Grazing Management of Evergreen Brushlands
in Greece1
Leonidas Liacos2
Greece is an east mediterranean country. Its
climate is typically mediterranean, ranging from
the arid to the perhumid of Emberger's (1955)
classification. The most significant of its
features from the standpoint of production and
management is that water is the main limiting and
regulating factor for plant growth. This is
especially true in the maquis zone. Increase in
soil water storage could contribute to an increase
in biomass production, particularly in the driest
zones, through improved evapotranspiration
efficiency and greater precocity of plant growth
(precipitation is concentrated in winter and early
spring).
Maquis vegetation occupies a great part of the
territory of Greece. A considerable part of
Greece's land area is covered by evergreen brush
vegetation, the dominant species of which is
kermes oak (Quercus coccifera L.), and this species
is also the most abundant plant in the typical
maquis formation. Kermes oak brushlands outside
the maquis zone are a degraded state of former
productive high forests, mainly deciduous broadleaf oaks. These formations, covering 783,000 ha,
and making up 15.4 percent of the total area of
Greece, are the typical browse rangelands.
The main use of these brushlands during the
long past of Greece's history was grazing by
livestock, especially goats. Their use for
fuelwood production was also quite intensive.
Irrational use of these natural resources over long
periods, coupled with frequent wildfires, has
greatly lowered their productivity. Therefore
bedrock now extends over a large part of the
ground surface, leaving a relatively small area to
shallow poor soils.
At present, the usefulness of Greece's sclerophyllous evergreen brushlands is multiple. The
Abstract: Evergreen brushlands in Greece occupy
783,000 ha. Their main use in the past and at
present is for grazing by livestock, especially
goats. Irrational long grazing has lowered brush
cover and density of the most productive and
desirable species. Now kermes oak is the dominant
species, represented by various browse types.
Production of natural kermes oak stands of 100
percent cover was found to be 30 kg meat/ha/yr.
Improvement experiments have shown that meat
production can be doubled if brush composition and
management form are improved, and increased by
four times if brush is partly converted to grass.
following uses should be emphasized:
a) Fuelwood: The increased cost of heating
houses with oil or electric energy has forced
people, especially in small towns and villages, to
return to wood for heating. Thus, an old market
has been reopened, making fuelwood production a
viable economic operation in managing maquis.
b) Production of Energy: The energy crisis,
especially distressing in the countries that, like
Greece, are poor in traditional energy resources,
brings about the use of maquis biomass for energy
production (Margaris 1980). Certainly, relative
research must specify the conditions under which
such utilization could be feasible and justified.
c) Landscape and Recreation: Maquis vegetation
has great esthetic and recreational value. It
extends over the low-elevation land of Greece
along and around its sea shores and beaches, which
are great tourist attractions. This fact might
even justify the exclusion of any other use.
d) Soil Protection: Evergreen brush vegetation
effectively protects the soil against erosion.
Under Greece's climatic conditions, particularly,
with heavy rains during the winter, evergreen
brush plays an important role in soil stability.
e) Water Production: Under the intensive
economic development of Greece, the availability
of the required water in relatively high quantity
(to supply the cities, for irrigation, and for
industry) is of paramount importance. Therefore,
the use and management of evergreen brush vegetation, covering a considerable part of the watersheds around crowded beaches, big cities, and
industrial centers, must guarantee the maximum
possible production of usable water.
Professor of Range Management, School of
Agriculture and Forestry, Aristotelion University,
Thessaloniki, Greece.
f) Forage: Goat raising, and to some extent
sheep raising also, depends greatly on browse and
grass produced on evergreen brushlands. This is
especially true for the period from late autumn to
late spring, when the upland ranges are not ready
to be grazed. However, under proper management
these evergreen brushlands might be profitably
used by grazing goats throughout the year, and thus
protect the productive forests, especially fir,
from the damaging effects of goat grazing pressure.
270
Gen. Tech. Rep. PSW-58. Berkeley, CA: Pacific Southwest Forest and Range
Experiment Station, Forest Service, U.S. Department of Agriculture; 1982.
1
Presented at the Symposium on Dynamics and
Management of Mediterranean-type Ecosystems, June
22-26, 1981, San Diego, California.
2
GRAZING USE OF EVERGREEN BRUSHLANDS
Sclerophyllous evergreen vegetation under
present use is the basis of goat grazing for a
period of 6 to 7 months from late autumn to late
spring. In summer, the majority of grazing goats
move to higher elevation rangelands, covered,
mainly, with deciduous oak or fir forests. Goat
operators, mostly nomads, believe that goats
cannot live in lowlands during the hot dry season.
