Variability of hygro-climatic conditions of forest vegetation in Poland during the period of 1951–2015

This work presents an assessment of changes in the hygro-climatic conditions determining the vegetation and productivity of forest areas. Selected indices such as the radiant index of climate aridity – RIA, optimal precipitation – Popt, critical value of precipitation – Pkrt and CVP index (Climate, Vegetation, Productivity), which describe annual biomass and wood production under climatic conditions, were used. The analysis is based on standard meteorological measurements taken from 21 stations from the period of 1951–2015. The daily data were employed to calculate the previously mentioned indices, and the next linear trend coefficient was used to assess changes in hygro-climatic conditions