Energy Flow
Sun--> Producers--> Primary Consumers --> Secondary Consumers-->Tertiary Consumers
Producers
Autotrophs. Produce food from photosynthesis.
Consumers
Heterotrophs. Use bodies of other organisms as a source of energy.
Primary Consumers
Herbivores. Only eat producers.
Secondary/ Tertiary Consumers
Carnivores.
Omnivores.
Eat plants and animals.
Detritus Feeders/Detritivores
Consumer that eats organic matter, such as carcasses, leaf litter, and feces.
-snails, clams, worms
Forms of Energy
1. Solar
2. Chemical
3. Radiant
4. Thermal
5. Nuclear
6. Electrical
Energy
Capacity or ability to do work.
-often expressed in kilojoules/kilocalories (Kcal)
-One Kcal raises H20 one degree celsius.
Decomposers or Saprotrophs
microbial heterotrophs that break down dead organic material and use it as energy.
Food Chain
energy from food passes from one organism to the next.
Trophic Level
Organism's position in a food chain, determined by its feeding relationships.
Food Web
interlocking food chains that connect all organisms in an ecosystem.
How many directions does energy flow?
One.
Ecological Pyramids
Graphically represent the relative energy values of each trophic level.
-Pyramid of Numbers
-Pyramid of Biomass
-Pyramid of Energy
Pyramid of Numbers
Shows number of organisms at each trophic level in a given ecosystem, with greater numbers illustrated by the larger of the pyramid.
Pyramid of Biomass
Total biomass (quantitive estimate of the total amount of living material) at each successive trophic level.
10% rule
Progressive reduction of biomass in succeeding trophic levels. 90% reduction per level in Biomass Pyramid.
Potential Energy
Stored Energy.
Kinetic Energy
Energy of Motion.
Pyramid of Energy
Expresses energy content as Kcals/square meter/year for each trophic level.
-Energy dissipates into the environment when going from one level to the next.
-Dramatic reduction in energy at each level explains why there are so few trophic levels.
Gross Primary Productivity (GPP)
Rate at which energy is captured in Photosynthesis.
Net Primary Productivity (NPP)
Equal to gross productivity minus energy used by primary producers for respiration.
-Most energy is used for cellular respiration to move muscles, and maintain/repair cells.
Extra energy is used for growth and production of young.
Energy per unit area of time
How GPP and NPP are expressed.
What is the Biome with the highest NPP?
Rainforest. Ecosystems differ in productivity.
What species consumes the most resources?
Humans. They use 32% of annual NPP of land-based ecosystems and only represent .5% or total biomass.
Evolution
Cumulative genetic changes that occur over time in a population of organisms. It explains many patterns observed in the natural world.
Adaptation
Evolutionary modernization that improves the changes of survival and reproductive success of a population.
Natural Selection
Proposed by Darwin in his "Origin Species" book. It made four observations about the world.
1. Overproduction
2. Variation
3. Limits on Population Growth/ Struggle for Existence
4. Differential Reproductive Success
Overproduction
Each species produce more offspring than will survive to maturity.
Variation
Individuals of a population exhibit variation; unique traits that are inherited.
Limits on Population Growth/ Struggle for Existence
Resources are limited.
Differential Reproductive Success
those with favorable characteristics will survive, reproduce, and pass on their traits.
Galapagos
Where Darwin formulated his ideas of evolution while studding Finches.
Community
An association of different populations of organisms that live and interact together in the same place and same time.
-organisms interdependent: compete for resources and rely on one another
Ecosystem
Biological community and its abiotic environment.
Succession
Stages of progress , the replacement of one type of community by another at a single location over a period of time.
-Once thought to lead to a stable and persistent community (Climax Community in a forest)
-Now believed that communities are in a constant
Primary Succession
Begins in an environment not inhabited before.
-No soil
-Bare rock surfaces (lava/rock sculpted by glaciers)
-Begins with Lichens which secrete acid and help break rock apart.
-Lichens-->mosses-->grasses-->shrubs-->trees
Sand Dunes
Studied by Henry Cowles in 1880s. Example of Primary Succession.
Secondary Succession
Begins in an environment following destruction of or part of an earlier community.
-Fire, Old farmland, tornadoes, etc.
-Take more than 100 years.
Secondary Succession on and abandoned field would look like what?
Annual weeds-->annual perennials-->pine seedlings/saplings-->young pine forest/understory hard woods-->mature hardwoods.
Animals follow succession and changes in vegetation.
Symbiosis
Individuals of one species live in or on individuals of another species.
