus hoffmanni

Three-toed Sloth (Bradypus variegatus) with baby - Costa Rica

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Tropical Rain Forest – Indicator Animal Species

Collared AracariPteroglossus torquatus

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Grasslands (Prairie)

• Wide-open spaces without trees• found in middle latitudes in the interiors of continents• short-grass: dry; hotter summers and colder winters• Argentina - grasslands are known as pampas• N. America – prairie• Russia - steppes• grasslands in southern hemisphere tend to get more

precipitation than those in the northern hemisphere• different types

• tall-grass: humid & very wet

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Grasslands (Prairie)

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Grasslands (Prairie)

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Grasslands (Prairie)• temperatures range from -40° C 22° C• growing season and a dormant season

• growing season is when there is no frost and plants can grow (which lasts from 100 to 175 days)• the length of the growing season is determined by

temperature (≥ 12° C)• dormant (not growing) season: nothing can grow

because its too cold

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Grasslands (Prairie)• average rainfall per year ranges from 25 – 95 cm• amount of rainfall is very important in determining which

areas are grasslands • hard for trees to compete with grasses in places

where the uppers layers of soil are moist during part of the year but where deeper layer of soil are always dry.

• tropical and sub-tropical grasslands: average rainfall per year ranges from 60 – 190 cm

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Grasslands– Indicator Plant SpeciesOld Field Habitat, Ohio

Grassland, North Dakota

Ironweed (Vernonia sp.) with Hedge Bindweed

Vine  (Calystegia sepium)

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Grasslands– Indicator Plant Species

Ironweed (Vernonia sp.)

Joe Pye WeedEupatorium purpureum

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Grasslands – Indicator Plant Species

Common TeaselDipsacus fullonum Queen Anne's Lace (Daucus carota)

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Grasslands – Indicator Animal Species

Bison (Bison bison) on the range, Theodore Roosevelt National Park, North Dakota

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Grasslands – Indicator Animal Species

Przewalski's horse (Equus caballus przewalskii), The Wilds, Ohio

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Grasslands – Indicator Animal Species

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Taiga• Cold forests of many coniferous trees and short brush• Russian word for forest • largest biome in the world• Eurasia, North America• located just below the tundra biome• many coniferous trees • Known in N. America as Boreal Forest

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Taiga• winter temperature range is -54 to -1° C (-65 to 30° F)• summer: -7° C to 21° C ((20° F - 70° F)• summers are very short (50 - 100 frost free days) • average yearly precipitation: 30 - 85 cm (12 - 33 in)• main seasons are winter and summer

• spring and autumn are very short • weather is either hot and humid or very cold

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Taiga

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Taiga – Indicator Plant Species

Balsam FirAbies balsamea

Black SprucePicea  mariana

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Taiga – Indicator Plant Species

Jack PinePinus banksiana

Paper BirchBetula papyrifera

White PoplarPopulus alba

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Taiga – Indicator Animal Species

American Black BearUrsus americanus

Bald EagleHaliaeetus leucocephalus

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Taiga – Indicator Animal Species

Long-eared OwlAiso otus

Snowshoe RabbitLepus americanus

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Desert – Evaporation Exceeds Precipitation• hot and dry with little vegetation: near Tropic of

Cancer/Tropic of Capricorn• cold: near the Arctic

• cover about one fifth of Earth's land surface• temperature

• hot & dry: ~ 25° C to ~ 49° C• cold: -2 to 4° C (winter) 21 to 26° C (summer)

• precipitation • hot & dry: very little rainfall and/or concentrated

rainfall in short periods between long rainless periods (< 15 cm/year)

• cold: 15 - 26 cm/year

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Desert

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Desert – Indicator Plant Species

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Desert – Indicator Plant Species

Saguaro Cactus Carnegiea gigantea

Fishhook Cactus Mammillaria microcarpa

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Desert – Indicator Plant Species

Trichomes

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Desert – Indicator Animal Species

Zebratail Lizard - Callisaurus draconides

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Desert – Indicator Animal Species

Rock hyrax (Procavia capensis)

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Desert – Indicator Animal Species

Bactrian Camel, Camelus bactrianus

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Temperate Deciduous Forest

• Medium temperature with trees that lose their leaves• temperature: 0 - 20 C Winter/summer seasonal variation• precipitation: ~ 50 – 200 cm/year – constant at all times

of the year• Winter – dormant• Summer – productive• Biome of this region

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Temperate Deciduous Forest

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Temperate Deciduous ForestIndicator Plant Species

Oaks (Quercus sp.)

