_A2_ 2 - Ecosystem Flashcards
(20 cards)
Population
All of the organisms of one species that live in the same place at the same time, and that can interbreed together
Habitat
The place where an organism lives
Community
All the populations of different species that live in the same place at the same time , and can interact withe each other
Trophic level
The level at which an organism feeds in a food chain
Gross Primary productivity
GPP
The total amount of energy fixed by photosynthesis
It is the net flux of carbon from the atmosphere to plants per unit time
Units e.g. MJ m^-2 yr^-1
Net primary Productivity
NPP= Primary productivity - Respiratory heat loss
GPP- Respiratory loss
The rate at which carbohydrate accumulates in the tissue of plants of an ecosystem and is measure in dry organic mass
such as (kg ha-1 yr-1)
Rate of production of organic food after allowing for that lost by respiration by the plant
The production of material that might be eaten by consumers
Succession
A directional change in a community of organisms over time
Carrying capacity
The maximum populations size that can be maintained over a period of time in a particular habitat
Limiting factor
(Often the factor in shortest supply)
A variable that limits the rate of a particular process. It is the one whose magnitude limits the rate of the process.
If the factor is increased then the process will take place at a faster rate
Competition
When resources (food water light space shelter) Are not present in adequate amounts to satisfy the needs of all the individuals who depend on those resources
Coppicing
Involves cutting a tree trunk close to the ground to encourage new growth
Conservation
What it involves
The maintenance of biodiversity, including
diversity between species,
genetic diversity within species
and maintenance of a variety of habitats and ecosystems
Ecosystem
All the living organisms and non living components
in a specific habitat
and their interactions
Producer
Autotrophic organisms (plants, som protictists and some bacteria) That convert light energy to chemical energy, which they then supply to consumers
Consumer
Living organisms that feed on other living organisms
Decomposer
Organisms that feed on dead organic matter, releasing minerals,
Minerals that then become available to other living organisms in that ecosystem
Niche
The role that a species plays in an ecosystem
Biotic factor
Caused by other living organisms
Abiotic factors
Involves non living components of the environment
Photosynthetic efficiency
Green plants convert Less than 3% of sunlight is into chemical energy
losses due to plant:
> Most light is reflected and not all wavelengths are used in photosynthesis
> some misses the leaf and some hits the leaf but misses the chlorophyll
> LOW CO2 limits photosynthesis
