Productivity and sanitary condition of brittle willow stands in the floodplain of the Don River

Brittle willow (Salix fragilis L.) is widespread in the floodplain of the Don River with flowing groundwater. It forms stands on the bulging banks of the meander on the floodplain allyuvial--turf layered sand and sandy loam soil, as well as in central and on the terrace floodplain on floodplain alluvial-turf layered clay-sandy soil. Floodplains with groundwater (in low water) closer than 2 meters are unsuitable for brittle willow. Inspection of brittle willow stands was made in August 2008 at the Woodland of the Davydov forestry of the Voronezh region. Test plots are located in the most characteristic for the growth of brittle willow elements of the floodplain of the Don. Stands of coppice origin are mostly old-growth, low-quality class (IV-V). Significant signs of weakening do not have only stands up to the age of 20 years. Already by the age of 25 willow groves are weakened, from 30 to 45 years greatly weakened, and from the age of 50 they dry out. The highest increase in the current stock of stem wood is marked up to 25 years of age stands (3.8-3.9 cubic meters per hectare per year), after which the pace of growth has slowed. From the age of 30 there is a significant deterioration in the health of the tree stand and a significant reduction in the rate of growth on the trunk of the stock wood. In stands older than 50 years, more than 70% of stocks fell on the shrink and dead trees. With 55 years the value of natural mortality exceeds biomass accumulation and reaches 4.0 cubic meters per hectare per year to 65 years of age. At the same age and equal fullness, growing in the central floodplain are more productive stands. Predominance in the floodplain of the Don of old-growth stands of willow determines the need for their rejuvenation. Materials may outlined in this paper may be used in the design of thinning, sanitary felling and reforestation.