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| 1 | 草原群落蒸发蒸腾的研究显示文摘在中国科学院内蒙古草原生态系统定位研究站,采用“土柱称重法”对典型草原群落蒸发蒸腾进行实验观测,主要研究结果如下:(1)土壤因子的影响:(a)在通常情况下,草原群落蒸发、蒸腾及蒸散均随土壤水分增加而增大;当土壤水分过多时,群落蒸腾由于植物受涝而降低。(b)在低土壤含水量条件下,群落蒸发随土壤粘粒含量增加呈线性降低;在高土壤含水量条件下,群落蒸发随土壤粘粒含量增加而升高。(c)不同土壤含水量的群落蒸发,均随土壤坚实度增大升高,并先后达最高值。土壤含水量愈低,蒸发达最高值愈滞后。(2)放牧因素的影响:群落蒸腾与牧压呈线性负相关;群落蒸发与牧压呈线性正相关。群落生物量随牧压增大而降低是导致群落蒸发和蒸腾与牧压呈正、负相关的主要原因。(3)退化群落及其恢复群落的蒸发蒸腾:群落退化导致群落蒸发升高,蒸腾降低;相应的群落恢复导致群落蒸发降低,蒸腾升高。在一定程度上,群落退化及其恢复演替虽然能明显改变群落T/E值,但却不会引起群落蒸散值的明显变化。(4)草原沙地、羊草草原和河漫滩草甸是本地区差异明显的三种群落。草甸蒸腾最大(92mm/d),比另两种群落高2~3倍;草甸蒸发最小(04mm/d),约为沙地的1/4,草原的? | 宋炳煜 | 1997 | 气候与环境研究1997，0，3： | 15 |
| 2 | Spatial-temporal variation in soil respiration and its controlling factors in three steppes of Stipa L. in Inner Mongolia, China显示文摘Grassland is the largest terrestrial ecosystem in China. It is of great significance to measure accurately the soil respiration of different grassland types for the contribution evaluation of the Chinese terrestrial ecosystem’s carbon emission to the atmospheric CO2 concentration. A three-year (2005-2007) field experiment was carried out on three steppes of Stipa L. in the Xilin River Basin, Inner Mongolia, China, using a static opaque chamber technique. The seasonal and interannual variations of soil respiration rates were analyzed, and the annual total soil respiration of the three steppes was estimated. The numerical models between soil respiration and water-heat factors were established respectively. Similar seasonal dynamic and high annual and interannual variations of soil respiration were found in all of the three steppes. In the growing season, the fluctuation of soil respiration was particularly evident. The coefficients of variation (CVs) for soil respiration in different growing seasons ranged from 54% to 93%, and the annual CVs were all above 115%. The interannual CV of soil respiration progressively decreased in the order of Stipa grandis (S. grandis) steppe > Stipa baicalensis (S. baicalensis) steppe > Stipa krylovii (S. krylovii) steppe. The annual total soil respiration for the S. baicalensis steppe was 223.62?299.24 gC m-2 a-1, 150.62-226.99 gC m-2 a-1 for the S. grandis steppe, and 111.31–131.55 gC m-2 a-1 for the S. krylovii steppe, which were consistent with the precipitation gradient. The variation in the best fitting temperature factor explained the 63.5%, 73.0%, and 73.2% change in soil respiration in the three steppes at an annual time scale, and the corresponding Q10 values were 2.16, 2.98, and 2.40, respectively. Moreover, the Q10 values that were calculated by soil temperature at different depths all expressed a 10 cm > 5 cm > surface in the three sampling sites. In the growing season, the soil respiration rates were related mostly to the surface soil moisture, and the 95.2%, 97.4%, and 93.2% variations in soil respiration in the three steppes were explained by the change in soil moisture at a depth of 0-10 cm, respectively. | QI YuChun DONG YunShe LIU LiXin LIU XingRen PENG Qin XIAO ShengSheng HE YaTing | 2010 | Science China Earth Sciences2010，53，5： | 12 |
| 3 | Daily variation characteristics of CO2 emission fluxes and contributions of environmental factors in semiarid grassland of Inner Mongolia, China显示文摘Fixed field experimental studies are carried out on daily variations of the undis- turbed community and soil respiration fluxes in different phenological phases of 2001―2002 in semiarid Aneurolepidium chinense steppe of Inner Mongolia, China using static black chamber method. Corresponding statistical analysis of the contributions of the water-heat factors (air temperature, ground temperature, surface soil water content) and ecological factors (above- ground biomass, underground biomass, litter biomass) to daily variation law of the undisturbed community and soil respiration fluxes as well as differences in daily respiration are also con- ducted. The results indicate that undisturbed community and soil respiration have apparent daily variation laws, daily variation patterns of respiration fluxes during different phenological phases are basically the same, and the variations of environmental factors only exert effect on CO2 emission intensities, while the effect on daily variation pattern of grassland CO2 emission fluxes is relatively small. The daily total respiration of the undisturbed community in different phenological phases ranges from 1.34―10.13 g·m?2; soil daily total respiration ranges from 0.98―5.17 g·m?2; both daily variations of undisturbed community and soil respiration fluxes are significantly corre- lated (p < 0.05) or extremely significantly correlated (p < 0.01) with air temperatures and ground surface temperatures, but