AS Biology - Biodiversity (11)

What technique is often used to estimate an animal population size, (particularly animals that are constantly moving or hidden)?

*Capture-mark-release-recapture* it involves capturing as many individuals of a species as possible. They are marked and then released back into the community. Time is allowed for them to redistribute themselves before another sample of animals is collected. Scientists can then compare the number of marked individuals with the number of unmarked individuals in the second sample to estimate population size.

What are the impacts of different diversities in a habitat that could be changed dramatically?

*Low biodiversity* - major effects on the whole ecosystem. *High biodiversity* - often relatively small effect

What are the impacts of different diversities in a habitat's number of successful species?

*Low biodiversity* - relatively few *High biodiversity* - a large number

What are the impacts of different diversities in a habitat on the adaptation of species to environment?

*Low biodiversity* - relatively few species live in the habitat, so often very specific adaptations for the environment. *High biodiversity* - many species live in the habitat, often with few specific adaptations to the environment.

What are the impacts of different diversities in a habitat's type of food webs?

*Low biodiversity* - relatively simple *High biodiversity* - complex

What are the impacts of different diversities in the nature of the environment in a habitat?

*Low biodiversity* - stressful and/or extreme with relatively few ecological niches. *High biodiversity* - relatively benign/ not stressful, with more ecological niches

How can a frame quadrat be used to sample the population of plants living in a habitat?

- *Density* - if individual large plants are present, count the number of them in a 1m by 1m square quadrat. This gives you the density per square meter. - *Frequency* - used where individual members of a species are hard to count, like grass or moss. Count the number of squares a species is present in. (e.g if clober is present in 65 out of 100 squares the frequency of its occurrence is 65%) - *Percentage cover* - it is used for speed as lots of data can be collected quickly. It is useful when a particular species is abundant, or hard to count. It is an estimate by eye of the area within a quadrat that a particular species covers.

Why may some organisms born in captivity not be suitable for release in the wild?

- *Diseases*; There may be a loss of resistance to local diseases. New diseases might exist in the the wild, to which captive animals have yet to develop resistance. - *Behaviour*; Some behavior is innate, but much has to be learned through copying or experience, so some animals may not have the skills to adapt. - *Genetic races*; the genetic makeup of captive animals can become so different from the original population that the two populations cannot interbreed. - *Habitat*; in many cases the natural habitat must be first restored to allow captive populations to be reintroduced. If only a small suitable habitat exists it is likely that there are already as many individuals as the habitat can support. The introduction of new individuals can lead to stress and tension as individuals fight for limited territory and resources such as food.

What are the main causes of a loss of biodiversity?

- *deforestation*, the permanent removal of large areas of forest to provide wood for building and fuel and to create space for roads, building and agriculture. - *agriculture* , an increasing amount of land has to be farmed in order to feed the growing population. This has resulted in large amounts of land being cleared and in many cases planted with a single crop (monoculture). - *climate change*, there is much evidence that the release of carbon dioxide and other pollutants into the atmosphere from the burning of fossil fuels is increasing global temperatures.

How can genetic biodiversity decrease?

- *selective breeding* (artificial selection) where only a few individuals within a population are selected for their advantageous characteristics and bred. - *captive breeding programmes*, in zoos and conservation centres, where only a small number of captive individuals of a species are available for breeding. - *artificial cloning*, (asexual reproduction, e.g using cuttings) - *natural selection*, species will evolve over time to contain primarily characteristics that are advantageous, others will be lost. - *genetic bottlenecks*, few individuals within a population survive an event or change, thus reducing their 'gene pool'. - *founder effect*, small number of individuals create a new colony, geographically isolated and their gene pool is small. - *genetic drift*, random nature of alleles being passed on from parents to their offspring, frequency of occurrence of an allele will vary. In some cases, it may disappear from an entire population all together. It is more pronounced in populations with a low genetic biodiversity.

Why is it important to maintain biodiversity for ecological reasons?

- All organisms are interdependent on others for survival. The removal of a species may have a significant effect on others, for example a food source or a place to live may be lost. - Some species play a key role in maintaining the structure of an ecological community. These are known as a keystone species. They have a disproportionately large effect on their environment relative to their abundance. When a keystone species is removed, the habitat is drastically changed.

