On Friday, 15 June, "Vides projekti" Ltd. within the framework of the project "Baltic Biomass Network" organized a visit to the Latvian State Forest research Institute "Silava" in Salaspils and to the plantation of fast growing aspens in the parish of Rembate.
Discussion on options of cultivation of fast growing see species in Latvia were attended by representatives from mass media and professionals from the Forest Research Institute "Silava": Arnis Gailis (Assistant for Forest Tree Breeding and Genetics), Mārtiņš Zeps (Assistant for Forest Tree Breeding and Genetics), Mudrīte Daugaviete (Senior Researcher for Forest Regeneration and Establishment), Andis Lazdiņš (Project Manager) and Dace Auzenbaha (Assistant in Laboratory of Tissue Culture).

Experts of the branch admitted that there are all conditions in Latvia to cultivate fast growing sallow trees, alders and aspens for biomass production, still at the moment this potential is not used adequately. Up to the moment in Latvia only the Forest Research Institute "Silava" and the company "Latvijas Valsts Meži" have seriously addressed the issues of cultivation of the fast growing species.

Due to the diversity of usage options as most prospective fast growing tree in Latvia the hybrid aspen is considered (crossbreed of American and local aspen trees). Having studied the aspen tree since sixties scientists have established that this tree can be used for production of round and sawn timber, high quality paper and cellulose and energetic wood as well. Although complex studies of the calorific value of the aspen has not been done yet, still it is established that the value is slightly higher than that of the spruce (wood only).
Planned growing length of the hybrid aspen is 20-25 years. The fast growing aspen is suitable for woodchips already in the first year. After three to four years shoots reach already the height of 2 meters.
Assistant Researcher of the Forest Research Institute "Silava" Mr. Arnis Gailis: "In our research breeding stand of hybrid aspens in Iecava, which is now more than 14 years old, the best clones of hybrid aspens reach the productivity of 250 cubical meters per hectare, still it should be noted that in this stand 2500 trees per hectare are planted. That is a very high density, as normally 1000 to 1100 trees are planted. Our observations show that in the first cycle the total mass of wood is lower – from 250 to 350 cubical meters per hectare. Whilst in the next rotation, developed already from the root shoots of the previous generation, the total wood mass could be higher. Scandinavians support the opinion that 3 following rotations are efficient, whilst after that, profitability assessed, more productive solutions should be selected."
In the other stand of hybrid aspens of "Silava" in Rembate Parish (last measurements were done in 2005, when stand was 8 years old) the best result during the 8 years period was 78 cubical meters per hectare. Still it shall be taken into account that here number of trees per hectare is just 1100, instead that of 2500 in Iecava, accordingly here the growing stock per hectare is lower.

Nevertheless scientists consider that the aspen is a high risk culture as it is endangered by lots of pests and animals: insects, mice, hears, roes, elks. Arnis Gailis: "Therefore, considering the expensiveness of the aspen planting material, preventive measures shall be tight". In order to protect the plantations, those shall be fenced in a height of at least 2 meters, special plastic cylinders, that eventually are decomposed by sunlight, shall protect the young trees from small rodents (especially mice). Also serious work shall be invested in maintenance of aspen plantations, as in order to obtain good results, stands shall be mown regularly.
Another restricting factor is that the hybrid aspen grows only in fertile and soft soils, consequently it is not suitable for growing in all regions of Latvia.

As good alternative for the aspen the grey alder is considered by scientists, as its productivity is higher and, if cultivated properly, it grows very fast also in poor soils. Still researchers have not been successful in finding other ways of use of this tree. Mudrīte Daugaviete: "At the time being no one has been successful to produce cellulose from the grey alder, as this tree has very specific yellow wood". Still she presumes that, upon finding the ways of processing the grey alder for cellulose, this tree doubtlessly would become a leader among other fast growing trees.
The researchers of the institute "Silava" point out that it is essential that producers should be involved in finding the types of application of fast growing tree species, as in that way, not only material basis for research is provided, but also the results obtained can be more swiftly applied in practice.

The specialists in this field believe that creation of fast growing tree plantations in Latvia has good prospects, as several essential national economy targets could be achieved by that: land resources would be used rationally, environment protection facilitated, wood resources provided, rural development in Latvia supported.
Although there are still lots of uncertainties about cultivation of fast growing tree species, forest scientists are sure that production and use of renewable energy resources has future in Latvia.

The visit tour is organized in cooperation with the LSFRI "Silava", cofinanced by the EU initiative programme INTERREG III B.
We also inform that shortly a study report "Necessity of Fast Growing Tree Plantations; Assessment of Development Options in Latvia", created under the "Baltic Biomass Network" project, will be available

Additional information: Margarita Apine, Manager of Public Awareness Department, “Vides projekti” Ltd., phone 7225377,
e-mail: Margarita.Apine@videsprojekti.lv.