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61 Cards in this Set
- Front
- Back
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What is biodiversity? |
Variety of living organisms in an area |
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Before a major project is undertaken what has to be done first? |
An Environmental Impact Assesment |
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What three levels can biodiversity be studied on? |
- Habitat biodiversity - Species biodiversity - Genetic biodiversity |
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What is habitat biodiversity? |
The number of habitats in an area |
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What are the two components of species biodiversity? |
- Species richness: number of different species - Species evenness: Comparison of the number of individuals of each species living in a community |
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What is genetic biodiversity? |
Variety of genes that make up a species |
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How many genes do humans have? |
About 25,000 |
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Why is genetic biodiversity important? |
Allows for better adaption to a changing environment and more likely to result in individuals who are resistant to disease |
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What is the number of individuals of a species known as? |
The abundance of the organism |
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What are the two ways sampling can be done? |
Random and non-random |
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What is opportunistic sampling? |
- Weakest form of sampling as it may not be representative of the population - Uses organisms that are conveniently available |
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What is stratified sampling? |
- Some populations can be divided into a number of strata based on a particular characteristic - Random sample is then taken from each of these strata proportional to its size |
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What is systematic sampling? |
Areas within an overall habitat are identified and then sampled separately |
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What is a line transect? |
Line is marked along the ground and samples are taken at specified points |
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What is a belt transect? |
Two parallel lines are marked along the ground and samples are taken of the area at specified points |
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For what reasons could a sample be unreliable? |
- Sampling bias: may be by accident, or may occur deliberately - Chance: may be selected by chance and not represent the whole population |
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How can sampling bias be tackled? |
Using random sampling |
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How can chance in a sample be tackled? |
Having a large sample size |
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What is a pooter? |
Used to catch small insects by sucking mouthpiece to draw insects into chamber |
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What are sweep nets used for? |
Catching insects in areas of long grass |
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What are pitfall traps? |
- Used to catch small, crawling invertebrates - Hole is dug in the ground which insects fall into and is deep enough so they cant escape - Covered with rain cover |
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What is tree beating? |
- Large white cloth is stretched out under a tree - Tree is shaken or beaten to dislodge invertebrates |
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What is kick sampling? |
- Used to study organisms living in a river - River bank and bed is kicked for a period of time to disturb substrate - Net is held downstream for a set period of time to capture any organisms released into flowing water |
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What are the two main types of quadrat? |
- Point quadrat: Consists of frame containing horizontal bar, set intervals along the bar long pins are pushed through to reach ground. Each species of plant the pin touches is recorded - Frame quadrat: Square frame divided into grid of equal sections |
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Using a frame quadrat, what are the three main ways of sampling a population of plants? |
- Density: If individual large plants can easily be seen count exactly - Frequency: Used when species is hard to count. Use small grids within a quadrat and count number of squares a particular species is present in - Percentage cover: Used for speed. Estimate by eye of the area within a quadrat a species covers |
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What is used to estimate animal populations? |
- Capture-mark-release-recapture - Organisms are captured, marked and released back into natural environment - Time is passed to allow redistribution and another sample is collected - The population size is estimated by comparing the number of marked individuals with the number of unmarked individuals - The greater the number of marked individuals recaptured |
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What are abiotic factors? |
Non-living conditions in a habitat |
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What are the advantages of using sensors? |
- Rapid changes can be detected - Human error in taking a reading is reduced - A high degree of precision can often be achieved - Data can be stored and tracked on a computer |
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How do you calculate biodiversity? |
Simpson's index of Diversity |
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How do mutations create genetic biodiversity? |
Creates a new allele |
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What is gene flow? |
When alleles are transferred from one population to another by interbreeding |
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How does selective breeding cause a decrease in genetic biodiversity? |
Also known as artificial breeding, where only a few individuals within a population are selected for their advantageous characteristics and bred |
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How do captive breeding programmes decrease genetic biodiversity? |
Only a small number of captive individuals of a species are available for breeding |
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How can rare breeds decrease genetic biodiversity? |
- A selectively bred species that has become less popular so the numbers fall catastrophically - Only a small number of the breed remains the genetic diversity of the remaining population will be low |
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How does natural selection decrease genetic biodiversity? |
Species will evolve to contain primarily the alleles which code for advantageous characteristics and the less advantageous characteristics will be lost from a population |
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What are genetic bottlenecks? |
When large numbers of a population die prior to reproducing, leading to reduced genetic biodiversity within the population |
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What is the founder effect? |
When a few individuals of a species colonise a new area, their offspring initially experience a loss in genetic variation, and rare alleles can become much more common in population? |
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What is one way in which scientists quantify genetic biodiversity? |
Measuring polymorphism |
