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18 Pags.- 5 Figs.- 1 Tabl. The definitive version is available at: https://onlinelibrary.wiley.com/journal/1099145x, Soil water deficit is one of the important abiotic stresses affecting vegetation restoration. The magnitude and spatiotemporal dynamics of soil water content (SWC) provide basic guidance for optimal vegetation restoration. In a semiarid Chinese area, the changes in the soil water storage (SWS) of five cultivated grasslands and one wasteland were observed, to evaluate the water consumption at different soil depths (0–100 cm), from 2008 to 2012. The plants of the three leguminous species consumed more water in deep soil layers (80–100 cm) and produced more aboveground biomass than the plants of the two gramineous species. The gramineous plants mainly consumed shallow soil water (0 ≤ 30 cm). The soil water deficit in the whole soil profile of Medicago sativa grassland (43–48%) was significantly higher than the deficit of the gramineous grasslands (p, This research was funded by the National Natural Science Foundation of China (NSFC 41722107, 41977063, 41930755), the Key R & D Program of Shaanxi Province (2017NY‐065), and the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS‐ASTIP‐2016‐LIHPS‐08).

23 Pags.- 7 Figs. The definitive version is available at: https://onlinelibrary.wiley.com/journal/10991085, Soil water content (SWC) is a key factor for successful vegetation restoration in arid and semiarid regions, and vegetation has significant influences on the spatial patterns and temporal dynamics of SWC. The aim of this study was to investigate the temporal stability of SWC under different restored grasslands in an arid hilly area of Central China. SWC was measured in the 0‐ to 300‐cm soil profile in the natural grassland (Stipa capillata) and three typical planted grasslands (Medicago sativa, Agropyron cristatum, and Caragana korshinskii) over two growing seasons (from June to October 2015 and 2016) under natural rainfall conditions. The results showed that the mean SWC in the natural grassland was approximately 30% higher than those in the planted grasslands. The SWC consumption of the planted legume grasslands in the deepest soil layers (below 200 cm) was higher than that of the natural grassland, owing to the deep root system of the legumes. Both natural and planted grasslands had low SWC temporal stability in the top soil layers (0–50 cm), whereas more stable conditions were gradually observed with increasing the soil depth. The mean value of the mean relative differences of SWC in natural grassland (ca. 15%) was lower than that in the planted grasslands (A. cristatum grasslands) and much lower than that in the scrubland, highlighting the stronger temporal stability of SWC in the natural grassland. In conclusion, natural grassland could maintain higher and stable SWC and is recommended to be used for achieving sustainable vegetation restoration in arid and semiarid regions., This research was funded by the National Natural Science Foundation of China (NSFC41722107, 41525003, 41390463), the West Light Foundation of the Chinese Academy of Science (XAB2015A04), the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2011288), and the Youth Talent Plan Foundation of Northwest A & F University (2452018025), and Open Project Program of Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration of North‐western China/Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in North‐western China of Ministry of Education (2017KF002, 2018KF05).

Precipitation infiltration is the most important process for soil water supply of vegetation in the arid regions. Higher infiltration rate is advantageous for vegetation growth and maintenance in the arid areas. Four grassland types (Medicago sativa, Agropyron cristatum, Caragana korshinskii and Stipa capillata) were selected in this study. Results showed that the infiltration capacity in the legume grasslands was about 30% higher than in the gramineous grasslands and the difference was significant (p 0·05). The below-ground biomass, total porosity, capillary porosity, soil organic matters and soil aggregate were the main factors to determine the soil infiltration rates. The capillary porosity and soil aggregate of the top soil presented significant negative effects on soil infiltration rate (p

Delphinium grandiflorum L. is a perennial herb, and has very high medicinal value. However, the evolutionary relationship analysis of D. grandiflorum is limited. Its cp genome was 157,339 bp in length, containing a pair of inverted repeated regions (52,304 bp), separated by a large single copy region of 88,098 bp, and a small single copy region of 16,937 bp. Moreover, a total of 117 functional genes were annotated, including 79 mRNA, 30 tRNA genes, and 8 rRNA genes. The phylogenetic relationships inferred that D. grandiflorum was closely related to Gymnaconitum gymnandrum. This study will provide a theoretical basis for species identification and biological research.

