2 Define Species Habitat Population Community Ecosystem Ecology AutotrophHeterotrophConsumerDetrivoreSaphrotroph
3 5.1 Communities and Ecosystems Ecology is the study of relationships between living organisms and between organisms and their environment.This means the relationship of all the living things (biotic) to all the non living things (abiotic) and their relationships to each other.
4 Definitions Ecosystem—a community and its abiotic environment. Population—a group of organisms of the same species who live in the same area at the same time.Community—a group of populations living and interacting with each other in an area.Species—a group of organisms which can interbreed and produce fertile offspring.Habitat—the environment in which a species normally lives or the location of a living organism.
5 5.1 Communities and Ecosystems One of the most important relationships between living things is: who eats whom? Feeding relationshipsAutotroph (producer) – organisms that use an external energy source to produce organic matter from inorganic raw materialsExamples: trees, plants, algae, bacteria
6 Most autotrophs use carbon dioxide from the atmosphere along with energy from the sun to fix carbon into organic molecules through a process called photosynthesis.Other autotrophs fix organic material without the use of the suns energy. They are called chemoautotrophs.
7 5.1 Communities and Ecosystems Heterotroph (consumer) – organisms that use the energy in organic matter, obtained from other organismsExamples: animals, protista, fungi
8 5.1 Communities and Ecosystems Types of heterotrophs:Consumers – an organisms that ingests matter from organisms that are living or recently killedDetritivore – an organisms that ingests non-living organic matter, examples: beetles, wormsSaprotroph- an organisms that lives on or in non-living organic, secreting digestive enzymes into it and absorbing the products of that digestion, examples: fungi, mold
10 5.1 Communities and Ecosystems Describe what is meant by a food chain giving three examples, each with at least three linkages (four organisms).A food chain is a sequence of relationships between trophic levels where each member feeds on the previous one.The arrow from one organism to the other indicates the direction of energy
12 Review Define: Ecology Ecosystem Biotic/abiotic Species Population communityAutotroph: 2 typesHeterotroph: 3 typesFood chain
13 5.1 Communities and Ecosystems Describe what is meant by a food web.A food web is a a diagram that shows the feeding relationships in a community. The arrows indicate the direction of energy flow.
14 Food web: make a food web including all of your organisms.
15 5.1 Communities and Ecosystems Define trophic level.A trophic level is where an organism is positioned on a food web (it’s feeding relationship to other organisms).Producer: 1st levelPrimary consumer: 2nd levelSecondary consumer: 3rd levelTertiary consumer: 4th level
16 5.1 Communities and Ecosystems QuaternaryconsumersDeduce the trophic level of organisms in a food chain and a food web.CarnivoreTertiaryconsumersCarnivoreSecondaryconsumersCarnivorePrimaryconsumersHerbivorePrimaryproducersPlantA terrestrial food chain
17 5.1 Communities and Ecosystems State that light is the initial energy source for almost all communities.
18 Explain the energy flow in a food chain. 5.1.10Explain the energy flow in a food chain.Microorganismsand otherdetritivoresTertiaryconsumersSecondaryDetritusPrimary consumersSunPrimary producersHeatKeyChemical cyclingEnergy flow
19 State that energy transformations are 10–20% efficient. (1) 5.1.11State that energy transformations are 10–20% efficient. (1)Growth (new biomass)CellularrespirationFeces100 J33 J67 J200 JPlant materialeaten by caterpillar
20 5.1.12Explain what is meant by a pyramid of energy and the reasons for its shape.Notice the loss of energy with each transfer in a food chain
21 5.1 Communities and Ecosystems Explain that energy can enter and leave an ecosystem, but that nutrients must be recycledEnergy enters as light and usually leaves as heat.Nutrients do not usually enter an ecosystem and must be used again and again. Nutrients include: Carbon, Nitrogen, and Phosphorus
24 Ecology and statistical analysis Ecologist often want to compare data from two populations to see if there are differences due to some biotic or abiotic factorExamples?So we could collect data on some aspect of the population, for instance mass of the organism.
25 Ecology and statistical analysis What statistical tests could we do to summarize the data? (these kinds of test are called descriptive tests- they help to describe the data)Mean, mode ,median, standard deviationWhat test could we do to look at the differences between the two populations?t test- this is an example of inferential statistical test, these help us to see if the differences we see on 2 groups of data are statistically significant.What other inferential test have we learned about?
