Except for students of botany, many readers may not know what the term ‘embryophytes’ connotes. Embryophytes is the botanical term for common plants that have leaves, undergo photosynthesis, have roots and are multi-cellular. They include all the common plants known to us like the herb variety including the Banana plant, trees of the tropical variety like coconut palms, date palms, deciduous trees like mango, Guava, etc., and coniferous tress like pine fir, birch, silver oak, etc.
The category of embryophytes also includes ferns and mosses. But the distinguishing element is their ability to carry out photosynthesis by extracting energy from sunlight for their survival. They give out oxygen and absorb carbon dioxide form the environment. This ability of plants makes them complementary to animal life as all animals life is dependent on inhaling oxygen that plants exhale during photosynthesis.
Hence the importance of green tree cover for cities where the concrete jungle replaces the real one. Hence the importance of trees and gardens that are looked upon as the lungs of a city. Hence the justification for afforestation and the concern against deforestation.
This is also the reason why people have plants indoors, as the potted plants purify the air inside the home and in turn give us good health. The reason why we go out on vacations to forested hills is to breathe in the fresh air there, all of which comes from this process of photosynthesis.
At the hill stations the preponderance of trees along with the lesser density of the human population makes for the air to be healthier.
To test out the quality of embryophytes take any sapling and place it in a jug full of water and place the root of the plant inside a test tube. Invert the test tube inside the jug full of water. Place the plant in direct sunlight and watch how gradually small bubbles are released by the root and these bubbles accumulate at the top of the test tube. These bubbles are the oxygen that is being released by the plant in the process of photosynthesis.
During this process of photosynthesis, plants absorb and break up carbon dioxide in to organic compounds and release oxygen in to the air, thus filling the air so necessary for human (and animal) life.This process represents the balance that nature has so artfully worked out between plant and animal life where one canto survive without the other. The reason why sensible folks raise their voice against deforestation and reduction of green cover is precisely this.
The entire case for the importance of embryophytes, which in common parlance are trees and plants, rests on this fact.
Sources:
Embryophyte
http://www.merriam-webster.com/dictionary/embryophytes
Embryophyte – Definition
http://www.wordiq.com/definition/Embryophyte
Wikipedia on Embryophyte
http://en.wikipedia.org/wiki/Embryophyte