Dutchman's-BreechesDicentra cucullaria

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Temperate Deciduous ForestIndicator Plant Species

SassafrasSassafras albidum

RedbudCercis canadensis

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Temperate Deciduous Forest – Succession• Farming has reduced the oak/hickory forest to open

areas• orderly succession of communities to a climax

community (biome)• primary succession: begins with bare rock exposed by

geologic activity• secondary succession: begins on soil from which

previous community has been removed (by fire, agriculture, etc.)• secondary succession can proceed much faster

because the soil has been prepared by the previous community

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Temperate Deciduous ForestIndicator Animal Species

American ToadBufo americanus

Box Turtle

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Temperate Deciduous ForestIndicator Animal Species

Eastern Chipmunk Tamias striatus

Eastern Gray SquirrelSciurus carolinensis

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Temperate Deciduous ForestIndicator Animal Species

Yellow-breasted chatIcteria virens

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Tundra• Ground is permanently frozen beneath top 10 cm• annual average temperature < 5 C• precipitation (mostly in the form of snow) < 100 mm/year• summer is brief

• temperatures above freezing last only a few weeks at most

• "warm" summer coincides with periods of almost 24 hour daylight, so plant growth can be explosive 

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Tundra

Anaktuvuk Pass, Alaska

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Tundra – Indicator Plant Species

Arctic Tundra Wildflowers - Alaska

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Tundra – Indicator Plant Species

Lichen

Polytrichum Moss(photographed in Ohio, not on the

Tundra)

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Tundra – Indicator Animal Species

Reindeer Rangifer tarandus

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Tundra – Indicator Animal Species

 Caribou On Autumn Tundra Denali National Park Alaska

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Savanna• rolling grassland scattered with shrubs and isolated trees

• found between a tropical rainforest and desert biome• not enough rain falls on a savanna to support forests• found in a wide band on either side of the equator on

the edges of tropical rainforests• warm temperature year round• very long dry season (winter): ~ 10 cm rain; none at all

from Dec - Feb• very wet season (summer): ~ 35-65 cm rain (monsoons)

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Savanna

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Savanna – Indicator Plant Species

BaobabAdansonia digitata

Umbrella Thorn AcaciaAcacia tortillis

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Savanna – Indicator Animal Species

Savanna ElephantLoxodonta africana

Black MambaDendroaspis polylepis

LionPanthera leo

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Chaparral• Mild temperatures with long dry periods• winter: mild and moist, but not rainy• summer: very hot and dry. • annual temperature range: between -1° and 38° C• annual precipitation: ~ 25-45 cm, mostly in the winter• California coastal regions

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Chaparral

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Chaparral – Indicator Plant Species

Blue OakQuercus douglasii

Common SagebrushArtemisia tridentata

Olive TreeOlea europaea

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Chaparral – Indicator Animal Species

Black-tailed JackrabbitLepus californicus

Golden JackalCanis aureus

 Spotted SkunkSpilogale gracilis

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The Freshwater Biome• Inland lakes, rivers and wetlands• low salt concentration — usually less than 1%

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The Freshwater Biome – Ponds and Lakes

From left: a view across Manzanita Lake toward Mt. Lassen, California; a forest pond near Donnelly, Idaho; a Great Blue Heron; Paranagat Lake, southeastern Nevada.

• Formed by runoff from snowmelt and rainfall

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The Freshwater Biome – Streams and Rivers

From left: McArthur-Burney Falls State Park, California; trout; Green River, Utah; Brooks River, Alaska.

• Flowing water moving in one direction

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The Freshwater Biome - Wetlands

From left: Pescadero Marsh, California; coastal marsh at Umpqua Dunes, Oregon; trees and bogs on Esther Island, Alaska.

• Standing water with abundant plant life• can include salt marshes on the edge of oceans

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The Marine Biome • Salt water systems in oceans and shallow areas

touching oceans• cover about three-fourths of the Earth's surface • marine algae supply much of the world's oxygen supply

and take in a huge amount of atmospheric carbon dioxide

• evaporation of the seawater provides rainwater for the land

• 3 different types of marine regions:• oceans• coral reefs• estuaries

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The Marine Biome - Oceans

From left: mussels, worms, and a spider crab at a hydrocarbon seep community in the Gulf of Mexico; a sea fan and brain coral in the Florida Keys National Marine Sanctuary; a school of Atlantic amberjack off North Carolina.

• Deep oceans and continental shelf areas just off the coast

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The Marine Biome – Coral Reefs

From left: reef life in the Gulf of Aqaba, Red Sea; a reef at Fanning Island atoll in the central Pacific; a reef in the Florida Keys National Marine Sanctuary.

• Warm shallow salt water near islands and continents

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The Marine Biome – Estuaries and Wetlands

From left: Mangrove roots, south Florida; wetlands and tidal streams in the Ashe Island area, ACE Basin National Estuarine Research Reserve, South Carolina; a salt marsh in Winyah Bay National Estuarine Research Reserve, South Carolina.

