In mid-June,the vast,rolling meadow steppe grasslands of Bayanwenduer Sumu in Ar Horqin Banner,Inner Mongolia Autonomous Region,once again stretched into the horizon like green waves with herds of cattle and sheep sca...In mid-June,the vast,rolling meadow steppe grasslands of Bayanwenduer Sumu in Ar Horqin Banner,Inner Mongolia Autonomous Region,once again stretched into the horizon like green waves with herds of cattle and sheep scattered across them like pearls in a green ocean.This flock was driven by herders on horseback,motorcycles,and agricultural vehicles,leading the animals to summer pastures in one of the most important migrations of the year.展开更多
Grassland ecosystems are experiencing severe deterioration due to ongoing climate fluctuation and human disturbance.Although numerous research centers on the patterns,processes,and functioning of degraded grassland,th...Grassland ecosystems are experiencing severe deterioration due to ongoing climate fluctuation and human disturbance.Although numerous research centers on the patterns,processes,and functioning of degraded grassland,there is still a lack of standards for defining and assessing degraded grassland,which restricts the cognition of the degraded grassland mechanisms and restoration practices.Therefore,we review current grassland degradation research for the sake of the common definitions and assessment methods worldwide.Grassland degradation definitions are divided into three stages,including biotic/abiotic factors,ecosystem functions,and ecosystem services/sustainability,and further combine the concept of“nature’s contributions to people”with the definition of grassland degradation.Moreover,grassland degradation assessment methods and indicators are diverse across scales.Additionally,we systematically explore the climate change and social system factors that affect grassland degradation,and reveal that grassland management policies play an essential role in grassland degradation and restoration.Overall,this review advances our understanding of grassland degradation and calls for a unified and effective global definition and assessment criteria,which will contribute to the sustainable management of the grassland ecosystem.展开更多
Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N de...Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.展开更多
The Leymus chinensis grassland is one of themost widely distributed associations in the warmtemperate grassland and due to overgrazing in recent years,it has experienced varying degrees of degradation.Vegetative regen...The Leymus chinensis grassland is one of themost widely distributed associations in the warmtemperate grassland and due to overgrazing in recent years,it has experienced varying degrees of degradation.Vegetative regeneration via bud banks serves as the primaryway of vegetation reproduction in the L.chinensis grassland ecosystem.However,the role of the bud bank in the vegetation regeneration of grazing grassland remains unclear.Based on the relationship between the under-ground bud bank and above-ground vegetation of L.chinensis grassland under different grazing stages,this study aimed to explore whether the grazing grassland could self-recover through the existing bud bank.The findings revealed that the bud density initially increased and then decreased with increasing grazing intensity,indicating that appropriate grazing promoted vegetation renewal.Moreover,grazing significantly influenced the composition of the bud bank:during the early grazing stage,the rhizome buds accounted for the main part,and tiller buds dominated during the mid-stage grazing;while during the late-stage grazing,root-sprouting buds prevailed.The meristem restriction index for light,moderate,and heavy grazing grasslands was close to one;conversely,overgrazing and extreme overgrazing grasslands exhibited the highermeristemrestriction index(2.00,3.19),suggesting that plant regeneration was constrained by bud banks under light-grazing conditions where regenerate rates failed to meet above-ground modular’s recovery requirements following overgrazing and extreme overgrazing events.Consequently,moderate grazing grasslands could achieve natural community recovery by continuously adjusting their vegetative regeneration strategies.Understanding the role of bud banks in vegetative regeneration in grazing grassland will not only supply theoretical support for the ecological succession process of degraded grassland but also provide practical experience for the sustainable management of the L.chinensis grassland ecosystem.展开更多
Understanding plant diversity within geographical ranges and identifying key species that drive community variation can provide crucial insights for the management of grasslands.However,the contribution of both local ...Understanding plant diversity within geographical ranges and identifying key species that drive community variation can provide crucial insights for the management of grasslands.However,the contribution of both local sites and plant species to beta diversity in grassland ecosystems has yet to be accurately assessed.This study applied the ecological uniqueness approach to examine both local contributions to beta diversity(LCBD)and species contributions to beta diversity(SCBD)across six major geographical ranges in alpine grasslands.We found that LCBD was driven by species turnover,with climate,plant communities,and their interactions influencing LCBD across spatial scales.LCBD values were high in areas with low evapotranspiration,high rainfall variability,and low species and functional richness.Precipitation seasonality predicted large-scale LCBD dynamics,while plant community abundance explained local LCBD variation.In addition,we found that SCBD were confined to species with moderate occupancy,although these species contributed less to plant biological traits.Our findings are crucial for understanding how ecological characteristics influence plant beta diversity in grasslands and how it responds to environmental and community factors.In addition,these findings have successfully identified key sites and priority plants for conservation,indicating that using standardized quadrats can support the assessment of the ecological uniqueness in grassland ecosystems.We hope these insights will inform the development of conservation strategies,thereby supporting regional plant diversity and resisting vegetation homogenization.展开更多
The response of plant functional diversity to external disturbances not only effectively predicts changes in the ecosystem but it also reflects how plant communities use external environmental resources.However,resear...The response of plant functional diversity to external disturbances not only effectively predicts changes in the ecosystem but it also reflects how plant communities use external environmental resources.However,research on how different herbivore assemblages affect plant functional diversity is limited.Therefore,this study systematically explored the effects of three typical herbivore assemblages(yak grazing,Tibetan sheep grazing,and mixed grazing by yaks and Tibetan sheep)on species richness,plant functional diversity,and soil physicochemical properties in alpine grasslands on the Qinghai-Tibet Plateau,China.This study further investigated the primary mechanisms driving the changes in plant functional diversity.The results indicate four key aspects of this system:(1)Grazing significantly enhanced plant functional diversity,particularly when the mixed grazing by yaks and Tibetan sheep was applied at a ratio of 1:2.This ratio showed the most substantial improvement in the functional dispersion index and Rao's quadratic entropy index.(2)Compared to enclosed treatments,grazing increased species richness andβ-diversity,contributing to higher plant functional diversity.(3)Grazing treatments affected various plant traits,such as reducing plant community height and leaf thickness while increasing specific leaf area.However,the impact on plant functional diversity was most pronounced under the mixed grazing by yaks and Tibetan sheep at a ratio of 1:2.(4)Speciesα-diversity was positively correlated with plant functional diversity.Changes in plant functional diversity were primarily regulated by variations in soil physicochemical properties.Specifically,increases in soil available nitrogen significantly promoted changes in plant functional diversity,while increases in soil available potassium and bulk density had a significant inhibitory effect on these changes.Long-term grazing significantly reduced the height of plant communities in alpine meadows,while a balanced mixture of yak and Tibetan sheep grazing,especially at a ratio of 1:2,enhanced plant functional diversity the most.This suggests that,under these conditions,the use of external environmental resources by the plant community is optimized.展开更多
