Environmental Biology by Mind Map: Environmental Biology
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Environmental Biology

Pollution

negative effect of harmful substances in the environment

water

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

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

concentration of pollutant increases along the food chain

known as biomagnification

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

susceptible species

con not tolerate changes in the environemnt

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

favoured species

can tolerate a wide range of conditions

invasive exotic species can be considered pollution

Energy fixation and flow

photosynthesis

energy fixation

autotrophic oorganisms, phototrophic organisms, light to chemical energy, chemotrophic, use energy from breakdown of inorganic molecules, A chemical compound that does not contain carbon., make complex organic molecules, involved in nitrogen cycle, nitrosomonas, nitrobacter

plants, autotrophs, store extra material, availiable to heterotrophs, basis of productivity, respires

respiration

heterotrophs, cannot synthesis energy rich molecules, consume ready made molecules

productivity

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

total primary productivity =, Gross primary productivity (GPP)

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

measured in biomass, dry wieght of vegetation ( g/m2/year), effected by, temperature, light intensity, CO2, nutrients, water, limiting nutrients, inorganic molecules essential for growth, phosphorus, nitrogen

Energy flow

producers

Consumers (heterotrophs), NPP availiable, herbivore, primary consumer, carnivore, secondry / tertiary consumer, predators, highly sussepatable to extinction due to small population and iwde spacing, carrion feeders, parasitic

decomposers, bacteria and funghi, convert orginc wate into inorganic compounds, essential, circulate nutrients

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)

Pyramids of, numbers, typrical shape, inverted, tree, insects, biomass, total mass of organisms at ecach level, typical shape, aquatic ecosystems, marine planktonic food chain, inverted pyramid, growth of primary producers is rapid, phytoplankton, producers eaten rapidly, outwieghed by zooplankton, productivity, typical shape, best, most reliable

Circulation of nutrients

soil

structure, pores inbetween particles, provide water and air for plants, inorganic components from rock, sandy, large partcile size, draage and loose nutrients by leaching, clay, poor drainage, retain water and nutrients, loams, sand and clay, best for plant growth

fauna, fungi, penicillium, decompose large plant molecules, nurtrient cycling, bacteria, NItrobacter, most abundant, imporant, nutrient cyles, nitrogen fixation, invertebrates, earth worms, woodlice, spiders, nematodes

rhizosphere, plant roots and soil contact, many micro-organisms here

detritivores and decomposers

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

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

Decomposition

undecomposed matter, litter

completely decomposed matter, humus

mineralisation, nutrients from dead organisms released

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

cycles

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

NItrogen, fixation, atmospheric nitrogen to ammonia, Cyanobacteria fix nitrogen, free living soil bacteria, Rhizobium, fix N in the root nodules of plants, NItrogenase, enzyme complex that catalases atmospheric nitrogen into ammonia, leghaemoglobin (made by plant and bacteria) limits O2 reaching bacteria, nitrogen fixation is an anaerobic process, nitrification, ammonium to nitrite to nitrates, Nitrosomonas, Nitrobacter, nitrates assimiliated by plants for protiens and amino acids., they are lost by leaching and denitrifying bacteria, dentrification, returns nitrogen to the atmosphere, ammonification, decomposition, organic nirtrogen to ammonia, effected by water saturation

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

Biotic Interactions

Biotic

interactions between organisms and living factors, predation, desease, food supply, competition

Abiotic

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

Density

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

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

interactions

interspecific, individuals of a different species

intraspecific, individuals of the same species

Predator/ prey

population growth curves

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, Batasian mimicry, edible or harmless species mimics a poisonousor harmful species, Mullerian mimicry, two or more inedible creatures evolve to have the same markings

interactions are cyclical, recurring in cycles

regulated by, other predators, availiability of food for prey, disease, parasitism

competition

interferance, when two organisms fight over a resource

Exploitation, two or more species use the same resurce

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

weak competitors, potential for growth if ecosystem changes

niche

fundamental, total resources a species can make use of without competition

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

Symbiotic interactions

interaction between any species living together

parasitism

one organism benifits while the other is harmed

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

relastionship may evolve to be highly specific

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

commensalism

one organism benifits, the other is unharmed

usually based on feeding

difficult to observe in nature

ie. clown fish in the tentacles of an anenome

Mutalism

both organisms benefit

both organisms share metabolites and are structirally compatible

ie. lichen - an interaction between fungus and alga

interactions -costs, benefits

positive

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

negative

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

neutral

no effect on species

the nature of an interaction may change

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

managing environmental factors

by use of, drugs, pesticides

improves health and host environemnt

herbicides used to manage plant competition

organisms have evolved to cope with environmental changes

tolerance/ compensation mechanisms

behavioural and physiological responces

Succession

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

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

system moves from

unstable community --> relatively stable community

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

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

example

grass colonise area

humus builds up

support and nutrients increased

ideal conditions for tree saplings developed

trees grow, blocking light

grass out competed

autogenic

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

allogenic

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

Examples include hurricanes, forest fires and climate changes.

primary

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

takes longer than secondary, due to lack of soil

secondary

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

pioneer species (first to colonise area)

lichens which colonise bare rock

annuals who seeds are blown into a cleared field

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

fast growing, high rate of reproduction

Climax community

mature

stable

no further succsesion takes place

Degradative

changes assosiated with stages of decomposition

when organisms die and decompose, certain species appear

also known as heterotrophic succession

Effects of intensive food production

increase in population has led to increased food production

traditional farming cannot meet demands

monoculture

growth of one species

advantages, high yeilds, large profits

disadvantages, effect on soil condition, nutrients used by plan population are depleated, fertilisers used, chemical/ inorganic, worse for environment, more expensive, better at promoting plant growth, orgainic, 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, ebcouraging use of pesticides, kills non target species, promotes secondry pest outbreaks, deveolopes pest resistenace, crops compete against weeds- encourgaing use of herbicides/ fungicides

Increase in energy needs

increase in human population has led to increase in energy demand

finite fossil fuel supplies are running out

must be conserved

alternatives must be found, nuclear, solar, wind, hydroelectric, wave, geothermal, biofuels

increase in fuel use has led to global warming

green house effect

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

the problem gasses, carbon dioxide, water, methane, nitrous oxide, CFCs

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.

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