Biodiversity

• What is biodiversity?

  The variety of life forms, including plants, animals, and microorganisms, in a particular ecosystem.
• How do we measure biodiversity?

  Habitat biodiversity, species biodiversity, and genetic biodiversity.
• What areas have the most biodiversity?

  Tropical, moist regions, while extremely cold or hot regions have less.
• What is a temperate climate?

  A moderate climate characterized by mild temperatures and distinct seasons, such as the UK, which has a moderate amount of biodiversity.
• Why is measuring biodiversity important?

  Conservation, as it informs scientists with a baseline of biodiversity from which they can measure the effect of any environmental changes, whether it be human activity, disease or climate change.
• What is habitat biodiversity?

  The number of habitats in an area, each supporting a variation of species; in general the greater the habitat diversity, the greater the species diversity.
• How does the UK have large habitat diversity?

  It has great habitat variety, such as woodlands, meadows, streams, and sand dunes; while places such as Antarctica have low biodiversity, due to being mainly ice.
• What is species diversity?

  Species diversity refers to the variety and abundance of different species within a specific habitat, and is split into two categories, species richness and species evenness.
• What is species richness?

  The number of different species present in a given habitat.
• What is species evenness?

  A comparison of the numbers of individuals of each species living in all the populations of living organisms within a habitat.
• What is genetic biodiversity?

  The variety of alleles of genes that make up a species, coding for a variation of characters.
• What is a benefit of greater genetic diversity?

  Increased adaptation to a changing environment, including resilience to diseases.
• What is an ecosystem?

  A community of living organisms and their interactions with each other and their physical environment.
• What is a community?

  All of the populations of living organisms in a habitat.
• What is sampling?


  The process of selecting a subset of individuals from a larger population in order to gather information or make inferences about the entire population, whether than be distribution or characteristics.
• What can sampling provide us with?

  An estimate for the abundance of individuals of a species within a habitat, and an estimate for the characteristics of a species.
• What is random sampling?

  This involves selecting individuals by chance, with each individuals in the population having an equal likelihood of selection.
• What can be used to obtain a random sample?

  Random number generators or computers.
• What is non random sampling?

  A method of selecting participants for a study that does not involve random selection, leading to a biased sample; consisting of opportunistic, stratified, and systematic sampling.
• What is opportunistic sampling?

  This uses organisms most conveniently available, making it the least representative of a population.
• What is stratified sampling?

  This involves dividing a population into a number of strata (sub groups) based on a particular characteristic, and samples being taken from each strata proportional to its size.
• What is systematic sampling?

  This involves identifying different areas within a habitat, each being sampled separately, often using a line or belt transect.
• What is a line transect?

  This involves marking a line along the ground between two poles and taking samples at specific points.
• What is a belt transect?

  This involves marking two parallel lines and taking samples of the area between the two lines.
• For what reasons could sampling lack reliability and not be representative?

  Sampling bias - the selection process may be biased, but the effects of this can be reduced using random sampling, which removes human involvement.

  Chance - the selection may by chance lack representation, but the effects can be reduced by using a large sample size, as this reduces the probability of chance influencing the results.
• What are the methods of animal sampling?

  Pooter, sweep nets, pitfall traps, tree beating, and kick sampling.
• What is a pooter?

  This is used to capture small insects by sucking on a mouthpiece, drawing insects into a holding chamber via an inlet tube, with a filter before the mouthpiece preventing any from being sucked into the mouth.
• What are sweep nets?

  These are used to capture insects in long grass areas, and is a long net with a wide opening.
• What is a pitfall trap?

  These are used to capture small invertebrates, and involves a hole being dug in the ground which insects fall into and are unable to crawl out of, with a roof structure on top preventing it from filling with water.
• What is tree beating?

  This is used to capture invertebrates living in tree or bush area by stretching a large white cloth under a tree or bush, while it is shaken to dislodge the invertebrates.
• What is kick sampling?

  This is used to capture organisms living in a river by kicking its bank and bed to disturb the substrate, while a net is held downstream in order to capture organisms released into the water.
• How are plants or slow moving animals sampled?

  A point or frame quadrat.
• What is a point quadrat?

  This consists of a frame containing a horizontal bar, and at set intervals long pins can be pushed through this bar and into the ground, with each species of plant it touches being recorded.
• What is a frame quadrat?

  This consists of a square frame divided into a grid of equal section, with the type and number of species within each section recorded; with a random sampling technique being used to collect the most representative sample.
• How can quadrats be used to study how the presence and distribution of organisms varies within an area?

  Placing quadrats systematically along a belt or line transect.
• What are the different ways a quadrat is used to sample of population?

  Density - If individual species members can be or counter clearly, count the number of them in a 1m by 1m quadrat to find the density per square metre.

  Frequency - If individual species members cannot be counted clearly, small grids within the quadrat are used, by counting the number of squares the species is present in, eg. if a clover is present 65/100, the frequency is 65%.

  Percentage cover - This is used when collecting data quickly, and is an estimate by eye of the area within a quadrat a particular species covers.
• How can animal population size be calculated?

  Capture-mark-release-recapture, in which individuals of a species in an area are captured, marked, and released back into their habitat. After time has allowed them to redistribute themselves, another sample is captured, and we can compare the number of marker to non marked individuals to estimate population size; from which species richness and evenness can be calculated.
• What are abiotic factors?

  Non-living components of an ecosystem that influence the organisms living within it, such as wind speed, light intensity, humidity, pH, temperature, and oxygen content of water.
• What is used to measure wind speed?

  Anemometer (m s-1).
• What is used to measure light intensity?

  Light metre (lx).