Unit 1: Living Environment Flashcards
Species
Organisms which can breed successfully and produce fertile offspring.
Population
A group of organisms of the same species.
Habitat
A place where an organism lives.
Community
All of the animals and plants in a habitat.
Ecosystem
The community and the habitat. It can also be described as all of the living things together with the non living environment.
Niche
Is the role occupied by an organism in a habitat - what it eats, what preys on it and where it lives (e.g. tree bark). It includes the use the organism makes of the resources in its ecosystem and its interactions with other organisms in the community which include; competition for resources, parasitism, light, temperature, nutrient availability. No two species can occupy exactly the same niche as they would be in direct competition for the exact same resources at every stage of their life cycle.
Adaptation
The adjustment or changes in behaviour, physiology and structure of an organism to become more suited to an environment over time (part of the evolutionary process).
Competition (Inter/Intra specific)
Is an interaction between organisms or species in which both the organisms or species are harmed. Interspecific - competition between organisms of different species. Intraspecific - competition between organisms of the same species.
Edaphic
Describes factors related to soil e.g. drainage, texture, or chemical properties such as soil pH.
Ecology
The study of ecosystems and the relationship between organisms and their environment.
Biomass
The total mass of living matter in a population.
Quantitative Techniques
Provide information about numbers of densities (cover/ distribution/ abundance/ frequency measures).
Qualitative Techniques
Give species lists.
The Number/ Abundance of Organisms Can Be Estimated Using;
Transects, Quadrats, Nets (Sweep, Mist (net for catching bats and birds), Dip), Traps (Mammal, Moth, Camera), Bat detectors - detects the echolocation calls of different species of bat, Electro-fishing - uses electricity to stun fish before they are caught (no permanent harm to fish).
Steps Should Be Taken To Represent The Ecosystem Studied
Samples must be taken at random to prevent bias in order to improve the validity of the method. Several samples should be taken in order to calculate an average to improve reliability of results.
Aquatic Factors
Water flow rate, Oxygen concentration, Water pH, Salinity, Tidal effects.
Terrestrial Factors
Temperature, Light intensity, Soil moisture, Soil pH, Humidity, Wind velocity and direction, Precipitation, Slope
The Need for Accurate Identification of Flora and Fauna
Biological keys are used to identify organisms based on discrete variation; Branching keys, Paired statement keys.
Aquatic Environment - The Great Barrier Reef
The Great Barrier Reef is the world’s largest biological organism. It is the home to some of the largest biodiversity of marine organisms on the planet. The biodiversity of the reef has been mainly affected by; Over-fishing, Pollution, Global warming, Ocean acidification. All of the above process leads to a decrease in biodiversity.
Aquatic Environment - The Great Barrier Reef (Over-Fishing)
Removal of fish reduces sources of food or predators on the reef. The food chain is disrupted causing an increase in some fish populations and a decrease in others. Examples are removal of the Grouper causes and increase in the Grouper’s prey Damselfish. The Damselfish eat more of the coral polyps, killing the reef.
Aquatic Environment - The Great Barrier Reef (Pollution)
Sediment runoff in rivers contain natural and toxic components e.g. nitrogen and phosphorus compounds from farming. Increases algal blooms in the ocean; Block sunlight for photosynthetic zooxanthellae causing death, Decreasing oxygen level through decomposition. Sediments can block sunlight as they are deposited on the coral reef, which block sunlight for photosynthetic zooxanthellae causing death.
Aquatic Environment - The Great Barrier Reef (Global Warming)
Coral is a symbiotic relationship between a poly and photosynthetic algae zooxanthellae. Increased ocean temperatures cause the zooxanthellae to produce harmful metabolites. The polyp expels the zooxanthellae. Leads to coral bleaching.
Aquatic Environment - The Great Barrier Reef (Ocean Acidification)
An increase in atmospheric carbon dioxide. Oceans absorb half of the atmospheric carbon dioxide, forming carbonic acid. This decreases the pH of the ocean. This slows the growth of corals and their skeletons are weaker. Corals are easily damaged by wave action.
Terrestrial Ecosystem - The Flow Country; Sutherland, Scotland
Scottish peatlands support nationally and internationally important biodiversity. Some peatland plant communities found in the UK are globally rare. Peatland species are adapted to surviving in acidic, low-nutrient, waterlogged environments. Key plant species are; Sphagnum mosses, cottongrass, cranberry, bog rosemary, cloudberry. Key animal species are; golden plover, dunlin, hen harrier, golden eagle, newts, frogs, adders, spiders, dragonflies and damselflies. Peatlands can be damaged through a range of land management practices such as; draining, burning, overgrazing, pollution, afforestation, extraction, establishment of windfarms, access paths. Damage can range from; slow lowering of water levels which might not have an obvious effect for many years, to complete removal of the vegetation layer with bare peat subject to severe erosion. The damage will result in a change of the environment altering the niche available to the inhabitants, this will reduce the biodiversity of the peatland.
