(4,5,6b) Ecology

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(4,5,6b) Ecology by Mind Map: (4,5,6b) Ecology

1. Study of the interactions between living things and their environment

1.1. Biosphere: Part of the planet in which life is found (contains many ecosystems

1.1.1. Ecosystem: Group of clearly distinguished organisms that interact with their environment as a unit (mehrere Oekosysteme: Biom) Community: All the different populations in an area Population: all the members of the same species in an area Niche: Functional role of an organism it plays in the community

1.2. To describe, explain, predict and control systems

2. Habitat: Place in which an organism lives. Is affected by:

2.1. abiotic (non-living) factors: altitude, steepness etc.

2.1.1. Climatic (long-term wheater) factors: temperature, rainfall, light intensity etc

2.1.2. Edaphic (soil) factors: pH, water/air/mineral content etc.

2.2. Biotic (living) factors: food, competition, predation etc.

2.2.1. Competition means when two or more organisms struggle for resources in short supply (such as food, space, shelter etc) Intra- and inter-specific competition Contest competition: only one organism gets the resource (i.e. territory fight) Scramble competition: all of the competing individuals get some of the resource, but often not enough (i.e. overcrowding of seedlings) Techniques to avoid competition: caterpillar can only chew on leaves, while the butterfly can only drink nectar from flowers

2.2.2. Predation is the catching, killing and eating of another organism Numbers of predator and prey show repeated cylces of rising and falling numbers Interact due to availability of food (prey) Concealment (hiding) also plays a role Movement of predators to new areas

2.2.3. Symbiosis; two organisms from different species living closely together where at least one benefits Parasitism, an organism living in or on another organism causing harm (only one benefits) Exoparasites live on the outside of the host Endoparasites live inside the host Have little effect on host numbers Mutualism (both benefit)

2.3. Aquatic habitats have special problems

2.3.1. Light may not penetrate

2.3.2. Wave action moves and damages organisms

2.3.3. Salt content means organisms adapt to either fresh water or salt water

2.3.4. Oxygen is in lower concentration

3. Food chain is a series of links with only one organism at each trophic level (feeding level)

3.1. Producer (make their own food from the sun through photosynthesis, autotroph)

3.1.1. Flora: All the plants in an ecosystem

3.2. Primary consumers (feed on producers: herbivores)

3.2.1. Fauna: All the animals in an ecosystem

3.2.2. Any consumer can't make their own food, they are said to be heterotroph

3.3. Secondary and tertiary consume (feed on animals: carnivores)

3.4. Decomposers: Organisms that feed on dead organic matter such as bacteria and fungi

3.5. Detritus feeders (saprophytes): Organisms that feed on dead and decaying plants and animals such as mussels and earthworms

3.6. Energy flows through the one-to-one series of organisms, but 90% is lost at each trophic level (feeding stage)

3.7. Food web is a series of interlinked food chains

3.8. A pyramid of numbers is a representation of the number of organisms at each trophic level

3.8.1. Number of organisms normally decreases as you ascend each pyramid

3.8.2. The size of the organisms can change the standard shape of the pyramid to an inverted one (often parasitic food chains) e.g. oak tree > greenfly > ladybird > robin

3.8.3. May be limited if not drawn by scale or doesn't take the size of organism into account

4. Humans affect ecosystems

4.1. Pollution: any harmful addition to the environment

4.1.1. Ozone depletion gas that absorbes ultraviolet radiation in the upper atmosphere is broken down by manufactured chemicals such as CFC's Problems: increased skin cancers, damage to plants and the immune system of animals Improved by using HFC's

4.1.2. Global warming through release of greenhouse gases such as CO2 Sea levels rise Climate and weather patterns change Gulf Stream may reverse its direction to flow

4.2. Conservation: wise managment of existing resources to protect biodiversity and keep the ecological balance

4.3. Waste managment: involves preventing pollution and conserving the environment

4.3.1. Reduce the consumption of unnecessary materials

4.3.2. Reuse as many materials as possible

4.3.3. Recycle as much as possible

4.3.4. Problems: may cause disease, poison, toxic, eutrophication, pollution, smelly

4.3.5. For example in forestry, any parts of trees not removed from the forest are allowed to decay and return nutritients to the soil

5. Nutritient recycling

5.1. Carbon cycle

5.1.1. CO2 is removed from the environment by photosynthesis in plants

5.1.2. CO2 is returned to the environment by Respiration Decay Combustion Weathering

5.2. Nitrogen cycle

5.2.1. Nitrogen-fixing bacteria (N2 into NH3 in legumes) so that plants can absorb them

5.2.2. Bacteria and fungi of decay (dead organic matter into NH3)

5.2.3. Nitrifying bacteria (NH3 into NO3)

5.2.4. Denitrifying bacteria (NO3 back into N2)

5.2.5. There is an archaelogical technique called Nitrogen Stable Isotope Analysis, which is based on the fact that different trophic stages have different nitrogen isotope ratios.

6. Study of an habitat(i.e. grassland)

6.1. Mapping

6.2. Identifying plants and animals

6.2.1. A qualitative study records the presence or absence of species

6.2.2. A suitable key is used to identify and name organisms

6.2.3. Plants Clover Dandelions Buttercups Nettles Thistles

6.2.4. Animals Earthworms (D) Snails (H) Slugs (H) Foxes (C) Rabbits (H) Foxes use their sharp eyes and teeth (adaption) to sneak up on their prey (adaptive technique). This is because evolution ensures that only those organisms that are adapted to their environment will survive.

6.3. Estimating the numbers of plants and animals

6.3.1. A quantitative study records the number of each species Subjective (depend on individual judgments) Objective (independent)

6.3.2. Quantitative study of plants Quadrats method examined for percentage cover of plants or stationary animals Frequency Transects method Line transect (rope marked at intervals: record what touches the line) Belt transect (equivalent to quadrats taken in a line: methods used are the same as for quadrats)

6.3.3. Quantitative study of animals capture-recapture method No. animals = (no. caught on first visit x no. caught on second visit) / no. marked on second visit

6.3.4. Collecting methods Knife for plants Trowel for plants Sweep net for insects Plankton net for plankton

6.4. Errors

6.4.1. Mistakes may be made in judgement and recording

6.4.2. Conditions change in the ecosystem over time

6.4.3. Accidental discoveries may be made

6.4.4. The habitats studied may not accurately reflect the overall ecosystem

6.5. Measuring the environmental (abiotic) factors

6.5.1. Examples and effects of abiotic factor

6.6. Presenting the information

6.6.1. presented in tables, lists, charts, graphs, diagrams etc.

6.6.2. should include food chains, food webs and pyramids of numbers