CHAPTER 23 ECOSYSTEMS AND BIOMES
SECTION 1     Energy flow in the ecosystem
3 types of energy Roles
    1. Producer - and organism able to capture the energy of sunlight and store it as food energy
        and organism that can make its own food
    2. Consumer - and organism that obtains energy buy feeding on other organisms
primary consumers are heterotrophs
heterotroph - can not make their own food the depend on producers for food and energy
herbivore -in Latin "herba"  means herb or plant   "vorare"  means eat  these are plant eaters
secondary consumers eat the heterotrophs
tertiary consumers can eat the heterotrophs and secondary consumers
carnivores - in Latin "carnis"  means flesh  these are consumers that only eats animals
omnivores - in Latin "omni"  means all   these are consumers that eats plants and animals
scavenger - a carnivore that feed on the bodies of dead organisms

    3. Decomposers - organisms that break down wastes and dead organism and return the raw material to the environment
        they return simple molecules to the environment.  fungi and bacteria mostly

when an organism eats it obtains energy

FOOD CHAIN -  is a series of events  in which one organism eats another and obtains energy
        grass --------------->  mouse --------------------> hawk
        producer   ---->  first level consumer -------> second level consumer
shows the possible path along which energy can move through an ecosystem

FOOD WEB  - consists of many overlapping food chain in an ecosystem.

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a more realistic way to show the flow of energy through an ecosystem

 ENERGY PYRAMIDS - A diagram that shows the amount of energy that moves from one feeding level to another in a food web. 

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    - Most energy is available at the producer level
    - At each level in the pyramid there is less available energy than at the level below
    - only about 10% of energy at one level of the food web is transferred
 to the next higher level 
    -  90% of the energy is used for the organism's life processes or is lost as heat to the environment
    - not enough energy to support many feeding levels
    - energy is lost at each level so it limits the number of consumers the ecosystem can support

SECTION 2 CYCLES OF MATTER
ENERGY IS NOT RECYCLED     ecosystem must be constantly supplied with energy usually from sunlight
   
MATTER CYCLES THROUGH AN ECOSYSTEM OVER AND OVER  samples of cycles
    1. water    2. oxygen    3. carbon    4. nitrogen    5. other substances

matter is made of atoms
atoms make up molecules

water cycle - the process of evaporation, condensation and precipitation 
evaporation - the process by which molecules of liquid water absorb energy and change to the gas state
condensation - the process by which a gas changes to a liquid
precipitation - as more water vapor condenses

 

carbon oxygen cycle -  In this process the plants (producers) use carbon from the carbon dioxide to produce  (food) other carbon-containing molecules.
   - oxygen is also release as a result of photosynthesis
-other organism take in oxygen from the atmosphere and use it in their life processes and they intern give off carbon dioxide the producers use

NITROGEN CYCLE - nitrogen moves form the air to the soil, into living things, and back into the air.
        air is 78% nitrogen
        most organisms can't use the nitrogen gas in the air
        NITROGEN GAS - is call "free nitrogen" it is not combined with other kinds of atoms
        FIXED NITROGEN -  has been combined with other kinds of atoms 
                    most organisms can only use this form of nitrogen

NITROGEN FIXATION - the process of changing free nitrogen gas into a usable form of nitrogen
    NODULES - bacteria live in bumps of roots of legumes  (plants) like beans, peas alfalfa, peanuts beans
    Mutualism - both species benefit 
            example:   bacteria feed on the plant's sugar and the plant is supplied with nitrogen in a usable form
    crop rotation - farmers will plant different crops every year. 
        example - soy beans one year to add nitrogen to the soil so they don't have to fertilize so much on next years corn crop
BACK TO NITROGEN GAS
    fixed nitrogen can be used by organism to build protein .  
    Decomposers break down proteins in wastes and dead organism
    nitrogen returns to soil
    bacteria eventually break down  nitrogen completely and it goes back to the air

