Biosphere 3 Flashcards
What is genetic diversity?
variation in individual genetics within and between populations
What is ecosystem diversity?
variety of ecosystems within the biosphere
What is taxonomic (species) diversity?
variety of taxa in a given area
What is functional diversity?
variety of ‘functions’ performed by the taxa in a given area
Translation:
variety of modes of life/variety of different
things the taxa ‘do
What are the 3 broad areas of diversity?
Species
Habitat
Genetic
How can species diversity be split?
Richness
Evenness
Dominance
What are the difficulties in measuring species richness?
Taxonomic level?
Sampling procedure
What is the effort vs reward with sampling procedures?
will be a point where effort of finding new species not ‘worth it’ but rare species are hard to find
What can influence terrestrial biomes?
Temperature
Precipitation
Atmospheric circulation
Topography
Latitude
Over time change (Milankovitch, long term climate change, evolution and continental drift)
What are marine biomes influenced by?
Depth
Distance from shore
Light levels
What is the photic and aphotic zone in water/ oceans?
Photic- ~100m, light penetration
Aphotic- ~400m, no light penetration
What are plankton, nekton and benthos?
Plankton- float in water column
Nekton- mobile species
Benthos- live on sea floor
What is pelagic and benthic?
pelagic in water column
Benthic on sea floor
What is a population?
group of individuals of the same species,
which interbreed and share genetic information
How can populations be distributed?
geographically clustered
Living in close proximity
How can species population change?
birth
death
survival
What are intrinsic factors?
factors within the population itself that affect size
What are some examples of intrinsic factors?
reproduction rate
need for food, light, space,
What are extrinsic factors?
factors external to the species
What are some examples of extrinsic factors?
Climate change
forest fire
predation
What is intraspecific competition?
between individuals of the same species
What is interspecific competition?
competition
predation
parasitism
mutualism
How is growth rate expressed?
as a ratio
r=N/N0
What do the letters in the growth rate ratio mean?
r= growth rate
N= population at the end of time period
N0= population at start of time period
What are the 2 theoretical types of population growth?
Exponential
Logistic
What is exponential population growth like?
small start population with lots of resources (space and food)
Population growth exponential (accelerating)
When is exponential population growth possible?
for short periods under specific conditions
What is logarithmic population growth like?
More individuals able available to reproduce, with resources/space are abundant and population growth is rapid however this diminishes resources, decreased reproduction and increased death rate
What happens to population when habitat carrying capacity is met?
birth and death rate stabilise creating static population
What is the most common population growth pattern?
Boom and bust cycles
What are some examples of boom and bust cycles with populations?
Climate rhythms
‘Events’
Intraspecies dependence
What are some examples of interspecies relationships?
Competition
Exploitation
Mutualism
Keystone species
What are some examples of exploitation as a interspecies relationship?
Predation
Parasitism
What are the 2 types of mutualism?
symbiosis - mutual benefit
Commensalism - unidirectional benefit
What do keystone have an impact on?
disproportionate impact on ecosystem function
What ways can a species be keystone?
Keystone predator - pop control (wolves Yellowstone -deer’s)
Ecosystem engineers- elephants paths and water holes
What is the difference between niche and habitat?
species can share a habitat
Niche is species specific
What are generalists?
Wide range of tolerances; large, broadly defined niches
What are specialists?
Narrow range of tolerances; smaller, more narrowly defined niches
What is the competitive exclusion principle?
2 species cannot occupy the same niche so one will be outcompeted and made extinct completely or just om area
What allows direct competition of niches to not occur as readily in environments?
Niche differentiation/ resources partitioning
What can allow species to occupy the same ecological role?
is they have a slightly different niche
What spatial/ temporal niche differentiation can allow the same ecological role to be occupied?
nocturnal or diurnal
Upper canopy and lower canopy
What is the Gaia hypothesis?
Life itself on planet is responsible for homeostasis
What does daisyworld show?
how temperature regulation can arise from organisms interacting with their environment
What is daisyworld like with plant life?(environmental regulation)
Black daises absorb light warming (25% albedo)
White daises reflect light cooling (75% albedo)
Barren land (50% albedo)
What are biogeophysical feedbacks?
arise because climate also affects the physical properties of ecosystems,
including the surface albedo
what is an example of a biogeophysical cycle?
Evergreen boreal forest
Absorb solar radiation even in winter
As poleward forest extent increase with warming lead to positive feedback
What do biogeochemical cycle arise fro?
climate affects the biologically mediated exchanges of GHGs and aerosols between ecosystems and the atmosphere
How does warming generally affect biological processes?
increase in them
What do plants mediate between land and atmosphere?
Plants mediate the exchange of water between land and atmosphere
How do photosynthetic organisms link the atmosphere and biosphere?
change colour and albedo of earths surface
How does vegetation structure link the atmosphere and biosphere?
Structure on land affects roughness chnaging flow of wind weather and climate
What are the 3 links between biosphere and lithosphere systems for ecological regulation?
Plant cover reduces dust production,
Plants roots increase physical weathering.
Plants increase evaporation and therefore decrease runoff. Roots stabilize soil, reducing rates of erosion
What is the link between the biosphere and hydrosphere for ecological regulation?
Influences the flux of particulate matter and solutes from the land to the oceans via streams and rivers.
Growth of marine organisms and sinking of OM affects surface ocean chemistry, gas transfer between ocean and atmosphere, deep ocean chemistry, transfer to marine sediments
What is the interaction between earth biosphere systems and the cryosphere?
Microbes in ice affect albedo, increasing melting