How can agriculture result in a decrease in biodiversity?

- Deforestation can occur in order to increase the area of land available for growing crops or rearing animals. - Removal of hedgerows to allow farmers to use large machinery to help them plant, fertilise and harvest crops. It also frees up extra land for crop growing, reducing the number of plant species present in an area and destroys the habitat of animals such as blackbirds, mice and other invertebrates. - Use of chemicals such as pesticides and herbicides that kills pests that would eat the crops or live on the animals, this destroys the food source of other organisms. - Herbicides are used to kill weeds. A weed is any plant growing in an area where is not wanted. Weeds are destroyed as they compete with cultivated plants for light, minerals etc. Plant diversity is reduced, animal diversity may also be reduced as weeds could be an important food source. - Monoculture results in the production of only one crop, with many acres of land being used for that species. It drastically lowers biodiversity as one plant species is present, and decreases the support for animal species.

What is systematic sampling?

- Different areas within an overall habitat are identified, which are then sampled separately. (e.g how plant species change as you move inland from the sea). - It is often carried out using a line or belt transect.

How is deforestation contributing to a loss in biodiversdity?

- It directly reduces the number of trees present in an area. - If only a specific type of tree if felled, the species diversity is reduced. eg, rosewood is often extracted from rainforests, but less useable trees may be left intact. - It reduces the number of animal species present in an area as it destroys their habitat, including their food source and home. This, in turn, reduces the number of other animal species that are present, by reducing or removing their food source. - Animals are forces to migrate to other areas to ensure their survival. The biodiversity of other areas increases.

What is opportunistic sampling?

- It is the weakest form of sampling as it may not be representative of the whole population. - It uses organisms that are conveniently available.

What is a captive breeding programme?

- It produced offspring of species in a human-controlled environment. These are often run and managed by zoos and aquatic centres. Scientists working on captive breeding programmes aim to create a stable, healthy population of a species, and then gradually reintroduce the species back into its natural habitat. - It provides animals with shelter, an abundant supply of nutritious food, an absence of predators and veterinary treatment.

What are the drawbacks of a captive breeding programme? How can this be overcome?

- Maintaining genetic diversity within a captive breeding population can be difficult. Only a small number of breeding partners are available, problems related to inbreeding can occur. - To overcome this, an international catalogue is maintained, detailing genealogical data on individuals, so mating can be arranged to ensure genetic diversity is maximised.

How can global warming reduce biodiversity?

- Melting of polar ice caps can lead to the extinction of few plant species and animal species living in these regions. Some species are migrating further north where it is cooler. - Rising sea levels could flow low-lying land, reducing the available terrestrial habitats. Saltwater would flow further up rivers, reducing the habitats of freshwater plants and animals living there. - Higher temperatures and less rainfall would result in some plant species failing to adapt, leading to xerophytes becoming more dominant. Some non-drought species would be lost. - Insect life cycles and populations will change as they adapt to climate change. Insects are key pollinators, so if the range of an insect changes, it could affect the lives of the plants it leaves behind, causing extinction. If tropical insects spread, this could result in the spread of tropical diseases towards the poles.

Why is it important to maintain biodiversity for economic reasons?

- Soil erosion and desertification may occur as a result of deforestation. This reduces a country's ability to grow crops and feed its people, which can lead to resource and economic dependence on other nations. - It is important to conserve all organisms that we use to make things. Non-suitable removal of resources, such as hardwood and timber will ultimately result in the collapse of industry in an area. It soon does not become economically viable to continue that industry. - Large-scale habitat and biodiversity losses mean that species with potential economic importance may become extinct before they are even discovered. - Continuous monoculture results in soil depletion, a reduction in the diversity of soil nutrients, making the ecosystem more fragile. The farmer becomes dependent on pesticides, herbicides etc. - High biodiversity provides protection against abiotic stresses and disease. - High biodiversity can promote tourism in an area. - Plant varieties are needed for crossbreeding, which can lead to better characteristics such as disease resistance or increased yield.

What is stratified sampling?

- Some populations can be divided into a number of strata, (sub-groups) based on a particular characteristic (e.g gender). - A random sample is then taken from each of these strata proportional to its size.

What can sampling estimate?