Grasslands are among the largest terrestrial ecosystems,offering critical ecological,economic,and cultural services worldwide(Bardgett et al.2021;Wang et al.2022).However,they face unprecedented challenges due to clim...Grasslands are among the largest terrestrial ecosystems,offering critical ecological,economic,and cultural services worldwide(Bardgett et al.2021;Wang et al.2022).However,they face unprecedented challenges due to climate change,overgrazing,and land-use change,which threaten their biodiversity,carbon sequestration potential,and the human livelihoods they support(Zhou et al.2023;Straffelini et al.2024).Despite the implementation of various management strategies,gaps remain in understanding the intricate dynamics of grassland ecosystems,their key drivers,and the most effective adaptive management practices(Li et al.2022).展开更多
Grassland degradation presents overwhelming challenges to biodiversity,ecosystem services,and the socioeconomic sustainability of dependent communities.However,a comprehensive synthesis of global knowledge on the fron...Grassland degradation presents overwhelming challenges to biodiversity,ecosystem services,and the socioeconomic sustainability of dependent communities.However,a comprehensive synthesis of global knowledge on the frontiers and key areas of grassland degradation research has not been achieved due to the limitations of traditional scientometrics methods.The present synthesis of information employed BERTopic,an advanced natural language processing tool,to analyze the extensive ecological literature on grassland degradation.We compiled a dataset of 4,504 publications from the Web of Science core collection database and used it to evaluate the geographic distribution and temporal evolution of different grassland types and available knowledge on the subject.Our analysis identified key topics in the global grassland degradation research domain,including the effects of grassland degradation on ecosystem functions,grassland ecological restoration and biodiversity conservation,erosion processes and hydrological models in grasslands,and others.The BERTopic analysis significantly outperforms traditional methods in identifying complex and evolving topics in large datasets of literature.Compared to traditional scientometrics analysis,BERTopic provides a more comprehensive perspective on the research areas,revealing not only popular topics but also emerging research areas that traditional methods may overlook,although scientometrics offers more specificity and detail.Therefore,we argue for the simultaneous use of both approaches to achieve more systematic and comprehensive assessments of specific research areas.This study represents an emerging application of BERTopic algorithms in ecological research,particularly in the critical research focused on global grassland degradation.It also highlights the need for integrating advanced computational methods in ecological research in this era of data explosion.Tools like the BERTopic algorithm are essential for enhancing our understanding of complex environmental problems,and it marks an important stride towards more sophisticated,data-driven analysis in ecology.展开更多
Petroleum extraction and its organic pollutants have numerous negative consequences on the composition and ecological function of grasslands,such as vegetation degradation,reduction in species diversity,and salinizati...Petroleum extraction and its organic pollutants have numerous negative consequences on the composition and ecological function of grasslands,such as vegetation degradation,reduction in species diversity,and salinization.Thus,finding a comprehensive method for polluted soil and restoring grasslands faces many challenges,and the mecha-nism to influence soil environments and microbial commu-nity composition remains unclear.In this study,container experiments explored the potential of sulfonic acid group(–SO3H groups)modified biochar combined with isolated bac-terium(named Y-1,Acinetobacter-spp.)on physicochemical properties and microbial communities of polluted soil.The results show that modified biochar and Y-1 combined addi-tion had the highest petroleum degradation rate(39.4%),and soil nutrients such as dissolved organic carbon(DOC),cat-ion exchange capacity(CEC),available nitrogen,invertase and urease activities in CK were decreased by 35.4,12.1,30,43.2 and 32.5%compared to treatments.The contents of available phosphorus in CM treatment were increased 2.4 times compared to CK.The-SO3H groups efficiently improve salinity by accumulating Ca2+and Mg2+and inhib-iting the aggregation of Na+.The correlation heatmap indi-cated that soil organic carbon,total nitrogen and CEC mark-edly interact with microbial communities.High-throughput sequencing indicated that the biomarkers enriched by the present integrated treatment are crucial for stimulating nitro-gen and phosphorus cycles.The results indicate that-SO3H groups modified biochar,and Y-1 has great potential to serve as a novel bioremediation technology to remediate soil from petroleum pollutants and alkalization and achieve better res-toration of degradation grasslands.展开更多
Agricultural land development is a pivotal strategy for addressing the global food security crisis.Barren grassland,especially those in mountainous regions,constitutes critical areas where cultivation can substantiall...Agricultural land development is a pivotal strategy for addressing the global food security crisis.Barren grassland,especially those in mountainous regions,constitutes critical areas where cultivation can substantially enhance land resources.This study highlights the necessity for a precise correlation between land development initiatives and constraints in order to optimize efficiency and enhance the effectiveness of such projects,with the core being the seamless integration of land development engineering and techniques to eliminate agricultural constraints.This study employs a systems engineering approach to classify improvement factors into mobile and fixed categories,elucidating the integration methods of constraint factors.Adhering to the Wooden Barrel Principle,these constraints were rigorously analyzed based on soil quality,land topography,water availability,and agricultural infrastructure.An innovative method of engineering type combination is proposed,which effectively explains the correlation between natural factors combination,project type combination,and target factors combination.It provides a convenient way for the selection of barren grassland development projects and lays a foundation for land planning,development project establishment,program selection,engineering design,and budget preparation.Taking Tang County of China as an example,it is divided into 19 factor improvement areas,a quick reference table of engineering types is established,and 14 main types of engineering combinations are obtained,which lays a foundation for the application of theoretical framework in practice.展开更多
Payment for Ecosystem Services(PES)has been widely acknowledged as an effective tool for mitigating grassland degradation and enhancing ecosystem services provision.However,critical factors,such as herders'willing...Payment for Ecosystem Services(PES)has been widely acknowledged as an effective tool for mitigating grassland degradation and enhancing ecosystem services provision.However,critical factors,such as herders'willingness to accept(WTA)preferences and compensation expectations,are often overlooked,leading to insufficient effectiveness of PES initiatives.This study focused on grassland ecological compensation policy(GECP),quantifying herders'WTA compensation for grassland grazing bans.Through face-to-face surveys and employing the contingent valuation method,we estimated households'WTA for participating in a grassland conservation program to bolster ecosystem service provision.Our findings indicated that herders required an average compensation of 237 CNY mu^(-1)yr^(-1)to engage in the grazing ban program.Notably,herders'environmental awareness positively influenced their willingness to participate,whereas larger family sizes were negatively correlated with WTA.Additionally,herders in better health,with higher livestock incomes or categorized as semi-herders,tended to accept lower compensation levels.These insights are crucial for improving the effectiveness of GECP and provide valuable reference points for similar analyses in economically disadvantaged and ecologically fragile regions.展开更多
