The study of dispersal of plants on the globe involves the consideration of nature and factors of dispersal, dispersal of flowering plants, role of man in plant dispersal etc. Nature and Factors of Dispersal: The present-day distribution of plants over the globe is the result of migration of plants over time into ecologically suitable areas. The spread or migration of [...]
In this article we will discuss about historical evolution of the plants that can be traced through the geological periods. (1) Evolution of organisms on the earth's surface begins from the pre-cambrian period when probably the first life in the form of single celled or unicellular microscopic organisms resembling the present-day cocoid or spheroid bacteria, was evolved in aquatic environment. [...]
There is a wide range of variations in the distribution of vegetation on the globe. There is a zonal pattern of vegetation from equator towards the poles and from seal level to vegetation level on the high mountains. The distribution of plants is affected and controlled by a variety of factors e.g.: (i) Climatic factors (sunlight, temperature, moisture and humidity, [...]