Fruit development in Lycium ruthenicum Murr. involves a succession of physiological and biochemical changes reflecting the transcriptional modulation of thousands of genes. Although recent studies have investigated the dynamic transcriptomic responses during fruit ripening in L. ruthenicum, most have been limited in scope, and thus systematic data representing the structural genes and transcription factors involved in anthocyanin biosynthesis are lacking. In this study, the transcriptomes of three ripening stages associated with anthocyanin accumulation, including S1 (green ripeness stage), S2 (skin color change) and S3 (complete ripeness stage) in L. ruthenicum were investigated using Illumina sequencing. Of a total of 43,573 assembled unigenes, 12,734 were differentially expressed during fruit ripening in L. ruthenicum. Twenty-five significantly differentially expressed structural genes (including PAL, C4H, 4CL, CHS, CHI, F3H, F3'H, F3'5'H, DFR, ANS and UFGT) were identified that might be associated with anthocyanin biosynthesis. Additionally, several transcription factors, including MYB, bHLH, WD40, NAC, WRKY, bZIP and MADS, were correlated with the structural genes, implying their important interaction with anthocyanin biosynthesis-related genes. Our findings provide insight into anthocyanin biosynthesis and regulation patterns in L. ruthenicum and offer a systematic basis for elucidating the molecular mechanisms governing anthocyanin biosynthesis in L. ruthenicum.

Soil water shortage is a critical limiting factor that threaten the growth of vegetation and their sustainability in semi-arid areas. Grasses directly respond to the soil water availability (SWA), and the soil water shortage degree can be studied through plant physiological response thresholds under soil drought stress. In this study, the lower-and-optimal limitation of SWA was evaluated with pots along the soil water gradient by quantifying plant gas exchange parameters. These parameters showed a strong cubic relationship with the relative soil water content (RWC) in four forage species. The lower limitation of RWC was obtained for Onobrychis viciifolia (4.0%–20.2%), followed by Astragalus adsurgens (15.5%–25.5%), Elymus nutans (16.1%–27.2%), and Lolium multiflorum (24.6%–35.8%). The average RWC was of 74.83%, and the water saturation point of water use efficiency (WSPWUE) showed a similar critical scope in the four species: Onobrychis viciifolia (71.2%–82.8%), Astragalus adsurgens (72.1%–84.2%), Elymus nutans (79.3%–85.1%), and Lolium multiflorum (76.7%–85.6%). The highest productivity with the highest availability of water (HPHAW) for Onobrychis viciifolia, Astragalus adsurgens, Elymus nutans and Lolium multiflorum was of 71.2%–82.8%, 72.1%–84.2%, 79.3%–85.1% and 76.7%–85.6%, respectively. The lower limitation of RWC, the maximum water use efficiency (WUEmax) and HPHAW in legumes were lower than those values obtained in gramineae, suggesting that legumes were more susceptible to soil drought stress. We concluded that plant gas exchange parameters acted as indicators for SWA under drought conditions, and represented a valuable tool for identifying SWA threshold response in environmental changes.

Carbon accumulation is an important research topic for grassland restoration. It is requisite to determine the dynamics of the soil carbon pools [soil organic carbon (SOC) and soil inorganic carbon (SIC)] for understanding regional carbon budgets. In this study, we chose a grassland restoration chronosequence (cropland, 0 years; grasslands restored for 5, 15 and 30 years, i.e. RG5, RG15 and RG30, respectively) to compare the SOC and SIC pools in different soil profiles. Our results showed that SOC stock in the 0- to 100-cm soil layer showed an initial decrease in RG5 and then an increase to net C gains in RG15 and RG30. Because of a decrease in the SIC stock, the percentage of SOC stock in the total soil C pool increased across the chronosequence. The SIC stock decreased at a rate of 0·75 Mg hm−2 y−1. The change of SOC was higher in the surface (0–10 cm, 0·40 Mg hm−2 y−1) than in the deeper soil (10–100 cm, 0·33 Mg hm−2 y−1) in RG5. The accumulation of C commenced >5 years after cropland conversion. Although the SIC content decreased, the SIC stock still represented a larger percentage of the soil C pool. Moreover, the soil total carbon showed an increasing trend during grassland restoration. Our results indicated that the soil C sequestration featured an increase in SOC, offsetting the decrease in SIC at the depth of 0–100 cm in the restored grasslands. Therefore, we suggest that both SOC and SIC should be considered during grassland restoration in semi-arid regions. Copyright © 2016 John Wiley & Sons, Ltd.

