Nitrogen(N)is an essential nutrient for both plants and soil microbes,but it often has limited availability.Currently,little is known about the effects of different vegetation patch types on the partitioning of N betw...Nitrogen(N)is an essential nutrient for both plants and soil microbes,but it often has limited availability.Currently,little is known about the effects of different vegetation patch types on the partitioning of N between plants and soil microorganisms in grassland ecosystems.In the present study,we performed a^(15)N-labelling experiment(using^(15)N-NO_(3)^(-)and^(15)N-NH_(4)^(+))to investigate N uptake by plant biomass and microbial biomass for five common vegetation patch types in a degraded alpine steppe on the Tibetan Plateau,China.The results showed that plants and soil microorganisms in all patches showed a clear preference for the uptake of NO_(3)^(-).Plants in patches dominated by palatable species absorbed more N than plants in unpalatable species patches,while N uptake in the microbial biomass in unpalatable species patches was higher than that in palatable species patches.For the two soil depths,plants in Poa litwinowiana patches had the highest N uptake(NO_(3)^(-):13.32-51.28 mg m^(-2);NH_(4)^(+):0.35-1.36 mg m^(-2)),whereas microbial biomass in Oxytropis glacialis patches had the highest N uptake(NO_(3)^(-):846.97-1,659.87 mg m^(-2);NH_(4)^(+):108.75-185.14 mg m^(-2))among the five vegetation patch types.For both forms of N,soil microorganisms acquired relatively more N than the plants in the five vegetation patch types(i.e.,the ratio of microbial biomass N uptake to plant biomass N uptake was greater than 1).The N-absorbing capacity of plants decreased,whereas the capacity of soil microorganisms to take up N increased with the degradation of vegetation patches.Microorganisms that compete more strongly for N might reduce the uptake of nutrients by plants in degraded patches,which would not be conducive to the restoration of vegetation in N-limited alpine grasslands.展开更多
The temporal dynamics of the biomass, as well as the carbon （C）, nitrogen （N）, phosphorus （P） concentrations and accumulation contents, in above- and below-ground vegetation components were determined in the alp...The temporal dynamics of the biomass, as well as the carbon （C）, nitrogen （N）, phosphorus （P） concentrations and accumulation contents, in above- and below-ground vegetation components were determined in the alpine steppe vegetation of Northern Tibet during the growing season of 2OLO. The highest levels of total biomass （311.68 g m-2）, total C （115.95 g m-2）, total N （2.60 g m-2）, and total P （0.90 g m-2） accumulation contents were obtained in August in 2010. Further, biomass and nutrient stocks in the below-ground components were higher than those of the above-ground components. The dominant species viz., Stipa purpurea and Carex moorcrofli had lower biomass and C, N, P accumulations than the companion species which including Oxytropis. spp., Artemisia capillaris Thunb., Aster tataricus L., and SO on.展开更多
The study of peach fruit quality and biochemical composition of cultivars and hybrids were conducted in terms of the steppe zone of Crimea. A total of 40 cultivars and hybrids from five periods of ripening were analyz...The study of peach fruit quality and biochemical composition of cultivars and hybrids were conducted in terms of the steppe zone of Crimea. A total of 40 cultivars and hybrids from five periods of ripening were analyzed for content of basic biochemical components： solids, sugars, acids, polyphenolic compounds and vitamin C. The main fruit quality parameters： the size, the attractive appearance, the consistency flesh, the stone adherence to flesh, taste and others have been evaluated. As a result of studies peach cultivars with a high content of sugar in the fruit under the steppe Crimea have highlighted： Kremlyovskiy （13.6）, Regina （13.2）, Velvet （12.9）, hybrids C7/38 （13.1） and C4/57 （12.9）. Cultivars and hybrids of peach 10607, C1/227 C7/38, C7/6, C8/162, C4/147, C16/87, C4/64, Early Red Haven, Miorita, 7/221, Kremlyovskiy, 10848 are characterized by the best biochemical and morphological indices of fruits. They are recommended for State cultivar testing or use in breeding work to improve the quality of peach fruits.展开更多
