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The
coppice area in Italy. General aspects, cultivation
trends and state of knowledge Emilio Amorini – Gianfranco Fabbio Annali Istituto Sperimentale per la Selvicoltura 1992, 23: 292-298 INTRODUCTION The large presence on the national territory and the extension of the interested forest area underline the importance of coppice forest in Italian silviculture. 3.600.000 hectars concerned represent in effect two thirds (about 63%) of the forest cover. The dominance of coppice forest in comparison to hight forest depends upon social and economic conditions which throughout centuries characterised the history of Italian silviculture until a recent past. The coppice area is quite diversified and covers all the vegetation layers from the mountain to the mediterranean one. The main forest types are: beech coppices, chestnut coppices, coppices with dominant hornbeam, deciduous oak coppices, turkey oak coppices, ever green oak coppices, cork oak coppices, mixed coppices. The
type of ownership, largely private (76.3%), strongly influenced up today
the management and the silvicultural interventions. Exception to this
general condition are the beech area, where public and private ownership
are equal, and the chestnut area almost totally belonging to private
owners. An other interesting aspect, concerns the extension of coppices in
age classes: below or above 20 years. Over the half of the area falls in
the other class, which underlines the important present tendency against
the shorter rotations generally applied in the past. In effect, in the
past decades, the coppice management system didn’t correspond anymore to
the present economic and social condition of the country. The usefulness
or necessity of coppice management has lost importanee, a new balance
between coppice and high forest has become possible. PRESENT
TECHNICAL TENDENCY Because
of a general reduetion of harvesting, very different situations appear
today according to species composition, age, stand structure, bioecological
conditions. In the private area, the increasing gap between price of
fuelwood and harvesting costs has led to the concentration of the
traditional coppice management on best sites; and to the prolungation of
the rotation in order to concentrate higher standing volumes, in marginal
conditions. Rapidly increasing costs have anyway cancelled the advantadge
of longer rotations: therefore, wider areas of coppice forest have become
economically marginal. The public ownership, on the contrary, stopped the
coppice management especially on poor sites, leading to the abandonment of
large areas and favouring the conversion unto high forest in better site
conditions. The consequences of these tendencies are quite evident, having
led to three areas characterized by a decreasing degree of silvicultural
activity. The
conversion area, less
extensive but most significant because of its silvicultural significance,
is the necessary reference for the future, alternative choices of coppice
management. Therefore a continuous, improved knowledge is needed in order
to give an experimental basis to the conversion techniques. The
area where the coppice management will be continued, the largest
one still today, needs a revision and updating of silvicultural
regulations in order to ensure a sustainable functional level of this
management system. The
area where any harvesting has been stopped is heterogeneous and
variable; largely different site conditions are to be found, from some
mediterranean maquis, to mixed ceoppices, to beech coppices. In this area,
different conflicting objectives coexist. The private owner waits for a
biomass store in order to continue coppicing with an economic gain. The
public organisation aims to a better evolution of the stand by natural way
or by means of silvicultural rules. The basic knowledge on the dynamics of
evolutive pattern developing in abandoned coppices needs to be greatly
improved. SILVICULTURAL
TECHNIQUES The
above described situation demands the solution of technical problems
specific for each of the characterized areas. Coppice
area. The
possible cultivation interventions aimed to the improvement of coppice
stands are: prolungation of the rotation cycle, regulation of standards
density, gaps reforestation, enrichment plantings. The prolungation of the
rotation cycle is a sure, positive implement because it ensures a richer
return of organic matter to the soil, and reduces the negative effects of
the previous short rotations upon site fertility. The regulation of
standards number is fundamental for a rational management of coppice
stands. The choice of the standards shall follow, besides the classical
quality criteria (good development, balance between stem and crown,
vegetative conditions), sound lines of interpretation of the specific
stand composition, in order to ensure a balanced presence of the different
tree species. Coppices enrichment (by planting or sowing the already
present or other species, broadleaves or conifers), ensures the
reconstitution of the stand structure and enriches the specific tree
composition. Area
where any harvesting has been stopped. The
large fan of stands which fall into this category puts indirect management
problems at the territorial level, such as the fire risk control and the
definition of the future stand use according to the biological and
structural evolution of the stands throughout the waiting time. Conversion
area. For
some species (evergreen oak and mixed coppices) the definition of
technical methods for the conversion into high forest is needed. For other
species (turkey oak and beech) the period of “transitory crop” must be
technically defined. Evaluation of the possible market of the products
(intermediate and final products). Evaluation of the technological
characters of wood from the different species. STATE
OF RESEARCH AND POSSIBLE DEVELOPMENT In
the first area - where the coppice management will go on -, besides the
present knowledge, new information elements capable to ensure a sound
basis sustainabie management of this cultivation model need to be acquired,
namely: ·
studies
on the agamic reproduction physiology; ·
studies
on standard density and evolutive pattern according to the multiple aim of
this technique, as well as on the relations between two structural
elements (shoots and standards) of the stand; ·
relation
site-management system; ·
dynamics
of shoot population; ·
study on
thinning techniques and final harvesting according to more rational
harvesting and logging methods, given the availability of equipments and
systems able to reduce soil and stand damages; In
the second area - no management - a better data base should be established
on the evolutive models of these typologies, poorly known because
inexistent before the cultural abandonment. This area includes a large
spectrum of reserch, which goes from species autoecology and stands-site
relations to the analysis of tree mixture dynamics, competition processes,
evolutive pattern of stand structure, biometric characterisation and
growth models which develop with age. In
the conversion area, more knowledge is needed on a bio-ecological basis to
define the management criteria, and the techniques of conversion into high
forest of typical mediterranean coppices (evergreen oak and mixed coppices),
the less studied species until today. The
intermediate management phase is the subject of analysis proposable he in
the historical conversion area which benefits of twenty years of
experience in the area of deciduous oaks. The following specific actions
may be outlined: ·
population
dynamics as a function of the applied management (social ranking and
competition processes); ·
relations
among the main crop, the stump sprouts and the shrub layer; ·
tinning
regime in transitory crop; ·
stand
functional efficiency in relation to silvicultural treatment intensity; · growth pattern of the tree fraction according to the social rank
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