Feeding requirements of grazing goats during
the cold, humid winter are met mainly by browsing
evergreen brush species, among which kermes oak is
most important from a production standpoint.
Between individual brush plants are found some
grass species, which contribute to the diet
selected by grazing animals. It is certain that
goats cannot meet all their feeding requirements
for maximum production from such browse and
forage. It could even be said that in most
instances the diet consumed is well below the
maintenance requirements of goats.
In the past, grazing management practices in
evergreen brushlands were mainly circumscribed by
the needs and perspectives of goat operators,
governed by their desire to increase their income
to the maximum. This was attempted almost
entirely by increasing the number of goats; the
result has been a pronounced deterioration of
brush cover. With time, brush height has been
lowered and brush cover reduced in proportion to
the intensity of grazing pressure. Now, the brush
community is usually composed of the less palatable and less productive species and types. Very
often, soil erosion is evident between brush clumps
because of overuse of grass species growing there,
and heavy trampling (fig. 1).
Often, fire is used by goat raisers in an
irrational way, to improve browse production and
particularly, palatability. This is done without
permission of responsible administration authorities. Goat operators have found by experience that
by burning the aboveground part of brush plants
they can rejuvenate them, and thus obtain a
significant improvement of the browse produced.
They do not realize, however, that this uncontrolled and irrationally practiced burning leads
gradually to a severe deterioration of the site.
Management working plans and grazing control
are applied in a very limited area. The
responsible authorities are limited to deciding
whether or not the various brushland units should
be protected from grazing. The areas burned by
accidental wildfires or dry fires started by goat
operators are protected for 3 to 5 years from
goats. When brushlands fall within the limits of
a torrent watershed, the period of protection
against any grazing can be prolonged according to
the specifications of the watershed management
plan.
Improvement practices to increase browse and
forage production in the brush-covered areas are
Fig. 1--Kermes oak clumps with grass-covered
surfaces between them, in a brushland north of
Thessaloniki. Soil erosion between clumps is
evident.
at present limited to an experimental scale. The
main reason is the great difficulty of changing
the customs of the goat raisers, who are strongly
attached to traditional practices. It is almost
impossible to persuade the small operators
(100-200 head) to group their animals in common
herds and lead them to graze in specific brushland
units at particular times, under the control of a
management plan. The improvements they are interested in and ask for are range development works,
such as roads to facilitate transportation of
supplements, animal products, etc., and animal
watering facilities. It is worthwhile to note
that such development works, in the absence of any
management plan, have led to more intensive misuse
and overuse of brushlands, with resulting heavier
deterioration of the site, and more pronounced
decrease in their carrying capacity.
PROPER USE AND MANAGEMENT
From the above discussion, it is rather obvious
that proper management of maquis vegetation, and
in general, of sclerophyllous evergreen brushlands
in Greece, must be based upon the principle of
multiple use. The management form and the vegetational structure which respond to this need might
vary according to existing specific conditions.
The various products and services expected from
evergreen brushlands could be obtained either
simultaneously from every small piece of land
under a complex management scheme over the total
area, or separately. If separately, each product
or certain selected products would be obtained
from small surface subunits, each under a specific
management plan. Thus a mosaic of vegetation types
would be created over the total brushland area.
This second type of management scheme seems to be
271
more suitable in Greece for the following main
reasons:
a) It is better adapted to the extremely
diversified topography, rockiness, soil depth and
fertility, etc. of the land.
b) It fulfills more efficiently the esthetic
requirements and the necessary conditions for
development of recreation facilities.
c) It offers the possibility of securing
protection against soil erosion by conserving a
thick brush stand on steep slopes and susceptible
sites, and at the same time improving usable water
production by establishing low water-consuming
plant cover on less vulnerable sites.
d) It renders easy the task of balancing browse
and grass forage production according to the diet
requirements of grazing animals.
In a considerable portion of evergreen brushland, the soil is relatively fertile and sufficiently deep to support productive forests, while
the most productive sites can be used for olive or
almond-tree orchards. Unfortunately, inventory
data about the acreage of such sites are not
available; it is estimated as 10 to 15 percent of
the total brushland area of Greece.
The main forest species used in reforestation
work in this area are aleppo pine (Pinus halepensis), brutia pine (P. brutia), maritime pine
(P. maritima) and parasol pine (P. pinaster).