Yak(Bos grunniens)and Tibetan sheep urine deposited onto the alpine grasslands of the Qinghai-Tibetan Plateau is an important pathway for nutrient return,and it is closely related to soil fertility and alpine grasslan...Yak(Bos grunniens)and Tibetan sheep urine deposited onto the alpine grasslands of the Qinghai-Tibetan Plateau is an important pathway for nutrient return,and it is closely related to soil fertility and alpine grassland productivity.However,hitherto,few studies have reported the effects of yak and Tibetan sheep urine deposition on soil carbon(C)and nitrogen(N)concentrations and the possible functional mechanisms under field conditions in alpine grasslands.To explore the status of soil C and N responding to the immediate N addition from livestock urine,we conducted a 28-d field experiment with three treatments,which include the application of yak urine(YU)and Tibetan sheep urine(TSU)application,and the control(CK,no application of urine).The results showed that YU treatment increased the soil moisture content and p H at 0-10 cm across the 28-day experimental period.Urine application resulted in the fluctuation of soil organic C(SOC)and increased topsoil SOC concentration during the middle and later periods of the experiment.Application of YU evidently increased the soil total N(TN)concentration in the 0-10 cm layer,while it did not affect the SOC concentrations in the 10-20 and 20-30 cm layers.Compared with the control,YU treatment significantly(P<0.05)increased the 0-10 and 10-20 cm soil ammonium-N(NH;-N)concentration throughout the 28 days,while the TSU treatment significantly(P<0.05)increased the 0-10 and 10-20 cm soil nitrate-N(NO;-N)concentration.Urine N input changed soil physicochemical properties,nitrification,denitrification,and N leaching processes,and therefore affected the availability of N accumulation and consumption in soil.Under these conditions,the trade-off between soil NH;-N and NO;-N under the influence of yak and Tibetan sheep urine application would change the form and concentration of available N,thereby altering the plant N uptake and utilization strategy of alpine grassland.The conclusions of this study could provide theoretical references for exploring the change characteristics of soil nutrient under the deposition of urine and optimizing the management strategies of livestock urine in the alpine grassland ecosystem.展开更多
Over the past 160 years,shrubs have expanded globally,significantly altering native ecosystem structures,functions,and services.However,a comprehensive bibliometric perspective on shrub encroachment remains underdevel...Over the past 160 years,shrubs have expanded globally,significantly altering native ecosystem structures,functions,and services.However,a comprehensive bibliometric perspective on shrub encroachment remains underdeveloped,and a holistic research framework is lacking to understand the evolution,current state,and emerging research frontiers.To address this,we conducted a bibliometric analysis and literature review using the R software package,based on the Web of Science Core Collection citation database.Keyword analysis revealed that research has focused on various grassland types,soil nutrients,climate change,and plant communities.Thematic mapping identified key themes,including influencing factors,feedback mechanisms,invasion processes,ecological consequences,shrub management,and quantitative monitoring.Basic themes encompass shrub encroachment,dynamics,fire,grazing,and climate change while emerging themes include decomposition,microbial biomass,and ecosystem function.We synthesized eight key factors driving shrub encroachment:atmospheric CO_(2)concentration,global warming,changes in rainfall patterns,atmospheric nitrogen deposition,topography,soils,herbivory,fire suppression,and land use change.The feedback mechanisms of shrub encroachment,driven by exogenous and maintained by endogenous factors,were categorized into three stages:seed dispersal,colonizing and establishment,and diffusion.Shrub encroachment also impacts ecosystem services,including provisioning(e.g.,forage productivity),regulating(e.g.,hydrological regulation),and supporting(e.g.,carbon sequestration and biodiversity).We also summarized four main approaches to shrub management:burning,biological,chemical,and physical removal.The connections between the ecosystem services affected by shrub encroachment and the United Nations Sustainable Development Goals(SDGs)were highlighted to achieve synergies across multiple objectives.We emphasize the importance of quantification and monitoring in understanding the causes,consequences,and management of shrub encroachment.We advocate for long-term,location-based,and globally networked experiments and recommend the integration of new technologies,such as LiDAR,drones,and artificial intelligence,into shrub encroachment research.In conclusion,our study provides a comprehensive dataset and research framework for scholars studying shrub encroachment,aiming to deepen our understanding of this ecological process.展开更多