Symbionts
Partners of symbiotic relationships.
Coevolution
Interdependent evolution of two or more interacting species
-Flower and its pollinator
-Three categories
1. Mutualism
2. Commensalism
3. Parasitism
Mutualism
Both partners benefit.
-Clown Fish Anemone
-bacteria and legumes
-fungi and roots
Commensalism
One organism benefits the other is neither helped nor harmed.
-tropical tree and epiphytes
Parasitism
One organism takes nourishment from the other. The parasite may weaken host, but rarely kills it (if it kills it, it is a pathogen).
-leech
-ticks
-tape worms
Predation
Animals eating other animals or plants.
Adaptions
Predatory strategies: Pursuit and ambush.
Prey strategies: Plant and animal defenses
Competition
Occurs when two or more individuals compete to use an essential resources.
-Intraspecific: competition with same species
-Interspecific: between different species.
Ecological Niche
An organisms role; totality of organisms adaptions, its use of resources, and lifestyle.
-Includes Habitat (local environment in which an organism lives)
Fundamental Niche
The full range of conditions that a species can tolerate and resources it can use.
Realized Niche
The part of its fundamental niche a species actually occupies
-An organism may not fulfill its fundamental niche because it is forced out by an invasive species.
What determines and Ecological Niche?
A species structural, physiological, and behavioral adaptations, along with limiting resources. Adaptions determine an organisms tolerance for environmental extremes, and a scare, limited resource restricts a niche.
Competitive Exclusion
Fundamental niches many overlap between species. No two species may indefinitely occupy the same niche in the same community because of competitive exclusion.
G.F Gause
Had a set of experiments that showed that competition between species determines an organisms realized niche.
-Two species of bacteria. Thrive apart, but together only one thrived.
-Conclusion: One set of conditions favor one species over another.
Resource Partitioning
coexisting species niches' differ from one another; may include time of feeding, location, rest sites, etc.
Species Richness
The number of different species in a community; varies from one community to the next.
-High in coral reefs and rain forests.
-Low in mountain tops and deserts.
-Determined by abundance of potential ecological niches, closeness to the margins of adjacent
Complex Community
Offers more niches than a simple one.
Ecotone
Transitional zone where two or more communities meet; contains all or most of the niches of the adjacent communities as well as niches specific to the ecotone.
Edge Effect
Change in species composition produced at ecotones.
Species richness is _________ related to isolation.
Inversely.
-Difficult to reach and colonize island
-Some species become extinct and are not readily replaced.
Species richness is ______ when one species has a large, disproportionate share of resources.
Reduced.
Species richness is ________ related to environmental stress.
Inversely.
-Species richness declines in a highly polluted stream.
The older an area of land, the _____ species richness. The younger an area of land, the ______ species richness.
more (example: rain forest), less (example: areas scoured by glaciers).
Ecosystem Services
Important environmental benefits and ecosystem provides. The greater species richness, the better supply of ecosystem services.
-clean H20 and air
-fertile soil
Community Stability
ability of a community to withstand environmental disturbances.
-community with more species richness is more stable
Biome
A major type of ecosystem with distinctive climates (temperature/rainfall), and organisms.
-Tundra
-Taiga
-Temperate Rain Forest
-Temperate Deciduous Forest
-Grassland
-Chaparral
-Desert
-Savannah
-Tropical Rainforest
Tropical Rainforest
-sunlight year round
-little seasonal variation
-climate ideal for growing plants
-most species rich biome
-soil usually thin and poor
-many trees form above ground roots
-plants grow in layers (canopy and undergrowth)
-camouflaged animals are common
-Thr
Temperate Forest
-North America Pacific NW, South America, Australia, and New Zealand
-Drop leaves each fall
-Soil rich and deep
-Plants grow in layers (canopy and undergrowth)
-Plants adapted to seasonal weather changes
-Cold winters warm summers
-Numerous habitats due t
Taiga
-terrain rough
-forest floor sparsely vegetated
-just below Arctic Circle
-winters long and extremely cold
-frost free season can be as short as 50 days
-constant daylight in summer
-most precipitation falls as snow
-conifer trees; seeds grow cones and ne
Tundra
-cold, wintery, dry
-Northern Hampshire, south of Polar Ice Caps; in Alaska, Canada, Greenland, Iceland, Norway, Asia
-one of largest biomes
-10% of earth
-few organisms, fragile ecosystem
-little precipitation, most falls as ice or snow
-summer days long
Desert
-lack of precipitation and extreme temps limit plant and animal life
-few, short thunderstorms are main source of precipitation
-desert pavement causes most rain to run off
-low moisture=great variation in temps.
