The Grain for Green Program (GGP), initiated in 1999, is the largest ecological restoration project in central and western China. Here, for the first time, we performed a meta-analysis and found that the GGP largely increased the soil organic carbon (SOC). The SOC was increased by 48.1%, 25.4%, and 25.5% at soil depths of 0–20 cm, 20–40 cm, and 40–60 cm, respectively. Moreover, this carbon accumulation has significantly increased over time since GGP implementation. The carbon accumulation showed a significantly more active response to the GGP in the top 20 cm of soil than in the deeper soil layers. Conversion of cropland to forest could lead to significantly greater SOC accumulation than would the conversion of cropland to grassland. Conversion from cropland to woodland could lead to greater SOC accumulation than would the conversion to either shrubland or orchard. Our results suggest that the GGP implementation caused SOC to accumulate and that there remains a large potential for further accumulation of carbon in the soil, which will help to mitigate climate change in the near future.

Moso bamboo can rapidly complete its growth in both height and diameter within only 35–40 days after shoot emergence. However, the underlying mechanism for this “explosive growth” remains poorly understood. We investigated the dynamics of non-structural carbohydrates (NSCs) in shoots and attached mature bamboos over a 20-month period. The results showed that Moso bamboos rapidly completed their height and diameter growth within 38 days. At the same time, attached mature bamboos transferred almost all the NSCs of their leaves, branches, and especially trunks and rhizomes to the “explosively growing” shoots via underground rhizomes for the structural growth and metabolism of shoots. Approximately 4 months after shoot emergence, this transfer stopped when the leaves of the young bamboos could independently provide enough photoassimilates to meet the carbon demands of the young bamboos. During this period, the NSC content of the leaves, branches, trunks and rhizomes of mature bamboos declined by 1.5, 23, 28 and 5 fold, respectively. The trunk contributed the most NSCs to the shoots. Our findings provide new insight and a possible rational mechanism explaining the “explosive growth” of Moso bamboo and shed new light on understanding the role of NSCs in the rapid growth of Moso bamboo.

Biome-specific soil respiration (Rs) has important yet different roles in both the carbon cycle and climate change from regional to global scales. To date, no comparable studies related to global biome-specific Rs have been conducted applying comprehensive global Rs databases. The goal of this study was to develop artificial neural network (ANN) models capable of spatially estimating global Rs and to evaluate the effects of interannual climate variations on 10 major biomes. We used 1976 annual Rs field records extracted from global Rs literature to train and test the ANN models. We determined that the best ANN model for predicting biome-specific global annual Rs was the one that applied mean annual temperature (MAT), mean annual precipitation (MAP), and biome type as inputs (r 2 = 0.60). The ANN models reported an average global Rs of 93.3 ± 6.1 Pg C yr −1 from 1960 to 2012 and an increasing trend in average global annual Rs of 0.04 Pg C yr −1 . Estimated annual Rs increased with increases in MAT and MAP in cropland, boreal forest, grassland, shrubland, and wetland biomes. Additionally, estimated annual Rs decreased with increases in MAT and increased with increases in MAP in desert and tundra biomes, and only significantly decreased with increases in MAT (r 2 = 0.87) in the savannah biome. The developed biome-specific global Rs database for global land and soil carbon models will aid in understanding the mechanisms underlying variations in soil carbon dynamics and in quantifying uncertainty in the global soil carbon cycle.

Biochar application to cropland has been recommended as a strategy to reduce increasing atmospheric CO2 concentrations and mitigate climate change. However, the direction and magnitude of responses of greenhouse gas (GHG) fluxes to biochar application to cropland remain unclear. Our meta‐analysis of 296 observations across 61 studies for the first time quantitatively estimated the effects of biochar amendment on fluxes of three GHGsCO2, N2O, and CH4. The results showed that biochar application led to a significant change in soil GHGs emissions: in general, 19% for CO2, −16% for N2O (P < 0.05), but no pronounced change in CH4 emissions; in paddy, −5% for CO2, −20% for N2O, but +19% for CH4 (P < 0.05); in upland, −18% for N2O, +12% for CO2, and high uncertainty for CH4. The responses of soil GHG fluxes to biochar application were regulated mainly by experiment length, biochar application rate, biochar properties, providing a new perspective for more comprehensive understanding on biochar. The biochar derived from husk was recommended to apply to cropland with an application rate of 20–30 t·ha−1.

