Unit 1: Living Environment Flashcards

Question

Human Influences on Biodiversity: Human Activities

Answer 1

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.

Answer 2

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.

Answer 3

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.

Answer 4

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.

Answer 5

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).

Answer 6

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.

Answer 7

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.

Answer 8

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.

Answer 9

Training programmes are in place for users of pesticides and fertilisers in order to increase awareness of the damaging effects of these substances.

Answer 10

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.

Answer 11

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.

Answer 12

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.

Answer 13

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.

Answer 14

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.

Answer 15

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.)

Answer 16

Reintroduction is defined as attempt to establish a species in an area that was once part of its historical range, but from which it has been extirpated or become extinct. Reintroduction can produce a healthy and resilient ecosystem. Resilient ecosystems are those capable of coping with disturbances, like storms, fire and pollution, without losing their overall structure and ability to function; to organise themselves and to recover from, or adapt to, change. A healthy ecosystem is one that continues to provide the services that support all life. It is also one in which species continue to find a niche, recognising that evolutionary forces may cause some species to decline or become extinct and new species to evolve or increase. Species which qualify for reintroduction through a UK Biodiversity Action Plan are assessed against questions about the practicality and feasibility of delivering benefits for biodiversity. Examples of species which have been reintroduced are the White Tailed Eagle, European Beaver and Red Kite. Examples of species which were historically present in Scotland and have potential for reintroduction are the Wolf, Bear and Lynx.

Answer 17

Non-native species are in competition with native species. This reduces the number of native species. Non-native species may breed with native species causing hybridisation. This pollutes the gene pool of the native population. Examples of non-native; Grey squirrel - have displaced native red squirrels from much of their former GB range. Grey squirrels damage trees by gnawing young bark, causing commercial damage to forestry and nuisance to gardeners. Grey squirrels are predators of birds' eggs and chicks. Sika deer - hybridise with red deer and there are likely to be only a few pure red or sika deer remaining in GB. They cause serious damage in some regions to crops, forestry, reedbeds, saltmarshes, bogs and heathland through grazing and trampling. Rhododendron ponticum - Its dense thickets shade out indigenous plants, preventing regeneration of trees in woods and obliterating the ground vegetation on moors. It is poisonous to livestock and cannot be controlled by grazing. It is host to the disease organisms which attack oak and beech.

Answer 18

Grey Squirrel - 1. Trapping 2. Poisoning with warfarin 3. Shooting in early spring 4. Drey poking in early spring Sika Deer - 1. Fencing off area to prevent access 2. Protecting saplings using plastic netting from grazing 3. Annual deer culls 4. Using ultrasound as a deer deterrent in small localised areas Rhododendron - 1. Injecting herbicide directly into the stems of large rhododendron results in their death within six months 2. Treat foliage with herbicide 3. Cutting back rhododendron and removing roots to prevent regrowth or flailing to turn the wood to mulch. 4. Herbicides applied to cut stumps to kill the growing roots. 5. Hand pull seedlings which have germinated.

Answer 19

Policies and legislations are required to; protect wildlife, protect the landscape and countryside for human amenity value, in particular informal recreation. There are a number of conservation and land and marine management policies; Wildlife and Countryside Act, Town and Planning Act, National Parks, and Access to the Countryside Act, Countryside (Scotland) Act, Marine (Scotland) Act. A number of organisations are in place in Scotland to enable others to comply with legislations and policies and to carry out good environmental practice.

Answer 20

Scottish Natural Heritage (SNH are responsible for; promote care for and improvement of the natural heritage, help people enjoy it responsibly, enable greater understanding and awareness of it, promote its sustainable use, now for future generations. The work they do includes; Scottish Environmental Protection Agency (SEPA) (Scotland's environmental regulator, SEPA's purpose, as set out in the Regularity Reform (Scotland) Act 2014). Responsible for; Purpose is to protect and improve the environment (including; the sustainable management of natural resources, contribute to improving the health and wellbeing of people in Scotland, achieving sustainable economic growth). Work they do includes; excellent environmental regulator, helping business and industry to understand their environmental responsibilities, enabling customers to comply with legislation and good practice and to realise the many economic benefits of good environmental practice, protect communities by regulating activities that can cause harmful pollution and by monitoring the quality of Scotland's air and land and water, regulations they implement also cover the keeping and use and the accumulation and disposals of radioactive substances. Forestry Commission Scotland (FCS) are responsible for delivery of multiple benefits by promoting the sustainable management of trees, woods and forests across Scotland. Work they do includes; Marine Scotland (MS) responsible for controlling the activities of fishing vessels and fishing effort in the North Sea and the West of Scotland both ensuring our own boats are abiding by Scottish and EU regulations and ensuring vessels from other countries follow our rules. The EU controls/ governs organisations such as; SEPA, SNH or FCS.

