Topic+2+Objectives

= Ecosystems =

=2.1.1 Distinguish between biotic and abiotic (physical) components of an ecosystem. = • Biotic  = Living. “A factor created by a living thing or any living component within an environment in which the action of the organism affects the life of another organism, for example a predator consuming its prey.” (from [|www.biology-online.org] ) ◦ Flora  = plants ◦ Fauna  = animals ◦ Predation  = hunting ◦ Interspecies competition  = different species competing for the same resources <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Intraspecies competition <span style="font-family: Calibri,serif;"> = members of the same species competing for the same resouces <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Abiotic <span style="font-family: Calibri,serif; line-height: 1.5;"> = non-living. “A non-living chemical or physical factor in the environment, such as soil, pH, forest fire, etc.” ( [|www.biology-online.org] ) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Edaphic factors <span style="font-family: Calibri,serif; line-height: 1.5;">: geology <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Soil composition & nature <span style="font-family: Calibri,serif;"> - <span style="font-family: Calibri,serif;">■ sand/silt/clay/OM content influences availability of water and nutrients for plant life <span style="font-family: Calibri,serif;">■ Salinity & pH also influence nutrient availability <span style="font-family: Calibri,serif;">■ Type of bedrock determines mineral content in soils <span style="font-family: Calibri,serif;">■ Aeration/compaction <span style="color: #0000ff; font-family: Calibri,serif;"> - <span style="font-family: Calibri,serif;">particle spacing within soil makes water & air more or less available to plants and micro-organisms living in the soil <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Topography <span style="font-family: Calibri,serif;"> - slope influences erosion, runoff, & soils’ ability to hold water <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Climatic factors <span style="font-family: Calibri,serif; line-height: 1.5;"> - Light, temperature, humidity, precipitation <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Social factors <span style="font-family: Calibri,serif; line-height: 1.5;"> - land and resource use <span style="font-family: Calibri,serif;">◦ Agriculture <span style="font-family: Calibri,serif;">◦ Large-scale forestry <span style="font-family: Calibri,serif;">◦ Urbanization <span style="font-family: Calibri,serif;">◦ Industry =<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.1.2 Define the term trophic level. = =<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.1.3 Identify and explain trophic levels in food chains and food webs selected from the local environment. = <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Trophic level <span style="font-family: Calibri,serif; line-height: 1.5;">: “A position in a food chain or Ecological Pyramid occupied by a group of organisms with similar feeding mode.” ( [|www.biology-online.org] ) Basically, where an organism falls within the web of living things in an ecosystem. <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Autotrophs <span style="font-family: Calibri,serif;"> = producers. “self-feeders” make their own food via photosynthesis <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Heterotrophs <span style="font-family: Calibri,serif;"> = consumers. Must get energy and nutrients from other living organisms. <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Primary consumers <span style="font-family: Calibri,serif;"> - herbivores eat only plant material <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Secondary consumers <span style="font-family: Calibri,serif;"> - omnivores eat primary consumers and producers <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Tertiary consumers <span style="font-family: Calibri,serif;"> - mostly carnivores that eat other consumers <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Quaternary consumers <span style="font-family: Calibri,serif;"> - top of the food chain carnivores, the big hunters <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Decomposers <span style="font-family: Calibri,serif;"> - obtain nutrients by breaking down dead organic matter <span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Detritivores <span style="font-family: Calibri,serif;"> - obtain nutrients by breaking down decomposing matter =<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.1.4 Explain the principles of pyramids of numbers, pyramids of biomass, and pyramids of productivity, and construct such pyramids from given data. = =<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.1.5 Discuss how the pyramid structure affects the functioning of an ecosystem. = <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Ecological pyramids <span style="font-family: Calibri,serif;"> - <span style="font-family: Calibri,serif;">Graphic models showing differences in living matter at each trophic level in an ecosystem <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Pyramids of numbers <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ show how many organisms at each trophic level <span style="font-family: Calibri,serif;">◦ base level (producers) usually greatest in number <span style="font-family: Calibri,serif;">◦ top level is least <span style="font-family: Calibri,serif;">◦ snapshot in time <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Pyramid of biomass <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ shows the total dry biomass at each trophic level <span style="font-family: Calibri,serif;">◦ must kill the organism to measure its dry biomass, so not practical or ethical to measure all the biomass at a trophic level <span style="font-family: Calibri,serif;">◦ snapshot in time <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Pyramid of productivity <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ energy being generated or available as food at each trophic level <span style="font-family: Calibri,serif;">◦ shows flow of energy over time among trophic levels <span style="font-family: Calibri,serif; font-size: 8pt;">Source: Rutherford, Jill. <span style="font-family: 'Calibri Italic',serif; font-size: 8pt;">Environmental Systems and Societies Course Companion <span style="font-family: Calibri,serif; font-size: 8pt;">. Oxford University Press. Oxford. 2009. =<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.1.6 Define the terms species, population, habitat, niche, community and ecosystem with reference to local examples. = <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Species <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ An individual belonging to a group of organisms (or the entire group itself) having common characteristics and (usually) are capable of mating with one another. (source: [|www.biology-online.org] ) <span style="font-family: Calibri,serif;">◦ taxonomic group whose members can interbreed (source: wordnetweb.princeton.edu/perl/webwn) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Population <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ A group of organisms of one species that interbreed and live in the same place at the same time (e.g. deer population). (source: biology-online.org) <span style="font-family: Calibri,serif;">◦ A group of individuals of one species, which live in a particular area and are much more likely to breed with one another than with individuals from another such group. (source: symposia.cbc.amnh.org/archives/seascapes/glossary.html) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Habitat <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ the type of environment in which an organism or group normally lives or occurs (source: wordnetweb.princeton.edu/perl/webwn) <span style="font-family: Calibri,serif;">◦ The home to a particular organism where the species will attempt to be as adaptive as possible to that particular environment. (source: biology-online.org) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Niche <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ The role or functional position of a species within the community of an ecosystem. <span style="font-family: Calibri,serif;">◦(Source: [|www.sdnhm.org/exhibits/mystery/fg_glossary.html] ) <span style="font-family: Calibri,serif;">◦ The interrelationship of a species with all the biotic and abiotic factors affecting