engleski

Moderate Wildfire severity impacts on soil properties in a shrubland located in Dalmatia (Croatia): First results

Summer wildfires are a natural phenomenon in the Mediterranean environment. In the recent decades there has been an increase in the wildfire season length as consequence of the longer drought periods. The most problematic are the high severity wildfires that destroy vegetation cover and increase the vulnerability of soils to erosion. Nevertheless, it is important to study the impacts of low and moderate wildfires in order to understand the resilience of the ecosystems to these wildfires. The aim of this work is to study the impacts of a moderate severity wildfire on soils with different characteristics, with a) high (HS) and b) low stoniness (LS) in a Shrubland located in Croatia, immediately after. A control (Con) plot was established in an unburnt area to identify the impact of the wildfire. The properties analyzed were: 1) soil water repellency (SWR) in different fractions (2-1 mm ; 1-05 mm ; 0.5-0.25 mm and <0.25 mm), using the water drop penetration test (WDPT), 2) mean weight diameter (MWD), 3) water stable aggregates (WSA) and 4) pH. The study area is located in Zadar County, Croatia (44°4’N, 15°31’E ; average elevation 204 masl) in gentle slope (1° inclination) with NE exposition. The fire affected an area of 3 to 4 ha covered by schurbland. Eight samples were collected per treatment. The results showed that significant differences were observed in SWR among treatments in all the studied fractions. LS areas had a significantly higher SWR than HS and Con. On average the soils in HS and Con plots were wettable (<5 seconds), while in LS there were different between the fractions. In the 2-1 mm fraction, the soil had a low SWR, while in the other fractions, had a strong SWR. Generally, there was an increase in SWR with the decreasing soil fraction. MWD and WSA was significantly higher in LS than in HR and Con. Soil pH was significantly HR compared to Con.

wildfire ; severity ; soil ; stoniness

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