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THE INTERCONNECTION OF FOREST ROADS WITH DIFFERENT SYSTEMS OF INNER FOREST TRANSPORT IN THE MOUNTAIN FORESTS OF ALBANIA

Panajot Koçi, Mihallaq Kotro and Avram Haxhi

Abstract

Albania is a Mediterranean country with a rough mountain relief. It has over 1 000 000 ha of forests which represent 37 percent of the total surface of the country. Standing wood volume is estimated at 82 million m3 and the average volume is 79.5 m3/ha. Annual average growth is 1.46 m3/ha. Species distribution is as follows: beech covers 21.6 percent of the area; conifers, 19.6 percent; oak 36.6 percent; and other species 22.3 percent. High forests (stumps) represent 45.5 percent of the total forest cover; coppice 29.5 percent; and shrub, 25 percent.

The forests are located in mountain terrain and in extreme mountainous terrain. The largest part is on slopes of 15-30° gradients. More than half of the volume is at an altitude of 1500-1850 m. The total area where transport should be effected amount to 103 000 ha and on about 68 percent mainly cable installations are utilized.

The exploitation technology applied in high forests is selective cutting in different plots although during the past few years the full-length method has been applied in many plots where the slope so permits. Considering the mountain character of our forests and the fragile root system in certain plots, different solutions had to be found for different situations

Experiments were carried out of wood transport within the forest with a combination of cable cars, drought animals, tractors and forest roads. This paper presents some solutions that were applied in difficult plots. The best results were obtained with the use of short cable cars of the tower kind, Gantner, FPU 500, etc. Electric cable cars TVA1500 were used successfully. As regards the economics of forest exploitation not using roads, experts' opinions differ.

It is concluded that the aim for the future is to reach a supply distance of 400-700 m and to use mainly tractors on 25 percent of the area for the transport of logs. Cable installations will be utilized to distances up to 500 m.

General information about the forests in Albania

Albania is a Mediterranean country with a rough mountain relief of an average altitude of 700 m, which is twice as high as the European average. The total area of the country is 28 000 km2. The area covered by forests is over one million ha or 37 percent of the total surface. This percentage is considered higher than the world's average. The forests are located in the hilly and mountain regions. Except for 3 000 ha of pines along the Adriatic coast, we do not have plantation forests. Even those few plantations that existed (especially on the hills) were felled for agricultural use, tree cultivation or fuelwood.

The distribution of forests on the territory is irregular. Especially in the western and southern parts of the country, there are many cities with no forests in the neighbourhood. Nonetheless, the average distribution is 0.31 ha per inhabitant, which is considered normal. Table 1 shows the distribution of forests according to tree species.

Table 1

Tree species

Percentage %

Area 1000 ha

Conifers (pine, fir tree, etc.)

19.5

196.0

Beech

21.6

371.1

Oak

36.6

226.8

Other species (horn beam, arbutus berry, acacia)

22.3

237.1

Total

100.0

1031.0

High forests for the production of large-size logs cover a small area and are over 100-120 years old, while young-age classes (1-20 years' old) and classes V-VI are prevailing. This is due to the fact that the plots close to the roads are subject to fellings while, in plots where the road density is lower, the forests have not been harvested.

Standing wood volume is estimated at about 82 million m3 and the average volume is 79.5 m3. Annual growth is 1.46 m3/ha and annual harvesting availability is estimated at 1 520 000 m3, of which 474 000 m3 is timber.

With regard to management pattern, the forests are distributed as shown in Table 2.

Table 2. Distribution of forests according to type of management

Type

Percentage
%

Area
1000 ha

High forests

45.5

469

Coppice

29.5

304

Different shrubs

25.0

258

Total

100.0

1031

Table 3. Distribution of forests according to wood species volume

Species

Percentage
%

Area
1000 m3

Beech

46.6

38100

Pine

14.9

12200

Oak

17.6

1430

Fir tree

4.7

3800

Others

16.2

13600

Total

100.0

83000

Approximately 90 percent of the forests in Albania are natural. The forests with a special protection function cover only 13 percent of the surface, which is a very small figure compared to other similar mountain areas in other countries.

The situation of the beech forests

Beech forests are found in the third phytoclimatic zone at altitudes up to 1 700 m in the north and 2 000 m in the south. Beech covers a more extensive area than any other species and is of higher industrial interest. It can be found in the old-age class (over 100 years' old), usually in single-species stands but also mixed with black pine and fir tree. Beech forests are harvested in three phases with the aim to allow natural regeneration. For this reason forest roads or crossings of new plots have been built year after year, but in many cases there have been delays to carry out the second and third felling phases. In these cases, the new shoots develop and grow up to 150-200 cm. As a consequence of this and of the rough configuration of the terrain, many difficulties were encountered in the exploitation of these plots.

