DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu



ŠUMARSKI LIST 7-8/1970 str. 19     <-- 19 -->        PDF

f) Visinska krivulja dominantne etaže sastojina iste starosti, a različite šumske
zajednice, razlikuju se uglavnom u položaju.
g) Starije sastojine hrasta lužnjaka imaju uglavnom strmije visinske krivulje,
što je posljedica podstojne etaže hrasta lužnjaka u tim sastojinama.


h) Prema našim istraživanjima na položaj visinskih krivulja iste šumske
zajednice utječe starost, a na njen oblik način gospodarenja (podstojna etaža
hrasta lužnjaka).


Standradne visinske krivulje hrasta lužnjaka trebale bi se izraditi posebno
za svaku šumsku zajednicu istog načina gospodarenja.


Tarife izrađene na osnovu ovih standardnih visinskih krivulja sigurno bi
imale zadovoljavajuću tačnost, a i određivanje sastojinskog visinskog prirasta
bilo bi omogućeno iz dviju standardnih visinskih krivulja.


Potrebno je naglasiti da je istraživanje visinskih krivulja hrasta lužnjaka
provedeno u relativno malom broju sastojina zbog skučenih financijskih sredstava
te bi se radi toga trebala provesti daljnja istraživanja u tom pravcu.


Summary


STAND HEIHT CURVES OF PEDUNCULATE OAK
(QUERCUS ROBUR L.)


The most widespread and valuable species in this country´s lowland forests is
Pedunculate Oak. It occurs in even-aged stands whose height curves h = f (d) are
of transient character.


The purpose of this work is to determine the form and position of Pedunculate
Oak height curves, the influence of age and site quality (forest type) on the course
of the height curve of individual parts of stands (storeys). This would somehow be
explanatory to some extent of the possibility of constructing standard height curves
of even-aged stands and one-entry volume tables for these stands.


Relevant data were taken in the area of the forest district of Lipovljani, management
unit »Josip Kozarac«. Measured were cca 4,000 tree heights by means of
»Haga« hypsometers (whose accuracy is lrj/o, while for each hypsometer a correction
of marks on the rod was made). The heights were measured within strips cca 30 m.
wide and cca 300—400 m. long in 50-, 70-, 90- and 120-year-old stands, compartments
Nos. 187, 148, 155 and 107. In each compartment were laid out 5 strips. Strips 1 and
3 represent with respect to the microrelief, soil and vegetational conditions different
sites, while strip No. 2 represents transitional forms between these two sites. On
microelevations called »greda«, i. e. the site of Pedunculate Oak and Hornbeam
(Carpino betuli-Quercetum roboriK, Anić 1959), there were laid out all strips No. 1.
In microdepressions called »niza«, i. e. the site of flooded forest of Pedunculate Oak
(Genisto-Quercetum roibori, Horvat 1938), there were laid out strips No. 3. Strips Nos.
4 and 5 were laid out perpendicularly to strips Nos. 1, 2 and 3, and they include
forests of Pedunculate Oak and Hornbeam, flooded Pedunculate Oak forests, as well
as the transition type between the mentioned stands (Fig. 1). During the measurement
of height the trees were classified into dominant, auxiliary and understory trees
according to the biological-economic classification by Dekanić (4). In 120-year-old
stands the heights were divided into two groups with respect to the 40 cm. diameter
breast high.


Taking into consideration that Furnival´s index of insertion (9) is approximately
equal for the examined functions (Tab. 1), there were presented both results of regression
analysis and results of testing height curves on the basis of Mihajlov´s
smoothing function in its logarithmic form In (h-1,3) = In a + bd-1.


Processing of data was carried out on an electric computer C 90—40 at the Institute
»Ruđer Bošković«.
The application of weights — in view of the heterogeneity of variances of actual
heights within the diameter sub-classes — was not taken into consideration, because