The Myanmar's forest is one of the greatest natural resources because they cover large areas and many of the trees and other plants in them have been used for timber, for wood, and many other products.So it is not the same the temperate forest which found that mostly pure forest .The used of the system in pure forest are clear felling. Myanmar timber production system are not the same as found in pure forest. In the early 20^th century, the German forester Dr.Brandis found the way of scientific management system for Myanmar's natural forest.These system was world-renown and it was called Burmese selection system and now Myanmar selection system (MSS).
Image source; Google image
Under the management of MSS, forest lands are organised into felling series, each of which divided into 30 blocks of approximately equal yield capacity. One block per year is harvested and the whole felling series is worked in the course of a 30 years felling cycle. In each block due for harvest, marketable trees with diameter at breast height (dbh) at or above the fix exploitable limit which vary depending on the forest type, are selected and cut. The extracted volume must be within the bound of the annual allowable cut which is determined for each felling series based on the principle of sustained yield management.
For teak, which is usually girdled and left standing to dry and season for three years before felling, the exploitable limit with the type and condition of the forestsforest, 73 cm (dbh) in moist forest with good growth rates and 63cm (dbh) drier types. But now teak is exploitable without using girdle rule.
The limit for other hardwoods, which are felled green vary by species. Exploitable limits are determined and fixed at sizes beyond which trees are not expected to put on appreciable increment and where their retention would interfere with the growth of young trees and impede regeneration. Howeve, some trees at or above the exploitable limit may be retained; where seed-bearers are, for example, superior tree at and above the exploitable limit may be cut as seed trees, while unhealthy trees below the limits can be removed if they are marketable and unlikely to survive through the next cycle. Trees retained at the time of selection are recorded to provide a reliable basis for calculating future yield.
Apart from the extraction of mature and senescent trees, which itself can be considered a cultural operation, various kind of silvilcultural treatment s are provided for a range of conditions to improve the natural regeneration of teak and to protect immature stock and assist it in attaining a healthy maturity. These include improvement felling, natural regeneration, thinning in congested naturally regenerated stands, felling of nyaungbat, climber-cutting etc.
MSS system is an excellent and also the only feasible way of working the multiple-species, complex natural teak bearing forests of Myanmar.It not only well growth to Myanmar's forest in which close to a thousand tree species grow but also causes little ecological damage.