Environmental and management controls of soil carbon storage in grasslands of southwestern China

D Balasubramanian; Wen-Jun Zhou; Hong-Li Ji; John Grace; Xiao-Long Bai; Qing-Hai Song; Yun-Tong Liu; Li-Qing Sha; Xue-Hai Fei; Xiang Zhang; Jun-Bin Zhao; Jun-Fu Zhao; Zheng-Hong Tan; Yi-Ping Zhang

doi:10.1016/j.jenvman.2019.109810

Environmental and management controls of soil carbon storage in grasslands of southwestern China

J Environ Manage. 2020 Jan 15:254:109810. doi: 10.1016/j.jenvman.2019.109810. Epub 2019 Nov 4.

Authors

D Balasubramanian¹, Wen-Jun Zhou², Hong-Li Ji³, John Grace⁴, Xiao-Long Bai⁵, Qing-Hai Song⁶, Yun-Tong Liu¹, Li-Qing Sha¹, Xue-Hai Fei⁷, Xiang Zhang⁵, Jun-Bin Zhao⁸, Jun-Fu Zhao⁹, Zheng-Hong Tan¹⁰, Yi-Ping Zhang¹¹

Affiliations

¹ CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, 666303, China.
² CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, 666303, China. Electronic address: zhouwj@xtbg.ac.cn.
³ Lushan Botanical Garden of Jiangxi Province, Chinese Academy of Sciences, Lushan Jiangxi, 332900, China.
⁴ School of GeoSciences, The University of Edinburgh, Edinburgh, EH9 3FF, UK.
⁵ CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, 666303, China; University of the Chinese Academy of Sciences, Beijing, 100039, China.
⁶ CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Xishuangbanna, 666303, China.
⁷ College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550018, China.
⁸ CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, 666303, China; Department of Terrestrial Ecology, Division of Environment and Natural Resources, Norwegian Institute of Bioeconomy Research, Ås, Norway.
⁹ Hainan University, Haikou, Hainan, 570228, China.
¹⁰ University of the Chinese Academy of Sciences, Beijing, 100039, China.
¹¹ CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Menglun, Yunnan, 666303, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Xishuangbanna, 666303, China. Electronic address: yipingzh@xtbg.ac.cn.

PMID: 31698300
DOI: 10.1016/j.jenvman.2019.109810

Abstract

In order to predict the effects of climate change on the global carbon cycle, it is crucial to understand the environmental factors that affect soil carbon storage in grasslands. In the present study, we attempted to explain the relationships between the distribution of soil carbon storage with climate, soil types, soil properties and topographical factors across different types of grasslands with different grazing regimes. We measured soil organic carbon in 92 locations at different soil depth increments, from 0 to 100 cm in southwestern China. Among soil types, brown earth soils (Luvisols) had the highest carbon storage with 19.5 ± 2.5 kg m^-2, while chernozem soils had the lowest with 6.8 ± 1.2 kg m^-2. Mean annual temperature and precipitation, exerted a significant, but, contrasting effects on soil carbon storage. Soil carbon storage increased as mean annual temperature decreased and as mean annual precipitation increased. Across different grassland types, the mean carbon storage for the top 100 cm varied from 7.6 ± 1.3 kg m^-2 for temperate desert to 17.3 ± 2.9 kg m^-2 for alpine meadow. Grazing/cutting regimes significantly affected soil carbon storage with lowest value (7.9 ± 1.5 kg m^-2) recorded for cutting grass, while seasonal (11.4 ± 1.3 kg m^-2) and year-long (12.2 ± 1.9 kg m^-2) grazing increased carbon storage. The highest carbon storage was found in the completely ungrazed areas (16.7 ± 2.9 kg m^-2). Climatic factors, along with soil types and topographical factors, controlled soil carbon density along a soil depth in grasslands. Environmental factors alone explained about 60% of the total variation in soil carbon storage. The actual depth-wise distribution of soil carbon contents was significantly influenced by the grazing intensity and topographical factors. Overall, policy-makers should focus on reducing the grazing intensity and land conversion for the sustainable management of grasslands and C sequestration.

Keywords: Grassland management; Grasslands; Grazing regimes; Soil carbon storage; Soil organic carbon; Topographical variation.

MeSH terms

Carbon Cycle
Carbon*
China
Grassland
Poaceae
Soil*

Substances

Soil
Carbon