the correlativity with the soil temperature at 5 and 10 cm depths is relatively weak; multiple regression analysis indicates that about 80% of the difference in daily respiration of the undisturbed community among different phenological phases is induced by the variation of the aboveground biomass, while the variations of the remaining factors can jointly explain around 20% of the daily respiration variations of the whole grassland ecosystem; about 83% of the soil daily respiration variation of the different phenological phases is caused by 0―20 cm underground biomass. Besides, surface soil water content is also an important environmental factor affecting soil daily respiration variations of the Aneurolepidium chinense steppe, but its partial correlation coefficient with soil daily respiration amount does not reach the significance level of 0.05. | QI Yuchun DONG Yunshe LIU Jiyuan GENG Yuanbo LI Mingfeng YANG Xiaohong LIU Lixin | 2005 | Science China Earth Sciences2005，48，7： | 11 |
| 4 | C:N:P stoichiometry of perennial herbs’ organs in the alpine steppe of the northern Tibetan Plateau显示文摘The patterns of C:N:P stoichiometry across ecosystems are important in understanding biogeochemical processes. The stoichiometry of nutrients at the leaf and root level have been reported previously, but relationships of other plant organs, such as stems and the reproductive organs, remain unclear. We collected 228 samples of leaves, roots, stems and reproductive organs from 11 common plant species at 25 sites on the Tibetan Plateau to explore the relationships of C:N:P stoichiometry both within and across plant organs. The average C concentrations in the roots, leaves, stems and reproductive organs were 427.32, 410.51, 421.11 and 416.72 mg g-1, respectively. The shoot tissues(leaves, stems and reproductive organs) had significantly higher N and P concentrations than the roots. The N and P concentrations had a significant positive correlation within the same organ. The nutrient concentrations(N and P) and nutrient ratios(C:N, C:P and N:P) were significantly correlated across all pairwise organ combinations. Our data suggest that alpine perennial herbs share similar evolutionary histories and have constrained patterns of covariation for C concentrations, with differential patterns for N and P stoichiometry across organs. Our data also indicate that covarying sets of nutrient traits are consistent across environments and biogeographical regions and demonstrate convergent evolution in plant nutritional characteristics in extreme alpine environments. | MA Xing-xing HONG Jiang-tao WANG Xiao-dan | 2019 | Journal of Mountain Science2019，16，9： | 8 |
| 5 | Degradation induces changes in the soil C:N:P stoichiometry of alpine steppe on the Tibetan Plateau显示文摘Due to the Tibetan Plateau’s unique high altitude and low temperature climate conditions,the region’s alpine steppe ecosystem is highly fragile and is suffering from severe degradation under the stress of increasing population,overgrazing,and climate change.The soil stoichiometry,a crucial part of ecological stoichiometry,provides a fundamental approach for understanding ecosystem processes by examining the relative proportions and balance of the three elements.Understanding the impact of degradation on the soil stoichiometry is vital for conservation and management in the alpine steppe on the Tibetan Plateau.This study aims to examine the response of soil stoichiometry to degradation and explore the underlying biotic and abiotic mechanisms in the alpine steppe.We conducted a field survey in a sequent degraded alpine steppe with seven levels inNorthern Tibet.The plant species,aboveground biomass,and physical and chemical soil properties such as the moisture content,temperature,pH,compactness,total carbon(C),total nitrogen(N),and total phosphorus(P)were measured and recorded.The results showed that the contents of soil C/N,C/P,and N/P consistently decreased along intensifying degradation gradients.Using regression analysis and a structural equation model(SEM),we found that the C/N,C/P,and N/P ratios were positively affected by the soil compactness,soil moisture content and species richness of graminoids but negatively affected by soil pH and the proportion of aboveground biomass of forbs.The soil temperature had a negative effect on the C/N ratio but showed positive effect on the C/P and N/P ratios.The current study shows that degradation-induced changes in abiotic and biotic conditions such as soil warming and drying,which accelerated the soil organic carbon mineralization,as well as the increase in the proportion of forbs,whichwere difficult to decompose and input less organic carbon into soil,resulted in the decreases in soil C/N,C/P,and N/P contents to a great extent.Our results provide a sound basis for sustainable conservation and management of the alpine steppe. | ZHANG Zhen-chao HOU Ge LIU Miao WEI Tian-xing SUN Jian | 2019 | Journal of Mountain Science2019，16，10： | 7 |
