TY - JOUR
T1 - Natural versus urban global soil organic carbon stocks
T2 - A meta-analysis
AU - Chien, Shih Chieh
AU - Krumins, Jennifer Adams
N1 - Funding Information:
We thank N. M. Goodey, B. Vaidya, D. Hagmann, and E. Dyson for reading this manuscript and providing valuable critique. We are especially grateful to three anonymous reviewers and our editor for their thoughtful comments and suggestions. This research did not receive funding from the public, commercial, or not-for-profit sectors.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021
Y1 - 2021
N2 - Increasingly, the human existence in urban environments is growing. In addition, anthropogenic activity has altered the global carbon (C) cycle and triggered climate change. Soil is the largest pool of organic C in terrestrial ecosystems, but its ability to retain and store C varies. As humans move forward to mitigate climate change, there is a growing need to understand the C storing capacity of soils and their interactions with factors like climate, vegetation or a footprint of human activity. Here, we constructed a meta-analysis which focused on 30 cm soil depth by collecting data from over 191 studies measuring soil organic carbon (SOC) stocks across natural, urban green space, and urban intensive habitats. We then compared the SOC data between different climatic zones, vegetation types, and anthropogenic influences with the human footprint index. The results indicate that SOC stocks in natural habitats (98.22 ± 49.10 Mg ha−1) are significantly higher than those of urban green spaces (54.61 ± 22.02 Mg ha−1) and urban intensive habitats (65.88 ± 35.27 Mg ha−1). We find a significant and negative relationship between the human footprint and SOC stocks of natural habitats but not between the human footprint and either of the urban habitats. Urban intensive and urban green space habitat soils store less C than natural ones. However, when compared across climatic zones or vegetation types, the capacity of natural soils to store C is variable and vulnerable to human activity. Carbon storage in urban soils is likely limited by persistent and stable anthropogenic influences keeping variability low. This is most pronounced in urban green spaces where human management is high (i.e. a golf course) and SOC is low. A comprehensive understanding of C storage in soils is essential to land management and climate mitigation measures.
AB - Increasingly, the human existence in urban environments is growing. In addition, anthropogenic activity has altered the global carbon (C) cycle and triggered climate change. Soil is the largest pool of organic C in terrestrial ecosystems, but its ability to retain and store C varies. As humans move forward to mitigate climate change, there is a growing need to understand the C storing capacity of soils and their interactions with factors like climate, vegetation or a footprint of human activity. Here, we constructed a meta-analysis which focused on 30 cm soil depth by collecting data from over 191 studies measuring soil organic carbon (SOC) stocks across natural, urban green space, and urban intensive habitats. We then compared the SOC data between different climatic zones, vegetation types, and anthropogenic influences with the human footprint index. The results indicate that SOC stocks in natural habitats (98.22 ± 49.10 Mg ha−1) are significantly higher than those of urban green spaces (54.61 ± 22.02 Mg ha−1) and urban intensive habitats (65.88 ± 35.27 Mg ha−1). We find a significant and negative relationship between the human footprint and SOC stocks of natural habitats but not between the human footprint and either of the urban habitats. Urban intensive and urban green space habitat soils store less C than natural ones. However, when compared across climatic zones or vegetation types, the capacity of natural soils to store C is variable and vulnerable to human activity. Carbon storage in urban soils is likely limited by persistent and stable anthropogenic influences keeping variability low. This is most pronounced in urban green spaces where human management is high (i.e. a golf course) and SOC is low. A comprehensive understanding of C storage in soils is essential to land management and climate mitigation measures.
KW - Climate
KW - Human footprint
KW - Meta-analysis
KW - Natural habitat
KW - Soil organic carbon
KW - Urban habitat
KW - Vegetation
UR - http://www.scopus.com/inward/record.url?scp=85117774937&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.150999
DO - 10.1016/j.scitotenv.2021.150999
M3 - Article
C2 - 34656570
AN - SCOPUS:85117774937
SN - 0048-9697
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 150999
ER -