Vc. Volin et J. Buongiorno, EFFECTS OF ALTERNATIVE MANAGEMENT REGIMES ON FOREST STAND STRUCTURE, SPECIES COMPOSITION, AND INCOME - A MODEL FOR THE ITALIAN DOLOMITES, Forest ecology and management, 87(1-3), 1996, pp. 107-125
The aim of this study was to predict the long-term effects of alternat
ive management regimes for uneven-aged mixed-species forests in the It
alian Dolomites, among the most beautiful in the Alps range. For this
purpose, a non-linear matrix model of stand growth was estimated from
re-measured stands, and the predictions compared with actual data. The
n, long-term simulations were used to determine the effects of (i) ext
racting some mortality only; (ii) applying Susmel's (1980) management
guides; (iii) cutting only trees above a diameter limit, (iv) saving t
he beech, and (v) continuing the current harvest rate. The ecological
criteria to evaluate the different management regimes were basal area
and stand composition by tree species and size. The economic criterion
was the net present value of the harvests. The results suggest that,
for a 10-year cutting cycle, applying Susmel's guide or a diameter-lim
it cut of 70 cm for conifers and 50 for beech would keep diversity of
species and size equal to that of an unmanaged stand, though lowering
basal area. Of the two, Susmel's guide would give 25% higher income. H
owever, income could be doubled by lowering the diameter-limit cut to
60 cm for conifers and 45 for beech. This would give the same basal ar
ea and species diversity, but decrease size diversity by about 6%. The
policy that did not allow to cut beech resulted in stands that had le
ss beech than those obtained by Susmel's guide or diameter-limit cuts.
Perpetuating the current cutting rate gave the highest tree size dive
rsity, but lower species diversity and the lowest income. Of cutting c
ycles of 5, 10, and 15 years, the longest gave, other things being equ
al, the highest basal area and size diversity, slightly lower species
diversity, but substantially lower income.