it. (source: biology-online.org) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Community <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ a group of interdependent organisms inhabiting the same region and interacting with each other <span style="font-family: Calibri,serif;">◦(source: wordnetweb.princeton.edu/perl/webwn) <span style="font-family: Calibri,serif;">◦ The organisms living in a community interact with one another, often, affecting each other’s abundance, distribution, adaptation, and existence. An ecological community may range in size from the very small community as in a pond or a tree to the huge regional or global community as in a biome. (source: biology-online.org) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Ecosystem <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ A system that includes all living organisms (biotic factors) in an area as well as its physical environment (abiotic factors) functioning together as a unit. (source: biology-online.org) <span style="font-family: Calibri,serif;">◦ a dynamic complex of plant, animal and micro-organism communities and their non-living environment, interacting as a functional unit, [applicable on a variety of scales]. <span style="font-family: Calibri,serif;">◦(source: citizenship.yara.com/en/resources/glossary/index.html <span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.1.7 Describe and explain population interactions using examples of named species. <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Bioaccumulation <span style="font-family: Calibri,serif;"> - a chemical or substance which does not break down (or breaks down slowly) in an organism's body will accumulate over time as that organism ingests more and more of the substance <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Biomagnification <span style="font-family: Calibri,serif;"> - concentrations of slowly-decomposing substances increase with each higher trophic level <span style="font-family: Calibri,serif; line-height: 1.5;">• Producer absorbs small amount of substance <span style="font-family: Calibri,serif; line-height: 1.5;">• 1st consumer eats many producers & absorbs substance from each one = higher concentration <span style="font-family: Calibri,serif; line-height: 1.5;">• 2nd consumer eats many 1st consumers & absorbs substance from each = still higher conc. <span style="font-family: Calibri,serif; line-height: 1.5;">• 3rd consumer eats many 2nd consumers & absorbs substance from each = even higher conc. <span style="font-family: Calibri,serif; line-height: 1.5;">• 4th consumer...pattern continues up the food chain/web with highest concentrations at top <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Mutualism <span style="font-family: Calibri,serif;"> - interaction between species which are mutually beneficial (i.e. both gain something positive from the interaction and neither suffers) <span style="font-family: Calibri,serif; line-height: 1.5;">• a.k.a. <span style="font-family: 'Calibri Bold Italic',serif; line-height: 1.5;">symbiotic <span style="font-family: Calibri,serif; line-height: 1.5;"> relationship <span style="font-family: Calibri,serif;">◦ Examples of symbiotic relationships: <span style="font-family: Calibri,serif;">■ <span style="font-family: 'Calibri Italic',serif;">Lichens <span style="font-family: Calibri,serif;"> are a combination of a fungus and either algae or cyanobacteria (photosynthetic bacteria). They exchange sugars, minerals, and water. <span style="font-family: Calibri,serif;">■ Nitrogen-fixing plants (family <span style="font-family: 'Calibri Italic',serif;">Leguminocae <span style="font-family: Calibri,serif;">) and the <span style="font-family: 'Calibri Italic',serif;">Rhizobium <span style="font-family: Calibri,serif;"> bacterium on their roots. The plant provides sugars, while the bacteria 'fix' atmospheric nitrogen in a form that the plant can use to build its biomass. <span style="font-family: Calibri,serif;">■ <span style="font-family: 'Calibri Italic',serif;">Mycorrhizal fungi <span style="font-family: Calibri,serif;"> grow on many tree roots. The fungi absorb phosphates from the soil and increase the surface area of the roots, which means the tree gains phosphates for growth and is also able to absorb more water and minerals from the surrounding soil. <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">parasitism <span style="font-family: Calibri,serif; line-height: 1.5;"> (below) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">commensalism <span style="font-family: Calibri,serif; line-height: 1.5;">, in which one organism gains something, while the other is either not harmed at all or not <span style="font-family: 'Calibri Italic',serif; line-height: 1.5;">significantly <span style="font-family: Calibri,serif; line-height: 1.5;"> harmed. In a commensal relationship, one organism distinctly gains something at a cost, however small, to the other organism. <span style="font-family: Calibri,serif;">◦ Examples of commensalism: <span style="font-family: Calibri,serif;">■ Heartworms live in the right side of dogs' hearts ingesting protein and nutrients from the blood; if the population of heartworms grows too quickly, they can clog the dog's heart and kill it, destroying the heartworms' colony <span style="font-family: Calibri,serif;">■ Remora sharks have a 'sucker' on the top of their heads they use to attach themselves to the underside of larger animals, usually whales. When the whales feed, the remora shark is there to gobble up any scraps the whale leaves behind or drops. (Source: [] ) <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Parasitism - <span style="font-family: Calibri,serif;">a form of mutualism in which one organism lives in or on another. <span style="font-family: Calibri,serif; line-height: 1.5;">• Generally speaking, parasites don't kill their hosts because they need the host in order to survive; without a living host, the parasite will also die. <span style="font-family: Calibri,serif; line-height: 1.5;">• Examples: <span style="font-family: Calibri,serif;">◦ tapeworms live in another organism's digestive tract and feed on the digested material <span style="font-family: Calibri,serif;">◦ fleas, ticks, and mosquitoes ingesting protein from the blood of their hosts <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Predation <span style="font-family: Calibri,serif;"> - simply put: hunting. <span style="font-family: Calibri,serif; line-height: 1.5;">• A predator kills and eats prey. <span style="font-family: Calibri,serif; line-height: 1.5;">• Predation is <span style="font-family: 'Calibri Bold Italic',serif; line-height: 1.5;">not <span style="font-family: Calibri,serif; line-height: 1.5;"> limited to animals eating animals! There are carnivorous plants that capture and digest animals: <span style="font-family: Calibri,serif; line-height: 1.5;">• Examples of predation: <span style="font-family: Calibri,serif;">◦ most of the interactions you've seen in the Tanzanian savanna (lions/zebras, cheetahs/antelope, etc) too many to list <span style="font-family: Calibri,serif;">◦ Venus flytraps ( <span style="font-family: 'Calibri Italic',serif;">Dionaea muscipula <span style="font-family: Calibri,serif;">) capture insects, arachnids, and occasionally small amphibians and rodents <span style="font-family: Calibri,serif;">◦ Pitcher plants (Genus <span style="font-family: 'Calibri Italic',serif;">Nepenthes <span style="font-family: Calibri,serif;">) have specialized leaves which hold water and digestive juices and are covered in a slippery surface so that whatever falls into the pitcher cannot climb out <span style="font-family: Calibri,serif;">◦ Bladderworts (Genus <span style="font-family: 'Calibri Italic',serif;">Utricularia <span style="font-family: Calibri,serif;">) like the Venus flytrap use trigger hairs to campture microbes or other small organisms <span style="font-family: Calibri,serif;">◦ Sundews (Genus <span style="font-family: 'Calibri Italic',serif;">Drosera <span style="font-family: Calibri,serif;">) produce sweet-smelling and very sticky nectar. When insects try to eat the nectar, they stick to the sundew and are digested by it. (Source:<span style="color: #000099; font-family: 'Calibri Bold',serif;">[] ) <span style="font-family: Calibri,serif; line-height: 1.5;">• Sir David Attenborough is one of my heroes. Check out this video of his about carnivorous plants (From "The Secret Life of Plants" via YouTube) media type="custom" key="24642212" align="center"

