B9 Flashcards
Different levels of organisation :
-individuals
-populations
-communities
-ecosystem
-single organism
-all organisms of one species in a habitat
-all organisms of different species living in a habitat
-community of organisms along with all non-living(abiotic) conditions.
Effects on communities from abiotic factors
temp-Bee-eater european(medditeranaean) bird in germany becasue of high temps.
Water amount-daisies grow in damp soil so change from conditions will decrease amount.
Light intensity-as trees gro and provide more shade grasses may be replaced by fungi which can grow in lower light.
Pollutant levels-lichen cannot survive if levels of sulfur dioxide are too high.
Same for biotic factors
Competition-organisms and members of own species compete for same resources meaning not enough for onw so die(squirrels)
Predation-Nummber of predator decreases prey may increase as fewer being eaten.
Importance of interdependency in a community
two organisms depend on each other for food and shelter inorder to survive and reproduce(interdependence). Means change in pop fore one species can have a huge knock on effect for other species in same community. Mutualism-both organisms are benefitted(flowering plants and bees). Parasites live closley to host species but only parasite benefits(fleas on mammals). Take what need to live but mammals dont.
Core practical:relationships between organisms and environments
1)Place 1 m^2 quadrat on ground at random point in 1st sample area.(divide and randomly generate coordinates).
2)Count all organism in said quadrat.
3)repeat steps lots of times.
4)Work out mean teh repaet with 2nd smaple area and comoare.
or
1)Mark out line in area want to study using a transect belt(is a tranbsect belt with all quadrats on)
2)collect data along line using quadrats placed next to each other
3)Collect by counting all organisms in interested species or by estimating percentage cover.
4)Could record other data(mean height of plants, abitoc factor)
5)Repeat 1 and 2 several times then find mean noumber of organisms for each quadrat.
6)Plot graph to see if chnaging abiotic factor is correlated with a chnage in the distributiin of the species.
For size of pop
1)use quadrat to find mean number of organism per m^2.
2)multiply mean by total area you have.
Trophic level processes
-sun source of enegy for nearly all life
-plants use small amount of light energy for ps but use some for glucose in resp and store rest as biomass.
-Primary consumer(eg rabbit) then eats the plant and uses some energy and rest stored as biomass.
-Secondary consumer(fox) eats rabbit and gets some if its energy in biomass.(simple food chain)
Energy is used by organusms in each stage to stay alove and lots of energy transferred to surroundings by heat.
-This nergy not stored so not transferred to next trophic level(lost to food chain)
-Energy stoired as biomass does not all get transferred to next trophic levelk either cos some dont get etaten so undigested lost in faeces.
-Hardky ever 5+ trophic levels in food chain because not enough energy to keep going.(tend to get fewer organisms at each trophuc level)
so less energy at each level cos useless transfer so nit as many organiusms can live iff it meaning decreases and then limits length if food chain because energy decreases.SAlso means pyramid of biomass gets smaller as goes up as biomass decreases cos less energy.
Biomass means
the weight of creatures all put togetyher at each level in the food chain.
efficinecy
energy transferreed to next level/energy available at previous level x 100
Fish framing impacts
neg-huge amounts of food wasted, and waste produced leak into open water and cause eutrophication and death of wild species, can act as breeding ground for parasites can infect wild animals(maybe kill them), predators attracted to nets and can be trapped and killed, farmed fish can escape into wild and cause problems for indeginouse species.
pos-can be farmed in large tanks which gets rid if these problems.
Introduction of non-indigenous species impacts
Compete with the indigenous species for resources and sometimes are better which means the indigenous spoeciues will decrease and eventually die out-reducing bio-diversity.
sometimes bring new diseases to habitat. Often infect and kill lots of indigenous species, reducing biuodiversity.
Eutrophication impacts
1)Fewrtilisers enter water
2)excess nitrates cause algae to grow fast and block out light
3)plants cant ps and die and then decompose
4)with mire food available, microrganisms feed oin decomposing plants and increase in number and then use upo O2 in water.
5)organisms that need O2 for resp die(fish).
Increasing biodiversity
reforestation-increase amount of types of plants and trees and animals as habitat is rebuilt so more can live there.
conservation if at risk species-protect habitat, zoos, captive breeding programmes to increase numbers, seed banks for rare and endangered plants.
Help to maintain the earths narural processes with a varied ecosystem or else will not be as effective and less O2, energy, food, more gases.
Benefits of maintaining biodiversity
-protecting human food supple
-ensuring minimal damage to food chains(one extinct species will affect the whole chain)
-Providing future medicines
-Cultural aspects
-Ecotourism
-providing new jobs
Biological factors infecting levels of food security
increasing human pop-more people to provide for means more food than is already produced needs to be
incressing animal farming and increased meat and fish consumption-wealthier=wider variety of food. less energy and biomass as you move up in food chain so for area of land can produce lots more food with croos compared to grazing animals and often crops that would be human food are fed to farmed animals and over-fishing is a problem for future.
New pests and pathogens- can damage crops and livestocks. When new ones emerge, have negative impacts on crop yields as wont be able to survive/.resistant against diseases.
environmental change caused bvy human activity- burning fossil fuels cause global warming. Means climate change which affects growth of crops and could reduce yeilds. Soil pollution can also reduce crop growth.
Sustainibility issues-biofuel crops take up land that could be used for food crops. Need to balance neded for food and sutainable energy niw and in future. high input costs of farming may make it too expensive in some areas for farmers to cintinue farming and maintain food productrion in future.(price of fertilisers, machinery, fuel).
