- Tytuł:
-
Wiek rębności w lesie normalnym oraz lesie celowym
Rotation age in normal and target forests - Autorzy:
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Klocek, A.
Piekutin, J. - Powiązania:
- https://bibliotekanauki.pl/articles/973332.pdf
- Data publikacji:
- 2015
- Wydawca:
- Polskie Towarzystwo Leśne
- Tematy:
-
model lasu celowego
model lasu normalnego
drzewostany
proces ubywania
proces przezywania
leśnictwo
wiek rębności
deterministic model of normal forest
probabilistic model of target forest
survival and mortality processes - Opis:
- The paper focuses on the deterministic model of normal forest, the probabilistic model of target forest and the processes related to the survival and mortality of forest stands suitable for these models. They are the basis for the assumptions, presented in this paper, of two different methods of regulating rotation age adequate for normal forest and target forest. Optimizing the rotation age of a stand is essential for the regulation of forest production. It aims to establish such an age−dependent state of stand, which is the most desirable from the point of view of the adopted forest management objectives. Because of the long−term cycle of stand development, optimizing the age at which a stand is considered mature for felling usually means maximizing the average annual increase in stand volume. Under the conditions of normal forest, the concept formulated in the first half of the nineteenth century, the above optimization criterion has the form of the equation [2]. The current annual increase of timber production (Pb (tu)) at the optimal rotationage (tu) is equal to the average annual increment (Pp(tu)). At this age, the intensity (rate) of thecurrent growth of the production function (Pb(tu)/P(tu)) becomes equal to the fractionof the stand area (1/tu). These relationships are illustrated in figure 3. The model of target forest is derived from the random nature of two opposing processes described as 'survival' and 'mortality' of forests. This is reflected in the transition probability matrix where a forest stand moves from the younger age class to the older or to the youngest age class. The probability function (U(t)) of stand survival in individual management periods (t) developed on the basis of these data, is one of the main parameters of the optimization equation for the rotation age of target forest [11]. Formula [13] indicates that the optimal rotation age (t=tu) is when the rate of growth in the volume of merchantable timber (Pb(t)/P(t)) and the negative growth rate (decline) for a part or the entirestand (Ub(t)/U(t)) are equal to a fraction of the stand area. These interactions are illustrated infigure 8, which additionally presents the effect of the decline in the survival rate on the optimal rotation age (tu). This age may be analyzed separately for natural disasters and for clear−cuttingof stands in accordance with the forest management plan. These two categories of effects mayalso be dealt with jointly.
- Źródło:
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Sylwan; 2015, 159, 12; 971-988
0039-7660 - Pojawia się w:
- Sylwan
- Dostawca treści:
- Biblioteka Nauki
Artykuł