Poaching refers to the illegal hunting of wild animals in violation of the laws which regulate hunting of wild animals. Over utilization refers to the exploitation of an animal to the point of extinction. Poaching activities include hunting and killing wild animals without licence, using illegal weapons to kill animals, killing animal out of season, etc. All these activities can lead to drastic reduction in the population of animal specie to the extent that the animals become extinct. A good example of an over utilized animal specie is passenger pigeon.
<u><em>Growing plants in space is tough -- low gravity means water distribution is difficult to manage, the roots are often starved of oxygen, and stagnant air reduces evaporation and increases the leaf temperature</em></u>