On the vast Hulun Buir steppe in north China’s Inner Mongolia Autonomous Region,grasslands stretch as far as the eye can see.Known as one of the world’s four great grasslands and celebrated as the“kingdom of flora ...On the vast Hulun Buir steppe in north China’s Inner Mongolia Autonomous Region,grasslands stretch as far as the eye can see.Known as one of the world’s four great grasslands and celebrated as the“kingdom of flora and fauna in north China,”the region has long been a cradle of traditional nomadic culture and a vital base for animal husbandry.展开更多
The response of N_(2)O emissions to nitrogen(N)addition is usually positive,but its response to phosphorus(P)addition varies,and the underlying mechanisms for the changes in N_(2)O emissions remain unclear.We conducte...The response of N_(2)O emissions to nitrogen(N)addition is usually positive,but its response to phosphorus(P)addition varies,and the underlying mechanisms for the changes in N_(2)O emissions remain unclear.We conducted field studies to examine the response of N_(2)O emissions to N and P addition over two years in three typical alpine grasslands,alpine meadow(AM),alpine steppe(AS),and alpine cultivated grassland(CG)on the Qinghai-Tibet Plateau(QTP).Our results showed consistent increases in N_(2)O emissions under N addition alone or with P addition,and insignificant change in N_(2)O emissions under P addition alone in all three grasslands.N addition increased N_(2)O emissions directly in AM,by lowering soil pH in AS,and by lowering abundance of denitrification genes in CG.N and P co-addition increased N_(2)O emissions in AM and AS but only showed an interactive effect in AM.P addition enhanced the increase in N_(2)O emissions caused by N addition mainly by promoting plant growth in AM.Overall,our results illustrate that short-term P addition cannot alleviate the stimulation of N_(2)O emissions by N deposition in alpine grassland ecosystems,and may even further stimulate N_(2)O emissions.展开更多
Grazing management significantly influences greenhouse gas(GHG)emissions and the global warming potential(GWP)in grasslands.Yet,a limited understanding of the impact of grazing and grazing exclusion on GHG emis-sions ...Grazing management significantly influences greenhouse gas(GHG)emissions and the global warming potential(GWP)in grasslands.Yet,a limited understanding of the impact of grazing and grazing exclusion on GHG emis-sions and GWP in grasslands hinders progress towards grassland ecosystem sustainability and GHG mitigation.We conducted a global meta-analysis of 75 published studies to investigate the effects of grazing and grazing exclusion on methane(CH_(4)),carbon dioxide(CO_(2)),nitrous oxide(N_(2 )O),and GWP.Our results revealed that grazing and grazing exclusion significantly increased the CO_(2) and CH4 emissions,respectively.The responses of GHG emissions and GWP to grazing were regulated by grazing intensity and elevation.We also found that light grazing significantly decreased GWP but heavy grazing increased GWP.Reducing grazing intensity was a simple and effective method through stocking rate adjustment,which promised a large GHG mitigation poten-tial.Our results demonstrated that GHG emissions increased with elevation under grassland grazing,implying that irrational grazing in high-elevation grasslands promoted GHG emissions.In comparison with grazing,only long-term grazing exclusion reduced the GWP,and CH4 emissions enhanced with grazing exclusion duration.However,long-term grazing exclusion may shift economic demand and grazing burden to other areas.Overall,we suggested that regulating the grazing intensity,rather than grazing exclusion,was an effective way to re-duce GHG emissions.Our study contributed to the enhancement of sustainable grazing management practices for GHG balance and GWP in global grasslands,and offered a global picture for understanding the changes in GHG emissions and GWP under different grazing management regimes.展开更多
The source region of the Yellow River, accounting for over 38% of its total runoff, is a critical catchment area,primarily characterized by alpine grasslands. In 2005, the Maqu land surface processes observational sit...The source region of the Yellow River, accounting for over 38% of its total runoff, is a critical catchment area,primarily characterized by alpine grasslands. In 2005, the Maqu land surface processes observational site was established to monitor climate, land surface dynamics, and hydrological variability in this region. Over a 10-year period(2010–19), an extensive observational dataset was compiled, now available to the scientific community. This dataset includes comprehensive details on site characteristics, instrumentation, and data processing methods, covering meteorological and radiative fluxes, energy exchanges, soil moisture dynamics, and heat transfer properties. The dataset is particularly valuable for researchers studying land surface processes, land–atmosphere interactions, and climate modeling, and may also benefit ecological, hydrological, and water resource studies. The report ends with a discussion on perspectives and challenges of continued observational monitoring in this region, focusing on issues such as cryosphere influences, complex topography,and ecological changes like the encroachment of weeds and scrubland.展开更多
The mining of limestone mines plays a crucial role in societal and economic advancement.However,mining activities have led to destructive variations in grassland ecology and soil,causing numerous environmental problem...The mining of limestone mines plays a crucial role in societal and economic advancement.However,mining activities have led to destructive variations in grassland ecology and soil,causing numerous environmental problems,and effective artificial restoration measures have been used to restore grasslands in the Shimenhe mining areas to different degrees.In this study,we investigated,examined and analyzed plant community structure and its correlation with soil properties across varying degrees of alpine grassland restoration in Qilian Mountains Shimenhe restoration mines using the sample method,and studied the changes in species diversity using five diversity indexes(Simpson index,Shannon index,Margalef index,Dominance index and Evenness index).This study showed that the plant community characteristics with high recovered degree(HRD)> middle recovered degree(MRD)> low recovered degree(LRD)> very low recovered degree(VLRD),11 plant genera comprising 11 species across 10 families were identified.Dominant families with robust ecological adaptability included Leguminosae,Rosaceae,Gramineae,Asteraceae,and Salicaceae.The highest Simpson,Shannon,Margalef and Evenness index of HRD grassland community species were 0.82,1.96,1.66 and 0.89,respectively.The highest Dominance index of VLRD grassland community species was 0.34,which required several restoration methods such as spraying and mulching.Soil pH and EC tended to decrease with increasing restoration,SOC,SMC,TP,AP,NH4-N,TN,AN and NO3-N tended to increase and the content of soil environmental factors contributed to vegetation growth across various restoration levels the mine grassland.In conclusion,our study indicated that the community structure gradually diversified and soil properties changed positively with the increase of restoration degrees in the Qilian Mountains Shimenhe mine,and the best results of HRD restoration were obtained.This study provides the theoretical basis for the restoration and conservation of grasslands in mining areas by demonstrating examined the correlation between plant characteristics and soil properties in restored grasslands in alpine mining areas.展开更多
The semi-arid grasslands in Inner Mongolia, China have been degraded by long-term grazing. A series of ecological restoration strategies have been implemented to improve grassland service. However, little is known abo...The semi-arid grasslands in Inner Mongolia, China have been degraded by long-term grazing. A series of ecological restoration strategies have been implemented to improve grassland service. However, little is known about the effect of these ecological restoration practices on soil carbon and nitrogen storage. In this study, characteristics of vegetation and soil properties under continued grazing and exclusion of livestock for six years due to a nationwide conservation program—′Returning Grazing Lands to Grasslands(RGLG)′ were examined in semi-arid Hulun Buir grassland in Inner Mongolia, China. The results show that removal of grazing for six years resulted in a significant recovery in vegetation with higher above and below-ground biomass, but a lower soil bulk density and pH value. After six years of grazing exclusion, soil organic C and total N storage increased by 13.9% and 17.1%, respectively, which could be partly explained by decreased loss and increased input of C and N to soil. The effects of grazing exclusion on soil C and N concentration and storage primarily occurred in the upper soil depths. The results indicate that removal of grazing pressure within the RGLG program was an effective restoration approach to control grassland degradation in this region. However, more comprehensive studies are needed to evaluate the effectiveness of the RGLG program and to improve the management strategies for grassland restoration in this area.展开更多