Answer 21

The interactions with other living organisms in the environment e.g. competition, predation (animals and plants), food supply, space, disease, parasitism.

Answer 22

The relationship between the organism and the conditions and non-living components of the environment e.g. temperature, light, pH, salinity.

Answer 23

These are generally biotic interactions. The effect of these factors in controlling a population increases as the density of a population increases. This is because as the population density increases these factors become limiting. Tend to regulate population density.

Answer 24

These are abiotic/ environmental factors e.g. floods, droughts, volcanic eruption (environmental disaster). These reduce population independently of their density. Although they don't regulate density they do affect the availability of resources and so affect the carrying capacity of the environment and can affect the biodiversity of the ecosystem. It also changes in food webs.

Answer 25

Interactions between members of different species e.g. predation, grazing, parasitism.

Answer 26

Interactions between members of the same species e.g. territorial behaviour, dominance, mating, competition for resources. Tends to be more intense as individuals have the same needs and are competing for the same resources.

Answer 27

When an environment is colonised by a species, the population grows to the highest level supportable the environment. The limit is known as the carrying capacity and occurs in the exponential phase. Oscillations in population caused by population overshoot and then dieback which occurs in the stationary phase. The first phase is the lag phase where the population begins to grow. the last phase is the death phase where the population number begins to decrease.

Answer 28

The relationship between the predator and the prey is very close (interactions between food resources and their consumers). This relationship exerts powerful controls on the population and the evolution of the interacting species. The predator benefits by receiving a source of energy and nutrients. The prey also benefits as it will have more; food, resources and less competition.

Answer 29

Predator and prey populations are linked and balanced. If conditions favour prey, their number will increase. As a result, there will be more food for predators, whose numbers will also rise. An increase in predator numbers will increase predation and therefore prey numbers will fall. Increased competition following this reduction in food will cause predator numbers to drop as some die of starvation. This brings the population back to its original state. Since there tends to be less predators than prey, population graphs of predator and prey numbers are usually very similar.

Answer 30

High hare population density causes a deterioration in their food quality through over eating, partial grazing and trampling. Biodiversity of plants/ vegetation reduces. This in turn reduces the hare population. If the Lynx was removed from this cycle another predator of the Snowhare would fill the Lynx's niche. If the Snowhare was removed the Lynx would have to find a new prey or more ecosystem.

Answer 31

Hunting decreased number of otters. Number of sea urchins increased. Decline in kelp forests. Reduced food for other herbivores. Reduced number of habitats for fish. Ecosystem diversity reduced. Kelp provides food for other herbivores and provides a habitat for many fish. Kelp -> Sea Urchins -> Sea Otter

Answer 32

Predators have an important role in maintaining diversity in an ecosystem. They do this by regulating the numbers of dominant species. This in turn prevents the weaker prey species being lost from the habitat (competitive exclusion).

Answer 33

Is a form of predation and interspecific interaction. A grazer is defined as any species that moves from one victim to another feeding on part of each victim without killing it outright. The victim is to the grazer as the prey is to the predator. Grazers can increase/ decrease species diversity depending on the intensity of the grazing and on the type of plant being grazed i.e. forestry commission -> rabbits.

Answer 34

Some plants, for example grasses and dandelions have meristems very low and close to the ground. These are known as basal meristems. When grazed by herbivores there leaves are eaten, but because their meristems are close to the ground they are left undamaged. As a result of this the plant is able to survive, keep growing and regenerate.

Answer 35

These meristems are found at the tips of shoots. They are typically found in bushy plants such as tree seedlings. When grazed by herbivores the meristems are damaged and the plant is unable to regenerate. Such plant swill be eliminated if heavily grazed. E.g. Oak seedling aerial meristems.