For these reasons a complex study was undertaken in 72 forest economic communes over a surface of 100 000 ha. All the plots in these forest communes are grouped according to slope of the terrain, state of the new shoots, above sea level height, etc. Transportation methods and equipment were also studied in many experimental plots with different characteristics to find adequate technological processes. In the first phase of the study, these experimental plots were located both in exploited and non-exploited communes.

In plots with new shoots up to 50 cm no major problem was encountered. Fellings were avoided during the period April-June and carried out in winter when the tender shoots are covered with snow. When the shoots reached a height of 50-100 cm, transport was tested with special forest tractors. In terrain with high slopes, a cable car was used. When rolling or hauling with agriculture tractors was used, this caused high damage to the tender shoot. In plots with tender shoots over 150 cm damage was caused to about 60-70 percent of them by falling trees and transport.

Each forest plot has its own characteristics; however, average parameters are given below to assist in the preparation of techno-economic studies for forest utilization. Of a total area of 103000 ha, the forests are grouped, according to slope gradient as shown in Table 4.

Table 4. Distribution of beech forests according to type of terrain

No.

Designation

Slope gradient degrees

Area %

ha

1

Terrain with small slope

up to 5

3

3 100

2

Terrain with average slope

5-15

19

19588

3

Terrain with big slope

15-30

63

64560

4

Terrain with very big slope

30-45

13

12987

5

Broken terrain (abyss)

over 45

2

2465


Total


100

102700

Table 5. Distribution of area and volume according to a.s.l. height

No.

Altitude
m

Area
%

Volume
%

1

1000-1300

35.8

35.1

2

1301-1500

17.3

9.2

3

1501-1850

46.9

55.7


Total

100.0

100.0

Definition of internal transport systems in mountain forests

From the study of the situation in the high forests of Albania, it can be concluded that inner transport with tractors is only possible on approximately 22 percent of the area, while on the remaining 78 percent special forest tractors, winches and different equipment with steel cables must be used. Consequently, the distribution of forests according to type of transport is shown in Table 6.

Table 6. Distribution of transport methods according to slopes

Slope grade

Means of transport

Area
%

Volume
%

0-15

Tractor + cable car

19.0

25.5

16-30

Mainly cable-car

67.8

67.8

over 30

Only cable installations

13.2

6.7

On forest areas with a relatively small slope, construction and expansion of the road network is foreseen.

It should be noted that in one-fourth of the high forests (stocks) there are no roads. Therefore, first main roads for motor vehicles must be built and then proper technology and utilization of each plot can be designed. Up to a few years ago selective felling was applied and transport was mainly by rolling with tractor use whenever possible. In some forest plots full tree length were transported using the forest tractor ZICE.50 equipment with a platform and winch. Use of different cable installations has also been tried, even in very difficult conditions, mainly the cable-cars Wyssen, Dinamo, FPU (Romania) VL.U4 (Czechoslovakia), Gantner (Austria), TVA 1500 (electrically driven) etc.

In 1989 and 1990, in the high forests 58 percent and 62 percent, respectively, of transport was mechanized, of which 8 percent and 6 percent was with cable installation. No mechanization was used in the low forests. As can be seen, transport by cable-cars is very low even though our terrain would be suitable for this method.

In situ studies were carried out in different situations and conditions to evaluate the best transport systems. In terrains with big slopes of up to 90 percent, cable-cars or dragging of the wood can be used but this method is expensive and the wood is damaged. In plots with slopes up to 35 percent, the Czech cable-car VL.U4, and in some cases animals, were used. When the slope is between 35 and 15 percent, we have used different tractors, mainly with chains, but the use of tractors with articulated tyres seems more appropriate. Cable-cars have an upper limit of 15 percent otherwise the wagon cannot descend by gravitation to be loaded.

In the Brosh-Bardhit forests (Tirana) or the Orosh forests (Mirdita), etc., the terrain presents pits and the material must go upward and downward. In these cases it would be better to use the Hintereger cable-car. Since it was not available, we used the FPU500 (Romania) cable-car with one traction and one lifting up cable with two drums. The cable-car is installed over the main road while the other side is installed on a tree. Logs are transported to the place of loading with special forest tractors.