Grasslands in northern China serve the country as both an ecological barrier and a livestock production base.There,installing enclosures has been becoming the major grassland restoration measure adopted by many local ...Grasslands in northern China serve the country as both an ecological barrier and a livestock production base.There,installing enclosures has been becoming the major grassland restoration measure adopted by many local governments.However,the effects of restoration on both ecological and production benefits of grassland remain unclear for implemented grassland restoration policies.Therefore,a representative rangeland in northern China,the Maodeng pasture in Inner Mongolia Autonomous Region was selected as the study area,and remote sensing monitoring analyses were carried out to quantify the ecological benefits and economic benefits from 2015 to 2021.The results showed that:1) in terms of ecological benefits,the grassland area with a grassland coverage rate of more than 60% accounts for 32.3% of the regional area,and 86.4% of its grassland grew significantly better than the same period in2015,showing a significant improvement in grassland growth.Using the average amount of carbon per unit area as the ecological benefit evaluation index,it increased by 27.1% to 32.48Tg C/yr from 2015 to 2021.2) In terms of economic benefits,both theoretical grass production and livestock carrying capacity increased from 2015 to 2021.Compared to 2015,the theoretical grass production in 2021 increased by 24.8% to 71 900 t.The livestock carrying capacity reached 52 100 sheep units in 2021,nearly 11 000 sheep units more than that in 2015.During the study period,multiple economic indicators(on a per capita basis of permanent residents) for the pastoral area of Xilinhot City to which the Maodeng pasture belongs,have grown steadily.Per capita total income rose from 29 630 yuan(RMB) in2015 to 62 859 yuan(RMB) in 2021.Relying on grassland resources to develop the pastoral ecology also broadens the potential economic development space.Overall,the establishment of the reserve and the experiment of implanting an enclosure policy have had a significant and positive impact on Maodeng pasture’s development from both an ecological and economic perspective.With the support of scientific evidence,enclosure policy can be extended to more than 110 000 km~2 of grasslands in northern China with similar precipitation and temperature conditions,enhancing the productive and ecological potential of grasslands.The above research results will contribute to the scientific formulation of grassland pasture quality improvement plans in northern China.展开更多
Soil erosion caused by unsustainable grazing is a major driver of grassland ecosystem degradation in many semi-arid hilly areas in China.Thus,grazing exclusion is considered as an effective method for solving this iss...Soil erosion caused by unsustainable grazing is a major driver of grassland ecosystem degradation in many semi-arid hilly areas in China.Thus,grazing exclusion is considered as an effective method for solving this issue in such areas.However,some ecological and economic problems,such as slow grassland rejuvenation and limited economic conditions,have become obstacles for the sustainable utilization of grassland ecosystem.Accordingly,we hypothesized that the conflict between grassland use and soil conservation may be balanced by a reasonable grazing intensity.In this study,a two-year grazing fence experiment with five grazing intensity gradients was conducted in a typical grassland of the Loess Plateau in China to evaluate the responses of vegetation characteristics and soil and water losses to grazing intensity.The five grazing intensity gradients were 2.2,3.0,4.2,6.7,and 16.7 goats/hm2,which were represented by G1-G5,respectively,and no grazing was used as control.The results showed that a reasonable grazing intensity was conducive to the sustainable utilization of grassland resources.Vegetation biomass under G1-G4 grazing intensity significantly increased by 51.9%,42.1%,36.9%,and 36.7%,respectively,compared with control.In addition,vegetation coverage increased by 19.6%under G1 grazing intensity.Species diversity showed a single peak trend with increasing grazing intensity.The Shannon-Wiener diversity index under G1-G4 grazing intensities significantly increased by 22.8%,22.5%,13.3%,and 8.3%,respectively,compared with control.Furthermore,grazing increased the risk of soil erosion.Compared with control,runoff yields under G1-G5 grazing intensities increased by 1.4,2.6,2.8,4.3,and 3.9 times,respectively,and sediment yields under G1-G5 grazing intensities were 3.0,13.0,20.8,34.3,and 37.7 times greater,respectively,than those under control.This result was mainly attributed to a visible decrease in litter biomass after grazing,which decreased by 50.5%,72.6%,79.0%,80.0%,and 76.9%,respectively,under G1-G5 grazing intensities.By weighing the grassland productivity and soil conservation function,we found that both two aims were achieved at a low grazing intensity of less than 3.5 goats/hm2.Therefore,it is recommended that grassland should be moderately utilized with grazing intensity below 3.5 goats/hm2 in semi-arid hilly areas to achieve the dual goals of ecological and economic benefits.The results provide a scientific basis for grassland utilization and health management in semi-arid hilly areas from the perspective of determining reasonable grazing intensity to maintain both grassland production and soil conservation functions.展开更多
Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored t...Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored the original spectral information of typical grasslands in Inner Mongolia and examined the influence of spectral information on aboveground biomass(AGB)estimation.In order to improve the accuracy of vegetation index inversion of grassland AGB,this study combined ground and Unmanned Aerial Vehicle(UAV)remote sensing technology and screened sensitive bands through ground hyperspectral data transformation and correlation analysis.The narrow band vegetation indices were calculated,and ground and airborne hyperspectral inversion models were established.Finally,the accuracy of the model was verified.The results showed that:(1)The vegetation indices constructed based on the ASD FieldSpec 4 and the UAV were significantly correlated with the dry and fresh weight of AGB.(2)The comparison between measured R^(2) with the prediction R^(2) indicated that the accuracy of the model was the best when using the Soil-Adjusted Vegetation Index(SAVI)as the independent variable in the analysis of AGB(fresh weight/dry weight)and four narrow-band vegetation indices.The SAVI vegetation index showed better applicability for biomass monitoring in typical grassland areas of Inner Mongolia.(3)The obtained ground and airborne hyperspectral data with the optimal vegetation index suggested that the dry weight of AGB has the best fitting effect with airborne hyperspectral data,where y=17.962e^(4.672x),the fitting R^(2) was 0.542,the prediction R^(2)was 0.424,and RMSE and REE were 57.03 and 0.65,respectively.Therefore,established vegetation indices by screening sensitive bands through hyperspectral feature analysis can significantly improve the inversion accuracy of typical grassland biomass in Inner Mongolia.Compared with ground monitoring,airborne hyperspectral monitoring better reflects the inversion of actual surface biomass.It provides a reliable modeling framework for grassland AGB monitoring and scientific and technological support for grazing management.展开更多
文摘In mid-June,the vast,rolling meadow steppe grasslands of Bayanwenduer Sumu in Ar Horqin Banner,Inner Mongolia Autonomous Region,once again stretched into the horizon like green waves with herds of cattle and sheep scattered across them like pearls in a green ocean.This flock was driven by herders on horseback,motorcycles,and agricultural vehicles,leading the animals to summer pastures in one of the most important migrations of the year.
基金supported by the Talent introduction program of Chinese Academy of Sciences,Institute of Tibetan Plateau Research.