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Herbivory - <span style="font-family: Calibri,serif;">just like predation, except that the predator kills and eats plants instead of animals. All grazing animals (cows, goats, sheep, buffalo, antelope, zebras to name a few) practice herbivory. <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Competition <span style="font-family: Calibri,serif;"> - different organisms compete against one another for limited resources. <span style="font-family: Calibri,serif; line-height: 1.5;">• 'Resources' can mean water, food, shelter, nesting sites, sunlight, space, or hunting grounds. <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Intraspecific <span style="font-family: Calibri,serif; line-height: 1.5;"> competition (competition within members of the same species) tends to limit the population of that species within an ecosystem. <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Interspecific <span style="font-family: Calibri,serif; line-height: 1.5;"> competition (between different species) can result in shared resources and relatively balanced populations of both species, OR one species can out-compete the other and remove the weaker species from the ecosystem. This is called <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">competitive exclusion <span style="font-family: Calibri,serif; line-height: 1.5;">.

=<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.2.1 List the significant abiotic (physical) factors of an ecosystem. = = = =<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.2.2 Describe and evaluate methods for measuring at least three abiotic (physical) factors within an ecosystem. =

<span style="color: #f30000; font-family: 'Calibri Bold',serif;">Assignment <span style="font-family: Calibri,serif;">: Measuring Abiotic Factors at IST - Practical Write-up assessed under DCP. <span style="color: #165500; font-family: 'Calibri Bold',serif;">Click here for the complete description and instructions.

<span style="font-family: Calibri,serif;">Read pp.306-309 in the IB ESS Course Companion before studying the notes below!

<span style="font-family: Calibri,serif;">There's a wide variety of <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">abiotic factors <span style="font-family: Calibri,serif;"> that influence what may live in an ecosystem, some examples of which are listed below:

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Marine ecosystems <span style="color: #0000ff; font-family: Calibri,serif;">: <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">salinity <span style="font-family: Calibri,serif; line-height: 1.5;"> - many marine organisms tolerate a variety of salt concentration levels in the water, which can be checked with a few tools:

<span style="font-family: Calibri,serif;">◦ <span style="font-family: 'Calibri Italic',serif;">hydrometer <span style="font-family: Calibri,serif;"> measures specific gravity or density of a sample (relative weight of 1.0L salt water compared to 1.0L pure fresh water)

<span style="font-family: Calibri,serif;">◦ <span style="font-family: 'Calibri Italic',serif;">refractometer <span style="font-family: Calibri,serif;"> measures differences in light refraction between the saltwater sample and a freshwater control

<span style="font-family: Calibri,serif;">◦ <span style="font-family: 'Calibri Italic',serif;">electrical conductivity <span style="font-family: Calibri,serif;"> can also indicate the amount of dissolved ions in solution <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">pH <span style="font-family: Calibri,serif; line-height: 1.5;"> - use a pH meter (available in the IST science building). The pH of saltwater is naturally higher (i.e. more alkaline) than that of fresh water. According to several marine aquarium websites, a pH of 8.2 is ideal for saltwater fish. <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">temperature <span style="font-family: Calibri,serif; line-height: 1.5;"> - every organism has an optimal temperature range in which it thrives. An organism may be able to survive at warmer or cooler temperatures, but it will do so under stress, which requires more energy (and therefore food), and decreases its' ability to compete for other resources within the ecosystem. This is particularly important for <span style="font-family: 'Calibri Bold Italic',serif; line-height: 1.5;">ectothermic <span style="font-family: Calibri,serif; line-height: 1.5;"> (cold-blooded) organisms, which are a majority of marine animals. A change in temperature can also influence the pH of water <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">dissolved oxygen (DO) <span style="font-family: Calibri,serif; line-height: 1.5;"> - the amount of oxygen available for marine organisms, like terrestrial organisms, determines which organisms can survive in a particular location. DO levels fall with increased temperature and organic compounds from either sewage, agriculture, or industry. DO can range from 0-18 ppm, but most healthy ecosystems have a DO level of 5-6 ppm <span style="font-family: Calibri,serif; font-size: 10pt;">( <span style="font-family: Calibri,serif; line-height: 1.5;"><span style="color: #000099; font-family: 'Calibri Bold',serif; font-size: 10pt;">[] <span style="font-family: Calibri,serif; font-size: 10pt;">) <span style="font-family: Calibri,serif; line-height: 1.5;">. Measuring DO can be tricky and labor-intensive, requiring either a complicated Winkler titration or oxygen-selective electrodes. <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">wave action <span style="font-family: Calibri,serif; line-height: 1.5;"> - waves carry energy; thus, larger and prolonged waves can move larger particles, thereby 'mixing' water, oxygen, and sediment more. Areas with a lot of wave action tend to have higher DO levels. Waves can also increase the turbidity of the water and determine the nature of a coast line - i.e. sandy vs rocky. (<span style="color: #000099; font-family: 'Calibri Bold',serif; font-size: 10pt;">[] )

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Freshwater ecosystems: <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">turbidity <span style="font-family: Calibri,serif; line-height: 1.5;"> - "A cloudy condition in water due to suspended silt or organic matter." <span style="font-family: Calibri,serif; font-size: 10pt;">( <span style="font-family: Calibri,serif; line-height: 1.5;"><span style="color: #000099; font-family: 'Calibri Bold',serif; font-size: 10pt;">[|www.groundwater.org/gi/gwglossary.html] <span style="font-family: Calibri,serif; font-size: 10pt;">) <span style="font-family: Calibri,serif; line-height: 1.5;"> Cloudy = high turbidity and clear = low turbidity. According to Wikipedia (I know, I know...)

<span style="font-family: Calibri,serif;">◦ "Turbidity in lakes, reservoirs, channels, and the ocean can be measured using a Secchi disk. This black and white disk is lowered into the water until it can no longer be seen; the depth (Secchi depth) is then recorded as a measure of the transparency of the water (inversely related to turbidity). The Secchi disk has the advantages of integrating turbidity over depth (where variable turbidity layers are present), being quick and easy to use, and inexpensive." <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">flow velocity <span style="font-family: Calibri,serif; line-height: 1.5;"> - the rate at which water moves through a specified area in a given amount of time. Some aquatic organisms prefer high flow velocity (fast water) while others thrive at lower flow velocities. The simplest way is to time how long a partially-submerged object takes to travel a certain distance. For an explanation of how to more precisely measure stream flow, <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|visit this site from the USGS] describing the method - it's complicated! <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">pH <span style="font-family: Calibri,serif; line-height: 1.5;"> - normal readings for freshwater ecosystems range from about 6.5 (acidic) to 8.5 (basic) depending on the underlying rock substrata, surrounding vegetation, and human activities within the watershed <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">temperature <span style="font-family: Calibri,serif; line-height: 1.5;"> - see notes above <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">dissolved oxygen <span style="font-family: Calibri,serif; line-height: 1.5;"> - see notes above

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Terrestrial ecosystems <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">temperature <span style="font-family: Calibri,serif; line-height: 1.5;"> - depends on insolation (incoming sunlight), wind & ventilation, latitude, color and texture of the surface. Measure temperature with liquid thermometers or datalogging <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">light intensity <span style="font-family: Calibri,serif; line-height: 1.5;"> - influences photosynthesis rates as well as body temperature of ectotherms (cold-blooded animals). Light intensity is highly variable with weather conditions, season, time of day, and surrounding terrain & vegetation cover. It can be measured with light meters available from photography stores or the IST science department. <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">wind speed <span style="font-family: Calibri,serif; line-height: 1.5;"> - wind carries sediment and acts as a dessicating (drying) force in ecosystems, increasing evaporation and transpiration rates. Wind speed is measured with a few different tools:

<span style="font-family: Calibri,serif;">◦ <span style="font-family: 'Calibri Italic',serif;">anemometer <span style="font-family: Calibri,serif;">: spinning cups on a permanent or hand-held post. The number of revolutions per time period can be converted to a wind velocity.

