Condition, structure and productivity of pine forests of State Enterprise “Lymanske Forest Economy”

Abstract

Introduction

Large forests play an important role in the steppe zone, especially in the regions most problematic for forest planting. Negative impacts of climate change become worsened as most pine forests are of artificial origin and are single-layer even-age pure stand. One of the largest forest areas in Donetsk Region is the forests in the State Enterprise (SE) “Lymanske Forest Economy” located in the Siversky Donets River basin. The great importance of these forests for the region is reflected in forest management specificities in. Its largest share (72%) is occupied by forests of conservational, scientific, historical and cultural purposes.

The aim of the study was to analyze the main stand characteristics and the condition of the pine stands in SE “Lymanske Forestry”.

Materials and Methods

The pine stands’ characteristics were studied using the data given in the Forest Fund database as of 01.01.2011 and generally accepted methods in forest mensuration. The condition of trees and stands was determined in accordance with the Sanitary Forests Regulations in Ukraine. At that, 18 sample plots (circular and polygonal) were surveyed for detailed assessment of the condition and structure of pine forests on a typological basis in July-August 2019. The Field-Map technology developed by experts from the Institute of Forest Ecosystem Research (Czech Republic) was used for works on sample plots and primary data processing.

Results

In most sites, stands of dominant tree species correspond to their forest types. However, they have a simplified structure. Thus, the share of pure pine stands is 94.2% of the area. The stands of VI, VII and VIII age classes cover the largest areas – 20.4%, 19.6% and 18.4% accordingly. Furthermore, the II productivity class stands occupy the largest area, namely 43.6%. The share of the I productivity class stands is 30.5% and the stands of the III productivity class cover 16.2% of the area. As for the density of stocking, the stands with that index of 0.8 occupy 47.7% of the area, the stands with the index of 0.7 – 24.3% and those with the index of 0.9 – 14.0%. The forest stands have uneven density of stocking.is. At that, the root rot foci are present there. The polygonal test plots were laid in the interspaces; the circular plots were laid, to compare, in damaged and undamaged parts of the stands. The carried out assessment showed that the health of the stands in the control plots was weakened (health condition indices of 2.27–2.87) and that in the damaged plots is severely weakened (health condition indices of 3.13–3.23). In areas damaged by forest fires, trees condition tends to deteriorate with increasing height and perimeter of fire damages.

Conclusions

The ratio of relief types determines a typological structure of the forests of SE “Lymanske Forest Economy”. Fresh and dry infertile pine forest types and fresh fairly infertile oak and pine forest types cover the largest areas in pine terraces. At that, the pine stands with the medium productivity class prevail: the average site index is I,7; the average density of stocking is 0.76. Comparative analysis of the forest inventory data and field studies showed that there is a necessity to specify forest types and define principal species. The health condition of the pine stands is weakened and severely weakened which is brought about by unfavorable conditions for the stands growth, anthropogenic impact (changes in hydrological regime caused, in particular, by the extraction of minerals and water intakes, and forest fires in 2014) and diseases. The worst condition was observed in the areas damaged by fires (health condition index excluding dead-standing tree was 2.49–2.70).

1 Fig., 5 Tables, 9 Refs.