Human Influences on Biodiversity: Human Activities
In Scotland through the Holocene period (period of time since the last glacial period, 11, 700 years ago) activities have affected ecosystems. Activities include; deforestation, afforestation, grazing, hunting, agriculture and industrial revolution, war, introduction of non-native species. Changes in ecosystems include; habitat destruction, species reduction, changes in biodiversity and extinction.
Development of Intensive Agriculture
Intensive agriculture is a system of cultivation using large amounts of labour and capital relative to land area. The system produces a significantly increased crop yield. The increase in yield is required due to an ever increasing global population. These include; Larger fields (but smaller fields that that of extensive farming), Use of fertilisers, Use of pesticides (herbicides, fungicides and insecticides), High-efficiently machinery for planting, cultivating and harvesting, Drainage of wetland, Keeping animals indoors for rearing. Intensive farming has impact on the ecosystem; Eutrophication, Bioaccumulation, Biomagnification - is the sequence of processes in an ecosystem by which higher concentrations of a particular chemical, such as the pesticide DDT, are reached in organisms higher up the food chain, generally through a series of prey-predator relationships. These impacts in turn causes a decrease in the biodiversity of the ecosystem.
Development of Intensive Agriculture: Eutrophication
Is an increase in nutrient levels into water, mainly nitrates and phosphates. Nutrients arrive from excessive use of fertilisers on fields. The nutrients either; run off the land with rain water, leached from the soils and enter the water table. Most water has very low levels of these nutrients. Most water has very low levels of these nutrients. This low concentration is rate limiting for growth of algae, cyanobacteria and bacteria. Release of ions or organic matter causes an increase in concentration and removes the limiting factor effect. This causes a large increase in population density, population explosion, an algal bloom. Bacteria use up dissolved oxygen, or algae die and are decomposed by saprophytic bacteria which use up dissolved oxygen. Aerobic bacteria are no longer able to give complete decomposition of organic material in water.
Development of Intensive Agriculture: Bioaccumulation
Is the selective absorption of molecules into the body tissues of organisms so that is greater than the background concentration. This may be essential to take in required nutrients. Harmful substances can also be taken by absorption. The organism is unable to metabolise the chemical, therefore, these build up in the body tissues. The accumulation of harmful substances becomes toxic and cause death to the organism.
Development of Intensive Agriculture: Biomagnification
This is the sequence of processes in an ecosystem by which higher concentrations of a particular chemical, such as the pesticide DDT, are reached in organisms higher up the food chain, generally through a series of prey-predator relationships.
DDT in water (o.ooooo3 ppm) -> DDT in zooplankton (0.04 ppm) -> DDT in small fish (0.5 ppm) -> DDT in large fish (2 ppm) -> DDT in fish eating birds (25 ppm).
Responses to Eutrophication, Bioaccumulation and Biomagnification: Fertilisers
The concentration of fertilisers added to fields has to be controlled to reduce the level of nitrates and phosphates entering fresh water systems. The concentrations are stated in government legislations and guidance on nutrients, fertilisers and manures and in codes of practice. The codes set out how you should; avoid polluting water, protect the soil as a valuable resource, meet minimum standards for new or improved manure stores. Abiding by the codes will reduce the incidence of eutrophication.
Responses to Eutrophication, Bioaccumulation and Biomagnification: Pesticides
Codes of practice when using pesticides (Government websites have the up to date legislation). Only approved pesticides can be used. The maximum residue levels (MRLs) for pesticides permitted in crops are laid down in legislation. Food and water sources are analysed to detect residues of pesticides. There is a ban an aerial spraying.
Responses to Eutrophication, Bioaccumulation and Biomagnification: Organic Farming
Vegetable and livestock production using natural sources of nutrients (such as compost, crop residues and manure) and natural methods of crop and weed control, instead of using synthetic or inorganic agrochemicals. This activity will reduce the levels of fertiliser and pesticide used.
Responses to Eutrophication, Bioaccumulation and Biomagnification: Education to Promote the Protection of Ecosystems
Training programmes are in place for users of pesticides and fertilisers in order to increase awareness of the damaging effects of these substances.