<span style="font-family: Calibri,serif;">◦ <span style="font-family: 'Calibri Italic',serif;">Ventimeters <span style="font-family: Calibri,serif;"> use differences in air pressure to determine the velocity of wind passing over the open end of a tube.

<span style="font-family: Calibri,serif;">◦ <span style="font-family: 'Calibri Italic',serif;">Beaufort scale <span style="font-family: Calibri,serif;"> of wind speed from 0 to 12. The table below describes it better than I can. Image source: (<span style="color: #000099; font-family: 'Calibri Bold',serif;">[] ) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">particle size <span style="font-family: Calibri,serif; line-height: 1.5;"> - influences how well a soil holds water as well as its cation exchange capacity (CEC) - the mechanism by which nutrients are swapped between the physical soil matrix and the organisms living in the soil. Soils with large average particle sizes (such as boulders, pebbles, and sand) drain more quickly and hold fewer cations than soils with small particles (silt and clay). Seiving through different size screens is the most frequently used method to determine particle sizes. <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">slope <span style="font-family: Calibri,serif; line-height: 1.5;"> - steep slopes drain water rapidly and dry out quickly, have thinner soil layers, and tend to have lower levels of organic matter (OM) than more gently-sloping areas. Steep slopes also erode faster than gentle slopes. Slope can be measured with a clinometer, a field level, or calculated as a % (rise/run). <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">soil moisture <span style="font-family: Calibri,serif; line-height: 1.5;"> - influenced by particle size and climatic factors. The easiest way to measure soil moisture is to measure the mass of a sample, then dry it for several days until its mass is constant. The difference in the two masses is the mass of the water evaporated from the sample. <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">drainage <span style="font-family: Calibri,serif; line-height: 1.5;"> - influenced by slope and particle size

<span style="font-family: Calibri,serif;">◦ internal drainage: how rapidly water percolates down through soil layers

<span style="font-family: Calibri,serif;">◦ external drainage: how rapidly water moves across the landscape <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">mineral content <span style="font-family: Calibri,serif; line-height: 1.5;"> - Soils are a combination of minerals from eroded rock, organic matter in the form of detritus, pore spaces (the gaps between particles) which hold air and/or water, and living organisms. Mineral content is usually measured by burning off all the living material in a sample at very high temperatures.

<span style="font-family: 'Calibri Bold',serif;">Questions to consider <span style="font-family: Calibri,serif;"> for the end-of-term exam OR the IB ESS exam in May 2011: <span style="font-family: Calibri,serif; line-height: 1.5;">1. How might each of these factors vary in a given ecosystem with depth? At different times of day? At different distances? During different seasons? <span style="font-family: Calibri,serif; line-height: 1.5;">2. Outline and evaluate a method for measuring <span style="font-family: 'Calibri Italic',serif; line-height: 1.5;">one <span style="font-family: Calibri,serif; line-height: 1.5;"> of the abiotic factors listed above.

=<span style="font-family: 'Calibri Bold',serif;">2.3.1 Construct simple keys and use published keys for the identification of organisms. =

<span style="font-family: Calibri,serif;"> Your key should start with the largest groups of organisms and split them into successively smaller groups until each organism is alone in its own group. No characteristic should be used twice to subdivide different groups.

<span style="font-family: Calibri,serif;">Here’s another selection of critters to classify with your own dichotomous key:



=<span style="font-family: 'Calibri Bold',serif;">2.3.2 Describe and evaluate methods for estimating abundance of organisms. =

<span style="font-family: Calibri,serif;">Because it's usually impractical to sample every single organism in an ecosystem, we use statistical sampling to estimate the abundance of species within the ecosystem.

<span style="font-family: Calibri,serif;">A <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">transect <span style="font-family: Calibri,serif;"> is a line across an ecosystem along which quadrats may be placed for sampling.

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Quadrats <span style="font-family: Calibri,serif;"> are square frames of a specific size, in which we count the number of each species of organism.


 * <span style="font-family: Calibri,serif;">• The <span style="font-family: 'Calibri Italic',serif;">size <span style="font-family: Calibri,serif;"> of the quadrat depends on the size of organism anticipated (i.e. small quadrats for small organisms and large quadrats for large organisms).
 * <span style="font-family: Calibri,serif;">• The <span style="font-family: 'Calibri Italic',serif;">number <span style="font-family: Calibri,serif;"> of quadrats used for sampling depends on the number of species found. If we plot the number of species found against the number of quadrats used, once the number of species is stable, it's no longer necessary to add more quadrats - we can assume we've found all the species in the sample area. Refer to Fig. 16.6 on p.315 of the IBO ESS Course Companion.
 * <span style="font-family: Calibri,serif;">• Placing quadrats: Quadrats can be placed randomly, continuously, or systematically.

<span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Random quadrats <span style="font-family: Calibri,serif;"> - use random number tables (easily generated online) to determine placement of quadrats. <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|Click here for an example of how to do this.]

<span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Continual quadrats <span style="font-family: Calibri,serif;"> - place quadrats adjacently along a transect line and every species along the line. This is quite accurate but can be extremely time-consuming.

<span style="font-family: Calibri,serif;">◦ <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Systematic quadrat <span style="font-family: Calibri,serif;">s - place quadrats along a transect at regular, pre-determined intervals.

<span style="font-family: Calibri,serif;">Estimating abundance depends on the type of organism being sampled.


 * <span style="font-family: Calibri,serif;">• Plants are stationary, so we can use the <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">percentage cover <span style="font-family: Calibri,serif;"> to estimate their abundance. Simply put, estimate the % of each quadrat covered by each species' leaf area. The total % in a quadrat do NOT have to total 100%!
 * <span style="font-family: Calibri,serif;">• We can also count the <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">density <span style="font-family: Calibri,serif;"> of individuals - how many per square meter.
 * <span style="font-family: Calibri,serif;">• <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Frequency <span style="font-family: Calibri,serif;"> of individuals is the % of the number of quadrats where a particular species is found (i.e. A <span style="font-family: 'Calibri Italic',serif;">cacia senegalensis <span style="font-family: Calibri,serif;"> was present in 47 of 92 quadrats, for a frequency of 51%).

<span style="font-family: Calibri,serif;"><span style="color: #000099; font-family: 'Calibri Bold',serif;">[|Here's a Youtube video podcast] showing how an AP Environmental Science class in North Carolina uses some of these field sampling techniques.

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Capture, mark, release, recapture <span style="font-family: Calibri,serif;">: Animals within an ecosystem are caught and marked so that they may be tracked in the future, then released back into their habitat. At a subsequent time, another capture event is held, and previously-marked animals are noted in the field notes. We must be careful to make sure that the way the animals are marked doesn't make them more prone to be killed and eaten by predators or harm their chances of survival in any other way (i.e. making it more difficult to hunt or find food for themselves).

