The Environment

3. a barrier built across a river to prevent the flow of the water or to retain water.
4. an organism that is not native to an ecosytem.
6. the loss of tosoil due to natural, animal, or human activity.
9. a fishing method in which a fishnet is dragged through deep waters.
10. the proces of cutting up into fragments the species´terrestrial or aquatic habitats.
12. a condition in which food or other resources are insufficientlyavailable.
14. the process in which a habitat becomes unable to meet the needs of its resident species.
15. the process in which a large portion of soil slides down a slope.

1. a species at a very high risk of becoming extinct.
2. the uncontolled spread of houses or buildings around a city.
5. the practice of cutting trees to sell them as timber or pulp.
7. the plants and animals that are native to a particular region of the world.
8. the process of damaging the natural habitat of species that results in serious biodiversity loss.
11. the excessive amount of water on dry land that the soil is unable to absorb.
13. a decline in the quality of a habitat.