It is a silvicultural system in which equal or equi-productive areas of mature crops are successively clear-felled in one operation to be regenerated most frequently, artificially but sometimes naturally also.
The entire crop of the coupe should be felled and removed in one operation, but in practice, some mature trees are uncut due to the following reasons:
- Frost protection (sometimes retained to serve as a nurse crop)
- To prevent the unnecessary sacrifice of immature crop
Types of Clear felling system
- Block-clear felling system
- Clear felling in patches
- The clear strip system
- The alternate strip system
1. Block-clear felling system
In this system successive clear felling and regeneration is carried out in a particular area (Block). This system is adopted in large area for sustainable yield production.
|Block I||Block II|
|Block III||Block IV|
2. Clear felling in patches
Clear felling is done in small or big patches. This system is applied on irregular terrain or even age stands that lack uniformity.
3. The clear strip system
In this silvicultural system, clear felling is done in the form of strips that progress successively in one direction across the regeneration area. The feeling is usually done against prevailing direction of the wind across the regeneration area. The area is divided into cutting sections, divided into a number of strips. In this case, the seeds from the un-felled area may be disseminated on the cleared strip. The width of the strip depends upon the distance to which the seed can be disseminated by the wind.
4. The alternate strip system
In this silvicultural system, clear felling is done in the form of strips in which clear felled strips alternate with un-felled stripes. The un-felled stripes provide protection against wind and also supply seeds to felled strips.
- It is the simplest method of all high forest systems.
- Yield per unit area is more and the cost of felling & extraction is low.
- The distribution of age class is very regular.
- There is no damage to new crops by felling.
- There is a provision for complete overhead light
- Desiccation and general degradation of the soil are a result of exposure to the sun, air, and water.
- Multiplication of insects, fungi, bacteria, etc which are harmful to the young crop.
- It sacrifices all immature crops that may be still putting on valuable increments.
- This system is not friendly for the wildlife, because wildlife loses habitat and as a result, migrates to some other place.
- Not suitable on the hilly and sloppy areas as there is an ever-present danger of landslides.
Application of Clear Felling System in Nepal
In the case of Nepal, the Clear felling system was introduced in 1979/1980 in Sagarnath Forest Development Project. The conversion of Sal forest to plantation forest was done through clear felling system. Similarly, the Ratuwa Mai plantation project and Nepalgunj plantation project also converted the high Sal forest into a plantation forest by a clear felling system (White, 1988). But it was a part of the conversion of the forest rather than the clear felling system.
Similarly, In Nepal, Clear felling system was practiced in scientific forests for the sustainable production and harvesting of forest resources.