Environmental Biology

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Environmental Biology by Mind Map: Environmental Biology

1. Circulation of nutrients

1.1. soil

1.1.1. structure pores inbetween particles provide water and air for plants inorganic components from rock sandy clay loams

1.1.2. fauna fungi penicillium decompose large plant molecules nurtrient cycling bacteria NItrobacter most abundant imporant invertebrates earth worms, woodlice, spiders, nematodes

1.1.3. rhizosphere plant roots and soil contact many micro-organisms here

1.2. detritivores and decomposers

1.2.1. detritivores invertebrates that feed on Detrius may be eaten by a larger animal, starting a detrius based food chian

1.2.2. decomposers bacteria, funghi release digestive enzymes absorb digested nutrients utilise energy as sources of energy carbon nutrients cellular respiration

1.3. Decomposition

1.3.1. undecomposed matter litter

1.3.2. completely decomposed matter humus

1.3.3. mineralisation nutrients from dead organisms released

1.3.4. rate type of organic matter number/ types of detritivores and decomposers environmental conditions

1.4. cycles

1.4.1. carbon cycle needed for carbohydrates, proteins, nucleic acid, lipids moves by abiotic to biotic environment by fixation during photosynthesis returned to atmosphere by respiration and decomposition

1.4.2. NItrogen fixation atmospheric nitrogen to ammonia nitrification ammonium to nitrite to nitrates dentrification returns nitrogen to the atmosphere ammonification decomposition effected by water saturation

1.4.3. Phosphate added to soil by weathering of rocks taken up by producers, returned by decomposition limiting factor in productivity of aqautic ecosystems enrichment can lead to eutrophication

2. Symbiotic interactions

2.1. interaction between any species living together

2.2. parasitism

2.2.1. one organism benifits while the other is harmed

2.2.2. often a balance is acheived between the parasitic damage and the host's defence

2.2.3. relastionship may evolve to be highly specific

2.2.4. parasites facultative can live with or without host obligate cannot survive without host organism Endoparasites within hosts body Ectoparasites on surface of host transmission vectors, secondry hosts direct contact resistant stages

2.3. commensalism

2.3.1. one organism benifits, the other is unharmed

2.3.2. usually based on feeding

2.3.3. difficult to observe in nature

2.3.4. ie. clown fish in the tentacles of an anenome

2.4. Mutalism

2.4.1. both organisms benefit

2.4.2. both organisms share metabolites and are structirally compatible

2.4.3. ie. lichen - an interaction between fungus and alga

3. Succession

3.1. series of changes in types of species which occupy an area in a given time

3.2. at each stage of succsession the current species creates the environmental conditions suitable for its competitors

3.3. system moves from

3.3.1. unstable community --> relatively stable community

3.3.2. simple --> complex number of species population sizes biological productivity increase in variety of habitats and niches increase in complexity of food webs

3.3.3. ecosystem may loose complexity due to monoculture diversity limited- one crop grown toxic pollution oxygen depleation algal blooms Eutrophication (more nutrient being put in that removed) larger animals die

3.4. example

3.4.1. grass colonise area

3.4.2. humus builds up

3.4.3. support and nutrients increased

3.4.4. ideal conditions for tree saplings developed

3.4.5. trees grow, blocking light

3.4.6. grass out competed

3.5. autogenic

3.5.1. changes in environemntal conditions which lead to change in species are caused by the biological processes of the organisms themselves

3.6. allogenic

3.6.1. changes in environmental conditions leading to changes in species composition are unrelated to the organisms present.

3.6.2. Examples include hurricanes, forest fires and climate changes.

3.7. primary

3.7.1. plants established on land not previously inhabitated, no soil bare rock, newly formed sand dunes

3.7.2. takes longer than secondary due to lack of soil

3.8. secondary

3.8.1. plants invade habitat previously inhabited by other plants, existing soil regeneration after forest fire

3.9. pioneer species (first to colonise area)

3.9.1. lichens which colonise bare rock

3.9.2. annuals who seeds are blown into a cleared field

3.9.3. can withstand difficult environmental conditions ie. dessication (drying out)

3.9.4. fast growing, high rate of reproduction

3.10. Climax community

3.10.1. mature

3.10.2. stable

3.10.3. no further succsesion takes place

3.11. Degradative

3.11.1. changes assosiated with stages of decomposition

3.11.2. when organisms die and decompose, certain species appear

3.11.3. also known as heterotrophic succession

4. Increase in energy needs

4.1. increase in human population has led to increase in energy demand

4.2. finite fossil fuel supplies are running out

4.2.1. must be conserved

4.2.2. alternatives must be found nuclear solar wind hydroelectric wave geothermal biofuels

4.3. increase in fuel use has led to global warming

4.3.1. green house effect

4.3.2. gas in the earths atmosphere prevents infrared heat from escaping, warming the earth

4.3.3. the problem gasses carbon dioxide water methane nitrous oxide CFCs

4.3.4. this may lead to reduction in diversity Coral bleaching Coral polyps with white Calcium Carbonate exoskeleton symbiotic relationship with coloured zooxanthellae increase in temperatures make these zooanthellae leave the polyps the white exo skeleton is left, the coral is bleached.