Aims The litter decomposition effects of N deposition in combination with management practices are still unclear. The aims of this study were to test the individual and interactive effects of the two factors on Moso bamboo leaf litter decomposition. Methods The experiment was conducted in Moso bamboo forests over a 24-month period and included three N addition treatments (low N, 30 kg N ha −1 yr −1 ;medium N, 60 kg N ha −1 yr −1 ; and high N, 90 kg N ha −1 yr −1 ) and two management practices (conventional management and intensive management). Results The low-N treatment significantly increased the annual decomposition rate, whereas the high-N treatment significantly decreased the annual decomposition rate (P<0.05). Intensive management alone did not significantly influence decomposition, but it amplified both the positive effects of the low-N treatment and the negative effects of the high-N treatment on litter decomposition. Intensive management weakened the positive effects of N addition on N loss but enhanced the positive effects on P loss during the early stage. Conclusions The effects of increasing N deposition in a plantation ecosystem were altered by the management practices, and these changes should be considered when estimating the biological effects of N deposition at regional and global scales.

The effects of nitrogen (N) deposition on soil organic carbon (C) and greenhouse gas (GHG) emissions in terrestrial ecosystems are the main drivers affecting GHG budgets under global climate change. Although many studies have been conducted on this topic, we still have little understanding of how N deposition affects soil C pools and GHG budgets at the global scale. We synthesized a comprehensive dataset of 275 sites from multiple terrestrial ecosystems around the world and quantified the responses of the global soil C pool and GHG fluxes induced by N enrichment. The results showed that the soil organic C concentration and the soil CO2, CH4 and N2O emissions increased by an average of 3.7%, 0.3%, 24.3% and 91.3% under N enrichment, respectively, and that the soil CH4 uptake decreased by 6.0%. Furthermore, the percentage increase in N2O emissions (91.3%) was two times lower than that (215%) reported by Liu and Greaver (Ecology Letters, 2009, 12:1103–1117). There was also greater stimulation of soil C pools (15.70 kg C ha−1 year−1 per kg N ha−1 year−1) than previously reported under N deposition globally. The global N deposition results showed that croplands were the largest GHG sources (calculated as CO2 equivalents), followed by wetlands. However, forests and grasslands were two important GHG sinks. Globally, N deposition increased the terrestrial soil C sink by 6.34 Pg CO2/year. It also increased net soil GHG emissions by 10.20 Pg CO2‐Geq (CO2 equivalents)/year. Therefore, N deposition not only increased the size of the soil C pool but also increased global GHG emissions, as calculated by the global warming potential approach.

Aberrant expression of circular RNAs (circRNAs) is involved in cancer progression through interaction with RNA-binding proteins (RBPs). Herein, we screened circRNA expression of A549 cells in circBase and the crosslinking immunoprecipitation (CLIP) data of human antigen R (HuR), an extensively studied RBP, and identified a circRNA, circ-defective in cullin neddylation 1 domain containing 4 (circDCUN1D4), originating from the DCUN1D4 gene transcript. circDCUN1D4 is downregulated in tumor samples under the mediation of DExH-box helicase 9 (DHX9), which inhibits the formation of circRNA by binding inverted repeat Alus (IRAlus) in flanking sequences. circDCUN1D4 depletion promoted invasion in vitro and metastasis in vivo. Importantly, the interaction between circDCUN1D4 and HuR increased the transportation of HuR to the cytoplasm. circDCUN1D4 acts as a scaffold to facilitate the interaction between the HuR protein and thioredoxin-interacting protein (TXNIP) mRNA, which enhances the stability of the TXNIP mRNA. Additionally, circDCUN1D4 directly interacts with TXNIP mRNA through base complementation, indicating the formation of the circDCUN1D4/HuR/TXNIP RNA-protein ternary complex. Furthermore, circDCUN1D4 suppressed metastasis and glycolysis of lung cancer cells in a TXNIP-dependent manner. Clinically, the downregulated expression of circDCUN1D4 was more prevalent in lymph node metastatic tissues and served as an independent risk factor for the overall survival of lung adenocarcinoma (LUAD) patients. These findings demonstrated that a novel circRNA, circDCUN1D4, is involved in the metastasis and glycolysis of LUAD.

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