The Institute of Wood Science and Technology (IWST), has conducted an analysis of plantations in five states — Tamil Nadu, Karnataka, Kerala, Andhra Pradesh and Telangana.
It has found that the loss to timber plant grower is because of the unnecessary pruning of the timber trees.
What is Pruning?
Pruning is the practice of removing a specific part of a tree or shrub drying or dying due to pests, diseases and lack of sunlight.
Several tree species self-prune; it is a part of their biological process.
Fruit farmers also prune trees, such as mango, pomegranate, moringa and mulberry after every harvest, based on recommendation from horticultural scientists.
But here, apart from maximising yield, the practice is also for convenience.
Pruning limits the height of the branches and ensures easy access to leaves, flowers and fruits. The removed limbs, if healthy, can then be replanted.
Similarly, trees in public parks and gardens are pruned to control their shape and structural integrity, thereby increasing their aesthetic value.
Effects of pruning:
The bark is the trees’ first line of defence; it protects the inner layers of the stem — sapwood, which forms the peripheral part of the trunk just beneath the bark and heartwood, the central core.
But when branches are pruned, the bark gets wounded and dries and the cut ends expose the inner tissues.
Bio-deteriorating organisms such as wood-decaying fungi (namely Allophoma tropica, Ganoderma applanatum and Xylaria berteroi) and insects like wood borers tend to feed on the dried bark and infest the cut ends of the stem.
Soon, they attack the inner layers and cause decay. This makes the tree weak; leaves grow small and fruits drop prematurely.
Pruning-induced wounds also hinder the natural growth of branches, leading them to bunch profusely at certain points.
This disrupts the tree’s balance and makes it vulnerable to heavy winds.
Pruned trees often need support from wooden planks to stay upright, but these too attract termites when they dry. In many instances, such trees die quickly.
Pruning has also restricted pollinating insects from accessing nutrient and nesting resources, affecting their foraging and nesting behaviour and phenology and reproduction.
This will have an adverse effect on cross-pollinating species like sandalwood and teak.