Trees have many uses to people. For this reason, the tree deserves to be given the recognition as "nature's greatest provider."
Trees and their management
From birth to death, man uses wood and other products from trees. The truth is, humanity would not have survived this long without trees. Taken collectively, trees supply life-giving oxygen and help purify the air. They provide shade and add beauty to the landscape. They serve as protective barrier for crops and animals against destructive wind. At the same time, the leaves, fruits and seeds of many species contribute to humankind's supply of work energy Furthermore, the roots of trees hold the soil together and help minimize erosion and the occurrence of floods during the rainy season. It is for these reasons that trees and woody perennials, in general, are important components of an agroforestry system.
One of the important characteristics of trees is their long life cycle (they are perennials). To a large extent, this characteristic is responsible for many of their beneficial influences to the environment and associated crops. For example, a canopy of trees provide long-term protection to soil against the erosive impact of raindrops. However, their long life also implies that farmers need to be careful in selecting trees to plant because once established, they are hard to replace.
Tree culture normally involves nursery management, tree establishment in the field, care and maintenance and harvesting.
There are cultural practices that are peculiar to trees. Seeds are not as widely available and there are usually no established centers where one can buy tree seeds. In many cases, farmers may have to rely on collecting seeds from standing trees. Tree seedlings take a longer time to raise than annual crops. Some trees may take as long as one year in the nursery before they are ready for field planting.
In the establishment of trees in the field, spacing is usually very important because it will largely control the rate of growth, size and form of the trees. One peculiar care and maintenance activity is pruning which is undertaken to remove unwanted branches or, in some cases, to suppress growth as in alley cropping.
A few years after planting, trees normally need minimal care while, at the same time, their beneficial effects continue to increase.
Harvesting of trees for wood is another unique activity.