Community composition strongly affected the soil C and N storages. However, the influences of community composition on native grassland remain poorly understood. The purpose of this study is to investigate the ability of plant communities including how legumes affect the soil C and N storages in the semi-arid grassland. Experimental grassland communities were separated by whether or not containing legumes. We measured soil C and N storages and determined above-ground and below-ground biomass, litter biomass, plant species richness, and species diversity to understand the mechanisms underlying the changes of soil C and N storages and to determine the relationship of species diversity and productivity. The results showed that legumes increased above-ground and below-ground biomass and C and N storages. Soil C and N storages were significantly and positively related to above-ground and below-ground biomass, litter biomass, plant species richness, and diversity in the presence of legumes. The presence of legumes increased soil C and N simultaneously but not synchronously, which resulting in a higher C:N ratio. This study indicated that legumes increased soil C and N storages possibly through increasing biomass and soil C and N inputs. The increases are mediated by plant diversity and plant functional complementarity. We suggest that the combination of legumes-grass species may greatly enhance ecosystem services such as soil C and N storages, productivity, and diversity in semi-arid grassland. Copyright © 2016 John Wiley & Sons, Ltd.

The trade-off between plant community structure and function is an important issue during grassland restoration. It is essential to assess changes of structure and function after converting farmland to grassland. Three restoration stages (5, 15, and 30 years) were studied to determine the optimum time when the trade-off between diversity and productivity occurs. The results showed that the vegetation coverage, height, and productivity significantly increased, but the species richness, diversity, and density significantly decreased along the restoration time. Grassland community presented a succession from small individuals and high density to larger individuals and lower density. The community changed from being dominated by grass and forb functional groups to being dominated only by the grass functional group. The dominant grass functional group plays a decisive role on community structure and function (productivity, diversity, and density) during grassland succession. Our results suggest that community structure and function were mainly driven by the dominant grass functional group during the long-term succession. Grassland should be utilized to suppress the leading role of the dominant functional groups in the 20th year for keeping the trade-off of diversity and productivity. We suggest that the restoration grassland should be considered to use appropriately in the 20th year. Our study could provide a key guidance for maintaining the community structure and function trade-off for cropland-converted grassland management in the semi-arid areas. Copyright (C) 2016 John Wiley & Sons, Ltd.

The establishment of grasslands on abandoned cropland has been proposed as an effective method to mitigate climate change. In this study, five cultivated grasslands (three leguminous species and two gramineous species), one abandoned cropland, and one natural grassland were studied to examine how soil organic carbon (SOC) sequestration rate and sequestration efficiency change in a semi-arid area in China. Our results showed that leguminous grasslands had greater total biomass (above- and belowground biomass), SOC storage, SOC sequestration rate, and efficiency than gramineous grasslands, abandoned cropland, and natural grassland during the experimental period. The largest soil carbon (C) accumulation in leguminous grassland was mainly attributed to the capacity to incorporate C and the higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha−1 yr−1. The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grassland sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grassland in arid and semi-arid areas. Our results provide a reference for ecological management in arid and semi-arid areas.

