Marjana Gajić-Čapka

Trends in precipitation indices in Croatia, 1961–2010

Precipitation data from the period 1961–2010 and from a dense rain-gauge network over Croatia is analysed for spatial characteristics of trends in precipitation amounts and precipitation indices. Besides large spatial variability, the area is characterized by large temporal (seasonal) variability. Thus, analysis is performed on annual and seasonal scales over seven predefined subregions. Ten precipitation indices are selected to assess the intensity and frequency of extreme events as well as their contribution to annual and seasonal precipitation changes. The results reveal that the changes in annual and seasonal amounts are predominantly weak. A significant trend is detected only for annual amounts (negative) in the mountainous region and for summer (negative) in the mountainous littoral, mountainous region and central hinterland. A significant positive trend for autumn appears in eastern mainland. Negative trends in summer are associated with a decrease in frequency of moderate wet days, in maximal 1- and 5-day precipitation and in an increase in light precipitation. A negative annual trend is mainly caused by a decrease in frequency of very wet days and their contribution to the total precipitation. A positive autumn trend is associated with more very wet days and an increase of their contribution to the total precipitation as well as an increase in maximal 1- and 5-day precipitation. This study complements the existing analysis of five Croatian secular data series of extreme precipitation indices by involving the whole precipitation dataset since the mid-twentieth century and fills the gap present in the trend assessment of precipitation trends in Mediterranean and Europe.

Climate variability, soil and forest ecosystem diversity of Dinaric Mountains

The Dinaric mountains in Croatia present one of the hot spots of European biodiversity, possessing a very large number of species and hosting most endemics. The Dinaric mountains in Croatia strongly affect the climate of the Adriatic region, making a distinct boundary between the maritime and a continental climate. In this chapter, an overview of climatic conditions of the Dinaric area is provided, including observed climatic changes of temperatures and precipitation in the last century. Existing soil types were assessed and described, in particular with respect to soil-forming processes. The role of climate as a dominant factor of soil formation was evaluated in relationship to other factors such as lithology and topography. Also, the occurrence of a specific broad range of forest associations in Dinarides was presented. We examined the correspondence between forest vegetation, soil, and climatic properties in the Dinaric area. As a finale, some future, very possible scenarios of regional climatic development are presented as a serious hazard to the sustainability of natural forest resources. We determined the variety of soil types, ranging from soils that are characteristic for Mediterranean (on limestone) such as Terra rossa with intensive red color, calcomelanosols and calcicambisols in high karst, to soils characteristic for continental climate (on flint or silica) such as dystric cambisols and luvisols. The forest vegetation of the Dinaric mountains constitutes 54 diverse forest ecosystem types, encompassing specific combinations of soil and phytocoenoses. Existing ecosystems form nine broader groups, that is, bioclimates, which are typical for Dinarides.