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The duration of climate anomalies has been increasing across the globe, leading to ecosystem function loss. Thus, we need to understand the responses of the ecosystem to long‐term climate anomalies. It remains unclear how ecosystem resistance and resilience respond to long‐term climate anomalies, for example, continuous dry years at a regional scale. Taking the opportunity of a 13‐year dry period in the temperate grasslands in northern China, we quantified the resistance and resilience of the grassland in response to this periodic dry period. We found vegetation resistance to the dry period increased with mean annual precipitation (MAP), while resilience increased at first until at MAP of 250 mm and then decreased slightly. No trade‐off between resistance and resilience was detected when MAP, Resistance and resilience of grasslands to a decade‐long dry climate was investigated. Resistance increased with mean annual precipitation (MAP), while resilience increased until at MAP of 250 mm and then decreased slightly. No trade‐off between resistance and resilience was found in xeric grasslands.

The sensitivity of vegetation productivity to precipitation (S

Grazing by livestock greatly affects the soil carbon (C) cycle in grassland ecosystems. However, the effects of grazing at different intensities and durations on the dynamics of soil C in its subsoil layers are not clearly understood. Here, we compiled data from 78 sites (in total 122 published studies) to examine the effects of varying grazing intensities and durations on soil C content at different depths for grasslands in China. Our meta-analysis revealed that grazing led to an overall decrease in soil C content and productivity of above-ground vegetation (e.g., above-ground biomass and litter) but an increase in below-ground biomass. Specifically, the effects of grazing on soil C content became less negative or even positive with increasing soil depths. An increase of soil C content was consequently found under light grazing (LG), although soil C content still decreased under moderate and heavy grazing. The increase in soil C content under LG could be largely attributed to the increase of soil C content in subsoil layers (>20 cm), despite that soil C content in surface soil layer (0-20 cm) decreased. Moreover, the magnitude of increase in soil C content under LG in subsoil layers increased with grazing duration. A possible reason of the increase in soil C content in the subsoil layers was due to the increases in below-ground biomass. Our study highlights that LG may modify the allocation of C input and promote its accumulation in subsoil layers, thus offsetting the negative impact of grazing on surface soil C content, a finding that has significant implications for C sequestration in grasslands.

Agricultural soils are widely recognized to be capable of carbon sequestration that contributes to mitigating CO2 emissions. To better understand soil organic carbon (SOC) stock dynamics and its driving and controlling factors corresponding with a period of rapid agronomic evolution from the 1980s to the 2010s in the North China Plain (NCP), we collected data from two region-wide soil sampling campaigns (in the 1980s and 2010s) and conducted an analysis of the controlling factors using the random forest model. Between the 1980s and 2010s, environmental (i.e. soil salinity/fertility) and societal (i.e. policy/techniques) factors both contributed to adoption of new management practices (i.e. chemical fertilizer application/mechanization). Results of our work indicate that SOC stocks in the NCP croplands increased significantly, which also closely related to soil total nitrogen changes. Samples collected near the surface (0-20 cm) and deeper (20-40 cm) both increased by an average of 9.4 and 5.1 Mg C ha-1 , respectively, which are equivalent to increases of 73% and 56% compared with initial SOC stocks in the 1980s. The annual carbon sequestration amount in surface soils reached 10.9 Tg C year-1 , which contributed an estimated 43% of total carbon sequestration in all of China's cropland on just 27% of its area. Successful desalinization and the subsequent increases in carbon (C) inputs, induced by agricultural projects and policies intended to support crop production (i.e. reconstruction of low yield farmland, and agricultural subsidies), combined with improved cultivation practices (i.e. fertilization and straw return) since the early 1980s were the main drivers for the SOC stock increase. This study suggests that rehabilitation of NCP soils to reduce salinity and increase crop yields have also served as a pathway for substantial soil C sequestration.

Soil quality evaluation as a decision-making tool to improve understanding of soil quality is essential for grading croplands and adopting proper agricultural practices. Various methods of soil quality evaluation have been developed, which have occasionally generated inconsistent evaluation results between differing soil types. The applicability of these techniques is seldom tested before implementing an evaluation method on a specific soil region. Fluvisol is an important soil resource for agriculture in China, especially for irrigation districts along the lower Yellow River. In the present study, the soil quality of two typical agricultural counties (Yucheng and Kenli) along the lower Yellow River was evaluated using four commonly utilized methods. In the two counties, the overall spatial patterns of soil quality derived from the four methods were similar, with differences in details existing among these methods. The soil quality in Yucheng, ranging from moderate to high, is superior to that observed in Kenli, where salinity is the primary limiting factor. In addition, the applicability of soil quality evaluation methods on the Fluvisol was investigated. It was found that the integrated quality indexing-linear scoring (IQI–LS) and the Nemoro indexing-linear scoring (NQI–LS) methods were the most accurate and practical of the four methods studied. These methods, which are based on the total data set of indicators, show better performance for soil quality evaluation on a Fluvisol. Further, different evaluation methods based on the minimum data set of indicators were compared, considering both the accuracy of the evaluation and the economic cost of obtaining the soil data. The results from the present study indicate that the IQI–LS method based on the minimum data set of indictors is recommended for large-scale soil quality evaluations.

