Сomplex assessment of black poplar Populus nigra L. shelterbelts in the south of Central Siberia

Abstract

The objects of the study were forest shelterbelts represented mainly by pure and mixed stands of black poplar Populus nigra L. in the Republics of Khakassia and Tyva. The sites differed according to soil conditions: southern chernozems, ordinary chernozems, sandy spilled soils. The stand structure along DBH distribution rows showed pure stands to possess a right-asymmetric shape with non-expressed maximum points. Mixed stands are characterized by a comb-shaped form with several extremum points. In comparison with mixed stands, pure (monospecific) forest belts are more stable. Black poplar is characterized by different state of trees growing in favorable conditions in pure stands (8.0–53.6 % – healthy trees) compared to a weakened state in mixed stands (12.9 % – healthy trees). Three growth strategies have been intensive, medium, and moderate. The strategy of intensive growth is characteristic of pure tree stands growing on ordinary chernozems. The strategy of moderate growth is characteristic for a mixed stands growing on southern chernozems. Black poplar has a more full-boled stem form in comparison with other tree species of forest shelterbelts from other administrative regions. The difference in the ratio of tree heights and diameters is due to the soil conditions,formation of shelterbelt, many other anthropogenic and natural factors. The stereometric method was used to obtain an empirical formula for determining the wood stock of black poplar. Complex evaluation of black poplar growth in forest shelterbelts in the south of Central Siberia made it possible to determine the features of agrotechnology, structure, the conditions of tree growth, stem shape, identification of the types of site conditions, and to choose the methods for assessing the current productivity of the stands. The obtained results contribute to developing the regulatory framework, and introduce economic measures for the creation, cultivation and care of black poplar forest belts in Central Siberia.

Keywords

• Populus nigra L.
• stand structure
• condition
• productivity