<span style="font-family: Calibri,serif;">The <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Lincoln Index <span style="font-family: Calibri,serif;"> is an important tool for estimating population size via capture-release programs. This method is frequently used but is not perfect. See some of the assumptions on p.317 of the IBO ESS Course Companion for further explanations. In class, <span style="font-family: 'Calibri Bold Italic',serif;">compelte the Lincoln Index calculations on p.317 <span style="font-family: Calibri,serif;">. The formula for calculating the Lincoln index is explained below:

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">N = (n1 x n2)/m2 <span style="font-family: Calibri,serif;"> where:


 * <span style="font-family: Calibri,serif;">• N = total population
 * <span style="font-family: Calibri,serif;">• n1 = number of animals first marked and released
 * <span style="font-family: Calibri,serif;">• n2 = number of animals captured in the second sample
 * <span style="font-family: Calibri,serif;">• m2 = number of marked animals in the second population

=<span style="font-family: 'Calibri Bold',serif;">2.3.3 Describe and evaluate methods for estimating the biomass of trophic levels in a community. =

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Biomass <span style="font-family: Calibri,serif;">, as the name implies, is a measurement of the mass of <span style="font-family: 'Calibri Bold Italic',serif;">living <span style="font-family: Calibri,serif;"> material at a trophic level or within an ecosystem. Because water is NOT living, we do not include it in our calculations.

<span style="font-family: Calibri,serif;">Since all organisms are made of roughly the same organic molecules in similar proportions, a measure of their <span style="font-family: 'Calibri Bold Italic',serif;">dry weight <span style="font-family: Calibri,serif;"> is a rough measure of the energy they contain. Therefore, material brought into the lab must be dried completely before measuring its mass. Normally, this is accomplished by placing the material in a warm - not hot - drying oven and allowing it to dry completely over a day or two before weighing it.


 * <span style="font-family: Calibri,serif;">• Use the <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Lincoln index <span style="font-family: Calibri,serif;"> (above) to estimate the total population of a secies of organisms.
 * <span style="font-family: Calibri,serif;">• Once the mass of an average organism within the population is known, that mass can be multiplied by the estimated population to determine the total biomass of the population of that species.
 * <span style="font-family: Calibri,serif;">• This process is repeated until all species at a trophic level have been accounted for.
 * <span style="font-family: Calibri,serif;">• (Source: <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [] <span style="font-family: Calibri,serif;">)

<span style="font-family: 'Calibri Bold',serif;">2.3.4 Define the term diversity.
<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Diversity <span style="font-family: Calibri,serif;"> (commonly <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">'biodiversity' <span style="font-family: Calibri,serif;"> when discussing ecological principles) is a measure of the relative abundance of different living organisms within an ecosystem. Diversity is not simply the number of different species found in an ecosystem - consideration must be given to the relative abundance of all species within the system.

<span style="font-family: Calibri,serif;">Two ecosystems may have the same number of species (called ' <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">species richness <span style="font-family: Calibri,serif;">'), but vary considerably in their diversity. If one or two species make up most of the total number of living organisms within the system, that system is considered less diverse than one in which the numbers of every species are relatively similar (called ' <span style="color: #0000ff; font-family: 'Calibri Bold',serif;">species evenness <span style="font-family: Calibri,serif;">').

<span style="font-family: Calibri,serif;">Look at the example on p.318 (recreated below). Both ecosystem 1 and ecosystem 2 have the same species richness - they each contain 3 different species. They also have similar numbers of organisms (70 and 72, respectively). However, the vast majority of organisms in ecosystem 2 are from a single species - species 'A'. Because the distribution of species in ecosystem 2 is skewed heavily to species A, ecosystem 2 is considered less diverse than ecosystem 1. How does Ecosystem # 3 compare to #1 and #2 in terms of species richness and species evenness?

<span style="font-family: 'Calibri Bold',serif;">Diversity of different ecosystems

|| || Species
 * # of Individuals ||
 * Ecosystem #1 ||  A  ||  25  ||
 * ^  ||  B  ||  24  ||
 * ^  ||  C  ||  21  ||
 * Ecosystem #2 ||  A  ||  65  ||
 * ^  ||  B  ||  3  ||
 * ^  ||  C  ||  4  ||
 * Ecosystem #3 ||  A  ||  28  ||
 * ^  ||  B  ||  32  ||
 * ^  ||  C  ||  12  ||

<span style="font-family: Calibri,serif;">Because ESS examines the <span style="font-family: 'Calibri Italic',serif;">science <span style="font-family: Calibri,serif;"> of ecosystems, we must be able to quantify or measure the diversity of ecosystems for the sake of comparison. How do we do that? Read below...

=<span style="font-family: 'Calibri Bold',serif;">2.3.5 Apply Simpson’s diversity index and outline its significance. =

<span style="font-family: Calibri,serif;">Simpson's diversity index is a mathematical model used to compare the relative biodiversity of different ecosystems. A full explanation can be found on p.318 of the <span style="font-family: 'Calibri Italic',serif;">IBO ESS Course Companion <span style="font-family: Calibri,serif;">. In short, the higher the numerical value of Simpson's diversity index, the greater the biodiversity of a system.

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">D = [N*(N-1)]/[Σ(n*(n-1)]

<span style="font-family: Calibri,serif;">Where...

<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">D <span style="font-family: Calibri,serif; line-height: 1.5;"> = diversity index <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">N <span style="font-family: Calibri,serif; line-height: 1.5;"> = total number of organisms of <span style="font-family: 'Calibri Italic',serif; line-height: 1.5;">all species <span style="font-family: Calibri,serif; line-height: 1.5;"> found <span style="font-family: 'Calibri Italic',serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">n <span style="font-family: Calibri,serif; line-height: 1.5;"> = number of individuals of <span style="font-family: 'Calibri Italic',serif; line-height: 1.5;">a particular species

<span style="font-family: Calibri,serif; line-height: 1.5;">1. Calculate the diversity index 'D' for a sample from ecosystem #3, the North American temperate deciduous forest. Sample data are listed in Table 1, below. <span style="font-family: Calibri,serif; line-height: 1.5;"> 2. What would happen to 'D' if all the oaks were harvested, leading to a 40% decline in the squirrel population, a decline of 25% in the woodpecker population, and a 30% decline in the warbler population in ecosystem #3?

<span style="font-family: 'Calibri Bold',serif;">Table 1 <span style="font-family: Calibri,serif;">: Species distribution in the eastern deciduous forest of North America, October 2009.

|| <span style="font-family: 'Calibri Bold',serif;">Species
 * <span style="font-family: 'Calibri Bold',serif;"># of individuals per species  ||
 * <span style="font-family: Calibri,serif;">Red oak ( <span style="font-family: 'Calibri Italic',serif;">Quercus rubrum <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">55   ||
 * <span style="font-family: Calibri,serif;">Silver maple ( <span style="font-family: 'Calibri Italic',serif;">Acer saccharinum <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">60   ||
 * <span style="font-family: Calibri,serif;">Eastern white pine ( <span style="font-family: 'Calibri Italic',serif;">Pinus strobus <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">32   ||
 * <span style="font-family: Calibri,serif;">Eastern white-tail deer ( <span style="font-family: 'Calibri Italic',serif;">Odocoileus virginianus <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">88   ||
 * <span style="font-family: Calibri,serif;">Eastern grey squirrel ( <span style="font-family: 'Calibri Italic',serif;">Sciurus carolinensis <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">110   ||
 * <span style="font-family: Calibri,serif;">Red bellied woodpecker ( <span style="font-family: 'Calibri Italic',serif;">Melanerpes carolinus <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">50   ||
 * <span style="font-family: Calibri,serif;">Yellow-rumped warbler ( <span style="font-family: 'Calibri Italic',serif;">Dendroica coronata <span style="font-family: Calibri,serif;">) || <span style="font-family: Calibri,serif;">42   ||

<span style="font-family: Calibri,serif;"><span style="color: #000099; font-family: 'Calibri Bold',serif;">[|This site] has a good step-by-step explanation of Simpson's Diversity Index.

