Carbon, Nitrogen and Phosphorus Contents of Wetland Soils in Relation to Environment Factors in Northeast China

Abstract

Soil organic carbon (OC) is sensitive to climatic change, and it can be expected to manifest measurable responses to global warming. Globally, nitrogen (N) and phosphorus (P) are the most common nutrients limiting plant growth and soil carbon storage. We collected soil samples at 17 marsh sites in August 2012 across Northeast China. These samples were analysed for variations in soil organic carbon (OC), total nitrogen (TN) and total phosphorus (TP) levels, and multiple controlling of environmental and biotic factors. Results showed the means to be as follows: 16,850.7 mmol kg−1 (OC), 540.5 mmol kg−1 (TN), 30.0 mmol kg−1 (TP), 29.9 (C:N), 516.5 (C:P) and 16.8 (N:P). The OC, TN, TP and C:N:P ratios decreased with increases in the mean annual temperature (MAT) and flooding depth, whereas the C:N ratio did not change significantly with the flooding depth. Quadratic relationships were observed between the OC, TN and TP and soil pH. Linear mixed-effect models showed that climate exerted great influences on soil nutrients. These results will improve our understanding of the ecological patterns of nutrient fluxes and the biogeochemical mechanisms of the response of vegetation to climate changes.