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[Display omitted] • Grassland degradation is the main reason for the decline in carbon storage. • The carbon storage of farmland has increased significantly. • The risk of carbon storage reduction in the future is still high. The carbon storage of terrestrial ecosystems is closely related to global climate change. Therefore, assessing the impact of land-use changes on carbon storage is instructive to reduce global carbon emissions. Taking an arid region in northwest China as an example, this paper analyzed the land-use changes in arid region from 1980 to 2015. It used the CA-Markov model to predict the land-use pattern from 2020 to 2050, the carbon storage and sequestration module in Integrated Valuation of Ecosystem Services and Tradeoffs (Invest) mode to assess and predict ecosystem carbon storage over the past 35 years and in the next 30 years and discusses the impact of land-use changes on the carbon storage of terrestrial ecosystems. The results showed that: (1) The high-value areas of carbon storage in arid region were primarily concentrated in grassland, forests and farmland, and the low-value areas of carbon storage were mainly in desert areas. (2) The carbon storage in arid region showed a downward trend. From 1980 to 2015, the carbon reserves of terrestrial ecosystems in arid region decreased by 90.95 Tg, and the net loss of carbon reserves from 2020 to 2050 was 14.72 Tg. Grassland degradation was the main reason for the reduction of carbon storage in arid region. (3) The carbon storage of farmland had increased significantly, but the expansion of farmland dominated by high carbon density grassland, wetland and forest, had reduced the overall carbon storage of the arid region. [ABSTRACT FROM AUTHOR]

Abstract: Atmospheric nitrogen (N) deposition has increased dramatically since preindustrial times and continues to increase across many regions of the Earth. In temperate forests, this agent of global change has increased soil carbon (C) storage, but the mechanisms underlying this response are not understood. One long‐standing hypothesis proposed to explain the accumulation of soil C proposes that higher inorganic N availability may suppress both the activity and abundance of fungi that decay lignin and other polyphenols in soil. In field studies, elevated rates of N deposition have reduced the activity of enzymes mediating lignin decay, but a decline in the abundance of lignolytic fungi has not been definitively documented to date. Here, we tested the hypothesis that elevated rates of anthropogenic N deposition reduce the abundance of lignolytic fungi. We conducted a field experiment in which we compared fungal communities colonizing low‐lignin, high‐lignin, and wood substrates in a northern hardwood forest that is part of a long‐term N deposition experiment. We reasoned that if lignolytic fungi decline under experimental N deposition, this effect should be most evident among fungi colonizing high‐lignin and wood substrates. Using molecular approaches, we provide evidence that anthropogenic N deposition reduces the relative abundance of lignolytic fungi on both wood and a high‐lignin substrate. Furthermore, experimental N deposition increased total fungal abundance on a low‐lignin substrate, reduced fungal abundance on wood, and had no significant effect on fungal abundance on a high‐lignin substrate. We simultaneously examined these responses in the surrounding soil and forest floor, in which we did not observe significant reductions in the relative abundance of lignolytic fungi or in the size of the fungal community; however, we did detect a change in community composition in the forest floor that appears to be driven by a shift away from lignolytic fungi and towards cellulolytic fungi. Our results provide direct evidence that reductions in the abundance of lignolytic fungi are part of the mechanism by which anthropogenic N deposition increases soil C storage. [ABSTRACT FROM AUTHOR]