Poplars in Yugoslavia

Accueil
Poplar Research Institute in Novi Sad
(IUFRO 1986)

First Poplar and Willow plantations

Autochthonous poplars in Yougoslavia wer used a long time ago for the establishment of different types of plantations. As in those days poplar and willowwood was not applied on a larger scale, plantations were established along the river dams as a protection from ice and waves or as wind protecting zones in the Pannonian Basin.

The first large poplar plantations were established in Yugoslavia around 1820 a large-scale action undertaken in order to fix sans in the sand dune area of Deliblato, known as "the European Sahara". Apart from the other forest species, domestic white and black poplars were also used for the establishment of forest plantations, as well as the first cultivars of European poplar known under the commun name "Canadian poplars" (Veseli, 1873).

Apart from the various types of plantations established with the aim of protection, poplars and willows were planted as decorative species in parks, alleys and villages.

Gradually, poplar and willow wood was used more and more in Voivodina and Slavonia mainly as fuelwood and later for construction purposes in rural settlements. At the beginning of the 20th century, poplar and willow wood began to be used in the manufacturing industry for matches production, or for veneering and sawing, etc. Gradual increase of the demand, as well as the increase of the market value of poplar and willow wood gave rise to the production of high quality assortments, which called for the application of numerous cultivation measures in natural polar and willow forest management, as well as for plantation establishment of the species mentioned above.

The increasing demand for poplar and willow wood gave rise to good economic effects, and also callec for skilled management in poplar and willow forests. For this reason, especially in the riparian forests along the Danube and Drava rivers, where the greatest areas are under poplars and willows these forests were subjected to the planning and measuring already at the beginning of the 20th century, in the same manner as was arranged for the more valuable forests. Within the management of these forests, the first poplar and willow plantations were established.

Poplar and Willow Plantations between the Two World Wars

The scope of poplar and willow plantation establishement increased considerably after World War I. The main reason for the establishment of such plantations was the shortage of softwood in Voivodina and Slavonia. This region had previously been supplied with softwood from forersts in the Carpathians, Bohemia and Austria. After the year 1918, consumers from this area were reffered to sources in Yugoslavia, and special attention was devoted to the better use of the natural resources from this region where riparian poplar and willow forests were situated.

At that time, forests industry and private individuals turned increasingly to poplar and willow wood, and therefore special attention was paid to the management and reforestation of poplar and willow forests, with an emphasis on artificial reforestation. In the Danube and Drava basins, where poplar and willow forests were the dominant species, a special type of forest management began to develop, known as "riparian forestry" (Vasilic 1963).

The most valuable products from this area, such as veneer logs and logs for matchstock were delivered not only to consumers in our country but also to consumers abroad, - in Hungary, Austria, Bohemia, Germany and some others countries.

For the establishment of new plantations, apart from the autochthonous poplars, the following cultivars of Euramerican so-called "Canadian poplars" were used increaingly : cv serotina - marilandica - regenerata - etc... The Robusta cultivar was brought to Yugoslavia in 1938. The good results obtained with this cultivar exerted a great influence on increased establishment of new plantations. Thus, approximately 4.000 hectares under Euramerican poplars were established between the two World Wars.

The first poplar plantations were mainly established with one-year-old plants obtained from cuttings taken from the surrounding trees of domestic black poplar or domesticated Euramerican cultivars. Soon it became obvious that several-year-old stool-bed were the best source for the production of cuttings. Cuttings taken from stool-bed were used for one-year-old plant production. Dense plantations were mainly established at 2 X 2 and 3 X 3 m spacing, and sometimes even denser. Planting was performed in 30 cm deep holes, usually on previously unprepared soil. On land suitable for the cultivation of field crops various crops were cultivated between rows of poplars, in the first 2-3 years, among which maize was the most frequent one. Rotations varied from 30 to 40 years under application of 2-3 thinnings.

Willow plantations were established with sets or shoots collected from natural regeneration or from sprouts taken from old trees. Willow plantations were mainly established in depressions often exposed to floods. Planting was most often practiced by inserting sets or sprouts in the soil with a special hand-planting tool (planting awl.). As a rule, willow plantations were denser than poplar plantations with spacing systems from 1 X 1 to 2 X 2 m. Rotation in willow plantations varied from 30-40 years with 2 to 4 thinnings, depending on the plantation density and the intensity of willow growth.