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What are polymorphic genes? |
A gene with more than one allele |
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What are the main ways in which humans disrupt ecology? |
- Deforestation: logging and to create space for roads, building and agriculture - Agriculture: monoculture (clearing large areas for one crop) - Climate change: burning fossil fuels |
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Overview: Deforestation's affects on biodiversity |
- Reduces number of trees present in an area - If only specific tree is felled species diversity reduces - Reduces number of animals present in an area as it destroys their habitat - Animals forced to migrate and may result in other areas' biodiversity increasing |
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Overview: Agriculture's affect on biodiversity |
- Deforestation to increase area of land to grow on - Removal of hedgerows, reduces number of plant species present in an area destroys habitat of number of animals - Use of chemicals such as pesticides and herbicides, reduces species biodiversity - Monoculture, enormous local effect in lowering biodiversity as only one species of plant is present |
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What are some of the main findings of climate change? |
- The warming trend over the last 50 years is nearly twice that for the previous 100 years - The average amount of water vapour in the atmosphere has increased since 1980s - Average Arctic temperatures have increased at almost twice the global average rate in the past 100 years |
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If global warming continues, how will biodiversity be affected? |
- Melting of polar ice caps could lead to extinction of some species, cause a shift of species north - Rising sea levels and thermal expansion could flood low-lying land and reduce availability of terrestrial habitats and habitats of freshwater species - Higher temperatures and less rainfall would result in some plant species dying and xerophytes becoming more dominant - Insect life cycles and populations will change as they adapt. Could cause plant extinction |
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What are the aesthetic reasons for maintaining biodiversity? |
- Enriches our lives - Provides inspiration for creatives - Studies have shown that patients recover more rapidly from stress and injury when they are supported by plants and a relatively natural environment |
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What are some of the economic reasons for maintaining biodiversity? |
- Soil erosion and desertification reduce crop yield - Important to conserve all organisms we use to make things - Large-scale habitat and biodiversity losses mean species with potential economic importance may become extinct before discovery - Continuous monoculture results in soil depletion - High biodiversity provides protection from abiotic stress and disease - Provide, pleasing attractive environment - Plant varieties are needed for cross breeding |
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What are the ecological reasons for maintaining biodiversity? |
- All organisms are interdependent on others for their survival - Some species play a key role in maintaining the structure of an ecological community known as a keystone species |
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What are the two main categories of conservation? |
- In situ: within the natural habitat - Ex situ: Out of the natural habitat |
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What abundance categories are species categorised into? |
- Extinct - Extinct in the wild - Endangered - Vulnerable - No threat |
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What is controlled grazing? |
Only allowing livestock to graze a particular area of land for a certain period of time to allow species to recover |
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What is meant by halting succession? |
- Succession is a natural process in which early colonising species are replaced over time until a stable mature population is achieved - To protect moorland, heath- or down- from becoming woodland succession must be halted |
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What are some examples of active management techniques (conservation) |
- Restricting human access: e.g. not allowing people to visit a beach during seal production - Controlling poaching legally - Feeding animals - Reintroduction of species - Culling or removal of invasive species |
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What are marine conservation zones? |
- Vital in preserving areas such as coral reefs - Create areas of refuge within which populations can build up and repopulate adjacent areas - Large areas of sea are required for marine reserves |
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Overview: Botanic gardens |
- To successfully grow plants - Managed to provide them with best resources to grow - Roughly 1500 botanic gardens conserving 35,000 species |
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Overview: Seed banks |
- Example of a gene bank - Seeds are stored so that new plants may be grown in the future - Dried and stored at temperatures of -20C slowing down the rate at which they germinate - Seed banks dont work for all plants, such as most tropical rainforest trees |
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What are captive breeding programmes? |
- Produce offspring of species in a human-controlled environment - Often run and managed by zoos and aquariums - Provide animals with shelter, an abundant supply of nutritious food, an absence of predators and veterinary treatment |
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What are some of the reasons why an organism born in captivity may not be suitable for release into the wild? |
- Diseases: loss of resistance or lack of resistance to new diseases - Behaviour: Much behaviour is learned through copying or experience - Genetic races: genetic make-up of captive animals can become so different from the original population that the two populations cannot interbreed - Habitat: natural habitat must first be restored to allow captive populations to be reintroduced |
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Overview: International Union for the Conservation of Nature |
- IUCN, assist in securing agreements between nations - Involved in establishment of CITES |
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What is the Convention on International Trade in Endangered Species? |
- CITES, regulates international trade of wild plant and animal specimens and their products - More than 35,000 species are protected by this treaty |
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Overview: The Rio Convention |
- 1992, 172 nations became known as Earth Summit, resulted in some new agreements - Convention on Biological Diversity (CBD): national strategies for sustainable development - United Nations Framework to Combat Desertification (UNCCD): prevent transformation of fertile land into desert and reduce effects of drought - The United Nations Framework Convention on Climate Change: Stabilise greenhouse gas concentrations |
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Overview: Countryside stewardship scheme |
- 1991-2014, offered governmental payments to farmers and other land managers to enhance and conserve English landscape - Sustaining the beauty and diversity of the landscape - Improving, extending and creating wildlife habitats - Restoring neglected land and conserving archaeological and historic features - Improving opportunities for countryside enjoyment - Replaced by Environmental Stewardship Scheme |