SECTION 3    BIOGEOGRAPHY

BIOGEOGRAPHY - the study of where organisms live 
    bio - means life
    geo -  means Earth
    graph - means description
CONTINENTAL DRIFT -  the very slow motion of the continents
        Pangaea - the continents of earth were connected
DISPERSAL - the movement of organism from one place to another
    can be caused by wind, water, or living things, including humans
native species  - species that have naturally evolved in an area
exotic species - organism that is carried into a new location by people

LIMITS TO DISPERSAL - three factors that limit dispersal of a species are physical barriers, competition and climate
physical barriers - mountains, water, deserts  hard to cross
competition - competition for resources with the species already there organism must find a unique niche to survive. 
climate - the typical weather pattern in a area over a long period of time
SECTION 4         EARTH'S BIOMES
http://www.blueplanetbiomes.org/world_biomes.htm

BIOME - is a group of ecosystems with similar climates and organisms
        helps ecologist describe the world
            generally scientist focus on 6 major land biomes and 2 major water biomes
    climate conditions -  temperature and rainfall determine the  biome in an area
                climate limits the distribution of plants
                plants determine the kinds of animal that live there
1. rainforest    2.desert    3. grassland    4. deciduous forest    5. boreal forest (TAIGA)  (coniferous)    6.tundra    7.mountains and ice (don't fall into any category)       1. freshwater        2. Marine 

1. rainforest  -  greatest diversity of species. > ½ of tropical forests have been destroyed,    near the equator,  latitudes 23.5 degrees N and 23.5 degrees S. 
     winter is absent, and only two seasons are present (rainy and dry). 
        The length of daylight is 12 hours and varies little.     
    Temperature is on average 20-25° C and varies:  by no more than 5 degrees.
    Precipitation is evenly distributed  annual rainfall exceeding 2000 mm.
    Soil is nutrient-poor, acidic. Decomposition is rapid  soils have heavy leaching.
    Canopy tall  leafy roof is multi-layered, continuous, allowing little light penetration.
    understory - second layer of shorter trees and vines   grow well in shade
    some plants thrive in near-darkness of the forest floor
    Flora is highly diver1 square kilo as many as 100 different tree species. 
        Trees are 25-35 m tall,  shallow roots, mostly evergreen. orchids,  vines, ferns,    
     Fauna include numerous birds, bats, small mammals, and insects.
 
2.desert 
    Temperatures - annual temp range  20-25° C.  max ranges from 43.5-49° C. Minimum temperatures sometimes drop to -18° C.
    Precipitation  - 1.5 cm. < 28 cm a year. Evap. rates can exceed rainfall rates
    Soil  - course, shallow, rocky,  sand particles with good drainage, no subsurface water. are coarse cause there's less chemical weathering.  
    Canopy  - Canopy in most deserts is very rare
    Flora - small, thick and covered with a thick cuticle (outer layer). cacti, the leaves are spines and photosynthesis in the stems. yuccas,  prickly pears, false mesquite, 
    Fauna -  small nocturnal (active at night) carnivores.   burrowers and kangaroo rats.  insects, arachnids, reptiles and birds. The animals stay inactive in protected hideaways during the hot day and come out to forage at dusk, dawn or at night, when the desert is cooler

3. grassland - (determined by temperature, rainfall, and soil conditions). seasonal drought, fires, and grazing by large mammals all prevent woody shrubs and trees from invading and becoming established.
PRAIRIE
    Temperatures - Summer temperatures can be well over 38° C (100 degrees Fahrenheit), while winter temperatures can be as low as -40° C (-40 degrees Fahrenheit
    Precipitation  most in the late spring & early summer.  annual ave ~ 50.8 to 88.9 cm (20-35 inches)
    Soil- very rich
    Flora grasses include purple needlegrass, blue grama, buffalo grass,  Flowers include asters, blazing stars, coneflowers, goldenrods, sunflowers, clovers 
    Fauna -  wolves, prairie dogs, jack rabbits, deer, mice, coyotes, foxes, skunks, badgers, blackbirds, grouses, meadowlarks, quails, sparrows, hawks, owls, snakes, grasshoppers, leafhoppers, and spiders.
SAVANNA -  cover almost half of Africa large areas of Australia, South America, and India. 
    Climate is warm or hot climates    
    annual rainfall is from about 50.8 to 127 cm (20-50 inches) per year. rainfall is concentrated in six or eight months of the year, followed by a long period of drought when fires can occur
STEEPES are dry areas of grassland hot summers and cold winters. 
         receive 25.4-50.8 cm (10-20 inches) of rainfall a year. Steppes occur in the interiors of North America and Europe. graze livestock, grow wheat and other crops. Overgrazing, plowing, and excess salts left behind by irrigation waters have harmed some steppes. Strong winds blow loose soil from the ground after plowing, especially during droughts. causes the dust storms of the Great Plains of the U.S.