<span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.4.1 Define the term biome. <span style="font-family: 'Calibri Bold',serif; font-size: 15pt;">2.4.2 Explain the distribution, structure and relative productivity of tropical rainforests, deserts, tundra and any other biome. <span style="font-family: Calibri,serif;">Here's a list of some useful websites covering all the major biomes and their distribution across the globe: <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|The World's Biomes] - University of California Museum of Paleontology <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|World Biomes] - BluePlanetBiomes.org <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|Biomes of the World] - Missouri Botanical Garden <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|Biomes of the World] - TheWildClassroom.com <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|World Biomes] - WorldBiomes.com <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="color: #165500; font-family: 'Calibri Bold',serif; line-height: 1.5;"> [|Marietta College Department of Biology and Environmental Science Biomes Main Page] <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Biome <span style="font-family: Calibri,serif; line-height: 1.5;">: Here are some definitions I found on the web. <span style="font-family: Calibri,serif; line-height: 1.5;"> • A major ecological community or complex of communities, extending over a large geographical area and characterized by a dominant type of vegetation. (<span style="color: #000099; font-family: 'Calibri Bold',serif;">[] ) <span style="font-family: Calibri,serif; line-height: 1.5;"> • A major ecological community, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment. (<span style="color: #000099; font-family: 'Calibri Bold',serif;">[|www.conservation.org/resources/glossary/Pages/b.aspx] ) <span style="font-family: Calibri,serif; line-height: 1.5;"> • a regional ecosystem characterized by distinct types of vegetation, animals, and microbes that have developed under specific soil and climatic conditions. (<span style="color: #000099; font-family: 'Calibri Bold',serif;">[] ) <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 1.3em; line-height: 1.5;">**Tropical rainforests** <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ tropical climate zone (duh!) <span style="font-family: Calibri,serif;">◦ 4 main areas - <span style="font-family: Calibri,serif;">■ Amazon basin in South America = 45.0% <span style="font-family: Calibri,serif;">■ Congo River basin in central Africa = 30.0% <span style="font-family: Calibri,serif;">■ Indomalayan or Asian rainforest = 16.0% <span style="font-family: Calibri,serif;">■ Australasian zone = 9.0% <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ at least 2 000 mm precipitation per year <span style="font-family: Calibri,serif;">◦ stable temperatures (generally 22-34 Celsius) <span style="font-family: Calibri,serif;">◦ 12 hours of daylight year-round <span style="font-family: Calibri,serif;">◦ Complex vertical layering produces separate but overlapping zones within the forest <span style="font-family: Calibri,serif;">◦ Food webs are intricately interwoven and interdependent <span style="font-family: Calibri,serif;">◦ poor quality soils (low nutrients) because nutrients are contained in the tree biomass <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif;">◦ Extremely high productivity due to year-round photosynthesis, stable temperature and precipitation. <span style="font-family: Calibri,serif;">◦ Biomass is concentrated in woody tissue of trees (i.e. most of the biomass in the rainforest is in the producers) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|http://rainforests.mongabay.com]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Deserts
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ tropical and temperate climate zones <span style="font-family: Calibri,serif;">◦ Hot deserts: <span style="font-family: Calibri,serif;">■ Africa (Sahara in the north, Namib and Kalahari in the south) <span style="font-family: Calibri,serif;">■ Arabian peninsula <span style="font-family: Calibri,serif;">■ Australia

**Temperate deserts**
<span style="font-family: Calibri,serif;">■ Central Asia (Gobi in Mongolia and China) <span style="font-family: Calibri,serif;">■ western USA (Sonora) <span style="font-family: Calibri,serif;">◦ Coastal deserts: <span style="font-family: Calibri,serif;">■ west coast of South America (Atacama in Chile and Peru)

<span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">:
<span style="font-family: Calibri,serif;">◦ evaporation exceeds precipitation - that's why they're dry! <span style="font-family: Calibri,serif;">◦ less than 50 mm precipitation annually <span style="font-family: Calibri,serif;">◦ average temperature 20-25 Celsius (includes both night and day) but will reach extremes of both hot and cold 12 - 49 Celsius <span style="font-family: Calibri,serif;">◦ drought-tolerant plant species <span style="font-family: Calibri,serif;">◦ rodents and other small mammals, insects, reptiles, & birds are predominant fauna <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity <span style="font-family: Calibri,serif;">◦ low productivity

<span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References:
<span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|University of Edinburgh, Scotland] <span style="font-family: Calibri,serif;"> - desert biome <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Biology Pages at Ultranet by J. Kimball] <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Energy Flow and Community Structure in Deserts] <span style="font-family: Calibri,serif;"> - Earlam University <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|University of California Museum of Paleontology] <span style="font-family: Calibri,serif;"> - desert biome