In plots where the upward slope is steep but downwards is only 15-50 percent, we have mainly used tractors up to the 50 percent limit but only when the terrain was not rocky. The use of Wyssen cable-cars combined with tractors is also possible to get close to the plots.

In our country a large part of the exploited areas is located on 50-90 percent slopes. In these cases, transport is done manually or with animals. Simple cable-cars have also been used to bring down the material after it has been piled up in the upper station. In suitable terrain we have used the Dinamo cable-car.

The last category comprises slopes over 90 percent, which are not exploited at all or transport is done by rolling down the logs. In some cases wood spouts are used for pine but the quality of the logs is not good because the wood is damaged.

Tests performed by different authors indicate that the daily productivity of the special forest tractors is higher than that of cable-cars in areas with slopes of 15-50 percent.

In the past few years we have used a long cable-car up to 2000 m of the type TVA 1500-2000, electrically operated. This type of cable-car has two carriages, two skylines and one main line. It has a high yield but the wood can be loaded only in the upper station. Up to the station the product is transported by other means.

In view of the topography of our forests, as well as the silvicultural and environmental aspects, specialists have indicated that transport by cableways should be preferred to traditional means.

Consequently in the forests of Kraba (Tirana) a cable-car TVA 1500 with a length of 650 m was built. The wood had to go down to a deep valley and then up to the main road. Three transport alternatives were studied:

· Animals and construction of a 3 km main road;
· Animals from the place of felling up to the storage area;
· Animals and cable-car TVA 1500.

The first alternative required a 3-km main road, partly on rocky terrain and partly on steep terrain, which required engineering works. With this alternative the total transport distance would increase. The second alternative - transport with animals from the place of felling to the storage area -had high costs, low yield and high labour requirements. This is the reason why the third alternative was chosen, resulting in a saving of lek 480 000 for the whole wood volume extracted and an increase in productivity up to 30 m3/shift.

In the forests of the north (Puka, 2 900 m of railway and 800 m of rolling were substituted with a 2 000 m skyline. In this way transport expenses were reduced 2.5 times. A system of cable-cars in the forest of Librahd substituted a 7 km main road.

Techno-economic discussions are taking place among experts about the utilization of high forests which have no roads and represent approximately 20-25 percent of the whole forest area. These forests are located on difficult terrain far from urban centres. Since long forest roads would be required with heavy investments, it has been proposed to use long cable-cars which cross main roads, thus reducing transport costs. Studies have been carried out on a system of two skylines and a pulling one with a continuous movement, with an engine power of 20-30 kW to 70-80 kW and a length of up to 5 km. Of course in these cases the quantity to be transported should be over 300 000 m3.

Although transport within the forests in mountainous terrain presents difficulties in our country, problems are also encountered in the transport over long distances. Main roads do not exist in all parts of the country and, from a technical point of view, loading is done with ZIS cranes and the cars used for transport are not suitable for the Czech (Skoda) vehicles.

Transport distances of the wood material from the forest to the processing centres are too long -approximately 100 km. As a result of these difficulties, in 1991 about 100 000 m3 of logs remained on the roadside.

Since in mountainous areas it is important to find the best combination of a forest roads network with other transport means for hauling the wood, on the basis of studies in other countries such as Austria, Germany, Sweden, France and Romania, we have tried to determine the optimum forest roads density in some areas in our country. In the calculation we have taken as a basis on the economic aspect, not the silvicultural one. The elements used in the calculations were the categories of terrain's slope, the degree of mechanization and the type of transport equipment. The results of this study are given in a separate paper.

In our opinion average extraction distance should be between 400 and 700 m. Cable installations up to 500 m can be used up to distance of 500 m. On about 25 percent of the forest area skidder roads should be built for the transport of full-length logs. Those forest roads which do not meet environmental protection standards due to lack of appropriate design and construction should be modified.

References

Heinrich, R. 1983. Forest road-net planning and wood harvesting.

Jonascu, Gheorghita. 1995. Transporturi forestiere.

Koçi, Panajot. 1978. Studim i pyjeve të ahut në Shqipëri.

Oprea, I. 1995. Organizarea santierelor de exploatare a lemnului.

Rotaru, C. 1994. Recherche des méthodes de sylviculture et d'exploitation par cable permettant une meilleure mobilisation de bois en montagne.

Trzesniowski, Anton. 1983. Logging techniques in Austria.

Ylli, Gusho. 1985. Studim mbi mënyrat e transportit me teleferik.


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