Título:	Efeitos do fogo na regeneração de Kielmeyera coriacea (Spr.) Mart. (Guttiferae) em áreas de cerrado sensu stricto : mecanismos de sobrevivência e época de queima
Autor(es):	Silva, Paulo Cirne da
Orientador(es):	Miranda, Heloisa Sinátora
Assunto:	Cerrados - vegetação Cerrados - queimada Reserva Ecológica do IBGE Dinâmica populacional Regeneração (Biologia) - Cerrados
Data de publicação:	20-Mai-2020
Data de defesa:	2002
Referência:	SILVA, Paulo Cirne da. Efeitos do fogo na regeneração de Kielmeyera coriacea (Spr.) Mart. (Guttiferae) em áreas de cerrado sensu stricto: mecanismos de sobrevivência e época de queima. 2002. viii, 83 f., il. Tese (Doutorado em Ecologia)—Universidade de Brasília, Brasília, 2002.
Abstract:	Fire is considered an ecological factor potentially involved in species selection and vegetation dynamics of the Cerrado, the neotropical savannas of Central Brazil. Nevertheless, researches examining the performance of plant populations in response to different fire regimes are scarce for this biome. This study was developed in areas of cerrado sensu stricto at Reserva Ecológica do IBGE, Brasília, DF, as part of long term ecological research (Projeto Fogo) and studied processes related to regeneration of Kielmeyera coriacea (Spr.) Mart. Guttiferae after prescribed biennial buming in the middle of the dry season of 1998 and 2000. This species is distributed in different physiognomies of Cerrado, exhibits shrub or tree habitus and phenological pattems highly related to climatic seasonality. Chapter 2 presents the individual size distribution of K. coriacea in areas bumed, since 1992, in the beginning (BP), middle (BM) and the end (BT) of the dry season. In Chapter 3 it is presented the pattems for post-fire resprouting, survival rates, production o f reproductive structures and the relations between these pattems and individual size. Moreover, it was examined aspects of population dynamics of K. coriacea in BP, BM and BT. In Chapter 4, the mechanisms involved in seed protection and survival during fire and the effect of fire on fruit opening are presented for BP and BM. Most individuais were in the first size classes (until 100 cm o f height (h), and 30 mm of basal diameter (db), and the proportion of young individuais was significantly greater (p < 0,05) in BT (96,8 ± 4,5%), when compared to BP (70,8 ± 6,6%) and BM (85,3 ± 10,0%). Considering ali individuais sampled in the three experimental areas, it was found a high survival rate after the 1998 and 2000 buming (96,3 e 94,2%, respectively). Temperature measurements to evaluate the insulation conferred by bark to the cambium demonstrated that maximum temperature at the cambium for a juvenile individual was greater than (78 °C) to that measured in an adult (49°C). It was found linear and positive relationships between shoot bark thickness of K. coriacea and individual size, and the capacity o f aerial resprouting was proportional to size. Although individual survival was not linearly related to size, it was observed a greater reduction in the number of adult individuais than juvenile ones. The mortality was smaller in BP when compared to BM and BT, specially when considering only larger individuais. In general, before the fires in BM and BT, the individuais had already allocated resources to bud activation, leaf production and/or stem growth.. The production of reproductive structures was restricted to individuais bigger than 150 cm in height and 45 mm in basal diameter. Moreover, considering only adult plants, the proportions of flowering individuais in different height classes were linearly related to h, and the proportions of flowering individuais in BT was smaller than in BP or BM, which can be explained in function of the smaller secondary branches production in BT. After the 1998 burning, germination in BP was smaller than in BM or in BT, although seedling recruitment and survival, in the following rainy and dry season periods had been similar between the treatments. During fire, externai maximum temperatures of fruits were in the range of 393°C to 734°C, while maximum fruit internai temperatures were between 61°C and 63°C. Seeds collected in closed fruits before burning, on soil or in opened fruits during fire did not germinate in laboratory, while those in fruits that opened only after fire showed a high germinability (79 ± 12% in BP and 69 ± 14% in BM). In BP and BM, fruit opening was more intense after burning. Negative effects on seeds were observed for fruits that did not open after the fires (41.0% in BP and 34.4% in BM). K. coriacea has shown to be resistant and resilient in relation to fire. However, in a high frequency fire regime, season of fire seems to be determinant in persistence of local plant populations of this species. Even so, the results demonstrated that vegetative and sexual regeneration are potentially important to the maintenance of K. coriacea in the fire regime considered. Long-term researches, at population levei, including different fire regime as frequency and season of burning can be important to the development of strategies aiming the management and conservation of Cerrado areas.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB)
Informações adicionais:	Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, 2002.
Programa de pós-graduação:	Programa de Pós-Graduação em Ecologia
Agência financiadora:	Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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