All are light-demanding species. Therefore, their
stands remain open, in general, during most of the
rotation time, promoting an understory of brush or
grass, or both (fig. 2).
Under the specific conditions governing the
functioning of the ecosystems within the bioclimatic zones in question, the competition for water
(the limiting factor in plant growth) exercised by
this understory vegetation against the plants of
the forest floor is extremely high. The result is
(a) considerable decrease in stand annual increment; (b) rapid depletion of soil moisture; and
(c) pronounced desiccation of biomass for a comparatively longer period of time during the dry
and hot summer, and hence, increased fire hazard.
No doubt, proper browsing or grazing of the
understory vegetation will diminish all these
undesirable effects. In addition, such control of
the understory vegetation, which is effective and
inexpensive, and of considerable benefit, will
permit intensification of the silvicultural
treatment of the forest tree floor for maximum
wood production (Liacos 1980). The International
Meeting of Scientists held in Palermo, Sicily
(Oct. 6-11, 1980) on "Conservation and Restoration
of Forest Cover in Mediterranean Regions" concluded with this recommendation: "In some cases
the rational silvo-pastoral use of mediterranean
forests might even improve their productive
function and better secure their protection."
272
Figure 2--Thick brush understory vegetation in a
70-year-old natural stand of brutia pine.
In the major part of Greece's brushlands, soils
are steep, shallow, and rocky. Because this area
is more suitable for livestock grazing, its
vegetation cover must meet the feeding requirements of grazing animals to the greatest extent
possible. It is rather obvious that the kind of
animals most adapted to evergreen brushlands are
goats (domestic or wild) and roe deer. However,
goats and roe deer as well cannot be entirely
satisfied with browse alone, and thus they cannot
reach their productive potential. They also need
some grass forage, which for domestic goats amounts
to about 40 percent of their daily requirements.
Consequently, the composition and structure of the
vegetation cover on brushlands would be ideal if
it could offer to grazing animals the daily required quantity of forage composed of about 60
percent browse and 40 percent grass. Besides,
such a diversified plant cover is more appropriate. By relative control trials (Nastis and
Liacos 1981) it has been found that the assimilated N of kermes oak foliage is almost zero,
although the digested N is about 40 percent, when
goats are fed only kermes oak foliage harvested
during the dormant season of plant growth.
The browse production of evergreen brushlands
in Greece is quantitatively and qualitatively low
at present. An experiment carried out in the
subhumid zone, with good soil conditions and
a brush cover of 100 percent, has shown that
annual browse production varies greatly (Liacos
and Moulopopoulos 1967). Five kermes oak types
were identified, differentiated by their botanical
characteristics such as color of new leaves, shape
and size of adult leaves, size and peduncle of
acorns, scales of acorn-cups, etc. The browse
produced annually by the different types varied,
with 762 kg/ha for the least productive type,
which is usually dwarf and of very low palatability for goats. Differences were also found in
browse nutritive value, specifically in crude
protein content. Again, the browse of the least
productive and least palatable type has the lowest
nutritive value. It is interesting to report here
that browse preference by domestic goats was
similar to host preference noticed for the larvae
of gypsy moth (Lymandria dispar), which is the
3
most damaging pest of all oak species in Greece.
The less productive, less palatable, and less
nutritive type of kermes oak is now the most
abundant in the evergreen brushlands of Greece,
misused and overused for many centuries.
Herbaceous vegetation cover in the evergreen
brushland area is more productive than brush
cover. An experiment to convert brush to grass
was carried out in the semiarid bioclimatic zone
by seeding grass forage species: hardinggrass
(Phalaris tuberosa), orchardgrass (Dactylis glomerata-palestina), rose clover (Trifolium hirtum).
Data show that forage production went up to 4500
kg/ha (fig. 3). That means that forage could be
increased by 7 to 10 times when brushlands are
converted to grasslands.
Certainly, this kind of improvement can be
applied only on good sites with gentle topography (slope 15 percent) and good conditions.
Considerable improvement could be obtained even on
rough areas, however, by applying the proper technique in each case. Liacos and others (1980), in
a conversion experiment, carried out in the
subhumid bioclimatic zone in rough country (40
percent slope), used controlled burning to clear
the ground and then seeded valuable forage species
on the ash--primarily orchardgrass, smooth brome
(Bromus inermis), hardinggrass (Phalaris tuberosa)
and birdsfoot trefoil (Lotus corniculatus).
