The Regional Changes of Climate as Primary Causes of Strong Withering of Pine Stands in Volyn Polissya

Abstract

Since the beginning of 21 century it has been established that the phenomenon of unprecedented degradation of pine-woods acquires global character in all continents. In recent years, Ukrainian Polissya has also recorded a progressive increase of threatening associations of pine stem pests in combination with the ophiostamoid fungi. In order to successfully resist the negative phenomenon, it is not only necessary to know the mechanism of his motion but also reasons or factors of appearance. In the research we analysed the archival metrological data from weather-stations in Kovel for period from 1946 to 2015 to observe general trends and patterns of climate in the area of location of the forests. Our work has revealed the following results. Firstly, withering of new type in the Volyn region, on the basis of which there is the destruction of pine-tree by aggressive barrel wreckers and pathogenic fungi, began to emerge in significant amounts in the last 2 years. During the inspection of pine plantations it was found that recently they have operated in fundamentally changed forest site conditions, where we observed an expressive deformation of hydrosite in direction of growth of dryness. Despite this, it was found that the characteristic feature of this type of weather is a steady trend of increasing the amount of precipitations. The brought materials testify convincingly, that the droughty phenomena and pathologies of the forest initiated by them is not the basis of a deficit of atmospheric precipitations. Further analysis of climate data revealed that in period from 1998 to 2002, there was a significant increase in the average temperature of the air, both for the year and for vegetation period. Thus, the conducted analysis provides reasonable grounds for the conclusions that in the area of the forest site we have long observed the phenomenon of drought that has an undoubtedly thermal origin. The primary causes of pathological processes of the forest are related not to profitable, but expense side of water balance. According to final evaluation, when predicting withering it is necessary to consider that the area of the pine forests staggered by new pathogenic complexes will only increase in the future.

Keywords

• amount of precipitations
• climate
• pathological processes of forest
• common pine (scots pine)
• temperature of air