文摘Grassland ecosystems are experiencing severe deterioration due to ongoing climate fluctuation and human disturbance.Although numerous research centers on the patterns,processes,and functioning of degraded grassland,there is still a lack of standards for defining and assessing degraded grassland,which restricts the cognition of the degraded grassland mechanisms and restoration practices.Therefore,we review current grassland degradation research for the sake of the common definitions and assessment methods worldwide.Grassland degradation definitions are divided into three stages,including biotic/abiotic factors,ecosystem functions,and ecosystem services/sustainability,and further combine the concept of“nature’s contributions to people”with the definition of grassland degradation.Moreover,grassland degradation assessment methods and indicators are diverse across scales.Additionally,we systematically explore the climate change and social system factors that affect grassland degradation,and reveal that grassland management policies play an essential role in grassland degradation and restoration.Overall,this review advances our understanding of grassland degradation and calls for a unified and effective global definition and assessment criteria,which will contribute to the sustainable management of the grassland ecosystem.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28110300)National Natural Science Foundation of China(No.U23A2004)+3 种基金Natural Science Foundation of Jilin Province,China(No.YDZJ202201ZYTS522)Science and Technology Cooperation Program between Jilin Province and Chinese Academy of Sciences(No.2023SYHZ0053)Innovation Team Program of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.2023CXTD02)the European Commission under Marie Sk?odowska-Curie(No.101034371)。
文摘Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.
基金supported by the National Natural Science Foundation of China(42377458 and 41907411).
文摘The Leymus chinensis grassland is one of themost widely distributed associations in the warmtemperate grassland and due to overgrazing in recent years,it has experienced varying degrees of degradation.Vegetative regeneration via bud banks serves as the primaryway of vegetation reproduction in the L.chinensis grassland ecosystem.However,the role of the bud bank in the vegetation regeneration of grazing grassland remains unclear.Based on the relationship between the under-ground bud bank and above-ground vegetation of L.chinensis grassland under different grazing stages,this study aimed to explore whether the grazing grassland could self-recover through the existing bud bank.The findings revealed that the bud density initially increased and then decreased with increasing grazing intensity,indicating that appropriate grazing promoted vegetation renewal.Moreover,grazing significantly influenced the composition of the bud bank:during the early grazing stage,the rhizome buds accounted for the main part,and tiller buds dominated during the mid-stage grazing;while during the late-stage grazing,root-sprouting buds prevailed.The meristem restriction index for light,moderate,and heavy grazing grasslands was close to one;conversely,overgrazing and extreme overgrazing grasslands exhibited the highermeristemrestriction index(2.00,3.19),suggesting that plant regeneration was constrained by bud banks under light-grazing conditions where regenerate rates failed to meet above-ground modular’s recovery requirements following overgrazing and extreme overgrazing events.Consequently,moderate grazing grasslands could achieve natural community recovery by continuously adjusting their vegetative regeneration strategies.Understanding the role of bud banks in vegetative regeneration in grazing grassland will not only supply theoretical support for the ecological succession process of degraded grassland but also provide practical experience for the sustainable management of the L.chinensis grassland ecosystem.
基金the National Key Research and Development Program of China(2023YFF1304302)the Qaidam basin and Qilian Mountains germplasm resources collection project(Grant No.SJCZFY2022-1-6)。
文摘Understanding plant diversity within geographical ranges and identifying key species that drive community variation can provide crucial insights for the management of grasslands.However,the contribution of both local sites and plant species to beta diversity in grassland ecosystems has yet to be accurately assessed.This study applied the ecological uniqueness approach to examine both local contributions to beta diversity(LCBD)and species contributions to beta diversity(SCBD)across six major geographical ranges in alpine grasslands.We found that LCBD was driven by species turnover,with climate,plant communities,and their interactions influencing LCBD across spatial scales.LCBD values were high in areas with low evapotranspiration,high rainfall variability,and low species and functional richness.Precipitation seasonality predicted large-scale LCBD dynamics,while plant community abundance explained local LCBD variation.In addition,we found that SCBD were confined to species with moderate occupancy,although these species contributed less to plant biological traits.Our findings are crucial for understanding how ecological characteristics influence plant beta diversity in grasslands and how it responds to environmental and community factors.In addition,these findings have successfully identified key sites and priority plants for conservation,indicating that using standardized quadrats can support the assessment of the ecological uniqueness in grassland ecosystems.We hope these insights will inform the development of conservation strategies,thereby supporting regional plant diversity and resisting vegetation homogenization.
基金financially supported by the National Natural Science Foundation of China(U20A2007 and 32160343)the Open Project of Key Laboratory of the Alpine Grassland Ecology in the Three Rivers Region(Qinghai University),Ministry of Education of China(2023-SJY-KF-02)the West Light Foundation of the Chinese Academy of Sciences。
文摘The response of plant functional diversity to external disturbances not only effectively predicts changes in the ecosystem but it also reflects how plant communities use external environmental resources.However,research on how different herbivore assemblages affect plant functional diversity is limited.Therefore,this study systematically explored the effects of three typical herbivore assemblages(yak grazing,Tibetan sheep grazing,and mixed grazing by yaks and Tibetan sheep)on species richness,plant functional diversity,and soil physicochemical properties in alpine grasslands on the Qinghai-Tibet Plateau,China.This study further investigated the primary mechanisms driving the changes in plant functional diversity.The results indicate four key aspects of this system:(1)Grazing significantly enhanced plant functional diversity,particularly when the mixed grazing by yaks and Tibetan sheep was applied at a ratio of 1:2.This ratio showed the most substantial improvement in the functional dispersion index and Rao's quadratic entropy index.(2)Compared to enclosed treatments,grazing increased species richness andβ-diversity,contributing to higher plant functional diversity.(3)Grazing treatments affected various plant traits,such as reducing plant community height and leaf thickness while increasing specific leaf area.However,the impact on plant functional diversity was most pronounced under the mixed grazing by yaks and Tibetan sheep at a ratio of 1:2.(4)Speciesα-diversity was positively correlated with plant functional diversity.Changes in plant functional diversity were primarily regulated by variations in soil physicochemical properties.Specifically,increases in soil available nitrogen significantly promoted changes in plant functional diversity,while increases in soil available potassium and bulk density had a significant inhibitory effect on these changes.Long-term grazing significantly reduced the height of plant communities in alpine meadows,while a balanced mixture of yak and Tibetan sheep grazing,especially at a ratio of 1:2,enhanced plant functional diversity the most.This suggests that,under these conditions,the use of external environmental resources by the plant community is optimized.
文摘Grasslands are among the largest terrestrial ecosystems,offering critical ecological,economic,and cultural services worldwide(Bardgett et al.2021;Wang et al.2022).However,they face unprecedented challenges due to climate change,overgrazing,and land-use change,which threaten their biodiversity,carbon sequestration potential,and the human livelihoods they support(Zhou et al.2023;Straffelini et al.2024).Despite the implementation of various management strategies,gaps remain in understanding the intricate dynamics of grassland ecosystems,their key drivers,and the most effective adaptive management practices(Li et al.2022).