26 Ecology and statistical analysis In ecology, as in most science experiments we are not going to measure every organism in the 2 populations in order to do any statistical analysis.We are going to sample the population.We hope that the sample is representative of the whole population.What things can we do to get closer to the real or parametric values?
27 Ecology and statistical analysis What is the starting hypothesis that will be tested with inferential statistics?Null hypothesisThe null hypothesis states that the differences we see in the samples are just due to chance.Because we don’t know the actual value, we need a statistical test to know how different the values need to be to say with confidence that the actual values are different.
28 Ecology and statistical analysis Inferential statistical tests give us a value that we then have to associate with a P value.The P value tells us the probability that our differences are due to chance or some other factor.In biology if the P value is 0.05 or less, then the differences we see are real/significant and we reject the null hypothesis and come up with an alternate hypothesis.It means that we can be 95% sure that these differences are real so the smaller the P value the more sure we are that they are significant.
29 Ecology and statistical analysis To get data to practice calculating both descriptive and inferential statistics we are going to go to the lake and find 2 populations of organisms to get data on.In pairs, you will select 2 populations of the same organism, decide what you will measure and your sample size.You will then collect what you need or take measurements in the field.Then you will calculate the following for each group: mean, sd and variance. Present this date in an appropriate graph.Next you will calculate a t test on the two populations.Use this site, or excel or your calculator.
30 Ecology and statistical analysis T test: paired or unpaired, one tailed or two tailed. ?The website I gave you explains this well.The short explanation: use paired if your data for the two populations are paired, have a one to one correspondence, like if you measure a plant before and after a treatment. If not, use unpaired.Use one tailed if you are looking for a difference, but you don’t know which one will be greater.
31 Energy flows through the ecosystem and must constantly be added. Nutrients , on the other hand are recycled.The organisms that do this are the saprotrophs and the decomposers.There are other biotic and abiotic mechanisms that cycle nutrients.
36 The Greenhouse effectThe greenhouse effect describes the process of warming due to our atmosphere.Like a greenhouse, when light enters the atmosphere, some of the heat energy is trapped. This causes the earth’s temperature to rise.Greenhouse gasses: water vapor, carbon dioxide, ozone, methane and oxides of nitrogen occur in the lower atmosphere- trophosphere.They absorb some of the infrared radiation that is radiated back from the earth’s surface.This causes their molecules to vibrate and transform the absorbed energy into longer infrared radiation (heat) in the trophosphereThis is a natural phenomenon and if it wasn’t for the greenhouse effect, the earth would be in a perpetual ice age, mean temperature would be -18C
37 Precautionary Principle: better safe than sorry The precautionary principle states that if an action taken by humans MAY have some large,negative affect on the environment, then it should not be undertaken.Even if there is not solid scientific knowledge to say that it would have a bad effect.The person/s wanting to take the action must prove that it would not do harmExamples of use:1994 the National Marine Fisheries Service adopted rules to prevent overfishingProtection of species such as elephants in AfricaProtection of habitat example logging areas in the Pacific Northwest, wilderness areas in Alaska slotted for oil pipelines
38 Precautionary Principle How is the PP applied to justify strong action in response to the threats posed by the enhanced greenhouse effect?
39 Greenhouse Effect http://www.ciel.org/Climate/Climate_Arctic.html What are the consequences of the rise of global temperatures on artic ecosystems?Average annual temperatures in the Arctic have increased by approximately double the increase in global average temperaturesthe Arctic has warmed at an alarming rate, and it is projected to continue to warm by as much as 18 degrees Fahrenheit by 2100This warming trend has had a devastating impact on Arctic ecosystems, including sea ice, permafrost, forests and tundra.Warming has contributed to increases in lake temperatures(5), permafrost thawing, increased stress on plant and animal populations(6) and the melting of glaciers(7) and sea ice.Research has revealed decreases in both sea ice extent (9) and cover.(10)
40 Greenhouse Effect* Melting sea ice affects populations of marine mammals, caribou, polar bears and the subsistence livelihoods of people that depend on them. Because sea ice forms a natural breakwater against storm wave action, ice melting allows larger storm surges to develop and causes erosion, sedimentation, and coastal inundation.(11)* Polar bears live on sea ice while hunting their prey and reductions in sea ice due to warming have resulted in shorter feeding periods and decreased accessibility to the seals that they hunt* Walrus populations are suffering from the retreat of the sea ice and changes in food supply as is evident by their recently low juvenile survival rates*Killer whales have been reported as feeding on sea otters since their prey of choice, sea lions and harbor seals, have followed changes in fish migration patterns and moved out of the killer whales' habitat range.(16)*Local coastal losses to erosion of up to 100 feet per year have been observed in some locations in the Siberian, Alaskan and Canadian Arctic.(17)
41 Greenhouse Effect*Rising temperatures have allowed spruce bark beetles to reproduce at twice their normal rate*A sustained outbreak of the beetles on the Kenai Peninsula has caused over 2.3 million acres of tree mortality, the largest loss from a single outbreak recorded in North America.(21) Outbreaks of other defoliating insects in the boreal forest, such as spruce budworm, coneworm, and larch sawfly, also have increased sharply in the past decade.*Climate warming and insect infestations make forests more susceptible to forest fire.
