FOREST FIRES AND GLOMALIN CONTENT IN SOILS UNDER CERRADO VEGETATION

Resumo

SUMMARY

THE NATIONAL PARK OF CHAPADA DOS VEADEIROS, CREATED IN 1961, COMPRISES AN AREA OF 240,614 HA AND IS SITUATED IN THE BRAZILIAN SAVANNAH CALLED CERRADO [1]. THE BRAZILIAN CERRADO HAS ONE OF THE LARGEST BIODIVERSITY ON THE PLANET, BECAUSE IT IS A TRANSITIONAL BIOME THAT IS IN DIRECT CONTACT WITH OTHER IMPORTANT BIOMES SUCH AS AMAZON, CAATINGA, MATA ATLÂNTICA AND PANTANAL. IT IS CURRENTLY THE MAIN FRONTIER OF AGRICULTURAL EXPANSION IN BRAZIL, AND IT HAS BEEN THE TARGET OF SEVERAL CRIMINAL ACTIVITIES, SUCH AS FIRE, WITH THE PURPOSE OF DEFORESTING NATIVE AREAS TO INCREASE THE PRODUCTIVE AREA [2]. THE MAIN TOOL USED TO EXPAND TO NEW AREAS IN THE CERRADO IS FIRE. WITH BURNINGS PROVOKED, AND IN MANY CASES, CRIMINAL, NEW AREAS ARE INTENDED FOR AGRICULTURAL PRODUCTION. UNCONTROLLED FIRE CAUSES LOSS OF NUTRIENTS, SOIL COMPACTION AND EROSION, DEGRADATION OF THE NATIVE BIOTA. ALL THIS IS MORE PRONOUNCED IN THE DRY SEASON OF THE YEAR, WHERE THE LOW HUMIDITY AMPLIFIES THE DAMAGES OF A POSSIBLE BURN. THE OBJECTIVE OF THIS WORK WAS TO EXTRACT AND QUANTIFY GLOMALIN-RELATED SOIL PROTEIN (PSRG) IN THE CERRADO BIOME, TO EVALUATE THE INTERFERENCE OF FIRES IN THE AMOUNT OF GLOMALIN EASILY EXTRACTABLE (GFE), AND TO CORRELATE THE AMOUNT OF GLOMALIN PRESENT IN THE SOIL AS A FUNCTION OF THE DENSITY OF ARBUSCULAR MYCORRHIZAL FUNGI FOUND IN THE RHIZOSPHERE. THE PRESENCE OF FIRE DIRECTLY INTERFERED WITH THE AMOUNT OF GLOMALIN-RELATED SOIL PROTEIN, AND HIGHER AMOUNTS WERE FOUND AFTER FIRE ACTION. THE DENSITY OF MYCORRHIZAL FUNGI INCREASED AFTER THE INCIDENCE OF FIRE. IT IS OBSERVED THAT THE HIGHER THE DENSITY OF ARBUSCULAR MYCORRHIZAL FUNGI IN RHIZOSPHERE OF CERRADO PLANTS, THE HIGHER THE GFE RATE. GLOMALIN RESPONDS ACCORDING TO THE DENSITY AND CONDITIONS OF THE ENVIRONMENT. AREAS OF STRICTO SENSU, CERRAD�O AND VEREDAS HAVE A GREATER AMOUNT OF GFE IN AREAS WITHOUT THE PRESENCE OF FIRES. GFE TENDS TO INCREASE AS THE TIME PASSES AFTER THE FIRE, AS WELL AS THE DENSITY OF MYCORRHIZAL FUNGI.