Subtropical evergreen sub-montane forests in Punjab,Pakistan,are vital for carbon sequestration and play an essential role in supporting local communities.While the global importance of tree species diversity in enhan...Subtropical evergreen sub-montane forests in Punjab,Pakistan,are vital for carbon sequestration and play an essential role in supporting local communities.While the global importance of tree species diversity in enhancing aboveground carbon(AGC)storage is well established,there remains limited empirical evidence from Pakistan’s forest ecosystems.This study investigated how taxonomic and functional diversity,alongside topographical variables,influence AGC across four districts in Punjab.Taxonomic metrics such as the Importance Value Index(IVI)and genus richness were computed,along with functional diversity indices including functional richness(FRic),functional dispersion(FDis),functional divergence(FDiv),and functional evenness(FEve).AGC was estimated using species-specific allometric equations,and linear mixed-effects models were applied to identify the most influential predictors.Acacia modesta and A.nilotica emerged as the dominant species in the studied sites.While species richness and biomass increased with elevation,Shannon diversity showed a negative relationship with elevation.AGC values ranged from 100 to 350 Mg ha⁻¹across the study sites.Among diversity metrics,FRic(0.042)and FDis(0.342)were significantly associated with higher AGC,whereas taxonomic diversity measures showed weaker correlations.Although elevation was a strong predictor of diversity patterns,it did not have a significant direct effect on carbon storage.These findings underscore the importance of incorporating functional trait diversity and topographic variability into forest management strategies to enhance carbon sequestration,strengthen ecosystem resilience and support sustainable rural livelihoods.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program,China(2019QZKK0404)the National Natural Science Foundation of China(42271070)+1 种基金the West Light Scholar of Chinese Academy of Sciences(xbzg-zdsys-202202)the Technology Major Project of Tibetan Autonomous Region of China(XZ202201ZD0005G01)。
文摘Nitrogen(N)is an essential nutrient for both plants and soil microbes,but it often has limited availability.Currently,little is known about the effects of different vegetation patch types on the partitioning of N between plants and soil microorganisms in grassland ecosystems.In the present study,we performed a^(15)N-labelling experiment(using^(15)N-NO_(3)^(-)and^(15)N-NH_(4)^(+))to investigate N uptake by plant biomass and microbial biomass for five common vegetation patch types in a degraded alpine steppe on the Tibetan Plateau,China.The results showed that plants and soil microorganisms in all patches showed a clear preference for the uptake of NO_(3)^(-).Plants in patches dominated by palatable species absorbed more N than plants in unpalatable species patches,while N uptake in the microbial biomass in unpalatable species patches was higher than that in palatable species patches.For the two soil depths,plants in Poa litwinowiana patches had the highest N uptake(NO_(3)^(-):13.32-51.28 mg m^(-2);NH_(4)^(+):0.35-1.36 mg m^(-2)),whereas microbial biomass in Oxytropis glacialis patches had the highest N uptake(NO_(3)^(-):846.97-1,659.87 mg m^(-2);NH_(4)^(+):108.75-185.14 mg m^(-2))among the five vegetation patch types.For both forms of N,soil microorganisms acquired relatively more N than the plants in the five vegetation patch types(i.e.,the ratio of microbial biomass N uptake to plant biomass N uptake was greater than 1).The N-absorbing capacity of plants decreased,whereas the capacity of soil microorganisms to take up N increased with the degradation of vegetation patches.Microorganisms that compete more strongly for N might reduce the uptake of nutrients by plants in degraded patches,which would not be conducive to the restoration of vegetation in N-limited alpine grasslands.