Poplar and Willow Plantations after World War II

Establishment of poplar and willow plantations in Yugoslavia on a large scale began after World War II. After the war, the greatest part of poplar and willow forests in Yugoslavia was nationalized. The permanent increase in wood consumption called for intensive growing of poplars and willows in Yugoslavia, especially in Voivodina, Slavonia and in the riparian zones of the great rivers all over Yugoslavia. Already in 1950 there were over 10.000 hectares under Euramerican poplar plantations in Yugoslavia. Apart from the plantations of Euramerican poplars in which the dominant cultivars were "serotina" - "marilandica" - "robusta", there were thousands of hectares under willows and domestic poplars.

In the period from 1950 to 1955 poplars plantations were exclusively established with cultivars of Euramerican poplars. In the same period, the area under these plantations amounted to 15.000 hectares. At that time nursury production of young poplar plants was organized. Plantations were established by using one-year-old plants, and the lower density - from 550 to 1.200 plants per hectare, with various combinations of spacing system : 6 X 2 - 6 X 3 - 4 X 2 - 4 X 4. One of the caracteristics of the poplar plantation technolofy in that period was the consociated planting of various deciduous species between rows of poplars, as follow: American and domestic ash, elm, alder, maple, mulberry tree, common maple and some other species. Plantations established in consociation with deciduous species mentioned above contained 550 - 1.250 poplar trees and 1.250 to 2.000 other deciduous tree per hectare with a spacing of 2 X 2 m. The aim of planting of hardwood deciduous species is forming the understory canopy of a stand, which makes possible natural pruning of poplar stems from branches in order to produce high-quality logs to be used for veenering.

In that period a large number of forest experts specialized in the production and growing of poplar and willows: engineers, technicians and skilled workers. At that time, poplar mass production started in Yugoslavia. The rapid development  of poplar growing in some European countries in that period exerted its influence on the beginning of the development of moderne large-scale poplar production in Yugoslavia.

Study tours of a number of Yugoslav experts to Italy, France and some other European countries resulted in a considerable increase of the fund of poplar and willow plantations in the next period, as well as in the application of the moderne methods in the technology of poplar and willow wood production in Yugoslavia. In 1955 the Yugoslav National Poplar Commission (YNPC) was formed as a member of the International Poplar Commission. The YNPC became the most important motive force which initiated both the planning and development of poplar growing in Yugoslavia. On YNPC suggestion, the Poplar Research Institute was founded in Novi Sad in 1958; it was responsible for the beginning of the development of organized research work in poplar growing in Yugoslavia.

Along with the introduction of the foreign poplar and willow selections in Yugoslav research work, numerous investigations were carried out concerning selection, breeding, study of the site conditions and establishment technology, the tending of cultures, as well as the problem of damages caused by diseases and insect pests on poplars and willows. In the late fifties, the technology of poplar plantation establisment assumed an entirely new approach with the following patterns:

- establisment of plantations mainly with with selected clones,
- two-years-old plants produced for planting in the nursery production system (rooting-bed and transplanting-bed),
- larger spacing systems, mostly 6 X 6 (6;5 X 5.63 m) - 5 X 5 m, less frequently 7 X 7 m,
- complete site preparation,
- planting in holes 80-100 cm, deep,
- field crops cultivated between rows of poplar culture, in the first 2-3 years,
- measures of disease and insect pest control in nurseries and plantations,
- mechanization in all stages of the working phases,
- a felling cycle of 10 to 15 years with an expected annual increment of wood volume from 20 to 30 m3 per hectare.

At the same time, the initial quantites of production stock of Italian poplar clones were imported, mostly clone "I 214", as well as the clones "I 154", "I 45/51", "Jacometti" and others. The first commercial-experimental plantations established under application of the new technology (in 1956) achieved good results, which caused its application on a large scale so that in the period from 1956 to 1960 almost 20.000 hectares under poplar plantations were established, and in the periode from 1961 to 1965 - almost 52.000 hectares.

The greatest part of the new plantations (70%) was established by means of the modern technology applied, the so-called "plantation" technology, a very intensive type of cultivation. In that period, the clone "I 214" was the dominant one, as well as the use of plants aged 2/3, with a plantation depth of 273 trees per hectare and spacing 6.5 X 5.63 m. Aconsiderable amount of new plantations was established beyond the flood areas and alluvial soils. A smaller part of these plantations (around 30%) was established in felling strips of poplars and willows under application of the so-called "standard" (old) technology. The plantations mentioned above were established mainly in regular cutting strips, and planting was performed on unprepared soil, with one-year-old plants between the stumps, mostly with spacing systems 6 X - 4 X 4 - and 5 X 5.