4. deciduous forest - Temperate forests occur in eastern North America, northeastern Asia, and western and central Europe. Well-defined seasons with a distinct winter. Moderate climate and a growing season of 140-200 days during 4-6 frost-free months.
    Temperature varies from -30° C to 30° C.
    Precipitation (75-150 cm) is distributed evenly throughout the year.
    Soil is fertile, enriched with decaying litter.
    Canopy is moderately dense and allows light to penetrate, diversified understory of  vegetation and  animals.
    Flora is characterized by 3-4 tree species per square kilometer. Trees have broad leaves that are lost annually include oak, hickory, maple, basswood, cottonwood, elm, willow, and spring-flowering herbs.
    Fauna  squirrels, rabbits, skunks, birds, deer, mountain lion, bobcat, timber wolf, fox, and black bear.

5. boreal forest (coniferous) - Boreal forests, or taiga,  the largest terrestrial biome. 
 between 50 and 60 degrees north latitudes,  two-thirds in Siberia with the rest in Scandinavia, Alaska, and Canada. Seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters. The length of the growing season in boreal forests is 130 days.
    Temperatures are very low.
    Precipitation is primarily in the form of snow, 40-100 cm annually.
    Soil is thin, nutrient-poor, and acidic.
    Canopy permits low light penetration,  understory is limited.
    Flora - cold-tolerant evergreen conifers needle-like leaves,  pine, fir, and spruce. needles have a waxy coat to prevent evaporation
    Fauna include woodpeckers, hawks, moose, bear, weasel, lynx, fox, wolf, deer, hares, chipmunks, shrews, and bats.

6.tundra  - Extremely cold, dry climate, Low biotic diversity, Simple plants, swampy, Short  growing and reproduction seasons, Energy and nutrients in the form of dead organic material, Large population changes 
    Temperatures cold, desert-like conditions. The growing season ranges from 50 to 60 days. The average winter temperature is -34° C (-30° F), but the average summer temperature is 3-12° C (37-54° F
    Precipitation Rainfall may vary in different regions of the arctic. Yearly precipitation, including melting snow, is 15 to 25 cm (6 to 10 inches
    Soil - formed slowly. A layer of permanently frozen subsoil called permafrost exists, consisting mostly of gravel and finer material. When water saturates the upper surface, bogs and ponds may form, providing moisture for plants
    Flora - low shrubs, sedges, reindeer mosses, liverworts,  grasses, 400 varieties of flowers, and  lichen no deep root systems in the vegetation of the arctic tundra,  about 1,700 kinds of plants 
    Fauna -  lemmings, voles, caribou, arctic hares and squirrels, arctic foxes, wolves, and polar bears, Migratory birds: ravens, snow buntings, falcons, loons, ravens, sandpipers, terns, snow birds, and various species of gulls,  mosquitoes, flies, moths, grasshoppers, blackflies and arctic bumble bees

7.mountains and ice ( don't fall into any category)  conditions change from the base to its summit

