Warming in Spring and Summer Lessens Carbon Accumulation over the Past Century in Temperate Wetlands of Northeast China

Abstract

Deciphering how climate change affects carbon accumulation rates (Carbonsq) is vital to understanding climate-carbon pool feedbacks on century scales. Carbon, nitrogen, and phosphorus accumulation rates were estimated by isotopic 210Pb dating technology from 10 temperate wetlands in Northeast China. Soil carbon, nitrogen and phosphorus accumulated at average rates of 164.75 gC m−2 yr.−1, 5.61gN m−2 yr.−1, and 1.83gP m−2 yr.−1 during the past 153 years, respectively. Climate warming tended to grow increasing along the latitude and was faster in winter than in summer. Asymmetrical warming in spring and summer would lessen Carbonsq and oppose wetland functions as carbon sinks. High positive correlation coefficients between precipitation and Carbonsq meant that increasing precipitation facilitated Carbonsq greatly. Conversely, it was shown that warming in conjunction with subsequent drought was impairing Carbonsq in wetlands. There were strong positive feedbacks between climate warming and Carbonsq that could weaken wetlands functioning as carbon sinks in Northeast China.