Forest ecosystems contribute significantly to store greenhouse gases. This paper aimed to investigate the spatial and vertical distribution of litter, roots, and soil carbon. We obtained biomass and carbon of compartments (litter, roots, and soil) in a vegetation from Cerrado biome, state of Minas Gerais, Brazil. The materials were collected in 7 0.5 m² sub-plots randomly allocated in the vegetation. Root and soil samples were taken from five soil layers across the 0-100 cm depth. Roots were classified into three diameter classes: fine (10 mm) roots. The carbon stock was mapped through geostatistical analysis. The results indicated averages of soil carbon stock of 208.5 Mg.ha^-1 (94.6% of the total carbon), root carbon of 6.8 Mg.ha^-1 (3.1%), and litter of 5 Mg.ha^-1 (2.3%). The root carbon was majority stored in coarse roots (83%), followed by fine (10%), and medium roots (7%). The largest portion of fine roots concentrated in the 0-10 cm soil depth, whereas medium and coarse roots were majority in the 10-20 cm depth. The largest portion of soil (53%) and root (85%) carbon were stored in superficial soil layers (above 40 cm). As conclusion, the carbon spatial distribution follows a reasonable trend among the compartments. There is a vertical relation of which the deeper the soil layer, the lower the soil and root carbon stock. Excepting the shallowest layer, coarse roots held the largest portion of carbon across the evaluated soil layers.

The Cerrado is the second largest biome in Brazil and the most biodiverse tropical savannah in the world and acts as a great sequester of atmospheric carbon. The lack of studies related to the quantification of its total biomass compromises the understanding of the dynamics of CO2 in this biome. Thus, it is relevant to develop studies aiming at obtaining accurate estimates of the carbon stock in the different phytophysiognomies that make the Cerrado, to include them in appropriate forest management models. Based on the hypothesis that the amount of carbon stored can vary according to the vegetation typology and vegetation compartments, the aerial stock of dry biomass and carbon were estimated in different compartments (arboreal, herbaceous-shrub and litter). The study was developed in open Brazilian savannah and soils on the sandstone and discussed the effect of fire on this phytophysiognomy. For the arboreal compartment were adjusted mathematical models to fit the biomass equations to estimate the individual stock of the trees in this compartment. The results of the stocks were discussed considering the effect of fire on the phytophysiognomy. Based on the precision and extra distribution measures, the Schumacher-Hall (non-logarithmic) equation presented better results to estimate the individual biomass and carbon stocks of the open Brazilian savannah trees. The aboveground biomass was 12.88 Mg ha−1, corresponding to a total carbon stock of 5.91 Mg ha−1, where most of the stocks are in the herbaceous-shrub compartment (44%). The arboreal compartment accounts for the smallest part of the stocks, followed by the litter. The observed values are in the interval verified for other areas of savannah studied in Brazil. The values verified for the open Brazilian savannah in sandy soils are at the lower limit of this range, due to the nutrient-poor nature of this type of soil. The distribution of stocks in the different compartments above the ground points to the fragility of this environment to the random fire effect, common in the region. That shows the need for conservation measures for vegetation maintenance and soil protection to preserve adequate nutrient cycling in the ecosystem.

O objetivo deste estudo foi ajustar modelos tradicionais de relação hipsométrica para plantios homogêneos da espécie candeia, sob diferentes espaçamentos. Foram ajustados dez modelos de relação hipsométrica e o critério de avaliação obedeceu ao maior coeficiente de determinação ajustado e ao menor erro padrão da estimativa em porcentagem. Também foram avaliados o teste F, a significância dos coeficientes de regressão, a análise gráfica dos resíduos e o teste de identidade nos casos em que um mesmo modelo foi selecionado para diferentes tratamentos. Foi observado que, ao longo do tempo, a curva hipsométrica reduz a sua inclinação, desloca-se para a direita e sobe de patamar, com redução do intervalo entre elas a partir do sexto ano de avaliação. Os modelos tradicionais de relação hipsométrica de Henricksen, Stofells, Assman, Trorey e Curtis são os mais eficientes para estimar a altura total da espécie candeia, em plantios homogêneos e com diferentes espaçamentos iniciais, no estado de Minas Gerais.The objective of this work was to adjust traditional models of hypsometric relations for homogeneous candeia stands, under different initial spacings. Ten models were adjusted for hypsometric relations. The assessment criteria obeyed the highest determination coefficient and the lowest standard error of estimate in percentage. The F test was also evaluated, as well as the significance of the regression coefficients, the graphical analysis of the residues and the identity test when the same model was selected for different treatments. It was observed that, over time, the hypsometric curves reduce their tilt, move to the right and elevate, reducing the interval among them from the sixth year. The traditional hypsometric relation models as Henricksen, Stofells, Assman, Trorey and Curtis are efficient to estimate the total height of candeia in homogeneous stands and under different initial spacing in Minas Gerais State, Brazi