基金funded by One Hundred Young Persons Project of Institute of Mountain Hazards and Environment (No.SDSQB-2010-02)the National Natural Science Foundation of China (No.41001177)Knowledge Innovation Program of the Chinese Academy of Sciences (Nos.KZCX2-YW-QN31,KZCX2-XB3-08)
文摘The temporal dynamics of the biomass, as well as the carbon （C）, nitrogen （N）, phosphorus （P） concentrations and accumulation contents, in above- and below-ground vegetation components were determined in the alpine steppe vegetation of Northern Tibet during the growing season of 2OLO. The highest levels of total biomass （311.68 g m-2）, total C （115.95 g m-2）, total N （2.60 g m-2）, and total P （0.90 g m-2） accumulation contents were obtained in August in 2010. Further, biomass and nutrient stocks in the below-ground components were higher than those of the above-ground components. The dominant species viz., Stipa purpurea and Carex moorcrofli had lower biomass and C, N, P accumulations than the companion species which including Oxytropis. spp., Artemisia capillaris Thunb., Aster tataricus L., and SO on.
基金This study was funded by the research grant No. 14-50-00079 of the Russian Science Foundation.
文摘The study of peach fruit quality and biochemical composition of cultivars and hybrids were conducted in terms of the steppe zone of Crimea. A total of 40 cultivars and hybrids from five periods of ripening were analyzed for content of basic biochemical components： solids, sugars, acids, polyphenolic compounds and vitamin C. The main fruit quality parameters： the size, the attractive appearance, the consistency flesh, the stone adherence to flesh, taste and others have been evaluated. As a result of studies peach cultivars with a high content of sugar in the fruit under the steppe Crimea have highlighted： Kremlyovskiy （13.6）, Regina （13.2）, Velvet （12.9）, hybrids C7/38 （13.1） and C4/57 （12.9）. Cultivars and hybrids of peach 10607, C1/227 C7/38, C7/6, C8/162, C4/147, C16/87, C4/64, Early Red Haven, Miorita, 7/221, Kremlyovskiy, 10848 are characterized by the best biochemical and morphological indices of fruits. They are recommended for State cultivar testing or use in breeding work to improve the quality of peach fruits.
基金supported by the National Natural Science Foundation of China(Grant NO.41807109)the Second Tibetan Plateau Scientific Expedition and Research Program(Grant NO.2019QZKK0404)the doctoral research launch fund project and National general cultivation project of China West Normal University(Grant NO.17E042,18B016)。
文摘Yak(Bos grunniens)and Tibetan sheep urine deposited onto the alpine grasslands of the Qinghai-Tibetan Plateau is an important pathway for nutrient return,and it is closely related to soil fertility and alpine grassland productivity.However,hitherto,few studies have reported the effects of yak and Tibetan sheep urine deposition on soil carbon(C)and nitrogen(N)concentrations and the possible functional mechanisms under field conditions in alpine grasslands.To explore the status of soil C and N responding to the immediate N addition from livestock urine,we conducted a 28-d field experiment with three treatments,which include the application of yak urine(YU)and Tibetan sheep urine(TSU)application,and the control(CK,no application of urine).The results showed that YU treatment increased the soil moisture content and p H at 0-10 cm across the 28-day experimental period.Urine application resulted in the fluctuation of soil organic C(SOC)and increased topsoil SOC concentration during the middle and later periods of the experiment.Application of YU evidently increased the soil total N(TN)concentration in the 0-10 cm layer,while it did not affect the SOC concentrations in the 10-20 and 20-30 cm layers.Compared with the control,YU treatment significantly(P<0.05)increased the 0-10 and 10-20 cm soil ammonium-N(NH;-N)concentration throughout the 28 days,while the TSU treatment significantly(P<0.05)increased the 0-10 and 10-20 cm soil nitrate-N(NO;-N)concentration.Urine N input changed soil physicochemical properties,nitrification,denitrification,and N leaching processes,and therefore affected the availability of N accumulation and consumption in soil.Under these conditions,the trade-off between soil NH;-N and NO;-N under the influence of yak and Tibetan sheep urine application would change the form and concentration of available N,thereby altering the plant N uptake and utilization strategy of alpine grassland.The conclusions of this study could provide theoretical references for exploring the change characteristics of soil nutrient under the deposition of urine and optimizing the management strategies of livestock urine in the alpine grassland ecosystem.