1. freshwater -   has a low salt concentration—usually less than 1%.   ponds and lakes, streams and rivers, and wetlands. Ponds and Lakes - may have limited species diversity since they are often isolated  Lakes and ponds  three different “zones”  determined by depth and distance from the shoreline.
     littoral zone. top zone,  warmest, shallow and can absorb more of the Sun’s heat.  many algae (like diatoms), rooted and floating  plants, snails, clams, insects, fishes, crustaceans, and amphibians, dragonflies, midges, the egg and larvae stages are found here. turtles, snakes, and ducks.
     limnetic zone - near-surface open water  well-lighted dominated by phytoplankton and zooplankton. fish also occupy this zone.
    Temperature varies in ponds and lakes seasonally. During the summer, the temperature can range from 4° C near the bottom to 22° C at the top. During the winter, the temperature at the bottom can be 4° C while the top is 0° C (ice). 

Streams and Rivers -  flowing water moving in one direction.  
        headwaters is were they start  by springs, snowmelt or lakes, 
         mouths where they end,  temperature is cooler, clearer, has higher oxygen levels, and freshwater fish such as trout and heterotrophs 
     middle part of stream/river, the width increases,  species diversity—numerous aquatic green plants and algae can be found. 
    mouth water gets murky from sediments  picked up, decreasing  light penetration through the water.  less light,  less diversity of flora, and because of the lower oxygen levels, fish that require less oxygen live here  catfish and carp 

2. Marine - cover ~ 3/4  Earth’s surface (oceans, coral reefs, & estuaries). 
         algae supply much of the world’s oxygen supply and take in a huge amount of carbon dioxide.     evaporation of seawater provides rainwater for the land.
    Oceans -largest  ecosystems,  separated into zones: intertidal, pelagic, abyssal, and benthic.  have a great diversity of species. 
  intertidal zone   is submerged and exposed, by waves and tides.  
        the communities are constantly changing. upper area has algae and small animals, such as herbivorous snails, crabs, sea stars, and small fishes.  
        the bottom  is exposed during the lowest tides, many invertebrates, fishes, and seaweed. on sandier shores is not as stratified as in the rocky areas. 
        Waves keep mud and sand constantly moving, thus very few algae and plants can establish themselves—the fauna include worms, clams, predatory crustaceans, crabs, and shorebirds.
    (surface) pelagic zone  open ocean.  
        generally cold  there is thermal stratification with a constant mixing of warm and cold ocean currents. 
        The flora in the pelagic zone include surface seaweeds. 
        The fauna include many species of fish and some mammals, such as whales and dolphins. Many feed on the  plankton.
    Neritic zone - extends over the continental shelf  (benthic zone)  below the pelagic zone, 
        The bottom of the zone consists of sand, slit, and/or dead organisms. 
        temperature decreases as depth increases 
        since light cannot penetrate through the deeper water.
         Flora  represented  seaweed 
          fauna - very nutrient-rich,  bacteria, fungi, sponges, sea anemones, worms, sea stars, and fishes.
    abyssal zone deep ocean.  very cold (around 3° C), highly pressured, high in oxygen content, but low in nutritional content.  supports many species of invertebrates and fishes.  
        hydrothermal vents, are found  along the ocean floors. Chemosynthetic bacteria thrive near these vents because of the large amounts of hydrogen sulfide and other minerals they emit. bacteria  start a food web 
    Coral Reefs -  in warm shallow waters.  as barriers along continents  Great Barrier Reef , fringing islands, and atolls. dominant organisms in  are corals.  fauna include microorganisms, invertebrates, fishes, sea urchins, octopuses, and sea stars.

SECTION 5 SUCCESSION
  SUCCESSION - series of predictable changes that occur in a community over time
    PRIMARY SUCCESSION - a series of changes that occur in an area where no ecosystem previously existed
            area of rock, volcanic area
     PIONEER SPECIES -  first species to populate an area
                can grow on bare rocks with little or no soil
                    help make soil                 lichen and mosses
                    provide nutrient that enrich the thin layer of soil 
SECONDARY SUCCESSION -  a series of changes that occur after a disturbance in an existing ecosystem  (fire, logging, tornadoes, farming etc)
        occurs in a place where an ecosystem has previously existed
        occurs more rapidly than primary succession

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