基金financially supported by the First-Class Curriculum Program at the School of Economics and Management,University of the Chinese Academy of Sciencesthe National Natural Science Foundation of China(42041005)the National Social Science Foundation of China(23BTQ054)。
文摘Grassland degradation presents overwhelming challenges to biodiversity,ecosystem services,and the socioeconomic sustainability of dependent communities.However,a comprehensive synthesis of global knowledge on the frontiers and key areas of grassland degradation research has not been achieved due to the limitations of traditional scientometrics methods.The present synthesis of information employed BERTopic,an advanced natural language processing tool,to analyze the extensive ecological literature on grassland degradation.We compiled a dataset of 4,504 publications from the Web of Science core collection database and used it to evaluate the geographic distribution and temporal evolution of different grassland types and available knowledge on the subject.Our analysis identified key topics in the global grassland degradation research domain,including the effects of grassland degradation on ecosystem functions,grassland ecological restoration and biodiversity conservation,erosion processes and hydrological models in grasslands,and others.The BERTopic analysis significantly outperforms traditional methods in identifying complex and evolving topics in large datasets of literature.Compared to traditional scientometrics analysis,BERTopic provides a more comprehensive perspective on the research areas,revealing not only popular topics but also emerging research areas that traditional methods may overlook,although scientometrics offers more specificity and detail.Therefore,we argue for the simultaneous use of both approaches to achieve more systematic and comprehensive assessments of specific research areas.This study represents an emerging application of BERTopic algorithms in ecological research,particularly in the critical research focused on global grassland degradation.It also highlights the need for integrating advanced computational methods in ecological research in this era of data explosion.Tools like the BERTopic algorithm are essential for enhancing our understanding of complex environmental problems,and it marks an important stride towards more sophisticated,data-driven analysis in ecology.
基金Natural Science Foundation of Heilongjiang Province(LH2023E009)the Fundamental Research Funds for the Central Universities(2572021BA01)the Ecological and Environmental Protection project of Heilongjiang Province(HST2022ST004).
文摘Petroleum extraction and its organic pollutants have numerous negative consequences on the composition and ecological function of grasslands,such as vegetation degradation,reduction in species diversity,and salinization.Thus,finding a comprehensive method for polluted soil and restoring grasslands faces many challenges,and the mecha-nism to influence soil environments and microbial commu-nity composition remains unclear.In this study,container experiments explored the potential of sulfonic acid group(–SO3H groups)modified biochar combined with isolated bac-terium(named Y-1,Acinetobacter-spp.)on physicochemical properties and microbial communities of polluted soil.The results show that modified biochar and Y-1 combined addi-tion had the highest petroleum degradation rate(39.4%),and soil nutrients such as dissolved organic carbon(DOC),cat-ion exchange capacity(CEC),available nitrogen,invertase and urease activities in CK were decreased by 35.4,12.1,30,43.2 and 32.5%compared to treatments.The contents of available phosphorus in CM treatment were increased 2.4 times compared to CK.The-SO3H groups efficiently improve salinity by accumulating Ca2+and Mg2+and inhib-iting the aggregation of Na+.The correlation heatmap indi-cated that soil organic carbon,total nitrogen and CEC mark-edly interact with microbial communities.High-throughput sequencing indicated that the biomarkers enriched by the present integrated treatment are crucial for stimulating nitro-gen and phosphorus cycles.The results indicate that-SO3H groups modified biochar,and Y-1 has great potential to serve as a novel bioremediation technology to remediate soil from petroleum pollutants and alkalization and achieve better res-toration of degradation grasslands.
基金funded by Science and Technology Project of Hebei Education Department[QN2023085].
文摘Agricultural land development is a pivotal strategy for addressing the global food security crisis.Barren grassland,especially those in mountainous regions,constitutes critical areas where cultivation can substantially enhance land resources.This study highlights the necessity for a precise correlation between land development initiatives and constraints in order to optimize efficiency and enhance the effectiveness of such projects,with the core being the seamless integration of land development engineering and techniques to eliminate agricultural constraints.This study employs a systems engineering approach to classify improvement factors into mobile and fixed categories,elucidating the integration methods of constraint factors.Adhering to the Wooden Barrel Principle,these constraints were rigorously analyzed based on soil quality,land topography,water availability,and agricultural infrastructure.An innovative method of engineering type combination is proposed,which effectively explains the correlation between natural factors combination,project type combination,and target factors combination.It provides a convenient way for the selection of barren grassland development projects and lays a foundation for land planning,development project establishment,program selection,engineering design,and budget preparation.Taking Tang County of China as an example,it is divided into 19 factor improvement areas,a quick reference table of engineering types is established,and 14 main types of engineering combinations are obtained,which lays a foundation for the application of theoretical framework in practice.
基金supported by the National Natural Science Foundation of China(71934003,72322008,and72348003).
文摘Payment for Ecosystem Services(PES)has been widely acknowledged as an effective tool for mitigating grassland degradation and enhancing ecosystem services provision.However,critical factors,such as herders'willingness to accept(WTA)preferences and compensation expectations,are often overlooked,leading to insufficient effectiveness of PES initiatives.This study focused on grassland ecological compensation policy(GECP),quantifying herders'WTA compensation for grassland grazing bans.Through face-to-face surveys and employing the contingent valuation method,we estimated households'WTA for participating in a grassland conservation program to bolster ecosystem service provision.Our findings indicated that herders required an average compensation of 237 CNY mu^(-1)yr^(-1)to engage in the grazing ban program.Notably,herders'environmental awareness positively influenced their willingness to participate,whereas larger family sizes were negatively correlated with WTA.Additionally,herders in better health,with higher livestock incomes or categorized as semi-herders,tended to accept lower compensation levels.These insights are crucial for improving the effectiveness of GECP and provide valuable reference points for similar analyses in economically disadvantaged and ecologically fragile regions.
文摘On the vast Hulun Buir steppe in north China’s Inner Mongolia Autonomous Region,grasslands stretch as far as the eye can see.Known as one of the world’s four great grasslands and celebrated as the“kingdom of flora and fauna in north China,”the region has long been a cradle of traditional nomadic culture and a vital base for animal husbandry.
基金funded by the National Key R&D Program of China(2021YFE0112400 and 2023YFF1304303)the National Natural Science Foundation of China(32361143870 and 32101315)。
文摘The response of N_(2)O emissions to nitrogen(N)addition is usually positive,but its response to phosphorus(P)addition varies,and the underlying mechanisms for the changes in N_(2)O emissions remain unclear.We conducted field studies to examine the response of N_(2)O emissions to N and P addition over two years in three typical alpine grasslands,alpine meadow(AM),alpine steppe(AS),and alpine cultivated grassland(CG)on the Qinghai-Tibet Plateau(QTP).Our results showed consistent increases in N_(2)O emissions under N addition alone or with P addition,and insignificant change in N_(2)O emissions under P addition alone in all three grasslands.N addition increased N_(2)O emissions directly in AM,by lowering soil pH in AS,and by lowering abundance of denitrification genes in CG.N and P co-addition increased N_(2)O emissions in AM and AS but only showed an interactive effect in AM.P addition enhanced the increase in N_(2)O emissions caused by N addition mainly by promoting plant growth in AM.Overall,our results illustrate that short-term P addition cannot alleviate the stimulation of N_(2)O emissions by N deposition in alpine grassland ecosystems,and may even further stimulate N_(2)O emissions.
