Chapter 3 ! Flashcards
Explain the process of evolution
Adaption to the environment
- New characteristics are produced through random mutations
- Then, natural selection takes place leading to individuals with better characteristics having an increased chance of survival
what is a range of tolerence ?
Adaption to the environment
the range of a condition/ factor that an organism can survive within
what does a large gene pool do for advantagous traits ?
Adaption to the environment
- Large gene pool → increases chance of surviving environmental changes
- The survivors will pass on their advantageous traits to offspring and rebuild the population
what are 4 abiotic factors that determine survival & distribution of species ?
Adaption to the environment
- light
- pH
- water
- nutrients and minerals
what happens when these abiotic factors become less suitable ?
Adaption to the environment
when less species are within thier range of tolerences then survival will decline
what are 5 biotic factors that affect survival & distribution of species ?
Adaption to the environment
- Food supply
- Pollination
- Seed dispersal
- Disease
- Presence/ absence of other species
Ecological succession
Ecological Succession
The process where the community in an area to become to climax community.
what is a pioneer species ?
Ecological Succession
They are species that colonise a new area, they’re adapted to extreme conditions that become less extreme once the habitat has a higher biomass
what is the process that means that pioneer species eventually die out ?
Ecological Succession
Over time they will change the habitat → becomes suitable for more organisms → may outcompete pioneer species → they die out
what is a climax community ?
Ecological Succession
Final community of species that remains dominant as long as the climate doesn’t change
what type of habitat can ecological succession be best seen and a good example ?
Ecological Succession
- newly created habitats with no current life
e.g. new pond, bare rock exposed by a retreating ice sheet
What is a sere ?
Seres
the sequence of stages in ecological succession during which an uncolonised habitat develops into the climax community
hydro = hydrotherapy = water
what is the process of the hydrosere going from open water to terrestrial habitat ?
Sere
- Open water
- Floating Plants rooted in water
- Emergent Plants on surface
- Reed Swamp
- Sedge Meadow
- Woodland
- Climax Forest
hydro = hydrotherapy = water
What is the definition of hydrosere ?
Sere
The developmental stages in a plant succession which commences on a soil submerged by fresh water
How does more plants lead to more animals arriving ?
Sere
More plants → more food & shelter → more animals arrive
how does plants dying lead to lakes filling with organic matter ?
Sere
Plants dying → lake gradually fills with organic matter, it will also fill with soil & sediments from the surrounding area
what is the definition of lithosere ?
Sere
development of a community of a species on a bare rock
what is the process of the lithosere going from bare rock to the climax forest ?
Sere
- Bare Rock (pioneer)
- Lichens and Mosses
- Herbaceous Plants
- Shrubs and Small Trees
- Mature Woodland
- Climax Forest
What is the definition of psammosere
Sere
The characteristic plant succession that develops on a new sand dune ecosystem and achieve
What is the process of the Psammosere going from bare sand to forested dunes ?
Sere
- Bare Sand
- Pioneer Plants
- Herbaceous Plants (beach vegetation)
- Shrub Zone
- Forested Dunes
- Climax Community
what is a plagioclimax community ?
Conservation of plagioclimax communities
These are communities that stay at their specific type of ecosystem due to human influence for our benefit E.G - farming
when are plagioclimax communitues produced and give an example ?
Conservation of plagioclimax communities
They are produced by long term balances between human activity and succession
e.g. grassland
what is a management method of lowland heathland ?
Conservation of plagioclimax communities
- grazing
- burning
what is a management method of hay meadow ?
Conservation of plagioclimax communities
Mowing
what is a management method of arable field ?
Conservation of plagioclimax communities
ploughing
what is secondary succession ?
Conservation of plagioclimax communities
human activity disturbing the climax community, recreates conditions that are suitable for the species who colonised the area earlier on, so they are able to recolonise → climax community is recreated
what happens to diversity in an extreme environment dominated by abiotic factors ?
Species diversity and ecological stability
low
what does the Simpson’s diversity index formula
help us find ?
Species diversity and ecological stability
a way of quantifying level of biodiversity and measuring it
how can large trees cause smaller plants to grow ?