Planted grassland is one of the most quickly and effective way for vegetation restoration in arid and semi-arid regions. However, inappropriate grasslands construction can cause soil water deficit and soil drying in arid areas. In the present study, we evaluated the soil water storage deficit and soil water balance characteristics of different grassland types under natural conditions. The relative growth rates of planted grasslands, especially the planted legume grasslands, were approximately double higher than that of the natural grassland. Soil water storage deficit degree was the highest in the 0–50 cm soil layers than below the 50 cm layers. Soil water deficit degree was higher in legume grasslands than in gramineous grasslands below the depth of 50 cm, and it was significantly lower in the natural grassland than in planted grasslands below the depth of 200 cm (P planted legume grassland and shrubland > natural grassland. None of the grasslands got sufficient water supply during the growing season for transpiration and growth. Our findings provided evidence that natural grasslands have lower water consumption, and indicated which vegetation types can maintain more soil water and facilitate vegetation sustainability when undertaking restoration in water-limited environments.

Drought can cause and accelerate the degradation of planted legume grassland, and the changes in plant community composition can further influence soil physical properties. Here, the soil water response of different plant functional groups (legumes, grass, and forbs) were studied along a legume grassland degradation succession according to the above-ground biomass and the proportion of each functional group. In particular, changes in the soil water storage (SWS), soil properties (soil capillary porosity (CP), and soil organic matter) and plant traits (proportion of functional groups and below-ground biomass) were quantified in a continuously cultivated legume grassland for fifteen, sixteen, eighteen, and twenty-two years, without any tillage. The experimental plots were located in the semi-arid region of the Chinese Loess Plateau, in a flat area without runoff contribution. All plant and soil samples, and measurements, were obtained in a few days to minimize the temporal variability. SWS increased at 50–150 cm soil depth when the proportion of legume functional group (LFG) decreased from 70% to 5%, and this increment was ca. 20% at 50–100 cm soil layers. The Shannon-Wiener diversity index (H), the species richness (R), LFG, CP, and the non-capillary porosity (NCP) were significantly correlated with SWS (P, This research was funded by the National Natural Science Foundation of China (NSFC 41722107 and 41525003), the Light of West China Program of Chinese Academy of Sciences (XAB2015A04 and XAB2018B09), and the Youth Talent Plan Foundation of Northwest A&F University (2452018025), and the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences (CAAS-ASTIP-2016-LIHPS-08

Soil respiration is considered to be the second largest terrestrial carbon flux, and is influenced by land use changes. The impact of a cropland to grassland program on soil respiration was quantified. It tried to identify the dominant factors driving soil respiration along the restoration project of “Grain for Green Program” on the semiarid Loess Plateau, China. Soil respiration and different abiotic and biotic factors were measured for cropland and grasslands after five, 15, and 30 years of natural restoration. Soil respiration (gCm � 2 d � 1 ) was significantly greater for grassland with litter left that had been restored for 15 years than for cropland and grassland (five years), but did not significantly change from 15 to 30 years. Soil temperature and litter were the main factors affecting soil respiration along the restoration chronosequence. The contribution of litter to soil respiration after 15 years restoration was about 12%. The temperature sensitivity of the soil respiration ranged from 1.30 in the wheat land to 2.44 in the 30 years restoration grassland with litter left, and it increased with litter removed in the grasslands. Our findings suggest that grasslands after 15-year natural restoration must be utilized properly to balance changes in soil respiration with the soil organic carbon accumulation during the cropland to grassland restoration process.

Trait-based approaches can provide a useful tool for linking plant attributes to community structure and ecosystem function. Seed mass and plant height play important roles in the dynamics of plant communities, but few empirical community level studies have tested this, especially in stressful environments. The aim of the present study was to determine if there is a relationship between functional traits (seed mass and plant height) and changes in species relative abundance (SRA) in response to grazing and fertilization. We measured SRA and plant functional traits for 40 common species in a Tibetan Plateau alpine meadow. In the fertilized meadow, seed mass and plant height was significantly positively correlated with the relative abundance of the species. In the grazed meadow, these variables were significantly negatively correlated. Our results demonstrates that plant functional traits can be used to predict the change of SRA in plant community. Grazing promotes the dominance of small-seeded and short-stature species, and fertilization facilitates the occurrence of large-seeded and tall-stature species.