42 Greenhouse Effect Increased rate of decomposition of detritus Expansion of range of habitatLoss of ice habitatChanges in distribution of prey species--> affects higher trophic levelsIncrease numbers of pests and pathogens
43 Nitrogen Cycle N2 in atmosphere Denitrifying bacteria Nitrogen-fixing AssimilationDenitrifyingbacteriaNO3–Nitrogen-fixingbacteria in rootnodules of legumesDecomposersNitrifyingbacteriaAmmonificationNitrificationNH3NH4+NO2–Nitrogen-fixingsoil bacteriaNitrifyingbacteria
44 G1 Community EcologyG.1.1 Outline the factors that affect the distribution of plant species, including temperature, water, light, soil pH, salinity, and mineral nutrients.
45 G1 Community EcologyG.1.2 Explain the factors that affect the distribution of animal species including temperature, water, breeding sites, food supply and territory.
46 First IA pause and Statistics Pause. Internal AssessmentThink about what will effect how plants are distributed in an ecosystem….First IA pause and Statistics Pause.
47 G1 Community Ecology G.1.5 Explain what is meant by the niche concept. The total of a species’ use of biotic and abiotic resources is called the species’ ecological niche.HabitatFeeding relationshipsSymbiotic/other interactions with organisms
48 G1 Community EcologyG.1.7 Explain the principle of competitive exclusion.two species competing for the same limiting resources cannot coexist in the same place – one must leave or becomes extinct
49 G1 Community Ecology G.1.8 Fundamental vs Realized Niches Fundamental = where the species is designed to live the bestRealized = where the species actually resides because of competition
50 G1 Community EcologyG.1.6 Outline the following interactions between species: competition, herbivory, predation, parasitism, and mutualism (with examples).
51 G1 Community EcologyG.1.9 Define biomass - each tier represents the dry weight of all organisms in one trophic levelTrophic levelDry weight(g/m2)Tertiary consumersSecondary consumersPrimary consumersPrimary producers1.51137809
52 G2 Ecosystems and biomes G.2.1 Define gross production and net production.Gross Production = the amount of light energy converted to chemical energy by autotrophs in an ecosystemNet Production = Energy able to be passed on by producers to consumersG.2.2 GP – R (Respiration) = NP
53 G2 Ecosystems and biomes G.2.5 Construct a pyramid of energy, given information.
54 G2 Ecosystems and biomes G.2.6 Distinguish between primary and secondary succession.Primary succession occurs where no soil exists when succession beginsSecondary succession begins in an area where soil remains after a disturbance
55 G2 Ecosystems and Biomes G.2.7 Outline the changes in species diversity and production during primary succession.Not very diverse: Lichen pioneer speciesVery diverse: Forest climax community
56 G2 Ecosystems and Biomes G.2.8 Explain the effects of living organisms on the abiotic environment, with reference to the changes occurring during primary succession.Small amount of soil formed by the lichens is colonized by mosses, which do not have roots and require little soilAs the seedless plants live and die decomposition increases the richness of the soilGrasses can successfully grow
57 G2 Ecosystems and biomes G.2.9 Distinguish between biome and biosphere.Biome = Communities on earth that contain similar plant and animal inhabitantsBiosphere = part of Earth that can contain life
58 G2 Ecosystems and Biomes G.2.11 Outline the characteristics (temperature, moisture, vegetation) of six major biomes.DesertGrasslandShrublandTemperate deciduous forestTropical rainforestTundra
59 G1 Community EcologyG.1.3 Describe one method of random sampling, based on quadrat methods, that is used to compare the population size of two plant or two animal species.
60 Mark off a large 10 x 10 meter grid area Toss a 1 x 1 meter square into the grid area randomlyIdentify and count all the larger plant species firstSmaller plant species, like grass, divide your square intoseveral smaller 10 x 10 cm squares. Count the number ofindividual plants in several of those smaller squares, average,and multiply by 100 to get an estimate.5) Toss the 1 x 1 m square to obtain more data.
