communities and biomes
DESCRIPTION
Communities and Biomes. Community. Community : A collection of several interacting populations that inhabit a common environment. Limiting Factors. - PowerPoint PPT PresentationTRANSCRIPT
Communities and Biomes
Community• Community: A collection of several interacting
populations that inhabit a common environment.
Limiting Factors
– Factors that affect an organism’s ability to survive in its environment, such as the availability of water and food, predators, and temperature, are called limiting factors.
• A limiting factor is any biotic or abiotic factor that restricts the existence, numbers, reproduction, or disturbance of organisms.
Ranges of Tolerance
• The ability of an organism to withstand fluctuations in biotic and abiotic environmental factors is known as tolerance
Ecological Succession• Ecosystems are constantly changing in response to
natural and human disturbances.• As an ecosystem changes, older inhabitants
gradually die out and new organisms move in, causing further changes in the community.
Ecological Succession• Ecological succession is the series of predictable
changes that occur in a community over time.– Primary succession takes place on bare rock
surfaces where no soil exists. Pioneer species are the first species to live in these areas.
– Secondary succession occurs when a disturbance changes a community without removing soil.
Primary Succession
Secondary Succession
Biotic and Abiotic Factors
• Organisms in ecosystems are affected by both biotic and abiotic factors.
• Biotic factors are all of the living things with which organisms interact.
• Abiotic factors are nonliving, physical things. (Ex. temperature and soil type)
• Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which and organism lives.
Biotic Factors
ECOSYSTEM
Abiotic Factors
Abiotic and Biotic Factors
Ecological Succession Video
• http://www.youtube.com/watch?v=V49IovRSJDs
Climate• In the atmosphere, temperature, precipitation,
and other environmental factors combine to produce weather and climate.
• Weather: is the day-to-day condition of Earth’s atmosphere at a certain time and place.
• Climate: is the average yearly condition of temperature and precipitation in a region.• Climate affects ecosystems.
The Greenhouse Effect• Carbon dioxide and other atmospheric gases trap
heat energy and maintain Earth’s temperature range.• These gases function like the glass windows of a
greenhouse.• The trapping of heat by gases in the atmosphere is
called the greenhouse effect.• This greenhouse effect helps temperatures on Earth stay
within a range that supports life.
The Greenhouse Effect
The Effect of Latitude on Climate
• Latitude also affects climate. Earth has 3 main climate zones: polar, temperate, and tropical.– Polar Zones are cold areas where the sun’s rays
strike Earth at a very long angle.– Temperate Zones sit between the polar zones and
the tropics. The climate in these zones ranges from hot to cold, depending on the season.
– The Tropical Zones or tropics, is near the equator. The climate here is almost always warm.
Sunlight
Most direct sunlight
Sunlight
Sunlight
Sunlight
90°N North Pole
66.5°N
23.5°N
0°
23.5°S
66.5°S90°S South Pole
Arctic circle
Tropic of Cancer
Equator
Tropic of Capricorn
Arctic circle
The Effect of Latitude on Climate
Heat Transport in the Biosphere• Unequal heating of Earth’s surface also causes
winds and ocean currents. • Wind and ocean currents move heat through
the biosphere.
Biomes
• A biome is a group of land communities that covers a large area and has a certain soil type and climate
• Within a biome, there maybe microclimates• A microclimate is a small area where the climate
differs from that of the surrounding area.
The Major Biomes• There are ten major biomes:
– Tropical Rain Forest, Tropical Dry Forest, Tropical Savanna
– Desert– Temperate Grassland, Temperate Woodland and
Shrubland, Temperate Forest– Northwestern Coniferous Forest, Boreal Forest (or
Taiga)– Tundra
• Each biome has its own set of abiotic factors and a typical collection of organisms.
• Some areas, such as mountains and polar ice caps, do not fall neatly into the major biomes
Compare/Contrast Table of Biomes
Ten Major BiomesBiome Precipitation Temperature Soil Diversity Trees GrassesTropical Rain Forest high hot poor high dense sparse
Tropical Dry Forest variable mild rich moderate medium medium
Tropical Savanna variable mild clay moderate sparse denseDesert low variable poor moderate sparse sparseTemperate Grassland moderate summer hot rich moderate absent dense
Temperate woodland and Shrubland
summer low, winter moderate
summer hot poor low medium medium
Temperate Forest moderate summer moderate, winter cold
rich high dense sparse
Northwestern Coniferous Forest
high summer mild, winter cold
rocky, acidic low dense sparse
Boreal Forest moderate summer mild, winter cool
poor, acidic moderate dense sparse
Tundra low summer mild, winter cold
poor low absent medium
Tropical rain forest
Tropical dry forest
Tropical savanna Temperate woodlandand shrubland
Desert
Temperate grassland
Boreal forest(Taiga)
Northwesternconiferous forest
Temperate forest
Mountains andice caps
Tundra
The World’s Major Land Biomes
Aquatic Biomes
• Unlike land biomes, which are grouped geographically, aquatic biomes are grouped by the abiotic factors that affect them.
• Aquatic biomes are described mainly by the depth, flow, temperature, and chemistry of their water.
Aquatic Energy• In many aquatic biomes, tiny free-floating swimming
organisms can be found. These organisms are called plankton.
• There are 2 types of plankton (phytoplankton and zooplankton)– Phytoplankton are single-celled algae that use nutrients in
water to make food. They form the base of many aquatic food webs.
– Zooplankton are animals that feed on phytoplankton
Aquatic Biomes• There are 3 main groups of aquatic biomes:• 1. Freshwater biomes can be divided into several
types.
– Flowing-water biomes (rivers and streams) flow over land.
– Standing-water biomes include lakes and ponds– Freshwater wetlands include bogs, marshes, and
swamps. In wetlands, water covers the soil or is present at or near the surface for at least part of year.
Bogs, Marshes, and Swamps
Aquatic Biomes
2. Estuaries are wetlands formed where rivers meet the sea. They contain a mixture of fresh and salt water. Most food made in estuaries enters food webs as tiny pieces of organic matter, called detritus.– Salt marshes are temperate estuaries. Salt-tolerant
grasses and sea grasses are the dominant plant life in salt marshes.
– Mangrove swamps are tropical estuaries. The dominant plant life in mangrove swamps includes several species of salt-tolerant trees, called mangroves, and sea grasses.
Aquatic Biomes
3. Marine biomes exist in the ocean. The ocean is divided into zones based on how much light penetrates the water.– The photic zone is the well-lit upper layer of water.
Photosynthesis can take place here.– The aphotic zone is the permanently dark lower layer
of water. Producers here use chemosynthesis to make food.
Oceans• The ocean is also divided into zones based on depth and
distance from shore: the intertidal zone, the coastal ocean, and the open ocean, and benthic zone.
Marine BiomesOrganisms in the intertidal zone are exposed to regular and extreme changes in their surroundings. (tides)
The coastal zone is relatively shallow, lies entirely within the photic zone, and is often rich in plankton and other organisms. Coral reefs grow in tropical coastal oceans.
Marine BiomesThe open ocean is the largest zone, covering more than 90 percent of the surface area of the world’s oceans. These areas typically have low levels of nutrients and support only small producers.
Benthic zone is the bottom of the ocean, contains organisms that live attached to or near the bottom.
landCoastalocean
Openocean
Oceantrench
Aphotic zone
Photic zone
Continentalshelf
Continental slope andcontinental rise
Abyssalplain
200m1000m
4000m
6000m
10,000m
Zones of a Marine Biomes