Energy flow & Biomes

Pay particular attention to thediagrams

Bacteria feed at EVERY trophic level!

Energy Movement

• Remember that organisms store energy to be used• Stored energy is then taken by an organism higher

up the food chain.• Not all energy is transferred: most is lost due to

metabolic activity and some is lost due to simplydeath.

• Unfortunately, not all substances are actuallydepleted as it moves through the food chain.

Toxins that do not follow theflow of energy model

• Biomaginification• This happens when an

organism has a smallamount of toxin in itssystem and whenconsumed, it passes allof that toxin to thenext organism.

• The cycle continuesup the food chain.

• Bioaccumullation• This happens when a

top predator consumesorganisms that have asmall amount of toxinin their bodies, butover time, that toxinbuilds up to harmfullevels in the toppredator.

Trophic Levels• This is a feeding step in a food chain or food web.• Each trophic level contains a certain amount of

energy available to the next level.• The lower trophic level always has more energy

stored than the level above…that’s just the wayenergy moves

• All trophic levels begin with the producers• Each trophic level can magnify the amount of

toxins in tissues significantly, placing a heavyburden on the highest trophic levels.

Rule of 10• This is the concept that only 10% of the

available energy at ANY trophic level getstransferred to the next highest level.

Producers (10,000 kilocalories)

1st order consumers (1,000 kilocalories)

2nd order consumers (100 kilocalories)

3rd order consumers (10 kilocalories)

Organization in Ecology

Biomes

• Estuary• Intertidal Zone• Tundra• Taiga• Desert• Grassland• Temperate forest• Tropical rainforest

Estuary• Estuaries are partially enclosed bodies of water where

freshwater meets salty ocean water. Bays, inlets and ocean-flooded river valleys are all examples of estuaries.

• Areas of extreme chemical and physical changes that canresult in large loss of life.

• Same extreme areas are rich with nutrients that support anenormous variety of aquatic & terrestrial life.

• They also show warning signs of pollution quicker thanother natural places due to the estuary’s sensitivity tochange.

Intertidal Zone

• Areas between the low tide and high tide, calledLittoral Zone.

• Organisms have specifically adapted to live in therapidly changing environment, such as changes insalinity, moisture, pH, DO, 7 food on a dailybasis.

• Organisms are so specialized that the zone can bedivided vertically to demonstrate the distributionof organisms.

Tundra

• This is referred to as a Polar desert because of:low rainfall & precipitation, slow decomposition,permafrost, long cold winters, very short growingseason, annual change from ~0-24 day light.

• Treeless, low shrubs, sedges, mosses& lichens• Does not recover well after it has been disturbed.• Caribou, musk ox, polar bears, birds,

MOSQUITOES.

Forest Biomes

• Taiga Forests (also called Boreal Forest)• Temperate Forests• Tropical Forests

Taiga Forest• Largest terrestrial biome located between 50 & 60

degrees north latitudes.• Low temperatures with a growing season of 130

days.• Most precipitation is in the form of snow, ~16-40

inches of snow per year.• Thin, nutrient poor soil, usually acidic due to

coniferous detritus.• Dominated by coniferous plant life which creates

thick canopy which lets little sunlight to the forestfloor.

• Animals include bats, shrews, chipmunks, deer,wolves, bear, moose, hawks etc.

Temperate Forest• Well defined seasons with a variety of flora & a

growing season of 140-200 days.• Temperature range common to what we

experience.• Precipitation around 30-60 inches distributed

evenly throughout the year.• Fertile soil with lost of organic matter & canopy

allows light to reach forest floor. Deciduous treeslocated here.

• Animals include black bear, wolf, bobcat, lion,deer, birds, skunks, porcupines, etc.

Tropical Forests

• Most species diverse terrestrial biome locatedalong the equator about 23 degrees north or south.

• Temperature varies little throughout year, notmore than 5 degrees C.

• Precipitation throughout entire year at over 80inches.

• Soil is poor & low in nutrients with lost of decay.• Canopy is multilayered & very dense allowing

little light to penetrate to the forest floor.• Continued next slide.

Tropical forest continued

• One square km can have up to 100 different treespecies.

• Animals include: birds, bats, lots of smallmammals, insects too many to count, reptiles etc.

• This is considered a rainforest, but only due toamount of rainfall. There are different kinds ofrainforests, temperate or tropical, which is why itis called simple “tropical” forest.

Desert• Major characteristic here is lack of moisture, less

than 20 inches a year.• Flora is specialized to survive long periods

without moisture, seeds have a long dormant stagethat is remarkable.

• Animals adapted to life with little vegetation aswell as harsh day & night conditions.

• Can be categorized as Hot & Dry, Semiarid,Coastal, and Cold.

• The Atacama Desert is one of the driest places onEarth.

Grasslands

There are different types of grasslands, butthey all have grasses are the dominantvegitation.

• Prairies• Pampas• Savanna• Steppe

Prairies (French for Meadow)

• Tall, Mixed & Short grass prairies are all prairiesbut with different types of grasses due to theamount of available moisture.

• Precipitation ranges from 21.7 inches to 12.6inches a year, yet every 30 years or so, longdroughts occur. i.e. 1930s Dust Bowl Years (alsocalled dirty 30s)

• Prairies are maintained by climate, fires andgazing. Natural fires swept across the prairies thatburned off thatch and saplings yet left the rootsystems undamaged.

• Root system is the most important structure tokeeping the prairie system alive

Prairies continued• Roots create a dense mat underground providing

habitat for millions of microbes & animals. Somegrass roots can grow 7-11 feet long, while thebuffalo gourd plant has a tap root over 3 feet indiameter and 5 feet deep (one root was dug up andweighed in at 178 pounds!)

• Only 1 to 2% of the original prairie exists today.Most native grazing animals do not exist as theyonce have. Many states are establishing prairierestoration projects and reintroducing native plantsand animals.

Pampas & Steppes

• Same as prairies but located in SouthAmerica and Europe.

• Animals range from gazelles, zebras &rhinoceroses, to wolves deer, mice, grouse,snakes, spiders.

• Temperatures range from over 100 degreeto -40 degrees.

Savanna• Cover almost half of Africa, somewhere around 5

million square miles, parts of Australia, SouthAmerica & India.

• Located in warm climates with 15-55 inches ofrain per year when most of it falls within a shorttime frame.

• Soil of Savannas is porous and drains quickly.There are trees here, but located in pockets withforbs.

• Dry season is extremely important for the Savannato remain a grassland where fires periodically burnsaplings and dead grasses.