- The number of organisms in an area without having to count them all. This is the abundance of the organism. - Can measure a particular characteristic of an organism, e.g height.

How can chance result in a sample never entirely being representative of the organisms present in a habitat?

- The organisms selected may not be representative of the whole population by chance. (e.g a sample of five worms collected in a trap may be the five longest in the habitat). - Chance can never be effectively removed but its effect can be minimised by using a large sample size. There is a lower probability that chance will influence the result.

Why is it important to maintain biodiversity for aesthetic reasons?

- The presence of different plants and animals in our environment enriches our lives. - The natural world provides inspiration for people such as musicians and writers, who in turn provide pleasure for many through music and books. - Studies have shown that patients recover more rapidly from stress and injury when they are supported by plants and a relatively natural environment.

How can sampling bias result in a sample never entirely being representative of the organisms present in a habitat?

- The selection process may be biased. This may be by accident or may occur deliberately. (e.g you may choose to sample an area that has more flowers because it looks interesting). - The effects of sampling bias can be reduced using random sampling, where human involvement in choosing the samples is removed.

What was some of the key findings in the 2007 Intergovernmental Panel on Climate Change?

- The warming trend for the past 50 years (~0.13°C per decade), is nearly twice that for the previous 100 years. - The average amount of water vapour in the atmosphere has increased since the 1980s over land and ocean. - Since 1961, the average temperature of the global ocean down to depths of 3km has increased. It has been absorbing 80% of the heat added to the climate system, causing seawater to expand and sea levels to rise. - The global average sea level rose by 1.8mm per year from 1961 to 2003. - Average Arctic temperatures have increased almost twice the global average in the past 100 years. - Mountain glaciers and snow cover have declined on average in both hemispheres. - Long term upward trends in the amount of precipitation have been observed over many regions from 1900 to 2005.

How can the number of possible alleles in a species increase?

- Through *mutations*, in the DNA of an organism, creating an allele. - *Interbreeding* between different populations. When an individual migrates from one population and breeds with a member of another population, alleles are transferred between the two populations → *gene flow*.

What three levels can biodiversity be studied at?

- habitat biodiversity. - species biodiversity. - genetic biodiversity.

Why is it advantageous that many abiotic factors can be measured quickly and accurately?

- rapid changes can be detected - human error in taking a reading is reduced - a high degree of precision is often achieved - data can be stored and tracked on a computer

What were the specific aims of the countryside stewardship scheme?

- 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.

What are some examples of an abiotic factor?

- wind speed - light intensity - relative humidity - pH - temperature - oxygen content in water

What is species evenness?

A comparison of the number of individuals of each species living in a community.

What is succession?

A natural process in which early colonising species are replaced over time until a stable mature population is achieved.

What does vulnerable mean?

A species that is considered likely to become endangered in the near future.

What does endangered mean?

A species that is in danger of extinction.

What is an oomycete?

A type of fungus.

How is the reintroduction of a species an active management technique?

Adding species to areas that have become locally extinct, or whose numbers have decreased significantly can allow the populations of certain species to grow again.

Before a major project is undertaken, what must take place?

An Environmental Impact Assessment (EIA). It aims to predict the positive and negative effects of a project on the biodiversity in that area.

What is non-random sampling?

An alternative sampling method where the sample is not chosen at random. It can be opportunistic, stratified or systematic.

How can wind speed be measured?

Anemometer, m s⁻¹

How can deforestation occur naturally?

As a result of forest fires caused by lightning or extreme heat and dry weather.

How can species evenness be calculated using the capture-mark-release-recapture method?

By comparing the total number of each organism present. Populations of plants or animals that are similar in size or density represent an even community and hence a high species evenness. It can also be expressed as a ratio between the numbers of each organism present.

What is ex situ conservation?

Conservation outside of the natural habitat.

What is in situ conservation?

Conservation within the natural habitat.

What are alleles? What effect do they have on biodiversity?

Different versions of genes. The differences in alleles among individuals of a species creates genetic biodiversity within the species, or within a population of the species. The more alleles present in a population, the more genetically diverse the population.

How can oxygen content in water be measured?

Dissolved oxygen probe, mg dm⁻³

What is sustainable development?

Economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs.