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Tundra
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution: <span style="font-family: Calibri,serif;">◦ polar climate zone <span style="font-family: Calibri,serif; line-height: 1.5;">◦ northern hemisphere ONLY (no land in corresponding latitudes of southern hemisphere) <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ Alaska, Canada, Scandinavia, Russia <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure: <span style="font-family: Calibri,serif; line-height: 1.5;">◦ frozen ground ( <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">permafrost <span style="font-family: Calibri,serif; line-height: 1.5;">) prevents deep root penetration <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ low nutrient content in soil due to minimal biological activity during long winters <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ short plants due to frozen ground and nutrient shortage <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ windy! <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ lichens, mosses, and heaths - no trees <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ mammals predominate; no reptiles or amphibians due to cold climate <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif; line-height: 1.5;">◦ low productivity <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References: <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Marietta College Tundra page] <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Biology Pages at Ultranet by J. Kimball]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Taiga (northern coniferous forest)
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ polar climate zone <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ Alaska, Canada, northern Europe and northern Asia <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ south of the tundra biome <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ harsh, long, cold winters; relatively cool summers <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ long nights (winter) long days (summer) <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ precipitation falls throughout the year - snow melt provides much water for flora <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ dominant vegitation is coniferous trees (Fir, spruce, pine species), mosses, grasses, & lichens <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ thin, nutrient-poor soil due to cold <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ acidic soil from evergreen needles <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif;">◦ relatively low, but large insect and bird migrations with seasons <span style="font-family: Calibri,serif;">◦ rodents and mammals dominate fauna <span style="font-family: Calibri,serif;">◦ low diversity <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|ICSU Scope 56] - Coniferous Forests, Grasslands, and Savanna <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ <span style="color: #165500; font-family: 'Calibri Bold',serif; line-height: 1.5;"> [|Biology Pages at Ultranet by J. Kimball] <span style="font-family: Calibri,serif; line-height: 1.5;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif; line-height: 1.5;"> [|Wikipedia Taiga page] <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 1.3em; line-height: 1.5;">**Temperate deciduous forest** <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ temperate climate zone <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ eastern North America, western Europe, China, Korea, Japan, Australia <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ precipitation falls throughout the year <span style="font-family: Calibri,serif;">◦ distinct summer and winter seasons with fluctuations in temperature and day length <span style="font-family: Calibri,serif;">◦ layers within the forest - large trees, small understory trees, shrubs, ground zone <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif; line-height: 1.5;">◦ high - 2nd highest after tropical rainforest <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ well-developed food webs <span style="font-family: Calibri,serif; line-height: 1.5;"> ◦ productivity fluctuates with seasons <span style="font-family: Calibri,serif; line-height: 1.5;"> • <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Biology Pages at Ultranet by J. Kimball] <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Mariette College Temperate forest page]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Prairies (temperate grasslands)
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ temperate climate zone <span style="font-family: Calibri,serif;">◦ north America (plains states), south America (Argentina), Africa (Zimbabwe), central Asia <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ less than 10% tree cover <span style="font-family: Calibri,serif;">◦ dominant vegetation is grasses <span style="font-family: Calibri,serif;">◦ deep, rich, high-quality soil with lots of nutrients <span style="font-family: Calibri,serif;">◦ humid; seasonal precipitation <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif;">◦ relatively high <span style="font-family: Calibri,serif;">◦ high fauna diversity due to large amount of producers supporting extensive food webs - lots of grazing animals <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|ICSU Scope 56] - Coniferous Forests, Grasslands, and Savanna <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Biology Pages at Ultranet by J. Kimball]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Savannas
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ tropical climate zone <span style="font-family: Calibri,serif;">◦ Africa, South America, India, Australia, parts of SE Asia (Burma, Thailand) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ 235 - 1 000 mm precipitation annually <span style="font-family: Calibri,serif;">◦ distinct wet and dry seasons with long periods of drought <span style="font-family: Calibri,serif;">◦ scattered shrubs and isolated trees <span style="font-family: Calibri,serif;">◦ warm throughout the year <span style="font-family: Calibri,serif;">◦ plants adapted for drought <span style="font-family: Calibri,serif;">◦ animals adapted for running (long legs, good eyesight) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relativeproductivity <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ relatively high - grasses and shrubs provide ample food for well-developed food webs <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ <span style="color: #000099; font-family: 'Calibri Bold',serif;">[|ICSU Scope 56] - Coniferous Forests, Grasslands, and Savanna <span style="font-family: Calibri,serif;">◦ Encyclopedia Brittanica <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|PlantzAfrica.com] <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|BluePlanetBiomes.org]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Chaparral (Scrub forest)
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ temperate climate zone <span style="font-family: Calibri,serif;">◦ northern California, coastal zones surrounding Mediterranean Sea, central Chile, western and southern Australia <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ 300 - 1 000 mm precipitation annually <span style="font-family: Calibri,serif;">◦ mild wet winters, hot dry summers <span style="font-family: Calibri,serif;">◦ stable temperatures year-round <span style="font-family: Calibri,serif;">◦ soil is thin, poor quality, rocky, and usually steep <span style="font-family: Calibri,serif;">◦ prone to wildfires <span style="font-family: Calibri,serif;">◦ plants adapted to drought <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif;">◦ dense populations of trees and shrubs <span style="font-family: Calibri,serif;">◦ medium-to-low productivity restricted by poor soil and seasonal precipitation <span style="font-family: Calibri,serif;">◦ fauna is mostly small mammals, birds, and insects; not many large animals <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Biology Pages at Ultranet by J. Kimball] <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Wikipedia chaparral page]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Coral reefs
<span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Distribution <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ tropical climate zones <span style="font-family: Calibri,serif;">◦ eastern coasts of Australia, Africa, central America, Oceania (Malaysia, Indonesia) <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Structure <span style="font-family: Calibri,serif; line-height: 1.5;">: <span style="font-family: Calibri,serif;">◦ warm, shallow water (less than 25 m) because sunlight required for photosynthesis <span style="font-family: Calibri,serif;">◦ algae and phytoplankton form foundation of coral reef food chain <span style="font-family: Calibri,serif;">◦ densely populated with corals and fish (fauna) <span style="font-family: Calibri,serif;">◦ salinity levels also dictate location <span style="font-family: Calibri,serif;">◦ wave action provides oxygen and helps clean the reef <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">Relative productivity: <span style="font-family: Calibri,serif;">◦ high - very diverse; compared to "rainforests of the sea" <span style="font-family: Calibri,serif; line-height: 1.5;">• <span style="font-family: 'Calibri Bold',serif; line-height: 1.5;">References: <span style="font-family: Calibri,serif;">◦ <span style="color: #165500; font-family: 'Calibri Bold',serif;"> [|Texas A&M University coral reef page]

