Effects of Changes in Precipitation and Temperature on Select Agrophage Risk in Poland, 1965-2009

Abstract

Agriculture is a branch of the economy seriously influenced by climate change, particularly in terms of the incidence and damage potential of crop agrophages. Precipitation and air temperature recorded over the last 44 years in five select locations in Poland were analyzed in order to determine whether and to what extent climate change had actually occurred. Monthly precipitation totals and mean air temperatures were analyzed in terms of seasons, taking into consideration the course of vegetation of both spring and winter crops and development of pests. The aim of the study was to determine how precipitation and air temperature change and to present a preliminary evaluation of their effects on the level of damages of economically important agrophages, for several decades covered by nationwide monitoring in Poland. On the basis of results of descriptive statistics it was found that the highest value of the coefficient of variation for precipitation over a period of 44 years was recorded in autumn, while for air temperature it was in winter. After the 44-year period had been divided into four 11-year periods, the last 11 years (1999-2009) showed that the mean value of air temperature in relation to the years 1988-98 (1.5oC) decreased only in winter, although the mean value was still above zero (0.9oC). In the other seasons in the years 1999-2009 it was the highest. In turn, mean precipitation levels for the last 11 years were highest only in winter. An increase in precipitation in the winter months could have been one of the factors contributing to a reduction of populations of wintering pest stages. Stable precipitation patterns and increasing temperatures in spring could have contributed to the development of e.g. the European corn borer, while it may have limited the intensity of fungal crop diseases.