What method could be used to calculate the number of polymorphic gene loci?

Gel electrophoresis

How can relative humidity be measured?

Humidity sensor, mg dm⁻³

What is the increasing human population linked to?

Improvements in medicine, housing and infrastructure.

What is the Rio Convention?

In 1992 a historic meeting of 172 nations was held in Rio de Janeiro which became known as the Earth Summit. - The Convention on Biological Diversity (CBD) requires countries to develop national strategies for sustainable development, thus ensuring the maintenance of biodiversity. - The United Nations Framework Convention on Climate Change (UNFCCC) is an agreement between nations to take steps to stabilise greenhouse gas concentrations within the atmosphere. - The United Nations Convention to Combat Desertification (UNCCD) aims to prevent the transformation of fertile land into desert and reduce the effects of drought through programmes of international cooperation.

On the Simpson's Index of Diversity, what does a value of 1 indicate?

Infinite diversity, the value is always between 0 and 1

How is halting succession an active management technique?

It allows beautiful habitats to be maintained for future generations, without them becoming something else, such as woodland as a result of natural succession.

How is restricting human access an active management technique?

It allows species time to recover, e.g not allowing people to visit a beach during the seal reproductive season, or providing paths which must be followed to prevent paths being trampled.

What was the International Union for the Conservation of Nature?

It assists in securing agreements between nations. At least once a year the IUCN publishes the Red List, detailing the current conservation status of threatened animals. Countries can then work together to conserve these species.

How is feeding animals an active management technique?

It can help ensure that more organisms survive to reproductive age.

What is a point quadrat?

It consists of a frame containing a horizontal bar. At set intervals along the bar, long pins can be pushed through the bar to reach the ground. Each species of plant the pin touches are recorded.

What is a frame quadrat?

It consists of a square frame divided into a grid of equal sections. The type and number of species within each section of the quadrat are recorded. They should be used following a random sampling technique to study the presence and distribution of organisms across an area of land varies, the quadrats can be placed systematically along a line or belt transect.

How is controlling poaching an active management technique?

It includes creating defences to prevent access, issuing fines, or more drastic steps as the removal of rhino horns.

What is a line transect?

It involves marking a line along the ground between two poles and taking samples at specified points, this can include all of the organisms which touch the line or distances of samples from the line.

What is the Simpson's Index of Diversity?

It is a measure of biodiversity that takes into account both species richness and species evenness. ∑ = sum of N = the total number of organisms of all species n = the total number of organisms of a particular species

What is a seed bank?

It is an example of a gene bank - a store of genetic material. Seeds are carefully stored so that new plants can be grown in the future. They are dried and stored at temperatures -20°C to maintain their viability, by slowing down the rate they lose their ability to germinate. Almost all temperate seeds, and many tropical seeds, can be stored this way. Scientists expect they will remain viable for centuries, providing a backup against the extinction of wild plants.

How is culling an active management technique?

It is the removal of an invasive species, this is an organism that is not native to an area, or has negative effects on the economy, environment, or health. They compete with native species for resources.

What is biodiversity?

It is the variety and variability of life on Earth. Biodiversity is typically a measure of variation at the genetic, species, and ecosystem level.

What is a sweep net?

It is used to catch insects in areas of long grass.

What is a pooter?

It is used to catch small insects, by sucking on the mouthpiece, insects are drawn into the holding chamber via the inlet tube. A filter before the mouthpiece prevents them from being sucked into the mouth.

What is a pitfall trap?

It is used to catch small, crawling invertebrates such as beetles, spiders and slugs. A hole is dug in the ground, which insects fall into. It must be deep enough so they do not crawl out and covered with a roof-structure propped above so that the trap does not fill with rainwater. It is usually left overnight, so that nocturnal species are also sampled.

What is kick sampling?

It is used to study organisms living in a river. The river bank is 'kicked' for a period of time to disturb the substrate. A net is held downstream for a set period of time to capture any organisms released into the flowing water.

What is tree beating?

It is used to take samples of invertebrates living in a tree or bush. A large white cloth is stretched out under the tree. The tree is shaken or beaten to dislodge the invertebrates. The animals will fall onto the sheet where they can be collected and studied.

What is the purpose of marine conservation zones?

