Šumski požari i zagrevanje zemljišta - rekonstrukcija požara u NP 'Tara' primenom modela FOFEM6

Abstract

U Republici Srbiji se, naročito u toku poslednje decenije, povećao broj šumskih požara, čime su značajno ugroženi ekonomija, ekosistemi i predeli. Tokom avgusta 2012. god., na planini Tari je izgorelo oko 1.700 ha šuma, uglavnom, bukve, smrče i borova. U ovom radu se razmatraju rezultati analiza rekonstrukcije ovog požara, sa aspekta uticaja na zagrevanje i sterilizaciju zemljišta, primenom modela FOFEM6 (First Order Fire Effects Model). Na osnovu profila temperatura, utvrđeno je da su se maksimalne temperature zemljišta razvile u površinskom sloju organogene crnice na krečnjaku u sastojini crnog bora, od 265OS posle 161 minuta, na smeđem zemljištu na krečnjaku (kalkokambisol) u sastojini bukve, od 339OS posle 159 minuta i na posmeđenom humusno-silikatnom zemljištu na serpentinitu u sastojini crnog i belog bora, od 262OS posle 162 minuta. Razvojem temperatura zemljišta na pojedinim dubinama, počev od 40OC, za koje se smatra da negativno utiču na žive organizme, uopšte, do letalnih za pojedine vrste organizama ili graničnih za različite komponente zemljišnog ekosistema, povećane temperature se odražavaju na smanjenu agregatnu stabilnost zemljišta, promene u kruženju hranljivih materija, a posebno na diverzitet mikrobiote i mezofaune. Usled dostizanja temperatura od 250-339OC, dolazi do izvesnih promena sastava minerala kao i promena pH vrednosti zemljišta. Sterilizacija zemljišta izazvana visokim temperaturama, u proučavanim uslovima će u budućnosti presudno uticati na brzinu obnove šumskih ekosistema.

The number of forest fires has been increased in Serbia, especially in the past decade, which significantly threatened the economy, ecosystems and landscapes. About 1.700 hectares of forests, mainly beech, spruce and pine forests, were burned on Tara mountain in August 2012. This paper discusses the results on the fire reconstruction analyses, from the aspect of the impact on heating and sterilizing the soil, applying the model FOFEM6 (First Order Fire Effects Model). Based on the temperatures profile, it was found that the maximum soil temperatures were developed in the surface layer of organogenic humus on limestone in the black pine stand, where it was 265OC after 161 minutes, on the brown soil on limestone (calcocambisol)) in the beech stand it was 339OC after 159 minutes, and on the brownish humus-siliceous soil on serpentinite in the black pine and Scots pine stands it was 262OC after 162 minutes. The development of soil temperatures at certain depths, ranging from 40OC, is considered to have a negative impact on the living organisms, in general, and those temperatures are even lethal for some species, or close to lethal for different components of soil ecosystems. The increased temperatures are reflected in the decreased aggregate stability of the soil, changes in the cycling of nutrients, and especially in the diversity of microbiota and mesofauna. The temperatures of 250-339OC cause certain changes in the composition of minerals, as well as changes in soil pH value. Soil sterilization caused by high temperatures will in the controlled conditions in the future have decisive influence on the rate of forest ecosystems rejuvenation.