5. Pollution

5.1. negative effect of harmful substances in the environment

5.2. water

5.2.1. organic material eg. dumping of sewage food for micro-organisms use up oxygen make water anoxic other naimals die

5.2.2. shown by BOD of water Biochemical Oxygen Demand the greater the BOD, the more micro-organisms, the more polluted the water is

5.3. concentration of pollutant increases along the food chain

5.3.1. known as biomagnification

5.3.2. DDT and heavy metal pollutants show high biomagnifictaion as they are large, persistant molecules

5.4. susceptible species

5.4.1. con not tolerate changes in the environemnt

5.4.2. indicator species eg. lichen and stonefly nymphs dsisappearance of lichens indicates rise in SO2 levels

5.5. favoured species

5.5.1. can tolerate a wide range of conditions

5.5.2. invasive exotic species can be considered pollution

6. Energy fixation and flow

6.1. photosynthesis

6.1.1. energy fixation

6.1.2. autotrophic oorganisms phototrophic organisms light to chemical energy chemotrophic use energy from breakdown of inorganic molecules make complex organic molecules involved in nitrogen cycle

6.1.3. plants autotrophs store extra material respires

6.2. respiration

6.2.1. heterotrophs cannot synthesis energy rich molecules consume ready made molecules

6.3. productivity

6.3.1. primary productivity the amount of light energy converted into chemical energy during a given period of time by autotrophs

6.3.2. total primary productivity = Gross primary productivity (GPP)

6.3.3. net primary production energy availiable in food web availiable to primary consumers (GPP) - energy used in plant respiration (R)= (NNP)

6.3.4. measured in biomass dry wieght of vegetation ( g/m2/year) effected by temperature light intensity CO2 nutrients water limiting nutrients

6.4. Energy flow

6.4.1. producers

6.4.2. Consumers (heterotrophs) NPP availiable herbivore primary consumer carnivore secondry / tertiary consumer predators carrion feeders parasitic

6.4.3. decomposers bacteria and funghi convert orginc wate into inorganic compounds essential

6.4.4. food chains arrows show direction of energy flow 10% passed onto each new levels trophic levels ecological efficiancy ratio of (NPP of one level) / (NPP of level below)

6.4.5. Pyramids of numbers typrical shape inverted biomass total mass of organisms at ecach level typical shape aquatic ecosystems productivity typical shape best

7. Biotic Interactions

7.1. Biotic

7.1.1. interactions between organisms and living factors predation desease food supply competition

7.2. Abiotic

7.2.1. between organisms and non living factors temperature light intensity soil pH water availiablity

7.3. Density

7.3.1. Dependant regulate population growth effects increase in proprtion to population size ie. predation, food supply and disease

7.3.2. Independant may regulate population growth effects independant of population size effect large and small populations equally

7.4. interactions

7.4.1. interspecific individuals of a different species

7.4.2. intraspecific individuals of the same species

7.5. Predator/ prey

7.5.1. population growth curves

7.5.2. predators lag behind prey/ slightly out of phase predators control numbers of dominant most competetive prey species, allowing less strong populations to increase ie. grazers grazers any species which eats part of an organism without killing it moderate grazing increases biodiversity prey have adapted sos not be eaten camouflage warning colouration mimicry

7.5.3. interactions are cyclical recurring in cycles

7.5.4. regulated by other predators availiability of food for prey disease parasitism

7.6. competition

7.6.1. interferance when two organisms fight over a resource

7.6.2. Exploitation two or more species use the same resurce

7.6.3. exotic species are not native, ie. been introduced may compete more succsefully than native species may change the habitat itself, making it unsuitable for native species ie. rhodedahdron

7.6.4. weak competitors potential for growth if ecosystem changes

7.7. niche

7.7.1. fundamental total resources a species can make use of without competition

7.7.2. realised actual resources a species makes use of with competition in mind

8. interactions -costs, benefits

8.1. positive

8.1.1. beneifits species symbiosis is a relationship in which at least one species will benefit

8.2. negative

8.2.1. harms species competition is a negative interaction for both species, neither will benifit

8.3. neutral

8.3.1. no effect on species

8.4. the nature of an interaction may change

8.4.1. parasitism positive environemntal factors will increase hosts health negative environmental factors will damage hosts health, favouring the parasite

8.5. managing environmental factors

8.5.1. by use of drugs pesticides

8.5.2. improves health and host environemnt

8.5.3. herbicides used to manage plant competition

8.6. organisms have evolved to cope with environmental changes

8.6.1. tolerance/ compensation mechanisms

8.6.2. behavioural and physiological responces

9. Effects of intensive food production

9.1. increase in population has led to increased food production

9.2. traditional farming cannot meet demands

9.3. monoculture

9.3.1. growth of one species

9.3.2. advantages high yeilds large profits

9.3.3. disadvantages effect on soil condition nutrients used by plan population are depleated plant debris not alowed to decompose in soil destruction of habitats hedgerows removed devestating effect on species diversity large field size breeding ground for pests lack of natural predators crops compete against weeds- encourgaing use of herbicides/ fungicides