PATTERNS AND DRIVERS OF SOIL RESPIRATION AND VEGETATION AT DIFFERENT ALTITUDES IN SOUTHERN CHINA
Applied Ecology and Environmental Research
The objective of the present study was to evaluate soil organic carbon stock and mineralization characteristics in forest ecosystems in subtropical China. We explored the factors underlying soil respiration and vegetation in 12 soils at different altitudes in Jiangxi province, Wuyi mountain national nature reserve. Soil organic carbon was applied to analysis field survey and indoor cultivation techniques. Our results showed uneven distribution of four perpendicular bands: meadow grassland,
... dow grassland, subalpine elfin, mixed coniferous and broad-leaved forests. Differences in total carbon (TC) and total nitrogen (TN) content in the soil were not significant. Soil pH was acidic. The crown density representing relative soil water content suggested fewer differences in low dissolved organic carbon (DOC) with altitude. The soil microbial biomass carbon (MBC) was the lowest in the meadow grassland soil, and in that of the mixed needle leaved forest. The NO3 --N levels decreased with altitude and the changes in NH4 + -N were not obvious. The respiratory rate of the meadow grassland soil was the lowest, and the respiratory rate of the subalpine elfin forest was high. Cumulative emissions without soil CO2 increased with altitude showing regular changes related to vegetation. In mixed needle the soil respiration was significantly stronger t han in the meadow grassland and broad-leaved forest soil. Carbon emissions produced by soil respiration and total carbon (TC) and C: N were positively correlated (P < 0.05), with no obvious correlation with MBC. The soluble and microbial carbon levels in the soils at different altitudes were positively but not significantly related. Soil pH and TC were negatively correlated with TN and NO 3 --N. The effect of soil total carbon, total nitrogen and crown density partially controlled soil respiration.