FESP 7 7

th INTERNATIONAL CONFERENCE ON FIRE EFFECTS ON SOIL PROPERTIES

UNIVERSITY OF HAIFA, ISRAEL 18-21.02.2019

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Moderate Wildfire severity impacts on soil properties in a shrubland located in Dalmatia (Croatia): First results Paulo Pereira1, Leon Josip Telak2, Igor Bogunovic2, Ivica Kisic2

1 Environmental Management Laboratory, Mykolas Romeris University, LT-08303 Vilnius, Lithuania.

2 Faculty of Agriculture, Univeristy of Zagreb, Zagreb, Croatia.

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.

Keywords: wildfire, severity, soil, stoniness

Acknowledgments

This work was supported by Croatian Science Foundation throughunder the project "Soil erosion and degradation in Croatia" (UIP-2017-05-7834) (SEDCRO).