61 G3 Impacts of humans on ecosystems G.3.1 Calculate the Simpson diversity index for two communities.N – total number of individual organisms (all species combined)n – number of individuals of a particular species
62 G3 Impacts of humans on ecosystems G.3.2 Analyze the biodiversity of the two local communities using the Simpson index.High Index (closer to one) – Higher the biodiversityThis index ranges from zero to one and is literally a measure of the probability that two organisms taken at random from the sample are different species. A number close to zero means low diversity and it is likely you will get the same species of organism and a number close to one means high diversity.
64 5.3 Populations5.3.1Outline how population size can be affected by natality, immigration, mortality and emigration.Natality – offspring are produced and added to the populationMortality – individuals die and are lost from the populationImmigration – individuals move into the area from somewhere else and add to the populationEmigration – individuals move out of the area and are lost from the population
65 5.3 Populations5.3.2Draw a graph showing the sigmoid (S-shaped) population growth curve.
67 5.3 Populations Exponential Phase: * Population increases exponentially because the natality rate is higher than the mortality rate.* This is because there is an abundance of food, and disease and predators are rare.
68 5.3 Populations Transitional Phase Difference between natality and mortality rates are not as great, but natality is still higher so population continues to grow, but at a slower rate.Food is no longer as abundant due to the increase in the population size. May also be increased predation and disease.
69 5.3 Populations Plateau Phase Natality and mortality are equal so the population size stays constant.Limiting Factors:shortage of food or other resourcesincrease in predatorsmore diseases or parasitesIf a population is limited, then it has reached its carrying capacity (K)
70 5.3 Populations Define carrying capacity. The maximum population size that can be supported by the environment
71 G.5 AHLIn a random sample, every individual in a population has an equal chance of being selected.Describe one technique used to estimate the population size of an animal species based on a capture-mark-release-recapture method. (2)Various mark and recapture methods exist.Knowledge of the Lincoln index (which involves one mark, release and recapture cycle) is required.
72 G.5 AHL population size = where . . . n1= number of individuals initially caught, marked and releasedn2 = total number of individuals caught in the second samplen3 = number of marked individuals in the second sample
74 5.2 Greenhouse effect5.2.1Draw the carbon cycle to show the processes involved.The details of the carbon cycle should include the interaction of living organisms and the biosphere through the processes of photosynthesis, respiration, fossilization and combustion. Recall of specific quantitative data is not required.
79 Greenhouse Effect Causes Light from the sun has short wavelengths and can pass through most of the atmosphere.This sunlight warms the earth which in turn emits long wave radiation.This long wave radiation is bounced back by the greenhouse gases, such as carbon dioxide, methane, water vapour, and sulphur dioxide
81 5.2 The greenhouse effect5.2.6 Outline the consequences of a global temperature rise on artic ecosystems.Loss of ice habitatIncreased success of pests
82 G3 Impacts of humans of ecosystems Ozone layer absorbs UV radiationCFCs are causing a hole in the ozone layerExcessive UV radiation can cause:Skin cancerVital bacteria would die
83 G3 Impacts of humans on ecosystems G.3.4/5 List 3 examples of introduced/alien species and discuss the impact.Purple Loosestrifespread alarmingly fast,removed from their natural controlling agents.dramatic disruption in waterflow in rivers and canals,- Native food and cover plant species, notably the cattails, are crowded out.
84 G3 Impacts of humans on ecosystems Zebra mussels were first detected in the Great Lakes in 1988 and have caused widespread damage in the ecosystem.Zebra Mussels are edible, but most experts advise against eating any found in areas of pollution concern since zebra mussels accumulate contaminants and toxins from the water that they filter.
85 G3 Impacts of humans on ecosystems - Round Goby- Survives well in degraded environmental conditionsCompetitive advantage compared to native species.Heavy feeding on invasive mussels(zebra and quagga) results in greater biomagnification- No predators due to defensive mechanism
86 Define biomagnification – At each trophic level, toxic substances (Hg, pesticides, TCDD, etc.) become more concentrated
87 G3 Impacts of humans on ecosystems How can we keep invasive species in check via a biological mechanism?Decide on a local area that is currently being impacted negatively by an invasive species.Find out what that negative impact is and which of the invasive species is causing it.Research a BIOLOGICAL means of controlling that species in order to stop the negative impact.Put together a proposal illustrating your method of restoring the ecosystem.
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