Articles containing the keyword 'kasvuennuste'

The purpose of the investigation was to study the factors which determine the amount of the largest permanent allowable cut and to work out a method to estimate it. There is a need to have a ’short cut’ formula for rough preliminary estimates. The preliminary estimates will be checked by stock development forecasts. The largest allowable cut and its sustained basis are only guaranteed by a forecast through a period during which all the present tree stands have reached maturity and exploited.

Estimations of the largest permanent allowable cut are based on the data of the present and desirable growing stock. The present stock was a growing stock of Scots pine (Pinus sylvestris L.) dominated stands on Vaccinium type forests in Southern Finland. The connected Austrian formula is a simple way for preliminary estimation of the largest cut but its sustained basis must be checked by a stock development forecast.

In a stock development forecast the future increment and cut are calculated. For this purpose, the average site quality, tree species, age class and average volume in each class seem to be sufficient variables. The forecast is carried out within the limiting data of the present and desirable stock.

If there is an abundance of mature and over-mature stands, the largest permanent allowable cut is greater than the present increment, provided, however, that bulk of the cut is drawn by determined generation measures. Measured in solid cubic meters, the sustained cut from the Southern Finnish pine stock exceeds the present increment by 11%. With regard to the sustained saw timber production the cut can exceed the present increment by 5–7%.

The PDF includes a summary in English.

• Kuusela, E-mail: kk@mm.unknown

The purpose of this study was to clarify increment forecast methods in connection with the cutting budget. The emphasis is laid on the Finnish increment per cent methods. A tentative attempt is made to carry out a passage calculation. Increment forecasts are accomplished for diameter class distribution of a 60 years old Scots pine (Pinus sylvestris L.) stand. The increment data for the growing stock are taken from the domestic increment calculating tables.

When comparing the results of the two methods, the increment values are expressed in rabatt per cent in which the forecasted annual increment is in proportion to the initial value of the growing stock. It will be emphasized that the weak point in the domestic budgets is in the relation between the increment of the developable stock and the increment of the exploitable stock. Almost all the Finnish increment data are from the developable trees and the estimates of the increment of the exploitable trees have not been on sufficient facts.

The PDF includes a summary in English.

• Kuusela, E-mail: kk@mm.unknown