Silviculture and Cinegetics Review - Societatea Progresul Silvic

FORESTRY BELTS SILVICULTURE AND CINEGETICS REVIEW XVII/30/2012
products and accessories; vi) increasing the surface
area covered by forest; vii) economic and social
protecting objectives and ways of communication
(forest belts prevent the heavy snow falls by
accumulation of snow in and near them); viii) creating
favorable conditions for development of wildlife; ix)
enhancing regional biodiversity; x) improving carbon
stock; xi) conserving energy; xii) rebuilding and
improving landscape.
To achieve protection forest belts in order to result in
a stable and sustainable agroforestry system there are
some technical elements to be observed. Thus, the
distance between forest belts should be 35 times the
maximum height of tree species, averaging from 150
to 150 m if necessary. For the effect of protection
forest belts to be maximized it will be placed
perpendicular to the main damaging winds. Protection
forest belts width varies from 5-7 rows, when placed
to improve microclimatic conditions, 7-8 (10) rows in
areas with strong and dry winds, 4-5 lines in areas
with less strong winds which have the role of snow
accumulation and distribution (Lupe, 1952). Planting
distance between rows of trees will be on average 2
m, and between trees on the line will be 1 m. For
maximum efficiency of the forest belt, its
uninterrupted length should exceed the height, the
ratio being at least 10: 1. In this way the influence of
turbulence on its end it's reduced. Its continuity also
influences the degree to which it shall function.
Species that make up forest belts must meet at least
three conditions, namely: i) should be resistant to
adverse stationary conditions (climate, soil, and
groundwater); ii) should have high growth; iii) should
ensure longevity of protection forest belt. For higher
ameliorative effect, forest belts are composed of
several species of trees and shrubs, arranged in a
specific order to be as resistant as possible to various
pests agents (wind, heat and / or excessive cold, etc.)
and produce as many resources (wood and
accessories).
Species of trees that make up a protection forest belt
may be: i) main or basic species, trees that can reach
large heights and diameters such as species of oak,
black locust, honey locust, ash, elm, poplar, etc.; ii)
secondary or help species, having a smaller size than
the basic ones such as maple, field maple, lime, pear,
flowering ash, Turkish cherry, etc.; iii) shrubs, small
wood species, used for shading and soil protection,
protection against the wind, soil improvement through
litter they give, such as privet, hawthorn, blackthorn,
oleaster, red dogwood, wild rose, smoke tree pea-tree,
five stamen tamarisk etc.
Although the main role of forest belts is the protection
of crops, the resulting agroforestry system presents
some important economic benefits, such as: i)
increasing agricultural production and improving its
quality; ii) diversification of production on the same
land area and therefore income diversification, which
may originate from both crops and from the forest; iii)
ensuring the sustainability of agricultural systems, by
creating stable cultures in time and avoiding any loss
of production.
3.4. Water courses protection forest belts
Water courses, lakes and ponds protection forest
belts, are strips of trees of certain widths, which are
planted between agricultural fields, pastures and water
surface, or between existing levees along watercourses
and surface for water quality protection, for the
stabilization of banks and for flood prevention or
mitigation, for improving the quality of agricultural
land and adjacent pastures (Fig. 5).
In general, concerns about water protection forest
belts were entered in the general issues related to
forest belts. But watercourses forest belts protection
have some characteristic features that distinguish them
from other groups of forest belts, namely: i)
watercourses protection forest belts extend over tens
or even hundreds of kilometers, crossing and thus
serving much larger areas than field protection forest
belts; ii) width of these forest belts is usually much
greater than the field protection forest belts; it can
vary between 30 and 300 m and can be made from one
or more bands, up to 100 m wide, alternating with
open corridors (Ionescu et al. 1960).
Fig. 5. Watercourses and field protection forest belts
(Bentrup, 2008)
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