Effects of land use, climate, topography and soil properties on regional soil organic carbon and total nitrogen in the Upstream Watershed of Miyun Reservoir, North China

Abstract

Soil organic carbon (SOC) and total nitrogen (TN) contents as well as their relationships with site characteristics are of profound importance in assessing current regional, continental and global soil C and N stocks and potentials for C sequestration and N conservation to offset anthropogenic emissions of greenhouse gases. This study investigated contents and distribution of SOC and TN under different land uses, and the quantitative relationships between SOC or TN and site characteristics in the Upstream Watershed of Miyun Reservoir, North China. Overall, both SOC and TN contents in natural secondary forests and grasslands were much higher than in plantations and croplands. Land use alone explained 37.2% and 38.4% of variations in SOC and TN contents, respectively. The optimal models for SOC and TN, achieved by multiple regression analysis combined with principal component analysis (PCA) to remove the multicollinearity among site variables, showed that elevation, slope, soil clay and water contents were the most significant factors controlling SOC and TN contents, jointly explaining 70.3% of SOC and 67.1% of TN contents variability. Only does additional 1.9% and 3% increase in the interpretations of SOC and TN contents variability respectively when land use was added to regressions, probably due to environment factors determine land use. Therefore, environmental variables were more important for SOC and TN variability than land use in the study area, and should be taken into consideration in properly evaluating effects of future land use changes on SOC and TN on a regional scale.

Ecosystem Carbon Stock Loss after Land Use Change in Subtropical Forests in China

“…A part of this high variability results from differences in the depth of soil sampling, commonly down to 50-100 cm [17,41,42], tree species and forest age [43]. Previous studies have indicated that the conversion from native forests to plantations decreased soil C stock [51]. Globally, land use change from native forests to plantations decreases SOC stock by about 13% [11].…”

Effects of land use on the Soil Organic Carbon storage potentiality and soil edaphic factors in Tripura, Northeast India

“…However, SOC in the tropical moist deciduous forest of Mizoram was 147 Mg C•ha −1 [34] and at another site it was reported 104.3 Mg C ha −1 in top 1 m of soil [33]. In China [36], forest land use change at upper 40 cm soil profile led to 37.2% variability in SOC. Similar result was also reported from peninsular Spain [37], where land use change explains 33% of SOC variability under different land uses and concluded that the SOC in secondary forest was higher than the plantations.…”

Spatial variability of soil nutrients in Juglans regia plantations in depressions between karst hills

“…In most plant growth conditions, soil nutrients show high spatial heterogeneity [3,4], which is a result of factors, including parent material, topography, vegetation, climate, and biological conditions [5,6,7]. Land use changes and agriculture also strongly influence soil nutrient concentrations [8,9].…”