We all know what trees are—we run around, climb on, play with, scribe on and some of us even chop down trees. Trees can be safely described as large plants which live longer than two years. Trees are essential to life. Every day, we see dozens of messages stressing on the importance of protecting trees and planting new ones. Trees are responsible for providing clean air, binding soil to ground and providing food and habitat to millions of organisms including mankind. These, however, are just primary uses of trees, the secondary functions of trees as providers for various products being limitless. Trees also affect the climatic condition of a particular place. They are not only responsible for rainfall, but also help balance the greenhouse effects. The trees across the world are divided into two types based on their reproduction techniques and shedding of leaves. In the following lines, we provide information on the different kinds of trees.
Different Kinds Of Trees
On The Basis Of Reproduction
Non-Seeding Trees (Ferns, Spores)
These are the kind of trees which do not produce seeds at all. Such trees reproduce from parts of the tree itself or spores. They are the oldest types of plants on the planet. They are not dependent on pollination or any other phenomenon for sustenance of species.
Seeding Trees (Spermatophytes)
These trees appeared relatively later in time. They reproduce by sexual or asexual reproduction, but the offspring are related to seeds, which are produced by the plants. Plants are mostly hermaphrodites with rarest exceptions. Seeding trees are again divided into two divisions namely gymnosperms and angiosperms.
Gymnosperms: These are seed-bearing plants, whose seeds do not form inside the fruits, but outside the ovum. They do not form flowers or fruits. Majority of seed-bearing plant types are gymnosperms including Conifers, Cycads, Ginkgo and Gnetales. There are between 700 and 900 species of gymnosperms in the world. Though Conifers (second most dominant types) are available in abundant numbers even now, Cycads, Ginkgo and Gnetales are all but extinct and very few species are left (if at all).
Angiosperms: These are the most dominant division of seed-bearing plants in the world today. Their distinguishing characteristics include flowers, endosperm within the seeds, and the production of fruits that contain the seeds. The precursors to flowering plants diverged from gymnosperms around 245–202 million years ago. Most of the plants that we see today are angiosperms.
On The Basis Of Shedding Leaves
These trees remain green year round; that is the trees belonging to this section never shed their leaves completely and have leaves throughout the seasons. Most trees belonging to the tropical rainforest and temperate warm climate are evergreens, replacing their leaves gradually throughout the year, as the leaves age and fall. Such trees more easily fall prey to pollution as compared to the deciduous varieties.
The term deciduous mean “falling off after maturity”. Such plants shed their leaves periodically, mostly during winter seasons. The process by which deciduous plants lose their leaves for a part of the year is called “abscission”. They are predominant in temperate areas with cooler climates, where winters are extreme. In areas including tropical, subtropical and arid regions of the world, the trees shed their leaves in dry summers or times with varying rainfall.