Título:	Efeito da queimada na estabilidade de agregados, na resistência ao selamento superficial e na taxa de infiltração de água em solos de cerrado
Outros títulos:	The effects of fire on stability of soil aggregates, resistance to surface sealing and water infiltration rate in soils under cerrado vegetation
Autor(es):	Kato, Eiyti
Orientador(es):	Haridasan, Mundayatan
Assunto:	Solos - Cerrados Solos - análise Queimada - Cerrados Solos - infiltração
Data de publicação:	19-Mai-2020
Data de defesa:	Jul-2001
Referência:	KATO, Kiyti. Efeito da queimada na estabilidade de agregados, na resistência ao selamento superficial e na taxa de infiltração de água em solos de cerrado. 2001. viii, 58 f., il. Tese (Doutorado em Ecologia)—Universidade de Brasília, Brasília, 2001.
Abstract:	The Cerrado biome extends over an area of approximately 200 million hectares in Brazil. In this region the climate is seasonal, characterized by a dry season, which favors high frequency of fires, and a rainy season. The fires cause important changes in the ecosystem, including the soil environment. In spite of the great influence of physical and chemical properties of soils on vegetation and processes affecting the functioning of these ecosystems, few studies are reported in the literature on the effects of fire on modifying soil properties in the cerrado region. The objective of the present study was to determine the effects of fire on the properties of soils under three physionomic types of the cerrado vegetation to test the hypotheses that fires diminish the stability of soil aggregates, fires contribute to an increase in surface sealing caused by rain and fires diminish the rate of water infiltration in the soil. Soils under the vegetations of campo sujo, dense cerrado and cerrado sensu stricto submitted to fire regimes of buming every 2 or 4 years for a 10-year period were investigated. The 2-year buming regime included three treatments where the vegetation was bumt at the beginning, in the middle or at the end of the dry season. In the 4-year buming regime, the vegetation was bumt in the middle fo the dry season. This study was carried out in the experimental plots set up under the long term research project, “Effects of different fire regimes on the structure and dynamics of the cerrado communities” at the Ecological Reserve of the IBGE in the Federal District. The soil samples for analysis were collected in April 2000 from three profiles in each plot at the depths of 0-5, 5-10, 10-15, 15-20, 20-30 e 30-40 cm. The soil samples were analyzed to determine aggregate stability, texture, percentage of dispersed clay, bulk density, particle density, porosity and organic carbon content. Infiltration rate was measured in the field every 15 minutes over a 2-hour period using concentric ring infiltrometers. A rainfall simulator was used for the induction of surface sealing which was evaluated by comparing the infiltration rates before and after the rain. The last burnings were carried out during the months of June to September 2000 in the plots of 2-year buming regime and in August 1999 in the plots of 4-year burning regime. The infiltration measurements were carried out between August 2000 and March 2001. The soils of the dense cerrado and cerrado sensu stricto were dark red latossol. The campo sujo plots were spread over dark red and red yellow latossols. Ali the soils had a clay texture and the content of dispersed clay ranged from 102 g kg'1 to 382 viii g kg'1. The bulk density varied from 0.73 g cm"3 to 0.86 g cm'3 and soil porosity from 69% to 73%. The organic carbon content ranged from 1.53% to 2.24%. The burning of the vegetation generally increased the stability of soil aggregates. The mean weight diameter of water stable aggregates was 2.88 mm in the campo sujo plot bumt every four years as compared to 2.79 mm in the unbumt plot and that bumt every two years. The highest values of mean weight diameter in the dense cerrado (2.85 mm) and cerrado sensu stricto (2.88 mm) were encountered in plots bumt every two years. The infiltration rate diminished in ali vegetation types with increasing fire frequency. The highest infiltration rate of 114 cm h"1 in campo sujo was observed in the unbumt plot and the lowest rate of 59 cm h '1 in the plot bumt every four years. In cerrado sensu stricto the plot bumt every four years showed an infiltration rate of 102 cm h'1 and the plot bumt every two years a rate of 96 cm h '1. In the dense cerrado, the unbumt plot showed an infiltration rate of 201 cm h'1 and the plot bumt every two years at the end of the dry season a rate of 182 cm h '1. Surface sealing did not vary under different fire regimes in the campo sujo. The average reduction in infiltration rate after induction of surface sealing was 33% in the campo sujo plots under different fire regimes.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB)
Informações adicionais:	Tese (Doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, 2001.
Programa de pós-graduação:	Programa de Pós-Graduação em Ecologia
Agência financiadora:	Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq) e Fundação de Empreendimentos Científicos e Tecnológicos (FINATEC).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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