The Impact of Sewage: Untreated Sewage
Untreated sewage contains organic matter, minerals and bacteria. The bacteria use the sewage as a respiratory substance. This depletes the dissolved oxygen in the fresh water. This causes an increase in the rivers biological oxygen demand (BOD). This causes death to many invertebrates and vertebrates in the river. Some bacteria breakdown the sewage releasing nitrates and phosphates, eutrophication. Eutrophication can lead to algal bloom. The algal bloom blocks the light to other aquatic plants causing their death due to the lack of photosynthesis. Dead plants and animals sink to the bottom and add to the decaying organic matter, causing a further increase in the BOD and eutrophication.
The Impact of Sewage: Treated Sewage
Sewage treatment plants, in secondary treatment, use bacteria to breakdown organic matter in the presence of oxygen. Secondary treatment will lead to the production of nitrates, phosphates and minerals. In sensitive areas of discharge, nitrate and phosphates are reduced in concentration. If the nitrates and phosphates are discharged into a water system it can lead to eutrophication. Eutrophication can lead to algal bloom. The algal bloom blocks the light to other aquatic plants causing their death due to the lack of photosynthesis. Dead plants and animals sink to the bottom and add to the decaying organic matter, causing a further increase in the BOD and eutrophication.
The Importance of Indicator Species
An indicator species is a group of organisms which shows the level of an environmental factor, such as pollution, by its presence or absence. Fresh water invertebrates are monitored. Act as indicator species for pollution of waterways by sewage or organic waste; Stonefly larvae indicate high levels of dissolved oxygen, Bloodworms indicate low levels of dissolved oxygen. Lichen species are monitored. Gives information on atmospheric pollution by sulphur dioxide. Low abundance of lichen indicates high levels of atmospheric sulphur dioxide.
Impacts on Biodiversity of Urbanisation
Environmental assessment is a procedure that ensures that the environmental implications of development are considered before a development is made. The assessments can be for; Individual projects, Environmental Impact Assessment (EIA), Public plans or programmes, Strategic Environmental Assessment (SEA). Projects or plans could be for; Change in land use, Recreational use of land and water, Construction of buildings and transport routes. When the assessment is carried out it should outline the likely significant effects on the environment, including on issues such as; biodiversity, population, human health, fauna, flora, soil, water, air, climatic factors, material assets, cultural heritage including architectural and archaeological heritage, landscape, the interrelationship between the above factors. These effects should include secondary, cumulative, short, medium and long-term permanent and temporary, positive and negative effects.
Formation of Acid Rain
The precipitation of dilute solutions of strong mineral acids from the atmosphere. Solutions are formed by mixing rain with industrial pollutants; Sulphur dioxide - burning of fossil fuels, Nitrogen oxides - vehicle exhausts, Hydrogen chloride. Acidic deposition can cause leaching of potassium, calcium and magnesium from leaves on trees. Plant roots become unhealthy and unable to extract nutrients from the soil. High levels of acid rainfall can cause metals in the soil, such as aluminium, to be flushed into water courses. This acidification of water can cause death to animals and disrupt the food chains.
The Impact of Climate Change on Biodiversity
Climate change is being brought about by increasing levels of greenhouse gases in the atmosphere. Greenhouse gases causes the Earth to retain more heat energy and warm up, global warming. Global warming is the average increase in the surface temperature of the Earth. Global warming causes changes in; Weather patterns (wind patterns, precipitation, seasonal temperature changes), Sea levels rise, Ocean currents, Ecological changes (ecosystems change and biodiversity). Biodiversity changes due to temperature changes; Increased temperature changes the growing season of plants (More vegetation for herbivores earlier in the year, Plants build up toxins before herbivores are present, Reduced number of herbivores due to toxins in plants), Plants with shallow roots could die in prolonged dry spells, Hibernating species may be able to feed longer, but their natural biological clock is imbalanced, Precipitation changes can decrease or increase wetland areas, Timing of major ecological events changed such flowering, migration and nesting. Examples of effects are; Higher spring temperatures causing earlier flowering of species e.g. blackthorn, Milder winters causing an increased number of overwintering migrant bird species e.g. blackcap, Non-native species thriving in new ecosystems (e.g. Ruddy duck, this duck’s aggressive courting behaviour and willingness to interbreed with the endangered native white-headed duck. New Zealand flatworm, it is an obligate predator of our native earthworms. Giant hogweed, originally from South West Asia, this plant has now fully established itself in the UK, grazers have little impact on its colonisation and as a result reduces species diversity. Himalayan balsam, introduced from the Himalayas, it spreads rapidly and prevents native species from growing. Japanese knotweed, it has been introduced from Japan where it is rare, but not rare in the UK, very invasive reducing species diversity.)