<span style="color: #0000ff; font-family: 'Calibri Bold',serif;">Estuaries
<span style="font-family: Calibri,serif; line-height: 1.5;">• Distribution: <span style="font-family: Calibri,serif; line-height: 1.5;"> • Structure: <span style="font-family: Calibri,serif; line-height: 1.5;"> • Relative productivity: <span style="font-family: Calibri,serif; line-height: 1.5;"> • References: <span style="color: #0000ff; font-family: 'Calibri Bold',serif; line-height: 1.5;">Lakes & Rivers <span style="font-family: Calibri,serif; line-height: 1.5;">• Distribution: <span style="font-family: Calibri,serif; line-height: 1.5;"> • Structure: <span style="font-family: Calibri,serif; line-height: 1.5;"> • Relative productivity: <span style="font-family: 'Calibri Bold',serif; font-size: 19pt;">2.5.1 Explain the role of producers, consumers and decomposers in the ecosystem. <span style="font-family: 'Calibri Bold',serif; font-size: 19pt;">2.5.2 Describe photosynthesis and respiration in terms of inputs, outputs and energy transformations. <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">Photosynthesis: 6CO <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">2 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;"> + 6H <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">2 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">O --> C <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">6 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">H <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">12 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">O <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">6 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;"> + 6O <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">• inputs: light energy, water, carbon dioxide <span style="font-family: Calibri,serif; font-size: 16pt;"> • outputs: oxygen gas, sugar (organic molecules) <span style="font-family: Calibri,serif; font-size: 16pt;"> • energy transformations: light to chemical <span style="font-family: Calibri,serif; font-size: 16pt;"> • respiration backwards! <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">Respiration <span style="color: #0000ff; font-family: Calibri,serif; font-size: 16pt;">: <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">C <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">6 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">H <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">12 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">O <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">6 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;"> + 6O <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">2 <span style="color: #0000ff; font-family: Calibri,serif; font-size: 16pt;"> --> <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">6CO <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">2 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;"> + 6H <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 13pt;">2 <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">O <span style="font-family: Calibri,serif; font-size: 16pt;">• inputs: oxygen gas, organic molecules (sugars) <span style="font-family: Calibri,serif; font-size: 16pt;"> • outputs: carbon dioxide, energy in ATP, waste heat <span style="font-family: Calibri,serif; font-size: 16pt;"> • energy transformations: chemical to heat <span style="font-family: Calibri,serif; font-size: 16pt;"> • photosynthesis backwards! <span style="font-family: 'Calibri Bold',serif; font-size: 19pt;">2.5.3 Describe and explain the transfer and transformation of energy as it flows through an ecosystem. <span style="font-family: Calibri,serif; font-size: 16pt;">Almost all energy enters Earth's ecosystems as solar insolation. That energy is then transformed and used by the diverse variety of organisms that make up food webs. <span style="font-family: Calibri,serif; font-size: 16pt;">Through <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">photosynthesis <span style="font-family: Calibri,serif; font-size: 16pt;">, producers transform sunlight (light energy) into glucose (chemical energy), which they then use for <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">respiration <span style="font-family: Calibri,serif; font-size: 16pt;">. <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">Chloroplasts <span style="font-family: Calibri,serif; font-size: 16pt;"> in plant cells use sunlight to convert CO <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;"> and water to glucose (sugar) and O <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;"> gas. The plants' mitochondria then use the sugars for energy to drive <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">respiration <span style="font-family: Calibri,serif; font-size: 16pt;">(their cellular processes required to stay alive). <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">Chlorophyll <span style="font-family: Calibri,serif; font-size: 16pt;"> is the pigment in chloroplasts that makes photosynthesis possible by absorbing light from the sun. Red and blue wavelengths are absorbed by the leaves and efficiently used in the energy transformation process, but not the green wavelengths. The green waves bounce off the leaf and reflect into our eyes, which is why leaves look green! <span style="font-family: 'Calibri Bold',serif; font-size: 19pt; line-height: 1.5;">2.5.4 Describe and explain the transfer and transformation of materials as they cycle within an ecosystem. <span style="font-family: 'Calibri Bold',serif; font-size: 19pt; line-height: 1.5;"> 2.5.5 Define the terms gross productivity, net productivity, primary productivity and secondary productivity. <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">productivity <span style="font-family: Calibri,serif; font-size: 16pt;">• the <span style="font-family: 'Calibri Italic',serif; font-size: 16pt;">rate <span style="font-family: Calibri,serif; font-size: 16pt;"> of growth (increase in biomass) in organisms <span style="font-family: Calibri,serif; font-size: 16pt;"> • i.e. how slow/fast an organism increases its biomass <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr (for biomass) or kJ/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr (kJ = <span style="font-family: 'Calibri Bold',serif; font-size: 16pt;">kiloJoules <span style="font-family: Calibri,serif; font-size: 16pt;">, which is a measure of energy) <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">gross productivity (GP) <span style="font-family: Calibri,serif; font-size: 16pt;">• total gain in energy or biomass per unit area over time before accounting for respiration or other energy/biomass losses <span style="font-family: Calibri,serif; font-size: 16pt;"> • the amount of biomass that <span style="font-family: 'Calibri Italic',serif; font-size: 16pt;">could be accumulated <span style="font-family: Calibri,serif; font-size: 16pt;"> in a measured area of an ecosystem in a given amount of time <span style="font-family: Calibri,serif; font-size: 16pt;"> • does <span style="font-family: 'Calibri Bold Italic',serif; font-size: 16pt;">not <span style="font-family: Calibri,serif; font-size: 16pt;"> factor in energy lost to respiration <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr <span style="font-family: Calibri,serif; font-size: 16pt;"> • difficult to measure because measurements must be taken in real time as producers convert sunlight to sugar, which means they must be killed, thereby stopping the process we're trying to measure <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">net productivity (NP) <span style="font-family: Calibri,serif; font-size: 16pt;">• the actual amount of biomass accumulated after respiration has been accounted for <span style="font-family: Calibri,serif; font-size: 16pt;"> • remember that this must be <span style="font-family: 'Calibri Italic',serif; font-size: 16pt;">dry biomass <span style="font-family: Calibri,serif; font-size: 16pt;"> - water is not a part of productivity <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">primary productivity (PP) <span style="font-family: Calibri,serif; font-size: 16pt;">• autotrophs are producers, and they are the 1st organisms in any food chain <span style="font-family: Calibri,serif; font-size: 16pt;"> • the biomass accumulated by autotrophs (plants, algae, cyanobacteria) <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">secondary productivity (SP) <span style="font-family: Calibri,serif; font-size: 16pt;">• biomass accumulated by consumers (heterotrophs) in an ecosystem <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr <span style="font-family: 'Calibri Bold',serif; font-size: 19pt; line-height: 1.5;">2.5.6 Define the terms and calculate the values of both gross primary productivity (GPP) and net primary productivity (NPP) from given data. <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">gross primary productivity (GPP) <span style="font-family: Calibri,serif; font-size: 16pt;">• how fast autotrophs photosynthesize (convert sunlight to glucose) <span style="font-family: Calibri,serif; font-size: 16pt;"> • some glucose is used to fuel the autotrophs' life processes: growth, respiration, homeostasis <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">, but very difficult to measure <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">net primary productivity (NPP) <span style="font-family: Calibri,serif; font-size: 16pt;">• the amount of biomass accumulated by autotrophs after respiration <span style="font-family: Calibri,serif; font-size: 16pt;"> • think of NPP as the food available to consumers within the ecosystem <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: 'Calibri Bold',serif; font-size: 19pt; line-height: 1.5;">2.5.7 Define the terms and calculate the values of both gross secondary productivity (GSP) and net secondary productivity (NSP) from given data. <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">gross secondary productivity (GSP) <span style="font-family: Calibri,serif; font-size: 16pt;">• the amount of biomass absorbed (eaten) by consumers before any energy is lost to respiration <span style="font-family: Calibri,serif; font-size: 16pt;"> • includes food that is <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt;">egested <span style="font-family: Calibri,serif; font-size: 16pt;"> (excreted as waste) by the consumer <span style="color: #0000ff; font-family: 'Calibri Bold',serif; font-size: 16pt; line-height: 1.5;">net secondary productivity (NSP) <span style="font-family: Calibri,serif; font-size: 16pt;">• the actual change in biomass in an ecosystem during a given period of time <span style="font-family: Calibri,serif; font-size: 16pt;"> • accounts for energy lost to respiration and biomass lost through egestion or other methods <span style="font-family: Calibri,serif; font-size: 16pt;"> • usually measured in g/m <span style="font-family: Calibri,serif; font-size: 13pt;">2 <span style="font-family: Calibri,serif; font-size: 16pt;">/yr (it's easier to measure biomass than energy) <span style="font-family: Calibri,serif; font-size: 16pt; line-height: 1.5;">To see calculations involving GPP, NPP, GSP, and NSP, see the review activity in the orange box on p.43 of the IB ESS Course Companion.