基金supported by the National Natural Science Foundation of China(32401433)National Key Research and Development Program of China(2023YFD1501001)+2 种基金the Natural Science Foundation of Ningxia(2024AAC03127)the Postdoctoral Fellowship Program of CPSF(GZC20232621)the Ningxia Higher Education Institutions First-Class Discipline Construction Project(NXYLXK2017A01).
文摘Over the past 160 years,shrubs have expanded globally,significantly altering native ecosystem structures,functions,and services.However,a comprehensive bibliometric perspective on shrub encroachment remains underdeveloped,and a holistic research framework is lacking to understand the evolution,current state,and emerging research frontiers.To address this,we conducted a bibliometric analysis and literature review using the R software package,based on the Web of Science Core Collection citation database.Keyword analysis revealed that research has focused on various grassland types,soil nutrients,climate change,and plant communities.Thematic mapping identified key themes,including influencing factors,feedback mechanisms,invasion processes,ecological consequences,shrub management,and quantitative monitoring.Basic themes encompass shrub encroachment,dynamics,fire,grazing,and climate change while emerging themes include decomposition,microbial biomass,and ecosystem function.We synthesized eight key factors driving shrub encroachment:atmospheric CO_(2)concentration,global warming,changes in rainfall patterns,atmospheric nitrogen deposition,topography,soils,herbivory,fire suppression,and land use change.The feedback mechanisms of shrub encroachment,driven by exogenous and maintained by endogenous factors,were categorized into three stages:seed dispersal,colonizing and establishment,and diffusion.Shrub encroachment also impacts ecosystem services,including provisioning(e.g.,forage productivity),regulating(e.g.,hydrological regulation),and supporting(e.g.,carbon sequestration and biodiversity).We also summarized four main approaches to shrub management:burning,biological,chemical,and physical removal.The connections between the ecosystem services affected by shrub encroachment and the United Nations Sustainable Development Goals(SDGs)were highlighted to achieve synergies across multiple objectives.We emphasize the importance of quantification and monitoring in understanding the causes,consequences,and management of shrub encroachment.We advocate for long-term,location-based,and globally networked experiments and recommend the integration of new technologies,such as LiDAR,drones,and artificial intelligence,into shrub encroachment research.In conclusion,our study provides a comprehensive dataset and research framework for scholars studying shrub encroachment,aiming to deepen our understanding of this ecological process.
文摘Subtropical evergreen sub-montane forests in Punjab,Pakistan,are vital for carbon sequestration and play an essential role in supporting local communities.While the global importance of tree species diversity in enhancing aboveground carbon(AGC)storage is well established,there remains limited empirical evidence from Pakistan’s forest ecosystems.This study investigated how taxonomic and functional diversity,alongside topographical variables,influence AGC across four districts in Punjab.Taxonomic metrics such as the Importance Value Index(IVI)and genus richness were computed,along with functional diversity indices including functional richness(FRic),functional dispersion(FDis),functional divergence(FDiv),and functional evenness(FEve).AGC was estimated using species-specific allometric equations,and linear mixed-effects models were applied to identify the most influential predictors.Acacia modesta and A.nilotica emerged as the dominant species in the studied sites.While species richness and biomass increased with elevation,Shannon diversity showed a negative relationship with elevation.AGC values ranged from 100 to 350 Mg ha⁻¹across the study sites.Among diversity metrics,FRic(0.042)and FDis(0.342)were significantly associated with higher AGC,whereas taxonomic diversity measures showed weaker correlations.Although elevation was a strong predictor of diversity patterns,it did not have a significant direct effect on carbon storage.These findings underscore the importance of incorporating functional trait diversity and topographic variability into forest management strategies to enhance carbon sequestration,strengthen ecosystem resilience and support sustainable rural livelihoods.