基金supported by National Natural Science Foundation of China(Grant No.72394401).
文摘Grazing management significantly influences greenhouse gas(GHG)emissions and the global warming potential(GWP)in grasslands.Yet,a limited understanding of the impact of grazing and grazing exclusion on GHG emis-sions and GWP in grasslands hinders progress towards grassland ecosystem sustainability and GHG mitigation.We conducted a global meta-analysis of 75 published studies to investigate the effects of grazing and grazing exclusion on methane(CH_(4)),carbon dioxide(CO_(2)),nitrous oxide(N_(2 )O),and GWP.Our results revealed that grazing and grazing exclusion significantly increased the CO_(2) and CH4 emissions,respectively.The responses of GHG emissions and GWP to grazing were regulated by grazing intensity and elevation.We also found that light grazing significantly decreased GWP but heavy grazing increased GWP.Reducing grazing intensity was a simple and effective method through stocking rate adjustment,which promised a large GHG mitigation poten-tial.Our results demonstrated that GHG emissions increased with elevation under grassland grazing,implying that irrational grazing in high-elevation grasslands promoted GHG emissions.In comparison with grazing,only long-term grazing exclusion reduced the GWP,and CH4 emissions enhanced with grazing exclusion duration.However,long-term grazing exclusion may shift economic demand and grazing burden to other areas.Overall,we suggested that regulating the grazing intensity,rather than grazing exclusion,was an effective way to re-duce GHG emissions.Our study contributed to the enhancement of sustainable grazing management practices for GHG balance and GWP in global grasslands,and offered a global picture for understanding the changes in GHG emissions and GWP under different grazing management regimes.
基金supported by the National Natural Science Foundation of China for Distinguished Young Scholars (Grant No.42325502)the 2nd Scientific Expedition to the Qinghai–Tibet Plateau (Grant No.2019QZKK0102)+3 种基金the West Light Foundation of the Chinese Academy of Sciences (Grant No.xbzg-zdsys-202215)the Science and Technology Research Plan of Gansu Province (Grant Nos.23JRRA654 and 20JR10RA070)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant No.QCH2019004)iLEAPS (integrated Land Ecosystem–Atmosphere Processes Study)。
文摘The source region of the Yellow River, accounting for over 38% of its total runoff, is a critical catchment area,primarily characterized by alpine grasslands. In 2005, the Maqu land surface processes observational site was established to monitor climate, land surface dynamics, and hydrological variability in this region. Over a 10-year period(2010–19), an extensive observational dataset was compiled, now available to the scientific community. This dataset includes comprehensive details on site characteristics, instrumentation, and data processing methods, covering meteorological and radiative fluxes, energy exchanges, soil moisture dynamics, and heat transfer properties. The dataset is particularly valuable for researchers studying land surface processes, land–atmosphere interactions, and climate modeling, and may also benefit ecological, hydrological, and water resource studies. The report ends with a discussion on perspectives and challenges of continued observational monitoring in this region, focusing on issues such as cryosphere influences, complex topography,and ecological changes like the encroachment of weeds and scrubland.
基金supported by the National Key R&D Program of China (Nos. 2022YFF1303301, 2022YFF1302603)the National Natural Science Foundation of China (Nos. 52179026, 42001035, 42101115)+5 种基金the Science and Technology Program of Gansu Province (Nos. 22JR5RA072, 22JR5RA068)the Postdoctoral Funding Program of Gansu Province (No. E339880139)the Natural Science Foundation of Gansu Province (No. E331040901)the Science and Technology Fund of Gansu Province (No. 23JRRA640)the Consulting and Research Project of the Gansu Research Institute of Chinese Engineering Science and Technology Development Strategy (No. GS2022ZDI03)the Open Fund of Technology Innovation Center for Mine Geological Environment Restoration in the Alpine and Arid Regions (No. HHGCKK2204)
文摘The mining of limestone mines plays a crucial role in societal and economic advancement.However,mining activities have led to destructive variations in grassland ecology and soil,causing numerous environmental problems,and effective artificial restoration measures have been used to restore grasslands in the Shimenhe mining areas to different degrees.In this study,we investigated,examined and analyzed plant community structure and its correlation with soil properties across varying degrees of alpine grassland restoration in Qilian Mountains Shimenhe restoration mines using the sample method,and studied the changes in species diversity using five diversity indexes(Simpson index,Shannon index,Margalef index,Dominance index and Evenness index).This study showed that the plant community characteristics with high recovered degree(HRD)> middle recovered degree(MRD)> low recovered degree(LRD)> very low recovered degree(VLRD),11 plant genera comprising 11 species across 10 families were identified.Dominant families with robust ecological adaptability included Leguminosae,Rosaceae,Gramineae,Asteraceae,and Salicaceae.The highest Simpson,Shannon,Margalef and Evenness index of HRD grassland community species were 0.82,1.96,1.66 and 0.89,respectively.The highest Dominance index of VLRD grassland community species was 0.34,which required several restoration methods such as spraying and mulching.Soil pH and EC tended to decrease with increasing restoration,SOC,SMC,TP,AP,NH4-N,TN,AN and NO3-N tended to increase and the content of soil environmental factors contributed to vegetation growth across various restoration levels the mine grassland.In conclusion,our study indicated that the community structure gradually diversified and soil properties changed positively with the increase of restoration degrees in the Qilian Mountains Shimenhe mine,and the best results of HRD restoration were obtained.This study provides the theoretical basis for the restoration and conservation of grasslands in mining areas by demonstrating examined the correlation between plant characteristics and soil properties in restored grasslands in alpine mining areas.
基金Under the auspices of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05060103)National Natural Science Foundation of China(No.41105117)State Key Laboratory of Forest and Soil Ecology(No.LFSE2013-06)
文摘The semi-arid grasslands in Inner Mongolia, China have been degraded by long-term grazing. A series of ecological restoration strategies have been implemented to improve grassland service. However, little is known about the effect of these ecological restoration practices on soil carbon and nitrogen storage. In this study, characteristics of vegetation and soil properties under continued grazing and exclusion of livestock for six years due to a nationwide conservation program—′Returning Grazing Lands to Grasslands(RGLG)′ were examined in semi-arid Hulun Buir grassland in Inner Mongolia, China. The results show that removal of grazing for six years resulted in a significant recovery in vegetation with higher above and below-ground biomass, but a lower soil bulk density and pH value. After six years of grazing exclusion, soil organic C and total N storage increased by 13.9% and 17.1%, respectively, which could be partly explained by decreased loss and increased input of C and N to soil. The effects of grazing exclusion on soil C and N concentration and storage primarily occurred in the upper soil depths. The results indicate that removal of grazing pressure within the RGLG program was an effective restoration approach to control grassland degradation in this region. However, more comprehensive studies are needed to evaluate the effectiveness of the RGLG program and to improve the management strategies for grassland restoration in this area.
