Unit 1: Living Environment Flashcards Preview

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Flashcards in Unit 1: Living Environment Deck (98)
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1

Species

Organisms which can breed successfully and produce fertile offspring.

2

Population

A group of organisms of the same species.

3

Habitat

A place where an organism lives.

4

Community

All of the animals and plants in a habitat.

5

Ecosystem

The community and the habitat. It can also be described as all of the living things together with the non living environment.

6

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.

7

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).

8

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.

9

Edaphic

Describes factors related to soil e.g. drainage, texture, or chemical properties such as soil pH.

10

Ecology

The study of ecosystems and the relationship between organisms and their environment.

11

Biomass

The total mass of living matter in a population.

12

Quantitative Techniques

Provide information about numbers of densities (cover/ distribution/ abundance/ frequency measures).

13

Qualitative Techniques

Give species lists.

14

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).

15

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.

16

Aquatic Factors

Water flow rate, Oxygen concentration, Water pH, Salinity, Tidal effects.

17

Terrestrial Factors

Temperature, Light intensity, Soil moisture, Soil pH, Humidity, Wind velocity and direction, Precipitation, Slope

18

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.

19

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.

20

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.

21

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.

22

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.

23

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.

24

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.

25

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.

26

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.

27

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.

28

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.

29

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).

30

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.