The performance of carried instruments in the work for the management and improvement of rangelands and meadows
The use of accessory machines in rangeland management and improvement is considered to be vital in the recent years. Works such as control of undesirable plants, seeding with forage species, fertilization of natural rangelands and meadows and soil treatment are done with the use of tractors and their added accessories. The latter might be drawn, semi-carried or carried, which are adjusted on the tractor in one, two or three points respectively. The rapid development of modern machinery, give us the opportunity to choose the proper equipment according to the nature of the work. The aim of this paper was to evaluate the performance of the rotary tiller with blades of type L. To achieve this, two different experimental sites, A and B within in an area of 10.000 m2 and 15000 m2 respectively, were set up, where the above machinery has worked. The performance Q was assessed for both sites after taking into account the step of cutting L in relation with the velocity of movement (u), the number of revolutions of the impeller (n) and the number of pairs of blades for each disk (z). The results showed that the performance of the equipment was affected by the dimensions and the type of rotary tiller, the velocity of tractor as well as from the slope, soil type and the way of the procedure which followed.
The calculation of stability of tractors in earthworks and in the management and improvement of rangelands and meadows
The calculation of tractors stability is a complicated problem the solution of which requires the full and safe knowledge of all factors affecting it. These factors are the technical components of the tractors such as the horsepower, the weight, the template of support, the velocity of movement, the height of gravity center, the suspension, the shock absorbers, the tires, the size of load of the hauled and carried machinery as well as the length and the height of their coupling. However, these factors which affect definitely the stability are the slope and the category of soil as well as the centrifugal force in turns. During the turns of tractors are developed, as is known, centrifugal tensions that may cause, under specific conditions, instability and side overturning of the tractor. In this paper was determined the moment of stability (WΧg) in the turns, of a classic four-wheel forest tractor. For this purpose was compiled a computer program and was calculated the moment of stability in respect to the distance (Xg) of the machine’s gravity center from the contact point of the wheel-ground (average level of tire), the height (Yg) of gravity center, the velocity of movement (u) and the revolution radius (r). From the results it came out that the stability, during the turns at horizontal ground, is small when the template of support is small, the height of gravity center big, the velocity of movement big and the radius of revolution small.
Rational planning of the rangeland areas’ opening up
The set-up of the correct and effective handling as well as the necessity of the improvements’ application in the rangelands demand some works of substructure, like the works for the basic opening-up of the rangelands, which are the rangeland roads. The rational planning of the rangeland areas’ opening-up should be done according to 3 basic principles: The Technique, the Economy and the Ecology. In this essay the technical and geometrical elements of the rangeland areas are analyzed, as well as the evolutionary model of the construction’s cost and preservation of these roads. In addition, we can see some suggestions that are given for the decrease or the avoidance of the disturbance and the damages that rangeland roads cause to the natural environment.
The grazing problem in Ranti forest, at Pafos county in Cyprus
Ranti forest is at the south of Cyprus, about 20 km east of the town of Pafos and 30 km west of the town of Limassol. It covers a total area of 1443 hectares of which 349,2 ha have been recently declared as National Forest Park, 345 ha are main state forest, 423,7 are minor state forest and 325,1 ha are private land. The climate of the area is typically Mediterranean; the annual average rainfall is about 363 mm, the dry period lasts from June to September and the 87% of the total rainfall falls in the period between November to March. At the largest part of the area the vegetation is composed of Mediterranean shrubs known as maquis, with scattered small trees. The maquis are divided into two categories, the “high maquis” dominated by Juniperus phoenicea Olea europaea and Ceratonia siliqua and the “low maquis” dominated by Pistacia lentiscus, Calycotome villosa, Inula viscosa and Sarcopoterium spinosum. The area attracts a great number of visitors, as it contains two locations that are connected with Greek mythology, Aphrodite’s birthplace and “Petra tou Romiou”. Also a large part of private land had been developed into a big hotel and villas complex. Livestock husbandry is highly developed in the area, to the point that it forms a major problem to the vegetation, leading the area to desertification. According to existing data, they graze 4942 sheep and (mostly) goats in the area. Grazing is practiced according to the village system without transhumance mainly without the presence of a shepherd. Given that private land is fenced the stocking density in the state forests and the National Forest Park is calculated to be 4,42 sheep equivalents/ha/year while the grazing capacity of the area is estimated to 1 sheep equivalents/ha/year.
Ecotope of Valonia Oak and livestock husbandry in Akarnanika Mountains
In the framework Natura 2000 program, the ecotope of Valonia Oak (Quercus ithaburencis subsp. macrolepis) was recognized and mapped in Akarnanika mounts. Valonia Oak constitutes unique type of deciduous oak in dry and warm regions of the country with multiple uses and values. Oak forests are ecosystems (agroforestry) with big ecological and economic value. They produce forage for wild fauna habitats (birds and mammals), recreation, environment, firewood, reserves of infrequent species of flora and fauna. In the past, the use of acorns’ cups in tannage was an important economic resource. It was resulted, that this ecotope reach up to 620 m altitude, groundcover varies in overstorey from 40- 50%, in middlestorey from 25-50% with dominant species Phlomis fruticosa and in understorey from 20-30% with herbs. Oak forests have dense herb vegetation, high plant diversity and contribute considerably in the diet of a big number of domestic animals, mainly sheep and goats, cattle, during the period of autumn – winter – spring. The forage is maintained green for a long period, due to microclimate that is created in these ecosystems. Also, acorns constitute precious food for the local pig of free grazing. In some areas, overgrazing and combination of frequent wildfires, prevent the natural oak regeneration. Additionally, this study resulted that oak ecotope is ecological sensitive and should be protected, aiming to improvement and sustainable management of livestock-farming, the maintenance of biodiversity and agroforestry landscape.