A pot experiment was conducted to elucidate the process of aggregate formation and the accumulation of soil organic C as affected by application of microbial fertilizer in coastal saline soils east of Shandong Province, China. The study was designed with five levels of electrical conductivity (EC): 0.33, 0.62, 1.13, 1.45 and 2.04 ds m −1 . For each EC level, a treatment group received microbial fertilizer (MF) and a control (CK) did not. The mass and organic C concentration of aggregates (>2000 μm large macroaggregate, 250–2000 μm small macroaggregate and 53–250 μm microaggregate, 1 –MF 5 and CK 1 –CK 5 from lowest to highest EC values. The soil organic C concentrations of MF 1 –MF 3 , but not MF 4 and MF 5 , were significantly higher than that of their controls. For MF 1 –MF 3 , application of microbial fertilizer significantly increased the proportion of macroaggregates. MF 1 –MF 3 treatments exhibited significantly increased organic C concentration in the large macro-aggregates and free silt + clay fractions, but the differences were not significant for EC values of 1.45 and 2.04 ds m −1 . The mass proportion of large and small macroaggregates was significantly related with organic C concentration in the microaggregates. For EC values 1.45 and 2.04 ds m −1 , the silt C was too low to form the microaggregates, and the aggregates were not significantly different. Significant linear relationships existed between the organic C concentration in the silt + clay fraction and mass ratio of the macro- to micro-aggregates. We suggested that microbial fertilizer reduced the silt + clay fraction and increased the microaggregate mass by increasing soil organic C in the silt + clay fraction, which promoted the formation of macroaggregates. The mass and organic C of microaggregates played an important role in aggregation and C accumulation.

Try to detect the spatiotemporal dynamics and the controlling factors of soil organic carbon (SOC) in the North China Plain (NCP) over the last 30 years: 1980s-2010s. We investigated the SOC evolution by compiling data from 32 published papers during the last 30 years. Then we examined the spatial pattern and controlling factors by analysing a two-period sampling observations (1980s and 2010s) and multiple explanatory variables in four typical counties. Over the last 30 years, the agronomy environment and management practice have been dramatically improved, which have largely increased the crop yield and subsequently enhanced the C input into the soil, made NCP the most effective region for C sequestration in China, ranging from 5.55 ± 1.28 g kg−1 in the 1980s to 8.71 ± 1.22 g kg−1 in the 2010s, with an average rate of 0.11 g kg−1 year−1. The SOC change (SOCC) exhibited spatial heterogeneity due to imbalanced agricultural management (i.e., rotation and irrigation) and environmental obstacles (i.e., salinity and water deficit). The mean SOCC rate in Fengqiu and Yucheng (> +0.15 g kg−1 year−1, with rotation of winter wheat and summer maize, less water deficit and salinity stress) were significantly (P

This study was aimed at qualifying the methane emission ability of different communities in alpine meadow, and monitoring if the dominant species from these communities could emit methane in a sand culture experiment. Using the static chamber technique and gas chromatography method, two experiments were conducted in the field and in laboratory. First, the methane flux rate was measured in plant communities: natural alpine meadows (NM), Elymus nutans pasture (EP), herbaceous community in shrub (HS), and a Poa fruticosa meadow (PS). A 3-month sand culture experiment was conducted to show the non-microbial methane emission from living plants. Average methane emission rates were estimated to be 16.83 mu g m(-2) h(-1)(range -49.3-107.8), 28.49 mu g m(-2) h(-1) (range -55.0-96.2) and 20.91 mu g m(-2) h(-1)(range -31.9-145.8) for NM, EP, and PS, respectively. Methane emission rate from EP was significantly higher than from NM during the growing season. The reclaim of grassland would enhance the methane emission in this aera through this one year's measurement, but whether this conclusion suit to the whole Tibet Plateau, it remains further longer time and larger spatial scale experiments to verify it. The result of the sand culture experiment showed that some plant species emitted methane in an aerobic, non-microbial environment, most of herbaceous species showed a methane emission characteristic, the methane emission from plant may have a species dependent characteristic.

Degradation of shrub meadows and reclamation of alpine meadows may heavily affect the soil sink for atmospheric methane (CH4), but this is poorly understood. Therefore, in situ measurements of atmospheric CH4 consumption were conducted in four landuse types: natural alpine meadow (NM), Elymus nutans pasture (EP), herbaceous meadow in shrub (HS), and a P. fruticosa shrub meadow (PS) within two years. CH4 fluxes were measured using static chambers and gas chromatography. All four types of land use showed atmospheric CH4 sink throughout the two years, with mean soil CH4 consumption rates at 24.6+/-10.9, 33.8+/-15.0, 39.8+/-10.3, and 28.1+/-12.1 mu g CH4.m(-2).hr(-1) for NM, EP, PS, and HS, respectively. Soil CH4 consumption increased by 40% by reclamation from NM to EP, while it decreased by 30% by degradation from PS to HS. Soil CH4 consumption in four types of land use was significantly correlated with temperature at 5 cm depth (P