IB biology: option C (II)

what do food chains show?

the linear feeding relationships between species in a community

what does a food web show?

how food chains are linked together into more complex interrrelated feeding relationships 

what is biomass?

the total dry weight of organic matter in organisms or ecosystems

what is the % of energy converted into biomass dependent on?

energy is lost as inedible materials (e.g bones),

energy is lost via excretion of undigested materials,

energy is lost as heat from cellular respiration

what is primary production?

the production of chemical energy in organic compounds by producers

what are the two types of primary production?

gross primary production (GPP) and net primary production (NPP)

what is gross primary/secondary production (GPP/GSP)?

the amount of chemical energy as biomass that a producer creates in a given length of time

what is net primary/secondary production (NPP/NSP)?

the amount of chemical energy that is not consumed by respiration (NPP/NSP = GPP – respiration)

what is secondary production?

the generation of biomass by heterotrophic organisms (consumers)

what are the two types of secondary production?

gross secondary production (GSP) and net secondary production (NSP)

what do feed conversion ratios measure?

the efficiency of an animal in converting the food provided into a desired output

what is the feed conversion ratio?

feed conversion ratio (FCR) = mass of feed / mass of desired output

the lower the feed conversion ratio…

the more efficient the method of food production

how can we minimise potential energy losses in livestock / create a low feed conversion ratio?

restricting animal movement, optimising feeding practises, slaughtering animals at a young age

what are different types of ecosystems?

open ecosystems and closed ecosystems

what is an open ecosystem?

an ecosystem in which energy and matter are exchanged with surrounding environments (e.g natural ecosystem)

what is a closed ecosystem?

an ecosystem in which energy but NOT MATTER is exchanged with its surroundings (e.g a mesocosm)

what is an ecosystem?

the interaction of living and non-living thins within an area (e.g a community and its abiotic environment)

what is a biome?

a geographical area that has a particular climate and sustains a specific community of plants and animals

what are examples of biomes? (3)

tropical rainforests,

taiga,

deserts

what are conditions like in tropical rainforests?

hot and humid environments near the equator with dense vegetation and high biodiversity

what are conditions like in taiga biomes?

coniferous forests near the poles that have cold temperatures and little precipitation (moisture trapped as snow / ice)

what are conditions like in deserts?

dry and arid environments that display extreme temperature conditions (hot and cold)

what is a climograph?

a graphical representation of monthly average temperature and precipitation at a given geographical location

what do pyramids of energy show?

the flow of energy between trophic levels and are measured in units of energy per area per time

what are the units for a pyramid of energy?

kJ m^-2 y^-1

how much energy is lost between each trophic level in a pyramid of energy?

90%

what are Gersmehl diagrams?

diagrams showing relationship between biomass, litter and soil in an ecosystem

Gersmehl Diagrams: tropical rainforest

main store is biomass,

fast transfer

Gersmehl Diagrams: taiga

main store is litter,

slow transfer

Gersmehl Diagrams: desert

main transfer is soil

slow transfer

what is ecological succession?

the process by which a sequence of increasingly complex communities develop over time

what is a climax community?

the community reached when succession has ended and the community has all of its characteristics

what is primary succession?

when communities develop on entirely new land without any established soil

what are pioneer species? typical examples?

the organisms which first colonise the region, typically lichen or moss

as more plants colonise an area…

soil depth will increase,

soil mineral content will increase,

soil will become aerated and water retention is increased

are disturbances to environment natural or artificial?

both, either natural and artificial

what is secondary succession?

when succession starts on existing soil following the upheaval of a pre-existing ecosystem

what can give rise to secondary succession?

disturbances to the environment

what are examples of causes of secondary succession? (5)

forest fire,

earthquake,

flooding,

dams,

human settlements

what is deforestation?

the permanent destruction of a forest via the removal or clearance of trees

what are consequences of deforestation? (4)

less litter,

rapid loss of nutrients from leaching,

soil will become acidic,

prevention vegetative growth

how can we measure the effect of an environmental disturbance on an ecosystem? (4)

population density,

species diversity and richness,

biomass,

indicator species