Sere
Large trees → dense canopy → shade → smaller plants grow
what do each symbol in the Simpsons diversity index formula mean ? (N, n, Σ, D)
Species diversity and ecological stability
N = Total number of organisms
n = total number of organsisms of indevidual species
Σ = total
D = Higher the value of D = higher the diversity
what is the Simpson’s diversity index formula ?
Species diversity and ecological stability
D = N(N-1) / Σn(n-1)
what is the rate of discovery of new species per year ?
Simpson’s diversity index formula
20,000
what are Population dynamics ?
Population dynamics and population regulation
processes that cause populations to change in size & structure
what does max birth rate mean ?
max birth rate is determined by the species ability to reproduce, species with lower chance of survival → higher birth rates
r –> rapid
what is an r-selected species ?
Population dynamics and population regulation
species that respond rapidly to to low survival rates (reach sexual maturity at a young age)
k = dead or slow reply
what is a k-selected species
Population dynamics and population regulation
Species that reply slowly to a decline in population = reach sexual maturity at older age
what are the factors determining population regulation ?
Population dynamics and population regulation
- birth rate
- death rate
- R-selected species
- K selected species
what is the maximum sustainable yield ?
Population dynamics and population regulation
an estimate of the greatest exploitation possible without causing unsustainable long- term population decline
what are 3 things needed to forecast popualtion change ?
Population dynamics and population regulation
- current population
- birth and death rate
- Number of individuals immigrating and emigrating
what are factors affecting mortality rates ?
Population dynamics and population regulation
- density independant factors (drought, flood etc)
- density dependant factors (disease or food supply)
what is a Density independent factor ?
Population dynamics and population regulation
Population density has no effect on chance of survival
Eg volcanic eruption
what are factors that affect mortality rates ?
Species diversity and ecological stability
Density independant factors :
- drought
- flood
Density dependant factors :
- food supply
- disease
what is a density dependant factor ?
Population dynamics and population regulation
Chance of survival will depend on population density of the species
Eg food supply
what is carrying capactiy ?
Population dynamics and population regulation
Greatest population an area can support without damaging or over exploiting the environment
predator-prey population relationships
Population dynamics and population regulation
When prey increases then its more food for the predators then the prey decreases so predators decrease = predator-prey relationships have the same shape and flow
when will artificial population control be necessary ?
Population dynamics and population regulation
- breeding rate is low (so captive breeding / release programme is needed)
- non-indigenous species is introduced to remove indigenous species because it is either a predator / competitor / pathogen
- indigenous predator has been removed so its prey has been overpopulated and needs to be culled
whats a taxonomy ?
Ecological terminology
scientific grouping of organisms due to similar features
whats a species ?
Ecological terminology
a group of closely related organisms that resemble each other more than other groups
what are 3 reasons why most species can’t produce fertile offspring with others ?
Ecological terminology
- Behavioural differences
- Anatomical differences → mating= impossible
- Difference in number/ shape of chromosomes makes fertilisation impossible
What is the process of naming species ?
Ecological terminology
- First part of species name= the genus (group of most closely related species
- Second part of species name= added to identify individual species within the genus
Latin names are given to avoid confusion between different languages
What is evolution ?
Ecological terminology
Is the process thta chnages the gene pool of a species
What is a habitat ?
Ecological terminology
Area or location where species or community of species live
what is an Ecological niche ?
Ecological terminology
It is the the role that a species plays in its habitat
what is a population ?
Ecological terminology
Includes all the indeviduals of a single specoes that live in a particular area
what is an ecosystem?
Ecological terminology
Combination of the biotic and abiotic features of an area
what is a biome ?
Ecological terminology
Large geographical regions with specific climatic conditions within which a characteristic community of species lives
what are differences between ecosystems and biomes ?
Ecological terminology
- Biomes are much larger geographical areas
- Each isolated area in a biome is a different ecosystem - eg separate coral reefs
- All coral reef ecosystems= belong to the coral reef biome
what are biospheres ?
Ecological terminology
all of planet earth that is inhabited by living organisms