Answer 36

In areas where little or no grazing occurs the dominant grass species will take over and the less robust species will dies out. Species diversity is reduced. In areas where moderate grazing occurs dominant species are eaten so less dominant species can grow. Species diversity increases. In areas where heavy grazing occurs plants without protective basal meristems will be eliminated. Species diversity reduced.

Answer 37

The source of energy for a food chain/ web is always the sun. A food chain shows the relationship between organisms which pass on their energy by feeding. the arrows in a food chain indicate the direction of energy flow. A food web shows all possible feeding relationships in an ecosystem or habitat.

Answer 38

The levels within a food web are known as trophic levels.

Answer 39

A heterotroph or consumer means an animal which depends on other living things (plants or 3 other animals) for its food. There are 3 types of consumer: Carnivores prey on other animals, Omnivores eat both plants and animals, Herbivores eat plants only.

Answer 40

The term autotroph or primary producer means a green plant which is able to produce its own food by photosynthesis.

Answer 41

Decay is an essential process within food webs, helping to "recycle" material which ensures the energy in dead material is still available to other organisms. DEcay is the work of 2 main groups: - Decomposers includes fungi and bacteria (single celled organisms) which break down organic matter chemically by releasing enzymes to speed up chemical reactions. The soluble components can be absorbed by these micro-organisms. - Detritivores are larger organisms which feed on detritus (dead material) e.g. earthworms (break down leaves); maggots (fly larvae which eat on animal tissue) and woodlice (eat dead wood). They also help break down organic matter into smaller pieces, so increasing the surface area for bacteria and fungi.

Answer 42

Photosynthesis is the critical process in food webs, where green plants (autotrophs) and certain other organisms transform light energy from the sun into chemical energy. Without these, life coul dnot be supported on earth.

Answer 43

Energy is passed between trophic levels within food chains and webs through predation. Usually a maximum of 10% of energy available is assed on to the trophic level above for new biomass to be produced. Energy is "lost" due to heat (temperature regulation), respiration, movement and undigested waste (e.g. bones). Energy is not lost due to death, excrement and faeces as this is still food for microbes, bacteria and other decomposers which help "recycle" nutrients.

Answer 44

Occurs in cells or organisms, it is the chemical process by whihc organic compounds (sugars) release energy for their metabolism.

Answer 45

Food chains can only usually support 6 trophic levels before all energy is used. Short food chains (with only 2 or 3 arrows) are more energy efficient and waste less energy than longer chains.

Answer 46

Is the amount of solar enrgy that is incorporated into biomass.

Answer 47

Is the energy "fixed" by the producers in photosynthesis and stored as chemical energy in glucose.

Answer 48

= Gross Productivity - Losses (due to respiration and heat).

Answer 49

(e.g. birds, mammals) can regulate their body temperatures and use more energy for heat and respiration, so have to eat more food to survive. Food webs with many endotherms are often short in length (3 or 4 trophic levels) as more energy is "lost" through heat and movement. As a response to this, some species migrate, hibernate or lower their metabolic rate to conserve energy during cold periods and to reduce their energy demand (e.g. polar bear in the Arctic).

Answer 50

(e.g. insects, fish, reptiles) have no metabolic method of regulating their body temperature and species such as lizards or snakes bask in sunlight or seek shade to warm up or cool down and as a result food webs with ectotherms are longer in length.

Answer 51

This is a very simple way of showing the number of organisms at each trophic level. Pyramids of numbers are often triangular (or pyramid) shaped, but can be almost any shape, depending of the size of the organisms. In particular very large producers (like trees) and very small consumers (like parasites) cause inverted pyramids. The drawbacks with a pyramid of numbers is that they don't consider the size of organisms or the energy transferred.

Answer 52

This is another fairly simple way of showing the number of organisms at each trophic level. The pyramid always narrows towards the top showing energy loss at each trophic level. However, it doesn't reveal anything about the chemical composition of organisms and how much energy is passed on (fat, protein); they also don't consider ecosystems with a high turnover rate such as grass in a field with an apparent low biomass.