Italian ryegrass (Lolium multiflorum) was also
used with the hope of depressing the kermes oak
sprouts by its strong competitive effect. During
the first year after burning, Italian ryegrass was
expected to grow vigorously, because the soil was
well fertilized by the ash, and it was relatively
rich in N from rich brush humus mineralization
over a long period before burning.
The effectiveness of this conversion technique
in rough country was compared, under the same
experimental design, to improved brush cover in
which all undesirable and less desirable species
and types of brush were eliminated. Additionally,
all brush plants were cut down to 0.40 m high, and
then left for two years to recover. The structure
of the cover was also improved to secure the
proper utilization by goats of all browse
produced. Yearling goats were used in both
treatments to check the effectiveness of the
improvement techniques applied. The annual grass
and browse production of the conversion treatment
was found to be 3400 kg/ha and 2000 kg/ha
respectively on the average for three consecutive
years. Meat production of the yearling goats used
3
The palatibility differences noted among the
various kermes oak types are now being
investigated by the author's associates.
Figure 3--High forage production in the brushland area of the semiarid zone after conversion to
grass. Brush cover was removed mechanically and
grass forage species were seeded.
in the experiment was about 120 kg/ha for the
conversion treatment and 60 kg/ha for the improved
brush cover, while meat production in unimproved
brush stands of 100 percent cover was found not to
exceed 30 kg/ha (Liacos and Moulopoulos 1967).
The brushland improvement experiments have shown
that the production of Greece's evergreen
brushlands, used for livestock grazing, can be
at least doubled by the proper improvement of brush
cover, and increased by four times by partial
conversion to grass.
Up to the present, the experimental data,
although very limited, show that the possibility for
improvement of Greece's evergreen brushlands and the
increase in forage and grazing animal production is
relatively high. To make this more concrete and
meaningful, it would be useful to say that in Greece,
within the evergreen brushlands suitable for
livestock grazing, meat production could be
increased by at least three times, on the average,
after the appropriate improvement of brush cover and
the application of proper management. Thus, the
estimated present meat production of 18,000 ton/year
could reach the amount of 72,000 ton/year. Greece's
evergreen brushlands suitable for grazing are
estimated at 600,000 ha out of a total area of
783,000 ha. Moreover, it is the author's belief
that the opportunity for further improvement of
forage production and an increase of animal products
from brushlands is great.
Management techniques to be applied in evergreen
brushlands, to secure the highest possible sustained yield of forage and livestock products, are
not well defined. It is not yet known which structure and form of vegetation is most productive. A
series of experiments are underway to approach the
solution to the problem. The following three forms
273
Figure 4--Improved brushland with controlled burning
of brush cover and seeding of valuable forage
species on the ash.
Figure 6--Dwarf brush stands with grass-covered soil
between brush patches and small tree-like
individuals of kermes oak interspersed, to support
spreading shoots and produce acorns for animal food.
are being investigated to evaluate their compatibility for the various brushland sites:
b) A vegetation form that seems quite promising
for relatively good sites is that shown in figure
4. Brush plants are low, spreading on the ground
surface, with grasses growing between in large or
small patches, occupying 30 to 40 percent of the
total area.
c) A brush form which is suitable for relatively
poor and rocky sites is shown in figure 5. Under
this form the individual brush plants are evenly
distributed all over the area at a height within the
reach of goats. The browse produced is organized
vertically over all the depth of the brush stand.
Grass forage produced under this form is very
limited. Therefore, in order to secure the forage
required by the livestock, the brush-covered land
should be incorporated in the same management
allotment with the required grass-covered area.
a) The third form, which has high esthetic value,
is an improved form of the first (fig. 6). Under
this form, a number of kermes oak shoots evenly
distributed all over the area are left to grow as
high as small trees. The main advantages expected
under this diversified form are (1) betterment of
microclimatic conditions with the aim of retaining a
greater quantity of water and improving the
evapotranspiration efficiency in the system; (2)
conservation of the vigor of spreading brush sprouts
which are heavily browsed; (3) production of a
considerable quantity of acorns, which are a
valuable feed for livestock during the most critical
season for browsing animals--late summer and early
autumn; and (4) a very significant improvement of
the landscape and the recreation conditions in an
area falling within the most touristically important
zone of Greece.
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Figure 5--Brushland improved by eliminating
undesirable brush plants and limiting the brush to a
height within the reach of browsing goats.
274
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