Carbon sequestration in grassland soil has been paid considerable attention in recent decades. However, the changes of soil organic carbon (SOC) still need clarification under the effect of environmental factors in semi-arid area. Here, twenty sampling sites were selected to study the effects of plant community (plant cover, biomass, litter, composition and diversity) and environmental factors (i.e. mean annual precipitation, mean annual temperature) on SOC sequestration in the semi-arid grasslands. The results showed that SOC was significant positively related to mean annual precipitation, soil water content and soil pH. The higher above- and below-ground biomass, species evenness and diversity presented the higher SOC. Specially, the species richness and proportion of gramineous species functional group significantly increased SOC. Below-ground biomass affected SOC mainly in the top 30 cm soil. Our results suggest that higher plant species richness and gramineous species proportion play a positive role in increasing the potential of soil carbon sequestration in semi-arid grassland.

The establishment of grassland on abandoned cropland has been proposed as an effective method of mitigating climate change by increasing soil organic carbon (SOC) storage. In this study, five cultivated grasslands were established (three leguminous species – Coronilla varia, Onobrychis viciaefolia, Medicago sativa, and two gramineous species – Poa annua, Agropyron cristatum), one uncultivated, one natural grassland to examine how the SOC storage, sequestration rate and sequestration efficiency to change for 5 years restoration in semi-arid area. Our results showed that the cultivated leguminous grasslands had greater total biomass, SOC storage, SOC sequestration rate and efficiency than gramineous grasslands. The greater soil carbon (C) accumulation in leguminous grassland was mainly attributed to higher biomass production. Leguminous grasslands accumulated more SOC than gramineous grasslands by 0.64 Mg C ha−1 yr−1. The average SOC sequestration efficiency in leguminous grassland (1.00) was about 2 times greater than gramineous grassland (0.34). The results indicate that cultivated leguminous grasslands sequestered more SOC with higher SOC sequestration efficiency than cultivated gramineous grasslands in arid and semi-arid areas.

Hordeum brevisubulatum, called as wild barley, is a useful monocotyledonous halophyte for soil improvement in northern China. Although previously studied, its main salt tolerance mechanism remained controversial. The current work showed that shoot Na

Successful reclamation of degraded mine land can contribute to recuperate the vegetation and soil carbon sequestration. In this study, soil carbon pool was assessed in a mining land after short-term reclamation. We measured above- and belowground biomass and soil carbon storage of artificial grassland (Astragalus adsurgens and Medicago sativa), which was established in the reclamation of mining land. The results showed that artificial grassland establishment significantly increased above- and belowground biomass after four-year restoration. Artificial grassland establishment increased soil inorganic and organic carbon content and storage. Soil organic and inorganic carbon content showed a positive increasing along the restoration time. Higher SOC and lower soil bulk density and water content all were attributed to the growth of artificial grassland. These results suggest that establishing artificial grassland with legumes is an effective restoration approach for improving soil carbon pool in the reclaimed mine soils.

Forage yield and density are common selection criteria for assessing the suitability of lucerne varieties in high rainfall conditions and under irrigation. However, selection criteria for assessing the suitability of lucerne varieties is not well defined in dryland farming systems. This study combines forage yield, plant density, root biomass and proline content in the plant leaf to compare the suitability of 1 local and 8 introduced lucerne (Medicago sativa) varieties over 3 years in the dry environment of west China. The results of this study indicated that the above measurements significantly differed among the 9 lucerne varieties, and also showed that suitability of lucerne varieties varied based on different indicators. Ameristand 201 and Algonquin performed well in terms of forage yield. Ameristand 201 and Sandili were well-adapted varieties based on root biomass and Ameristand 201 was the first selected variety in terms of drought resistance. Combining initial establishment density and its decline over years indicated that Sandili maintained good persistence. A cluster analysis of 9 lucerne varieties indicated that Ameristand 201 was very suitable for sowing in the dry Loess Plateau, a high water-erosion region in west China.