Today, scientists are aware of around 320,000-500,000 different species of plants, but they estimate this number to be much higher. Many of the known trees and flowers come from Asia, while other species of plants thrive in the tropical rain forests. Some plants have adapted to live in or below water, whereas some have adapted to live in the desert areas. Algae, lichen, and moss also belong to the plant kingdom. Lichen: Many lichens grow in inhospitable terrain; for instance, in the rocky highlands and cold Arctic. They also grow on the walls of the houses in big cities. The growth rate of lichens very slow -a few species grow less than one millimetre in a year. If you step on them, you may destroy in seconds a plant that took hundreds of years to grow. Since lichens are very sensitive to air pollution, they are often used as pollution indicators. The cleaner the air the more lichen will grow. ...
Diversity of Species: Deer, bears, salmons, pelicans, elephants, oaks, cacti, algae, lichens -any list illustrating the huge diversity of species on the Earth is inevitably and unending one. Many animals and plants inhabit our gardens; others live on high mountains or in colourful shimmering coral reefs. All of them have adapted to their environment in order to survive. This is all the more true in the case of animals that live in deserts or in extremely cold regions. Unfortunately, we are increasingly destroying the habitats of animals. We are clearing forests and polluting seas and coastal areas. What do plants live on? We know very well what animals eat. But what do plants do to live? almost all plants and animals need air, water, light, and nutrition to grow. Green plants use a complicated chemical process, called photosynthesis, to create energy for survival and growth. In this process the chloroplast inside the green leaves o...