NA. 6.5 Ecosystems, Not on adv Flashcards
Define Sustainable resource
A renewable resource which is being economically exploited in such a way that it will not diminish or run out
Define Ecosystem
All the interacting living organisms and non living conditions in an area
Define Decomposition
Chemical reactions in which a compound is broken down into simpler compounds or its constituent elements
Define Interspecific competition
Competition between organisms of different species
Define Intraspecific competition
Competition between organisms of the same species
Define Ecological efficiency
The efficiency with which energy or biomass is transferred from one trophies level to the next
Define Biomass, how can we measure this?
The total weight of living matter in a certain area, transferred up trophic levels through consumption. Can be measured in terms of mass of carbon, or dry mass of tissue.
Define Hummus
The organic component of soil formed by the decomposition of leaves and other plant material by soil microorganisms
Define Decomposer
An organism that breaks down dead organisms releasing nutrients back into the ecosystem
Define Trophic level
Stage in a food chain
Define Plagioclimax
The stage in succession where artificial or natural factors prevent the natural climax community from forming
Define Carrying capacity
The maximum population size that an environment can support
Define Dominant species
The most abundant species in an ecosystem
Define Seral stages
The stages of succession
Describe Biotic and Abiotic factors, giving examples
Biotic= living features of an ecosystem
e.g. predators, disease.
Abiotic= non-living features of an ecosystem e.g. light, temperature.
How can human activities affect biomass transfer?
- Light, water, temperature maximised.
- Increased nutrients in soil.
- Pests and weeds removed.
- Growth rates boosted through steroids, selective breeding, etc.
Outline the roles of microorganisms in the Nitrogen cycle.
- Nitrogen-fixing bacteria e.g. Rhizobium in roots and Azotobacter in soil, convert gaseous nitrogen into ammonia.
- Nitrifying bacteria e.g. Nitrosomonas convert ammonium compounds into nitrites. Nitrobacter then convert nitrites to nitrates.
Outline the role of organisms in the Carbon cycle.
- Respiration of plants and animals add carbon dioxide into the atmosphere.
- Photosynthesis of plants removes carbon dioxide from the atmosphere.
- Decomposers (microorganisms) decay plant and animal material into carbon dioxide.
What is meant by Primary succession?
Where an area previously devoid of life is colonised by a community of organisms.
Summarise the process of Primary succession.
- Pioneer species, able to survive harsh conditions, colonise the area.
- They die, decompose, and add nutrients to the ground.
- Over time, this allows more complex organisms to survive.
What is the Climax community and how is it reached?
The final stage of succession, where the ecosystem is balanced and stable. It is reached when the soil is rich enough to support large trees or shrubs, and the environment is no longer changing.
What is Deflected succession?
Where succession is interrupted, usually by human interference.
What is Sampling?
Selecting a group of individuals that will represent the whole target population. Allows us to measure the distribution and abundance of organisms.
Give methods of sampling and explain how they are used.
- Quadrats= used in small areas. Randomly or regularly placed across habitat. Frequency or % cover calculated.
- Transects= used in larger areas. Sample taken along a line that crosses the habitat. Can be
What is a Pioneer species?
a species that begins the succession process, often colonizing and making it habitable
What is Gross Primary Productivity?
The rate at which plants convert light to chemical energy(through photosynthesis)
What is Net Primary Productivity?
The energy from the sun that enters the food chain (a very little amount aproxx between 1-8%)
How can you improve Primary productivity?
Drought and pest resistant plants to prevent deaths
Crop rotation to maximise available nutrients
Any method hat improves photosynthesis:
• Maximising light levels (ligh banks etc.)
• Growing plants in green houses( warmer temps)
How can you improve Secondary productivity?
- selectively breed animals with faster growth and Yield rates
- Treat animals with medicine to prevent unnecessary deaths
- keep animals in temp controlled cages so they don’t wast energy finding food and thermoregulating
- kill animals just before adulthood
In what ways are energy and material lost from the food chain?
energy may be lost as
• heat (released during respiration),
• through movement,
• in materials that the consumer does not digest (dead organism that only decomposers use)