| 6 | 草原红牛转铁蛋白和后转铁蛋白多态性及其与生产性能相关性研究(英文)显示文摘[Objective] The aim of this study was to investigate the correlation between blood protein polymorphism of red steppe and its performance.[Method]Two blood protein polymorphic loci were detected in transferring(Tf)and posttremsferr(Ptf)from thirteen red steppes and eighteen hybrid of limousin and red steppe by polyacrylamide gel electrophoresis.[Result]Tf and Ptf were controlled by three and two alleles respectively.[Conclusion]The variance analysis of blood protein polymorphic loci and its performance indicates that two protein loci have a positive or negative correlation with some traits of red steppe and the improved limousin cattle population. | 张永宏 潘英树 高妍 马倩 刘同欣 秦莹 赵志辉 张嘉保 | 2008 | Agricultural Science & Technology2008，9，5： | 6 |
| 7 | Grassland ecology in China: perspectives and challenges显示文摘During the last few decades, there have been an increasing number of studies on grassland ecology in China, involving the classic ecology concepts or theories and the applicable ecological principles of grassland conservation or management. This paper reviews the main progress in the following aspects.(1) Research on grassland species adaptation and resistance, population dynamics and foraging behavior, and biodiversity and community stability.(2) Research on managed grassland ecosystems(grassland grazing ecology) including grazing effects on grassland ecosystem function and foraging behavior by large herbivores.(3) Global climate change and grassland processes and functioning.(4) Applied research on grassland restoration and ecosystem health assessments such as vegetation restoration, restoration of ecosystem functioning, and assessment methods. There have been significant advances in grassland ecology,including the functions of ecosystem biodiversity, the ecological stoichiometry mechanisms affecting grassland community stability, grazing regulation of plant diversity and nutrient cycling. Grassland ecologists have succeeded in making these advances through observational, experimental and theoretical studies. Nevertheless, there are still significant challenges for the grassland ecology research,including understanding of grassland spatial processes,grassland grazing and multi-functionality, integrated effects of global climate change across grassland areas,as well as the ecological methodology and experimental techniques in grassland ecology. | Deli WANG Ling WANG Jushan LIU Hui ZHU Zhiwei ZHONG | 2018 | Frontiers of Agricultural Science and Engineering2018，5，1： | 6 |
| 8 | Characteristics of ^(137)Cs deposition in steppe area显示文摘Soil wind erosion in the semiarid steppe area was studied using the 137Cs tracing technique. Comparisons of 137Cs deposition characteristics between different soil profiles indicated that slight aeolian activities occurred on sandy grasslands and semi-fixed dunes with erosion/deposition rates of less than 0.108 cm/a, whereas they were intense on semi-shifting dunes with erosion/deposition rates of higher than 1.35 cm/a. | ZHANG Chunlai, ZOU Xueyong,DONG Guangrong, ZHANG Xinbao & QIN ZhiLaboratory of Blown Sand Physics and Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China China Center of D | 2002 | Chinese Science Bulletin2002，47，10： | 5 |
| 9 | Changes in plant species composition and diversity of alpine Kobresia (Kobresia pygmaea) steppe meadow at different stages of desertification in the North Tibetan plateau显示文摘The impacts of desertification on the vegetation composition, structure, and species diversity of alpine Kobresia steppe meadow were evaluated in an area of severe desertification in Anduo County, Tibet Autonomous Region, northern China. We investigated and analyzed the floristic features of communities at four different stages of desertification (slight desertification [SLD], moderate desertification [MD], severe desertification [SD], and very severe desertification [VSD]). The composition and structure of the alpine Kobresia steppe meadow at the SLD site differed significantly from that at the MD, SD, and VSD sites. Species that were more drought resistant and inedible by livestock were the dominant species at the SD site. No plants were found in the shifting dunes of the VSD site. Species diversity also decreased with increasing desertification. The SLD site had the largest mean number of species and individuals and the largest richness index; the MD grassland had the largest Shannon-Wiener index and evenness index, but the smallest Simpson's index. The vegetation cover declined from 91.8% to 34.8% as desertification increased from SLD to SD, and reached 0% in VSD areas with shifting dunes. | XingHu Wei 1*, Ping Yang 2, Sen Li 1, YuXiang Dong 3, ChunLai Zhang 41. Department of Resources and Environmental of Foshan University, Foshan, Guangdong 528000, China.2. Resources and Environmental Bureau , Chinese Academy of Science, Lanzhou, Gansu 730000, China. 