-hot at day, cold at night
-plants need to
Grassland
1. Savannah
a. Tropical
-west african plains
-Tropics, near the equator
-greatest collection of grazing animals in the world as well as predators
-little rain, few trees
-fires during dry season
-plants resistant to droughts, fires and grazing animals
-RU
What affects the size and texture of grass?
Water. Drier areas= thinner and finer leaves. Wetter areas have thick leave (bamboo).
Steeps vs. Prairies
Steeps:
-rain evaporates quickly
-short grass, mostly bunchgrass
-roots are shallow
Prairies:
-soil hold water well
-root form a mat of sod
-soil held together, resists erosion
-as grass dies layer of organic matter, or HUMUS is formed. Helps hold H20 and
Problems with Steeps and Prairies?
-Farming and Ranching
-Overgrazing, replacing of native grasses with those poorly adapted to the area (dust bowl)
-Native animals displaced (bison, wolves)
What does Photosynthesis do to carbon?
It removes CO2 from the air by plants and fixed into compounds such as sugar.
What does respiration do to carbon?
It returns CO2 into the atmosphere.
Molecules essential to life contain ________.
Carbon, Nitrogen, Oxygen, Hydrogen, Sulfur, Phosphorous
What forms are Carbon found in?
CO2,
CO3(2-),
HCO3(-)
What are some things that keep Carbon in biological molecules longer?
Large, old trees, and fossil fuels
The atmosphere is 78% _________.
Nitrogen. (N2)
Is N2 stable?
Yes. It will not readily bond with other elements. Must be broken apart first through the Nitrogen Cycle.
Nitrogen Cycle
1. Nitrogen Fixation
2. Nitrification
3. Assimilation
4. Ammonification
5. Denitrification
Nitrogen Fixation
N2--> NH3
-Combustion, volcanoes, lighting and industry supply enough energy to break apart N2
-bacteria in the soil (living in nodules or swellings of plant roots) can split N2 with the enzyme "nirtogenase" which only works in the absence of oxygen.
Nitrification
NH3 or NH4--> NO3
1. Soil bacteria converts NH3 or NH4
2. Other soil bacteria oxidizes nitrite to nitrate
Assimilation
-Plant roots absorb nitrate, NH3, or NH4
-Nitrogen is assimilated into nucleic acids
-If an animal consumes a plant it converts the nucleic acids into protein
Ammonification
Proteins or Nucleic acids--> NH3 or NH4
-urea in urine, uric acid in bird feces, and decomposing organisms
Denitrification
NO3--> N2
-bacteria reverses the action of nitrogen-fixing and returns nitrogen to atmosphere
-bacteria lives where there is little or no oxygen
Phosphorus cycle
land-->sediments in ocean-->land
-water run offs carry minerals containing phosphorus
-Erosion of minerals releases phosphorous into soil, where plant roots absorb it as inorganic phosphorous
-In cells, it is incorporated into ATP and nucleic acids
-Anima
Sulfur Cycle
Most sulfur is underground in sedimentary rocks and minerals.
-overtime rocks containing sulfur erode into the ocean
-Sulfur gases enter atmosphere from sea spray, forest fires, dust storms, and volcanoes
-Sulfur compounds are reactive (easily bond)
-some
Hydrologic Cycle
Results in balance of water among land, ocean, and atmosphere.
-Precipitation, evaporation, transpiration (loss of H20 vapor to plants)
-Runoff: movement of H20 to rivers, lakes, wetlands, and ocean
-Watershed: area of land drained by runoff
-H20 seeps do
Disturbances in bio-geochemical Cycles?
-Industrial Revolution: Burning of fossil fuels, destruction of rainforests. Affects Carbon cycle.
-Combustion of cars converts Nitrogen to nitrogen oxides which produce photochemical smog and chemical rain.
-Use of fixed nitrogen in nitrogen fertilizers:
Thermodynamics
The study of energy transformations that occur in a collection of matter.
Laws of Thermodynamics
1. Organisms cannot create the energy they require to live, rather they capture it from the environment.
2. Heat energy is transferred to surroundings. No other organism can reuse it.
-Amount of usable energy available decreases over time with leads to di
Equation for Photosynthesis
6CO2+12H20+energy--> C6H12O6+6H20+602
Equation for Respiration
C6H12O6+6H20+602-->6CO2+12H20+energy
Biosphere
Layers of the earth containing all living organisms.
-atmosphere
-hydrosphere
-lithosphere