Answer 53

This is the most relaible pyramid and represents the amount of energy flowing from 1 trophic level to the next. it is usually expressed in kilojoules per metre squared per year (kJ/m2/year). Since energy is always lost at each trophic level, they always form upright pyramids.

Answer 54

Where both organisms benefit from each other. E.g. Lichens consists of both a fungus and and alga. The fungus attaches itself to objects and helps protect the alga. Inreturn the alga photosynthesizes, producing food for the fungus.

Answer 55

When one organism benefits but the other is largely unaffected. E.g. Cattle egrets (a small type of heron) feed in pastures next to livestock, which stir up insects as they move. The cattle are largely unaffected.

Answer 56

Where one organism benefits at the expense of another (the host), although killing the host will not benefit the parasite. E.g. Plasmodium disease is transferred to animals by mosquitoes during feeding. The Plasmodium disease gains nutrients from the host to the hosts expense.

Answer 57

High population density of a species can allow infectious disease to be transmitted, particularly where there is a shortage of food and organisms are malnourished and cannot fight off infections. Parasites are also easily transmitted. This is oftn a natural check on population growth.

Answer 58

At high popluation densities, waste products froom organisms build up, creating poisonous conditions which prevent further growth of the population.

Answer 59

Occurs in areas where there is no soil or bare rock.

Answer 60

Occurs in areas where soil is already present and there has been disruption to the ecosystem (e.g. fire).

Answer 61

Primary colonisers (Pioneer species which can adopt to the lack of soil). Intermediate colonisers (Taller plants which take hold in deeper soils formed as pioneer plants die off). Climax community (The end point of succession usually woodland).

Answer 62

They are self sustaining ecosystems, replaced only by themselves. The area usually has the greatest biodiversity and the tallest species. It is in balance/ equilibrim.

Answer 63

Climax communites are subject to change, particularly through the action of humans. Where human activity has prevented the ecosystem from depending further, a plagioclimax develops.

Answer 64

Heather moorland is managed by humans for grazing and for shooting game, principally grouse. Gamemakers will burn patches of heather (known as muirburn) to create differnet types of habitat and cover for grouse as burning stimulates secondary succession and it can also remove long grasses which harbour ticks and parasites which can affect livestock (sheep). There are restictions on muirburn and it can only occure in winter (outside nesting seasons).

Answer 65

Human activities (principally grazing) and the influence of rabbits prevent the development of the scrub woodland climax community of beech and box. The grassland ecosystem which is allowed to prevail (by conservationists) actually supports a wide diversity of flowers (orchids), insects and butterflies, which thrive in the thin, but well drained alkali soils. Some of these landscapes have been lost for arable farmland since WW2.

Answer 66

- pH declines - Salinity decreases - Age of dune increases - Available nutrients increases - Available fresh water increases - Humus content (soil increases) - Shelter inceases

Answer 67

- Frosted Orache - Saltwort - Sandwort - Sea Rocket - Sand Couch - Lyme Grass

Answer 68

- Marram Grass (80%) - Sea Holly - Sand Sedge - Ragwort - Thistles

Answer 69

``` Dunes: - Lichens and Mosses (grey colour) - Red Rascue - Dandelion Slacks: - Cotton Grass - Reeds and Rushes - Williow ```

Answer 70

- Heather - Gorse - Dog Rose - Sea Buckthorn - Oak - Scots Pine

Answer 71

- Scattered individuals (lack nutrients) - Alkaline tolerance e.g. sea rocket (shells) - Low growing (out of wind) - Waxy leaves (reduce moisture loss) - drought tolerants plants - Salt tolerant (sea spray)

Answer 72

- Marram grass thrives on being buried by sand - Underground rhizomes stabilise sand and dune system - Long tap roots (probe for moisture) - Inrolled leaves (reduce water loss)

Answer 73

- Stabilising plants like dandelions succeed marram as it dies out - increased soil depth and humus - Surface lichens give dune grey colour - Increasing shelter restricts supply of sand blown from shore - Damp hollows (slacks) colonised by cotton grass and rushes, thrive in wet conditions

Answer 74

- Woody perennials plus understorey - heathland and woodland - Increased rnage of species due to increased organic matter in soils; soils which prefer more acidic conditions (heather)

Unit 1: Living Environment Flashcards

(98 cards)