VARIAÇÃO ESPACIAL DOS ATRIBUTOS FÍSICOS E ESTOQUES DE CARBONO DO SOLO EM PLANTIO DE Schizolobium amazonicum NA AMAZÔNIA

Tree plantations provide an increase in soil carbon stocks, but studies involving native Amazonian species are incipient. The objective was to evaluate the spatial variation of physical attributes and soil organic carbon stock in a paricá plantation. In the study area, soil samples were collected at depths of 0 to 20 cm and 20 to 40 cm and the parameters analyzed were: soil texture, macroporosity, microporosity, soil bulk density, mechanical soil resistance to penetration, and soil organic carbon content and stocks. The data were interpolated by the inverse of the square of the distance. The spatial variation of soil physical attributes at planting was influenced by texture. There was a low range of spatial variation in soil organic carbon content and stocks. Paricá planting was efficient in fixing soil carbon at depth.Plantios de árvores proporcionam aumento dos estoques de carbono do solo, mas estudos envolvendo espécies nativas da Amazônia são incipientes. Objetivou-se avaliar a variação espacial dos atributos físicos e estoque de carbono orgânico no solo em plantio de paricá. Na área de estudo, coletaram-se amostras de solo nas profundidades de 0 a 20 cm e de 20 a 40 cm e os parâmetros analisados foram: textura do solo, macroporosidade, microporosidade, densidade aparente do solo, resistência mecânica do solo à penetração, teores e os estoques de carbono orgânico do solo. Interpolou-se os dados pelo inverso do quadrado da distância. A variação espacial dos atributos físicos do solo no plantio foi influenciada pela textura. Houve baixa amplitude da variação espacial dos teores e estoques de carbono orgânico do solo. O plantio de paricá apresentou eficiência na fixação de carbono no solo em profundidade. Palavras-chave: silvicultura; sequestro de carbono; física do solo; mudança climática.   Spatial variation of physical attributes and soil carbon stocks in a Schizolobium amazonicum plantation in the amazon   ABSTRACT: Tree plantations provide an increase in soil carbon stocks, but studies involving native Amazonian species are incipient. The objective was to evaluate the spatial variation of physical attributes and soil organic carbon stock in a paricá plantation. In the study area, soil samples were collected at depths of 0 to 20 cm and 20 to 40 cm and the parameters analyzed were: soil texture, macroporosity, microporosity, soil bulk density, mechanical soil resistance to penetration, and soil organic carbon content and stocks. The data were interpolated by the inverse of the square of the distance. The spatial variation of soil physical attributes at planting was influenced by texture. There was a low range of spatial variation in soil organic carbon content and stocks. Paricá planting was efficient in fixing soil carbon at depth. Keywords: silviculture; carbon sequestration; soil physics; climate change

BIOMASSA E CARBONO EM PLANTIO COMERCIAL DE PARICÁ NA AMAZÔNIA

Planted forests stand out in the context of the mitigation of greenhouse gases, as they are renewable stocks that give continuity to carbon stocks. The objective was to quantify the stock of biomass and carbon in the aerial part in a commercial plantation of paricá (Schizolobium parahyba var. amazonicum). Trees distributed in five diameter at breast height (DBH) classes were selected, defined by the forest inventory. The trees were felled and the trunk, bark, branches and leaves were separated. For basic density, the highest values ​​were found in DBH classes between 19.4 and 28.2 cm (380 kg m-3 and 345 kg m-3). The plantation accumulated 41.94 Mg ha-1 of biomass and the intermediate classes (10.6 to 19.4 cm) represented 84% of the total biomass. Regarding the compartments, it was observed that both the biomass and the accumulated carbon content increased in the following order: stem > branch > leaf > bark. The biomass stored in the stem represented 72.2% of the total estimated for planting. The total carbon stock found for the stand was 16.6 Mg ha-1. The paricá plantation showed considerable accumulations of biomass and carbon. The cultivation of paricá can contribute to carbon credit programs.As florestas plantadas destacam-se no contexto da mitigação de gases de efeito estufa, pois são estoques renováveis que dão perenidade aos estoques de carbono. Objetivou-se quantificar o estoque de biomassa e carbono na parte aérea em plantio comercial de paricá (Schizolobium parahyba var. amazonicum) em Rolim de Moura, Rondônia. Selecionaram-se árvores distribuídas em cinco classes de diâmetro à altura do peito (DAP), definidas pelo inventário florestal. As árvores foram abatidas e tiveram os compartimentos fuste, casca, galhos e folhas separados. Para densidade básica, os maiores valores foram encontrados nas classes de DAP entre 19,4 e 28,2 cm (380 kg m-3 e 345 kg m-3). O plantio acumulou 41,94 Mg ha-1 de biomassa total e as classes intermediárias (10,6 até 19,4 cm) representaram 84% dessa biomassa. Em relação aos compartimentos, observou-se que tanto a biomassa quanto o teor de carbono acumulados foram crescentes na seguinte ordem: fuste > galho > folha > casca. A biomassa de fuste representou 72,2% do total estimado no plantio. O estoque de carbono total encontrado para o plantio foi em torno de 16,6 Mg ha-1, que foi distribuído em 74,9% para o fuste, 6,3% para casca, 10,4% para galhos e 8,3% para folhas. O plantio de paricá apresentou acúmulos consideráveis de biomassa e carbono e pode contribuir para programas de crédito de carbono. Palavras-chave: serviços ecossistêmicos; gases de efeito estufa; silvicultura tropical.   Biomass and carbon in commercial paricá plantations in the Amazon   ABSTRACT: Planted forests stand out in the context of greenhouse gas mitigation, because they are renewable stocks that provide perpetuity to carbon stocks. The objective was to quantify the aboveground biomass and carbon stock in a commercial plantation of paricá (Schizolobium parahyba var. amazonicum) in Rolim de Moura, Rondônia. Trees were selected in five diameters at breast height (DBH) classes, defined by the forest inventory. The trees were cut down and the stem, bark, twigs and leaves were separated. For basic density, the highest values were found in DBH classes between 19.4 and 28.2 cm (380 kg m-3 and 345 kg m-3). The plantation accumulated 41.94 Mg ha-1 of total biomass and the intermediate classes (10.6 to 19.4 cm) represented 84% of this biomass. The biomass and carbon content accumulated in each compartment increased in the following order: stem > twig > leaf > bark. The stem biomass represented 72.2% of the total estimated in the plantation. The total carbon stock found for the plantation was around 16.6 Mg ha-1, which was distributed in 74.9% for the stem, 6.3% for bark, 10.4% for branches and 8.3% for leaves. The paricá plantation presented considerable accumulations of biomass and carbon and can contribute to carbon credit programs. Keywords: ecosystem services; greenhouse gases; tropical forestry