3. Department of Geography of Zhongshan University, Guangzhou, Guangdong 510275, China. 4. Beijing Normal University, Beijing 100875, China. | 2009 | Research in Cold and Arid Regions2009，1，1： | 3 |
| 10 | Plant diversity-productivity patterns in the alpine steppe environment of the Central Tianshan Mountains显示文摘The biodiversity-productivity relationship is an important topic in the research of bio- diversity and ecosystem function. The plant diversity-productivity pattern is commonly unimodal and positively correlated. This paper researches the characteristics of plant diversity-productivity patterns in the Bayanbuluk alpine steppe in the central Tianshan Mountains, Xinjiang, China, and analyzes the effects of environmental factors on the distribution of plant communities, species composition, plant diversity and productivity in the steppe. The results show a positive correlation between plant diversity and productivity. DCCA (detrended canonical correspondence analysis) ordination reveals a significant relationship between the effects of air temperature, soil moisture content, available soil nitrogen, relative humidity and pH value on the distribution and composition of plant communities. There are significant correlations between the soil moisture content, relative humidity, pH value, air temperature and species richness and the aboveground biomass of Gramineae and Cyperaceae, and also significant correlations between the relative humidity, pH values and the total aboveground biomass of plant communities. | Hu, YuKun Li, KaiHui Gong, YanMing Yin, Wei | 2009 | Journal of Arid Land2009，1，1： | 3 |
| 11 | Trait complementarity between fine roots of Stipa purpurea and their associated arbuscular mycorrhizal fungi along a precipitation gradient in Tibetan alpine steppe显示文摘Development of fine roots and formation of symbiosis with arbuscular mycorrhizal(AM) fungi represent two strategies for plants to acquire nutrient and water from soil. Here, we elucidated how fine root development and symbolized mycorrhizal fungi with Stipa purpurea responded to the precipitation change in Tibetan alpine steppe ecosystem across a precipitation gradient from 50 mm to 400 mm. As precipitation increased, the proportion of thinner fine roots(diameter < 0.4 mm) in total roots increased significantly; while the mycorrhizal colonization percentage, either associated with thinner or thicker roots, decreased. This phenomenon indicated that fine root development and symbolized mycorrhizal fungi are likely alternative, and plant preferred to develop fine root rather than build a symbiotic relationship with mycorrhizal fungi in more benign niches with higher precipitation. Also, root diameter was negatively correlated with specific root length(SRL), but positively correlated with AM fungal colonization percentage, indicating thicker-root species rely more on mycorrhizal fungi in alpine steppe. The complementarity between fine root and mycorrhizal fungi of S. purpurea is mediated by precipitation in Tibetan alpine steppe. | ZHANG Jing WANG Ping XUE Ka HAO Yan-bin WANG Yan-fen CUI Xiao-yong | 2019 | Journal of Mountain Science2019，16，3： | 2 |
| 12 | CH_4 uptake flux of Leymus chinensis steppe during rapid growth season in Inner Mongolia,China显示文摘The influence of near ground atmosphere CH4 concentration, soil water content, soil Eh, plants, soil temperature, and pH on CH4 uptake flux of Leymus chinensis steppe during rapid growth season was studied using field in-situ measurement in Xilin River basin of Inner Mongolia, China. The results showed that CH4 uptake flux was positively correlated with near ground atmosphere CH4 concentration and soil Eh but negatively correlated with soil water content. Precipitation may decrease the CH4 flux by increasing the soil water content. The average fluxes of three treatments during the observation period were 1.52 (natural conditions, 1.51 (aboveground plants were excluded), and 2.00 mg m?2 d?1 (all plants were removed), respectively. The difference between the CH4 flux of natural condition treatment and that of removing aboveground plants treatment is small, whereas the flux of removing all plants treatment is larger than the other two treatments. This means that the contribution of aboveground plants to CH4 uptake flux is smaller than that of roots or roots-removing process. CH4 uptake flux is not sensitive to soil temperature and the narrow-ranged soil pH (6.36–7.86). The Leymus chinensis steppe acts as a sink for CH4, and thus more studies should be focused on its affecting factors and related mechanisms. | GENG YuanBo1, LUO GuangQiang1,2 & YUAN GuoFu1 1 Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China | 2010 | Science China Earth Sciences2010，53，7： | 1 |
