ABSTRACT Post-fire response by vegetation may reflect the severity of the damage suffered, but we still know little about the species-specific nature of responses to fire or their predictors. Here, we evaluated 26 woody species before and after a fire event in an Cerrado sensu stricto area (typical Brazilian savanna-type) in order to evaluate mortality rates and the type of resprouting (epigeal, hypogeal or epigeal + hypogeal). We evaluated the relative importance of stem diameter, height, and bark thickness as predictors of the type of post-fire resprouting, using a sequential logistic regression model (SLRM). Mortality was 4 %, while epigeal resprouting was recorded in 57 % of the individuals, hypogeal resprouting was recorded in 24 %, and epigeal + hypogeal resprouting in 15 %. Our SLRM analysis indicated that bark thickness, followed by stem diameter, were the best predictors of the type of resprouting. There was a greater than 60 % probability that individuals with bark thicker than 1.6 cm resprouted only epigeally. Our results confirm the resistance (low mortality) and resilience (high resprouting capacity) of the woody vegetation of the Cerrado sensu stricto to fire, and that thick bark is an effective protection against fire damage.

RESUMO Este estudo teve como objetivo verificar a eficiência de carvão vegetal pirogênico como condicionante de substrato para o desenvolvimento de mudas florestais de alto vigor, testando-se o carvoeiro (Tachigali vulgaris) como espécie representativa do Bioma Cerrado. Foram tomados como modelo de produtividade os solos de elevada capacidade de troca catiônica com Horizonte A antrópico da Amazônia (Terras Pretas de Índio), ricos em carbono pirogênico derivado de carvão vegetal. O experimento foi realizado no viveiro da Universidade do Estado de Mato Grosso, no município de Nova Xavantina-MT. Foram utilizadas quatro concentrações de carvão de eucalipto (Eucalyptus sp.) com 5; 12,5; 25 e 50% do volume total do substrato base e 0% como testemunha. Foi avaliada a porcentagem de emergência no início do experimento. Durante oito meses, a cada 30 dias, foi contado o número de folhas e medida a altura total das mudas. No oitavo mês foi medido o diâmetro do coleto e determinada à massa seca da raiz e da parte aérea. Os tratamentos e a testemunha apresentaram emergência superior a 80%, não havendo influência do carvão. Entretanto, o carvão vegetal incrementou significativamente a altura das mudas, o número de folhas, o diâmetro do coleto e a massa seca radicular e da parte aérea, o que ficou evidenciado pela forte correlação positiva com as concentrações de carvão. Portanto, o carvão vegetal pirogênico é uma alternativa viável como condicionante de origem biológica do substrato para a produção de mudas potencialmente mais resistentes, requerimento importante para plantios em campo sob condições mais severas, como na recuperação de áreas degradadas no Bioma Cerrado.

ABSTRACT The objective of the present study was to investigate the efficiency of charcoal as amendment to the substrate used for high vigor of growing seedlings, testing Tachigali vulgaris as representative species of the ‘Cerrado’ Biome. Amazonian dark earth soil (Terra Preta de Índio), enriched by pyrogenic carbon and available nutrients were taken as model example. The experiment was carried out in the nursery of the State University of Mato Grosso, in Nova Xavantina, Mato Grosso state, Brazil. The treatments consisted of 0, 5, 12.5, 25 and 50% (v/v) of Eucalyptus sp. charcoal mixed with the standard substrate. Seed germination was evaluated at the beginning of the experiment, as well as the height and stem diameter of seedlings and the number of leaves was measured every 30 days during eight months. At the end of the 8th month, the stem diameter and the dry matter of the seedling biomass (aerial part and root system) were measured. The germination of the seeds was above 80% in all treatments and no differences were observed between them. The charcoal, however, had significant effect on the other parameters determined, all of them showing significant and positive correlation with the charcoal doses. Consequently, charcoal is a good option as biological amendment to the substrate for the creation of healthy and more resistant seedlings of Tachigali vulgaris, an important requirement for adverse field conditions, such as restoration of degraded areas in the Cerrado Biome.