基金Under the auspices of the Inner Mongolia Autonomous Region Science and Technology Achievement Transformation Special Project(No.2020CG0123)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA26050301-01)。
文摘Grasslands in northern China serve the country as both an ecological barrier and a livestock production base.There,installing enclosures has been becoming the major grassland restoration measure adopted by many local governments.However,the effects of restoration on both ecological and production benefits of grassland remain unclear for implemented grassland restoration policies.Therefore,a representative rangeland in northern China,the Maodeng pasture in Inner Mongolia Autonomous Region was selected as the study area,and remote sensing monitoring analyses were carried out to quantify the ecological benefits and economic benefits from 2015 to 2021.The results showed that:1) in terms of ecological benefits,the grassland area with a grassland coverage rate of more than 60% accounts for 32.3% of the regional area,and 86.4% of its grassland grew significantly better than the same period in2015,showing a significant improvement in grassland growth.Using the average amount of carbon per unit area as the ecological benefit evaluation index,it increased by 27.1% to 32.48Tg C/yr from 2015 to 2021.2) In terms of economic benefits,both theoretical grass production and livestock carrying capacity increased from 2015 to 2021.Compared to 2015,the theoretical grass production in 2021 increased by 24.8% to 71 900 t.The livestock carrying capacity reached 52 100 sheep units in 2021,nearly 11 000 sheep units more than that in 2015.During the study period,multiple economic indicators(on a per capita basis of permanent residents) for the pastoral area of Xilinhot City to which the Maodeng pasture belongs,have grown steadily.Per capita total income rose from 29 630 yuan(RMB) in2015 to 62 859 yuan(RMB) in 2021.Relying on grassland resources to develop the pastoral ecology also broadens the potential economic development space.Overall,the establishment of the reserve and the experiment of implanting an enclosure policy have had a significant and positive impact on Maodeng pasture’s development from both an ecological and economic perspective.With the support of scientific evidence,enclosure policy can be extended to more than 110 000 km~2 of grasslands in northern China with similar precipitation and temperature conditions,enhancing the productive and ecological potential of grasslands.The above research results will contribute to the scientific formulation of grassland pasture quality improvement plans in northern China.
基金National Key Research and Development Program of China(2022YFD1300803)National Natural Science Foundation of China(42377357).
文摘Soil erosion caused by unsustainable grazing is a major driver of grassland ecosystem degradation in many semi-arid hilly areas in China.Thus,grazing exclusion is considered as an effective method for solving this issue in such areas.However,some ecological and economic problems,such as slow grassland rejuvenation and limited economic conditions,have become obstacles for the sustainable utilization of grassland ecosystem.Accordingly,we hypothesized that the conflict between grassland use and soil conservation may be balanced by a reasonable grazing intensity.In this study,a two-year grazing fence experiment with five grazing intensity gradients was conducted in a typical grassland of the Loess Plateau in China to evaluate the responses of vegetation characteristics and soil and water losses to grazing intensity.The five grazing intensity gradients were 2.2,3.0,4.2,6.7,and 16.7 goats/hm2,which were represented by G1-G5,respectively,and no grazing was used as control.The results showed that a reasonable grazing intensity was conducive to the sustainable utilization of grassland resources.Vegetation biomass under G1-G4 grazing intensity significantly increased by 51.9%,42.1%,36.9%,and 36.7%,respectively,compared with control.In addition,vegetation coverage increased by 19.6%under G1 grazing intensity.Species diversity showed a single peak trend with increasing grazing intensity.The Shannon-Wiener diversity index under G1-G4 grazing intensities significantly increased by 22.8%,22.5%,13.3%,and 8.3%,respectively,compared with control.Furthermore,grazing increased the risk of soil erosion.Compared with control,runoff yields under G1-G5 grazing intensities increased by 1.4,2.6,2.8,4.3,and 3.9 times,respectively,and sediment yields under G1-G5 grazing intensities were 3.0,13.0,20.8,34.3,and 37.7 times greater,respectively,than those under control.This result was mainly attributed to a visible decrease in litter biomass after grazing,which decreased by 50.5%,72.6%,79.0%,80.0%,and 76.9%,respectively,under G1-G5 grazing intensities.By weighing the grassland productivity and soil conservation function,we found that both two aims were achieved at a low grazing intensity of less than 3.5 goats/hm2.Therefore,it is recommended that grassland should be moderately utilized with grazing intensity below 3.5 goats/hm2 in semi-arid hilly areas to achieve the dual goals of ecological and economic benefits.The results provide a scientific basis for grassland utilization and health management in semi-arid hilly areas from the perspective of determining reasonable grazing intensity to maintain both grassland production and soil conservation functions.
基金This study was supported by the Basic Research Business Fee Project of Universities Directly under the Inner Mongolia Autonomous Region(JY20220108)the Inner Mongolia Autonomous Region Natural Science Foundation Project(2022LHMS03006)+1 种基金the Inner Mongolia University of Technology Doctoral Research Initiation Fund Project(DC2300001284)the Inner Mongolia Autonomous Region Natural Science Foundation Project(2021MS03082).
文摘Grassland biomass is an important parameter of grassland ecosystems.The complexity of the grassland canopy vegetation spectrum makes the long-term assessment of grassland growth a challenge.Few studies have explored the original spectral information of typical grasslands in Inner Mongolia and examined the influence of spectral information on aboveground biomass(AGB)estimation.In order to improve the accuracy of vegetation index inversion of grassland AGB,this study combined ground and Unmanned Aerial Vehicle(UAV)remote sensing technology and screened sensitive bands through ground hyperspectral data transformation and correlation analysis.The narrow band vegetation indices were calculated,and ground and airborne hyperspectral inversion models were established.Finally,the accuracy of the model was verified.The results showed that:(1)The vegetation indices constructed based on the ASD FieldSpec 4 and the UAV were significantly correlated with the dry and fresh weight of AGB.(2)The comparison between measured R^(2) with the prediction R^(2) indicated that the accuracy of the model was the best when using the Soil-Adjusted Vegetation Index(SAVI)as the independent variable in the analysis of AGB(fresh weight/dry weight)and four narrow-band vegetation indices.The SAVI vegetation index showed better applicability for biomass monitoring in typical grassland areas of Inner Mongolia.(3)The obtained ground and airborne hyperspectral data with the optimal vegetation index suggested that the dry weight of AGB has the best fitting effect with airborne hyperspectral data,where y=17.962e^(4.672x),the fitting R^(2) was 0.542,the prediction R^(2)was 0.424,and RMSE and REE were 57.03 and 0.65,respectively.Therefore,established vegetation indices by screening sensitive bands through hyperspectral feature analysis can significantly improve the inversion accuracy of typical grassland biomass in Inner Mongolia.Compared with ground monitoring,airborne hyperspectral monitoring better reflects the inversion of actual surface biomass.It provides a reliable modeling framework for grassland AGB monitoring and scientific and technological support for grazing management.
