We then meet our energy needs, along with our nutritional requirements, from the plants, either directly, when we eat the plants, or indirectly, when we consume animals who themselves have plants at the beginning of their food chains. Of course, plants give us much more than energy and nutrition. They play a large role in regulating and maintaining the temperature and the liquid and gas makeup of the atmosphere. By absorbing water and by holding soils in place they prevent flooding. They provide natural beauty, materials for shelter and clothing, and components of soaps, oils, resins, and cosmetics we use every day.
Plants now go extinct at a rate of two to three species per day.
Many more are in danger of extinction, and the rate is likely to go up as human activities take their toll on the plants' natural habitats. The less there is of such genetic diversity, the more likely the species is to face endangerment or even extinction. There are many reasons to protect endangered plants and their habitats. Even for food plants found widely throughout the world, rare strains exist that hold the genetic keys to healthier and more nutritious varieties. Perhaps the most compelling reason to save plant species is to give us time to learn what we can do about their medical and other properties.