| 13 | Responses and sensitivity of N, P and mobile carbohydrates of dominant species to increased water, N and P availability in semi- arid grasslands in northern China显示文摘Aims We aimed to improve the understanding of the carbon and nutri-ent physiological responses and adaptation of semi-arid grassland plants to environmental changes.Methods We investigated plant leaf non-structural carbohydrate(NSC=solu-ble sugars+starch),nitrogen(N)and phosphorus(P)levels in an Inner Mongolian semi-arid grassland community treated with water,N and P additions for 8 years.Two dominant grasses(Agropyron cris-tatum(L.)Gaertn.,Stipa krylovii Roshev.)and two forbs(Artemisia frigida Willd.,Potentilla bifurca L.)were analyzed.Important Findings Water addition decreased plant leaf N and P concentrations,whereas N and P addition increased them,indicating that the semi-arid grassland studied suffers from a shortage of N and P sup-ply.Both N and P addition decreased the levels of soluble sugars,starch and thus also NSC in plant leaves,which may be attributed to(i)increased carbohydrate consumption associated with a higher growth rate,and(ii)a dilution effect of greater plant size under N and P addition.Water addition tended to increase the leaf NSC levels both in the grasses(+9.2%)and forbs(+0.6%only),which may be a result of increased photosynthesis of plants with increased water availability.Under conditions of ambient and increased water supply in the present study,N addition resulted in an N/P ratio of>16 in the grasses but a significantly lower N/P ratio of<11 in the forb species.This finding implies that growth of the two grass spe-cies will be limited mainly by P availability but the forbs will still be mainly limited by N supply if N deposition,alone or in combination with summer precipitation,continues to increase as predicted in Inner Mongolia. | Xue Wang Zhuwen Xu Caifeng Yan Wentao Luo Ruzhen Wang Xingguo Han Yong Jiang Mai-He Li | 2017 | Journal of Plant Ecology2017，10，3： | 1 |
| 14 | Snow resisting capacity of Caragana microphylla and Achnatherum splendens in a typical steppe region of Inner Mongolia,China显示文摘Snow resisting capacity of vegetation is important for secondary distribution of water resources in seasonal snow areas of grassland because it affects the regeneration,growth and nutrient circulation of vegetation in grassland.This study investigated vegetation characteristics(canopy height,canopy length and crown width)of Caragana microphylla Lam.(shrub)and Achnatherum splendens(Trin.)Nevski.(herb),and snow morphologies(snow depth,snow width and snow braid length)in a typical steppe region of Inner Mongolia,China in 2017.And the influence of vegetation characteristic on snow resisting capacity(the indices of bottom area of snow and snow volume reflect snow resisting capacity)was analyzed.The results showed that snow morphology depends on vegetation characteristics of shrub and herb.The canopy height was found to have the greatest influence on snow depth and the crown width had the greatest influence on snow width.The canopy length was found to have little influence on morphological parameters of snow.When the windward areas of C.microphylla and A.splendens were within the ranges of 0.0-0.5 m2 and 0.0-8.0 m2,respectively,the variation of snow cover was large;however,beyond these areas,the variation of snow cover became gradually stable.The potential area of snow retardation for a single plant was 1.5-2.5 m2 and the amount of snow resistance was 0.15-0.20 m3.The bottom area of snow and snow volume(i.e.,snow resisting capacity)of clumped C.microphylla and A.splendens was found to be 4 and 25 times that of individual plant,respectively.The results could provide a theoretical basis both for the estimation of snow cover and the establishment of a plant-based technical system for the control of windblown snow in the typical steppe region of Inner Mongolia. | YAN Min ZUO Hejun WANG Haibing DONG Zhi LI Gangtie | 2020 | Journal of Arid Land2020，12，2： | 1 |
