Across
- 5. The gain by consumers in energy or biomass per unit area per unit time remaining after allowing for respiratory losses (R).
- 9. The arrangement or patterning of plant communities or ecosystems into parallel or sub - parallel bands in response to change, over a distance,
- 10. The orderly process of change over time in a community. Changes in the community of organisms frequently cause changes in the physical environment that allow another community to become established and replace the former through competition. The later communities in such a sequence or sere are more complex than those that appear earlier.
- 13. Use of global resources at a rate that allows natural regeneration and minimizes damage to the environment.
- 15. The critical threshold when even a small change can have dramatic effects and cause a disproportionately large resource in the overall system
- 16. The condition of a system in which there is a tendency for it to return to a previous equilibrium condition following disturbance.
- 18. A group of organisms that interbreed and produce fertile offspring.
- 20. The condition of an open system in which there are no changes over the longer term, but in which there may be oscillations in the very short term. There are continuing inputs and outputs of matter and energy, but the system as a whole remains in a more or less constant state.
- 22. An arbitrary group of individuals who share some common characteristic such as geographical location, cultural background, historical timeframe, religious perspective or value system.
- 23. A vertical section through a soil, from the surface down to the parent material, revealing the soil layers or horizons.
Down
- 1. A system in which both matter and energy are exchanged with its surroundings (for example, natural ecosystems).
- 2. The gain in energy or biomass per unit area per unit time remaining after allowing for respiratory losses (R).
- 3. The term used for any haziness in the atmosphere caused by air pollutants. Photochemical smog is produced through the effect of ultraviolet light on the products of internal combustion engines. It may contain ozone and is damaging to the human respiratory system and eyes.
- 4. The total gain by consumers in energy or biomass per unit area per unit time through absorption.
- 6. When energy or matter flows and changes location but does not change its state
- 7. Species that tend to spread their reproductive investment among a large number of offspring so that they are well adapted to colonize new habitats rapidly and make opportunistic use of short-lived resources.
- 8. The total gain in energy or biomass per unit area per unit time fixed by photosynthesis in green plants. crude birth rate – crude death rate
- 11. A system in which energy, but not matter, is exchanged with its surroundings.
- 12. A set of inter-related parts working together to make a complex whole
- 14. The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains.
- 17. The process through which new species form. See also evolution .
- 19. A mixture of mineral particles and organic material that covers the land, and in which terrestrial plants grow.
- 21. When energy or matter flows and changes its state (chemical or physical change)