Dados do Trabalho

Título

MICROSCALE DRIVERS OF SOIL CARBON STOCKS IN A SEASONALLY DRY TROPICAL FOREST

Resumo

Tropical forests have an important role in the carbon cycle because they can work either as a sink or a source of carbon. Most of the carbon stored in forests is in the soil and must be well addressed to aid decision-making in forest and soil management to fight climate change. This study aimed to quantify the carbon stocks in the soil and their spatial variability in a seasonally dry tropical forest (Atlantic Forest). Soil samples were taken from seven layers (0-5; 5-10; 10-20; 20-30; 30-40; 40-60; 60-100 cm) during four field campaigns in ten inventory plots. The carbon content was determined by dry combustion in a TOC analyzer and its microscale drivers (soil, forest, and hydrological characteristics) were highlighted by redundancy analysis (RDA). The coefficient of variation of soil carbon stocks decreases with depth, indicating an increased homogeneity in the spatial distribution. The soil carbon stocks in the 1-meter layer ranged from 201 Mg C ha-1 to 396 Mg C ha-1 (average 268.5 Mg C ha-1) with 50% stored in the first 30 cm. The RDA indicated the importance of four variables to describe the spatial distribution of carbon stocks: (i) the carbon concentration in litter and long-term throughfall (in the 0-5 and 5-10 cm layers); and (ii) the variation in tree size and the long-term soil moisture dynamics (from 10-20 to 60-100 cm layers). In summary, soil carbon stocks are more stable in deeper layers and their microscale spatial variability is driven by forest, soil, and hydrological characteristics.

Palavras-chave

climate change; Atlantic Forest; forest hydrology; redundancy analysis.

Instituição financiadora

Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)