• Freshwater streams merge with oceans in shallow areas

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Ecological Notes

These are the biomes, in order of their productivity (highest first)

1. estuaries and tropical rain forest  (highest)2. temperate forest3. agricultural land4. temperate grassland5. lakes and streams6. coastal zone7. tundra8. open ocean9. desert   (lowest)

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Biomes

Terrestrial• Tropical Rain Forest• Savannah• Desert• Chaparral• Temperate Forest• Prairie• Taiga• Tundra

Aquatic• Freshwater Lakes

and Ponds• Rivers and Streams• Wetlands• Open Oceans• Coral Reefs• Estuaries

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Ecological Notes

In order to be productive and have a lot of living material standing around (biomass), an ecosystem has to have 4 basic necessities for plant life to thrive (if there are enough plants, the ecosystem will also support a lot of animals).  The four things are:

1. Sunlight2. Nutrients3. Warm temperatures4. Water

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Biomes Video

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Biomes Summary• Biomes are the major ecological communities of earth,

characterized mostly by the vegetation present. Different biomes result from differences in temperature and precipitation, and the extent to which they vary from season to season.

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Challenge Question 15.2• Terrestrial biomes are determined by the temperature

and precipitation amounts as well as whether those factors are constant or vary by season. By contrast, how are aquatic biomes determined?

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Physical forces interacting create weather

15.3 Global air circulation patterns create deserts and rain forests.

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Water also cycles through ecosystems. It continually moves from the ocean to the air and land, then returns to the ocean in a cyclic pattern.

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Weather Patterns• Global patterns of weather are largely determined by the

earth’s round shape. Solar energy hits the equator at a more direct angle than at the Poles, leading to warmer temperatures at lower latitudes. This temperature gradient generates atmospheric circulation patterns that result in heavy rain at the equator and many deserts at 30° latitude.

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Sunshine and Weather 15.3• Global weather patterns are mainly determined by the

amount of solar energy falling on an area. The amount of solar energy that falls on an area largely depends on the angle at which this light hits the earth.

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Physical forces interacting create weather

15.4 Local topography influences the weather.

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15.4 Local topography influences the weather• High altitudes have lower temperatures

• With increasing elevation, the air pressure drops—this is because the weight of the atmosphere becomes lower as altitude increases.

• When pressure is lower, the temperature drops. For each 1000 meters above sea level, the temperature drops by about 6° C.

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15.4 Local topography influences the weather

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15.4 Local topography influences the weather

• Asphalt, cement, and tops of buildings absorb heat, raising the temperature.

• Tall buildings force wind downward.

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15.4 Local topography influences the weather

Which place would you expect to have the highest temperature during the summer?

1. Denver, Colorado (the mile high city)2. Dallas, Texas (large city)3. Farmer’s Branch, Texas (small town outside of

Dallas)4. Freeport, Maine (small town)

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Topography Summary 15.4• Local features of topography influence the weather. With

higher altitude, the temperature drops. On the windward side of mountains, rainfall is high; on the backside, descending air reduces rainfall, causing rain shadow deserts. Urban development increases the absorption of solar energy, leading to higher temperatures, and creates wind near the bottom of tall buildings.

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Challenge Question 15.4• A rain shadow is a dry region on the landward side of a

mountain range. How is it formed?

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Rain Shadow• Warm air on the coast rises to go over mountains• As it rises, it cools which makes it hold less water• The rain/snow falls on the mountain• On the other side of the mountain the air descends but it

has less water• The dry air will cause less rainfall on the land

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Physical forces interacting create weather

15.5 Ocean currents affect the weather.

15.5 Ocean currents affect the weather• water is continuously moving and mixing due to a

combination of forces • wind• earth’s rotation• gravitational pull of the moon• temperature• salt concentration

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15.5 Ocean currents affect the weather

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15.5 Ocean currents affect the weather• Beach communities have milder weather than more

inland communities.• Beaches on the east coast of the United States have

warmer water than west coast beaches at the same latitudes – why?

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15.5 Ocean currents affect the weather

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15.5 Ocean currents affect the weather

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Water can affect the climate in which example below?

1. Ecosystems located near large bodies of water2. El Niño3. Temperatures in Europe compared to North America4. All of the above

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Ocean Currents• Oceans have global circulation patterns. Disruptions in

these patterns occur every few years and can cause extreme climate disruptions around the world.

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Ocean Current Question 15.5• Why is most of Europe significantly warmer than regions

in Canada at the same latitude?• The gulf stream moves warmer water eastward, behind

it, the land is still cold due to latitude.

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