ABSTRACT The objective of the present study was to evaluate the influence of spacing, species richness, and sampling time on accumulated litter in forest restoration areas in the state of Espírito Santo, Brazil. The experiment was conducted under a randomized complete block design, in a subdivided plot scheme. Six treatments were evaluated, consisting of a combination of spacing levels and species richness. Accumulated litter samples were weighed and chemically analyzed to obtain nutrient concentrations. The variables analyzed in the restoration process, in general, did not influence litter biomass and nutrient concentrations. The time elapsed between restoration implantation and data sampling for the present study may have been insufficient for the occurrence of differences in variables evaluated. Despite the small amount of accumulated litter, it is of great importance for soil physical protection and fertility improvement, generating conditions for the stabilization of new forest species in the restoration area.

O objetivo deste trabalho foi estimar a biomassa e o carbono orgânico em plantios de Araucaria angustifolia com diferentes idades. Os plantios de Araucaria angustifolia estudados não tiveram intervenções silviculturais relacionadas à desrama, porém, em todos os povoamentos ocorreram práticas de desbaste em diferentes épocas. Nos povoamentos com 32 e 31 anos de idade foram realizados três desbastes. Nos plantios com 30, 29, 25, 24 e 23 anos foram realizados dois desbastes. A determinação de biomassa no campo foi realizada de acordo com o método destrutivo de quantificação, utilizando-se para tanto a amostragem de sete árvores distribuídas aleatoriamente pelo povoamento em cada uma das idades. Os indivíduos foram abatidos, obtendo-se inicialmente as variáveis dendrométricas: DAP, altura total e altura comercial (diâmetro mínimo de 8 cm). O plantio com 23 anos apresentou o maior volume de lenho do fuste (613,02 m³ ha-1), superior aos plantios com 30, 31 e 32 anos (418,41; 520,21 e 518,48 m³ ha-1), respectivamente. Porém, em termos de biomassa do fuste os resultados foram próximos, sendo que o plantio com 23 anos totalizou 138,02 Mg ha-1 e os plantios com 30, 31 e 32 anos somaram 118,77; 128,97 e 155,01 Mg ha-1, respectivamente. Nos plantios de Araucaria angustifolia o estoque total de biomassa e carbono orgânico arbóreo nas diferentes idades consideradas variaram de 60,72 a 289,84 Mg ha-1 e 21,73 a 123,86 Mg ha-1, respectivamente. Ficou evidente que a densidade de plantas e a intensidade de desbaste influenciaram diretamente a biomassa e o carbono estocados.

The objective was to estimate the biomass and organic carbon in Araucaria angustifolia stands with different ages. The Araucaria angustifolia stands studied were not pruning but were thinning in difference ages. In stands of 32 and 31 years-old, were three thinnings. In stands of 30, 29, 25, 24 and 23 years-old, were two thinnings. Biomass avaliation was conducted according to the destructive method, using the sampling of seven trees were randomly distributed in each stand. The plants were harvested, after were obtained the dendrometric variables: DBH, total height and commercial height (minimum diameter of 8 cm). Stand with 23 years had the highest volume of stem wood (613.02 m3 ha-1), followed by 30, 31 and 32 years-old stands (418.41, 520.21 and 518.48 m³ ha-1), respectively. However, in terms of stem biomass the results were similar, 23 years-old stand had 138.02 Mg ha-1 and 30, 31 to 32 years-old totaled 118.77, 128.97 and 155.01 Mg ha-1, respectively. In Araucaria angustifolia stands the total stock biomass and organic carbon in different ages ranged from 60.72 to 289.84 Mg ha-1 and 21.73 to 123.86 Mg ha-1, respectively. Plant densitie and thinning intensity were directly influenced the biomass and carbon stored.

RESUMOEste estudo objetivou quantificar a biomassa, teor e conteúdo de nutrientes na serapilheira acumulada, correlacionando com a precipitação e a temperatura. A amostragem foi realizada em cinco transectos (50 m x 2 m) e coletada com um gabarito (0,25 m x 0,25 m), de maio de 2011 a abril de 2012, bem como separada na fração “outras espécies” (mistura de folhas, galhos, flores e frutos de diversas espécies) e fração “pseudobombax” (material da Pseudobombax aff. campestre). Utilizou-se um delineamento inteiramente casualizado com 12 tratamentos e cinco repetições para biomassa; para teores, foram 12 tratamentos e três repetições. A correlação de Pearson entre os atributos da biomassa com a pluviosidade e a temperatura foi realizada e sua significância, testada. A média acumulada foi de 8.900 kg ha-1, com distribuição ao longo do ano, sendo N, Ca e Fe os nutrientes com maiores acúmulos na serapilheira. Houve correlação entre ambas as frações e variáveis climáticas para os macronutrientes N, P e S e para os micronutrientes Fe e Cu na fração “pseudobombax”.

ABSTRACTThis study aimed to quantify the biomass, content of nutrients in accumulated litter, correlating with rainfall and temperature. Sampling was conducted in five transects (50m x 2m), collected with a template (0.25 m x 0.25 m) from May 2011 to April 2012. Fraction was separated in “other species” (a mixture of leaves, twigs, flowers, fruits of various species), and “pseudobombax” (material of the Pseudobombax aff. campestre). A completely randomized design was used with twelve treatments and five replications for biomass; for contents: twelve treatments and three replications. The Pearson correlation between the attributes of biomass with rainfall and temperature was performed and its significance was tested. The accumulated average was 8,900 kg ha-1, distributed throughout the year, N, Ca and Fe were the nutrients with higher accumulation in the litter. Correlation existed between both fractions and climatic variables for macronutrients: N, P and S, and the micronutrients Fe and Cu in fraction “pseudobombax”.