Doctoral Program in Environmental Science and Management, Montclair State University, Montclair, NJ 07043, USA.
Department of Biology, Montclair State University, Montclair, NJ 07043, USA.
Sci Total Environ. 2022 Feb 10;807(Pt 3):150999. doi: 10.1016/j.scitotenv.2021.150999. Epub 2021 Oct 14.
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) are significantly higher than those of urban green spaces (54.61 ± 22.02 Mg ha) and urban intensive habitats (65.88 ± 35.27 Mg ha). 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.
城市环境中的人类生存空间日益扩大。此外，人为活动改变了全球碳（C）循环并引发了气候变化。土壤是陆地生态系统中最大的有机碳（C）库，但土壤保持和储存 C 的能力存在差异。随着人类努力缓解气候变化，越来越需要了解土壤的 C 储存能力及其与气候、植被或人类活动足迹等因素的相互作用。在这里，我们通过收集超过 191 项研究的数据，重点关注 30 厘米土壤深度，进行了荟萃分析，这些研究测量了跨越自然、城市绿地和城市密集生境的土壤有机碳（SOC）储量。然后，我们将不同气候带、植被类型和人为影响下的 SOC 数据与人类足迹指数进行了比较。结果表明，自然生境中的 SOC 储量（98.22 ± 49.10 Mg ha）明显高于城市绿地（54.61 ± 22.02 Mg ha）和城市密集生境（65.88 ± 35.27 Mg ha）。我们发现，人类足迹与自然生境的 SOC 储量之间存在显著的负相关关系，但与城市生境之间不存在这种关系。城市密集和城市绿地生境土壤储存的 C 比自然土壤少。然而，当跨气候带或植被类型进行比较时，自然土壤储存 C 的能力是可变的，容易受到人类活动的影响。城市土壤中的碳储存可能受到持续和稳定的人为影响的限制，从而降低了变异性。在城市绿地中，这种情况最为明显，因为那里的人类管理强度高（例如高尔夫球场），SOC 水平低。全面了解土壤中的 C 储存对于土地管理和气候缓解措施至关重要。
