Comparison of two mapping methods of potential distribution of pests under present and changed climate

Abstract

The study compares two methods for modeling the potential distribution of pests when applied to the European corn borer (Ostrinia nubilalis Hubner). The development of the European corn borer (ECB) is known to be closely correlated with daily air temperature as well as other climate variables. The climatic parameters are, therefore, used to predict the potential geographical distribution using tested tools such as CLIMEX or ECAMON. These models consider the climatic suitability of a given site/region for the pest's development and, thus, the possible establishment of a population at a given location. In this study, meteorological data from 1961 to 2000 and from 45 meteorological stations were used to characterise the current climate conditions in the Czech Republic. Validation was based on available field data of the occurrence of ECB in the same period. The climate parameters were later modified according to the estimates based on the combination of three SRES emission scenarios and three global circulation models. Under all climate change scenarios, we noted a marked shift of the pest's potential niches to higher altitudes, which might lead to an increase in the infestation pressure during the first half of this century. The present area of the univoltine population will increase due to temperature increases even above 800 m a.s.l. In addition there is a risk of the establishment of a bivoltine population in the main agricultural areas and 38% of arable land in the Czech Republic before 2050.