Species richness
-Number of different species living in a habitat.
-Interspecific variation between species.
-Intraspecific variation within species.
Species evenness
-A comparison of the number of individuals of each species living in a community.
Capture Recapture (Method)
-Capture a number of a species in a defined period of time.
-Mark then unobtrusively.
-Release them into the population.
-After a set period of time capture the same species over the same time as the first.
-Count how many are marked compared to not marked.
Pop size = Number in 1st x Number in 2nd/Number marked in 2nd.
Capture/Recapture limitations
-Assumes no death, births or migration.
-Marking may affect survival rate of animals.
-In methods such as the Longworth (tunnel) trap, the animals may realise the trap is harmless and use it as a source of food.
Random Sampling (method)
-Mark out a grid at right angles.
-Pick x and y co-ordinates with a random number generator.
-Take a sample from that location.
Random sampling (Advantages and disadvantages)
-Data not biased by selective sampling.
-Each individual has an equal chance of being picked.
-May not cover all areas equally.
-Species with low presence may be missed, leading to an underestimate of biodiversity.
Systematic sampling (methods)
-Samples taken at fixed intervals across the habitat.
-Can be done along a transect line, and then quadrats placed.
Systematic sampling (Advantages and disadvantages)
-Useful in clear gradient of environmental factors (eg coastline)
-Only species on the transect are recorded, leading to an underestimate.
Stratified sampling (method)
-Divide habitat into areas of difference (eg grassland, forest, bare ground) and sample each section equally.
Stratified sampling (Advantages and disadvantages)
-All areas of habitat are sampled.
-Could have a disproportionate portion of samples taken in smaller areas.
Opportunistic sampling (method)
-Samples are taken based on prior knowledge of the area and the species inside it.
Opportunistic sampling (Advantages and disadvantages)
-Easier and faster.
-Data may be biased.
-Overestimate the biodiversity, and importance of interesting species.
Simpson’s Index of Diversity
-A way to measure species diversity that takes into account species richness and evenness.
-Value closer to 1 equals a more diverse area.
-1-(sum of (n/N)^2).
Genetic diversity
-The biological variation of alleles that occurs within species.
-When there is more than one allele at loci, leading to differing phenotypes.
-Makes it possible for species to adapt to environmental changes.
Calculating genetic diversity
Proportion of heterozygous (differing) gene loci = no of heterozygous gene loci/total no of loci.
-Loci with more than two alleles are known as polymorphic gene loci.
Reasons for loss of biodiversity
-Deforestation/habitat destruction.
-Agriculture due to pesticides.
-Monocultures of one strain of a species eg palm oil.
-Selective breeding leading to genetic erosion.
-Climate change.
-Demand from human population growth.
Conservation methods
-In Situ: marine zones and wildlife reserves.
-Preserve natural environment, as well protecting heritage and culture within it, and allowing for scientific research on a natural area.
-Areas may not be large enough to conserve species, or already too damaged to recover. Can also attract poachers.
-Ex Situ: seed banks, botanic gardens and zoos.
-Organisms protected from predation and habitat destruction, can be easily monitored, and bred to increase numbers.
-Limited genetic diversity, lose natural instincts and diet, and likely unable to successfully reintegrate into the environment.
Millennium Seed Bank
-Norway, at low temperatures that preserve seed life.
-1 billion seeds.
-34,000 species.
-Provides a back up in case of extinction.
Convention on International Trade in Endangered Species (CITES)
-1973.
-Limit trade in select endangered species through licensing.
-Ensure trade does not endanger wild populations, encourages artificially propagated plant trade, with permits.
-Raise awareness of threats to biodiversity.
Rio Convention on Biological Diversity
-1992, by 150 leaders.
-Develop international strategies for conservation.
-Using plant and animal products sustainably.
-Make conservation international law, and knowledge and technologies are required to be shared.
-Shared access to genetic resources.
-Provide guidance to governments on conservation.
Environmental Stewardship Scheme
-In Britain, 2005, replaces 1991 countryside SS.
-Promotes sustainable land management methods.
-Gives grant to landowners who uphold policies.
-Improve and extend habitats, and improving opportunities for public access to the countryside.
-Uphold traditional character and features of land.
Taxonomic levels
-Domain
-Kingdom
-Phylum (body plan eg backbone)
-Class (general traits eg no of legs)
-Order (nature of organism eg diet)
-Family
-Genus (closely related)
-Species
-Binomial system takes genus and species, devised by Carl Linnaeus.
3 domains
-Archaea
-Eubacteria
-Eukaryote
5 kingdoms
-Plantae
-Animalia
-Fungi
-Protoctista
-Prokaryotae
-Used to be only animals and plants, with single celled organisms exhibiting some traits of a kingdom being added.
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Cell Structure55
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Plant Transport51
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Animal transport64
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Biological Molecules58
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Cell Division and Specialisation33
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Exchange surfaces34
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Enzymes30
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Disease57
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Biodiversity and Evolution63
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Microscopes6
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Cellular Control47
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Respiration and Photosynthesis79
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Hormones and homeostatis63
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Patterns of Inheritance63
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Plant hormones12
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Ecosystems33
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Biotechnology17
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Molecule tests10
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Excretion63
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Nerves and Muscles102
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idk63
