image: (a) Carbon stocks (Tg C) in different components of urban forests. Veg, vegetation; Eco, ecosystem. (b) Carbon stocks (Tg C) in existing (area of urban forest remaining unchanged) and new urban forests (urban forests converted from other land types). (c) Carbon sequestration rates (Tg C a−1) in China’s urban forests. (d) Carbon sink (Tg C) in China’s urban forests from 1995 to 2060 and the relative contributions of different components. The error bar represents the standard deviation
Credit: ©Science China Press
This study is led by Weixiang Cai (College of Soil and Water Conservation Science and Engineering (Institute of Soil and Water Conservation), Northwest A&F University), Li Xu (Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences), and Prof. Nianpeng He (Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University).
The researchers applied a forest carbon sequestration (FCS) model based on a classical logistic equation between forest age and biomass to estimate carbon sequestration rates (CSR) of urban forests in China from 2010 to 2060 under future climate scenarios. The results show that the urban area in China increased by 16.07 × 104 km2, with an average growth rate of 0.64 × 104 km2 a−1, The carbon sequestration rate (CSR) of China’s urban forests exhibited a pattern of initial increase followed by a decline, reaching its peak in 2015–2020. In total, China’s urban forests stored 522.7 ± 9.6 Tg C during 1995–2060, with 222.5 ± 6.6 Tg C and 300.2 ± 3.9 Tg C in vegetation and soil, respectively. The CSR of urban forests in China between 1995 and 2060 varied between 1.92 and 22.8 Tg C a−1, averaging 8.04 ± 0.15 Tg C a−1. Carbon sink increment efficiency index showed negative correlation with the levels of provincial development and was highest in the northwestern provinces.
Their findings present a comprehensive assessment of the carbon sink dynamics in China urban forests and provide new insights into the formulation of coordinated urban planning and carbon management policies with the development of socio-economic levels in China.