It isn't to prevent fishermen from visiting, but to create areas of refuge within which populations can build up and repopulate adjacent areas. Large areas of sea are required for marine reserves as the target species often move large distances, or breed in geographically different areas.

Why is in situ conservation useful?

It maintains the genetic diversity of a species, as well as the evolutionary adaptations that enable a species to adapt continually to changing environmental conditions, and preserves their interdependent relationships present in a habitat, therefore linked species may also be preserved.

What is random sampling?

It means selecting individuals by chance. In a random sample, each individual in the population has an equal likelihood of selection. Random number tables or computers can be used to avoid bias.

What is sampling?

It means taking measurements of a limited number of individual organisms present in a particular area.

How is controlled grazing an active management technique?

It only allows livestock to graze a particular area of land for a certain period of time, to allow species time to recover, or keeping controlled number of animals in a habitat to maintain it.

What is the countryside stewardship scheme?

It operates from 1991-2014, and offered governmental payments to farmers and other land managers to enhance and conserve the English landscape. Its general aim was to make conservation a part of normal farming and land management practice.

What is a belt transect?

It provides more information than a line transect, two parallel lines are marked, and samples are taken of the area between the two lines.

What is the locus of a gene?

It refers to the position of the gene on a chromosome.

What is genetic biodiversity?

It refers to the variety of genes that make up a species and can lead to quite different characteristics being exhibited. Greater genetic biodiversity allows for better adaptation to a changing environment, and is more likely to result in individuals who are resistant to disease.

What is the Convention on International Trade in Endangered Species (CITES)?

It regulates the international trade of wild plant and animal specimens and their products. As the trade in wild animals and plants cross borders between countries, the effort to regulate it requires international cooperation to safeguard certain species from over-exploitation. Today, more than 35,000 species of animals and plants are protected by this treaty.

How can light intensity be measured?

Light meter, lx

What are some examples of in situ conservation?

Marine (saltwater), aquatic (freshwater) and terrestrial nature reserves.

What are genes called that only have a single allele for one gene? Why is this important?

Monomorphic, it ensures that the basic structure of individuals within a species remains consistent.

On the Simpson's Index of Diversity, what does a value of 0 indicate?

No diversity

What does extinct mean?

No organisms of the species exist anywhere in the world.

What are abiotic factors?

Non-living conditions in a habitat. They have a direct effect on the living organisms that reside there.

What does extinct in the wild mean?

Organisms of the species only exist in captivity.

How are botanic gardens an example of ex situ conservation?

Plant species can be grown successfully in botanic gardens. The species are actively managed to provide them with the best resources to grow, such as the provision of soil nutrients, sufficient watering and the removal or prevention of pests.

Why may it be important to conserve some habitats with low biodiversity?

Some rare species may exist there that do not have adaptations to survive elsewhere, as their adaptations are very specific.

If climate change was slow, why may there not be a loss in biodiversity?

Species may have time to adapt and migrate, there could be a loss in native species, but not an overall loss in biodiversity.

How can temperature be measured?

Temperature probe, °C

What is conservation?

The name given to the preservation and careful management of the environment and of natural resources.

What is habitat biodiversity?

The number of different habitats found within an area. Each habitat can support a number of different species. The greater the habitat diversity, the greater the species biodiversity will be within that area.

What is species richness?

The number of different species living in a particular area.

Why are species with greater genetic biodiversity more likely to survive changes in their environment?

They are more likely to adapt. There are likely to be some organisms within the population that carry an advantageous allele, which enables them to survive in the altered conditions.

What is the issue with seed banks?

They don't work for all plants, some seeds die when dried and frozen, and sadly the seeds of most tropical rainforest trees fall into this category.

What are polymorphic genes?

They have more than one allele.

What areas have the most biodiversity?

Tropical, moist regions. Generally, the closer the a region is to the Equator, the greater the biodiversity.

How can pH be measured?

Using a pH probe

What areas have the least biodiversity?

Very cold areas such as the Arctic, or very dry areas such as deserts.

What is the equation for the proportion of polymorphic gene loci?

proportion of polymorphic gene loci = number of polymorphic gene loci ÷ total number of loci The greater the proportion of polymorphic gene loci, the greater the genetic biodiversity within the population.