Obtaining Woody Greens Enriched with L-Arginine during Forestry Management of Young Scots Pine Stands (Scientific Review)
Authors:   Forest Research Institute of the Karelian Research Centre of the Russian Academy of Sciences, Robonen E.V. , Chernobrovkina N.P. , Raevsky B.V. , Egorova A.V. , Zaitseva M.I. ,   Petrozavodsk State University, Kolesnikov G.N. 
Published: November 2020

Forests produce a huge amount of organic matter, which is a source of renewable raw materials for the production of technical, feed, food and pharmaceutical products. The logging and woodworking industry in Karelia, as in Russia as a whole, is based exclusively on stem wood. Woody greens are formed while felling ripe and over-mature stands, thinning and implementation of measures for the conservation, protection and reproduction of forests including forest stands cutting. The development of technologies for the use of woody greens is necessary for the multi-purpose utilization of the entire phytomass produced by forest plant communities. An additional economic incentive for young stands thinning and limbing, that are used to improve the quality of logs, is the ability to reduce costs or even ensure the profitability of these measures driven by the development of processing plants and the use of wastes generated during transportation: thinners, low-quality and low-value decidous wood, woody greens, that are raw materials for the production of biologically active preparations of various action. The urgent tasks are to increase the use of importsubstituting pharmaceutical substances and to search the alternative methods for producing raw materials for nutrient mixtures and feed stuff. Technologies for modifying the biochemical composition of coniferous greens, resulting in production of plant raw materials enriched with target biologically active substances, are being developed for the exploration of new plant sources. The water-soluble fraction of coniferous greens contains free amino acids, in particular L-arginine, which plays an important role in the life of animals. A promising way is to increase the free amino acids content in coniferous raw materials and change their quantitative ratio by regulation of the mineral nutrition regime of woody plants. An original scheme of additional supply of coniferous plants with nitrogen and boron is proposed in order to obtain coniferous greens enriched with L-arginine. The use of conifers as bioproducers of L-arginine and the study of its metabolism with reference to climatic factors, conditions of mineral nutrition, seasonal and daily dynamics in the natural environment, the search for ways to increase its level in organs and tissues is of current interest both on the theoretical and practical sides. Obtaining coniferous greens enriched with L-arginine will allow organizing the production of coniferous products for nutrient and pharmaceutical use. It is necessary to analyze the potential sources of raw materials taking into account their availability, costs for enriching the needles with L-arginine and product yield per unit area to assess the economic feasibility of organizing such production. A developed sequence of forestry measures will make it possible to obtain needles enriched with L-arginine, both in the process of implementing various types of forest use, and in carrying out activities aimed at increasing the productivity of forests and preserving their useful functions. Herewith, it is possible to turn costly cleaning and fertilizing of young Scots pine stands into profitable ones with additional products. Technologies of intentional changes in the chemical composition and pharmacological properties of plant raw materials obtained from woody plants will allow the development of new raw materials for biologically active substances.