| 15 | The Relationship Between Plant Community Characteristics and Soil Organic Matter Content of Sedentary Grazing Pastures in a Typical Steppe显示文摘In order to discuss the relationship between the characteristics of plant communities and the content of topsoil organic matter under the condition of two-season sedentary grazing, authors of this paper selected a Stipa krylovii steppe for research and studied the plant community characteristics and the topsoil organic matter content. The results showed that in the sedentary grazing area, the perennial plant species decreased, the annual plant species increased, and the topsoil organic matter content decreased. There were a negative correlation between plant biomass and topsoil organic matter content, and a positive correlation between total coverage and topsoil organic matter content. The change of plant community characteristics in the sedentary grazing area was related to the implementation of the system of transferring the pasture use rights to the herdsmen and controlled grazing. | SARULA SAIXIYALATU CHUN Feng ZHANG Weiqing | 2019 | Journal of Landscape Research2019，11，1： | 1 |
| 16 | Artemisia pollen-indicated steppe distribution in southern China during the Last Glacial Maximum显示文摘The Last Glacial Maximum (LGM) was the coldest period during the previous 20,000 years.There have been different points of views on steppe distribution during the LGM period in southern China,partly due to the different interpretations of Artemisia occurrences.To make a reliable interpretation of the pollen fossil Artemisia,the modern distribution of Artemisia species and the relationship of pollen with climate and vegetation over a large spatial scale in China was thoroughly analyzed.Information about Artemisia species and pollen distributions used in this paper were collected from published works completed by other researchers as well as ourselves.The southern limit of steppe vegetation during the LGM period was interpreted from the published contour map of Artemisia pollen percentages during the LGM.Artemisia species in China are mostly distributed either in the horizontally distributed steppe regions or in the vertically distributed desert-steppe in the desert region,which indicates a cold and dry climate.The steppe is a distribution center of Artemisia pollen.Fractions of Artemisia in surface pollen assemblages are lower in both the desert and the temperate forest.Neither high Artemisia species cover nor high percentages of Artemisia pollen were found in the coast areas of China.Twenty-five percent of Artemisia pollen in sediments might indicate a local occurrence of steppe vegetation.Percentages of Artemisia pollen in the subtropical and tropical forest are less than 10%.A close relationship between Artemisia pollen and temperate steppe in China is demonstrated.The southern edge of the steppe vegetation during the LGM might be along the middle reach of the Yangtze River.Our results support the hypothesis that the isolated high fraction of Artemisia pollen along the northern edge of the South China Sea was transported from a large source area. | Liu Hongyan Liu Kan Wei Fangling | 2013 | Journal of Palaeogeography2013，2，3： | 0 |
| 17 | SOME APPROACHES FOR STUDYING THE INTENSITY OF SMALL RIVER AGGRADATION显示文摘SOMEAPPROACHESFORSTUDYINGTHEINTENSITYOFSMALLRIVERAGGRADATIONV.N.Golosov(LaboratoryofSoilandFluvialProcesses,FacultyofGeograph... | V.N.Golosov( Faculty of Geography,Moscow State University,Moscow,Russia,1198899) | 1996 | International Journal of Sediment Research1996，11，2： | 0 |
| 18 | Autumn nitrogen enrichment destabilizes ecosystem biomass production in a semiarid grassland显示文摘Nitrogen(N)deposition decreases the temporal stability of ecosystem aboveground biomass production(ecosystem stability).However,little is known about how the responses of ecosystem stability differ based on seasonal N enrichment.By adding N in autumn,winter,or growing season,from October 2014 to May 2020,in a temperate grassland in northern China,we found that only N addition in autumn resulted in a significantly positive correlation between ecosystem mean aboveground net primary productivity(ANPP)and its standard deviation and significantly reduced ecosystem stability.Autumn N-induced reduction in ecosystem stability was associated with the vanished negative effect of community-wide species asynchrony(asynchronous dynamics among populations to environmental perturbations)on the standard deviation of ecosystem ANPP in combination with the emerged positive effect of dominance(Simpson's dominance index that indicates the relative weight of dominant species in a community).Our findings indicate that autumn N addition might overestimate the negative effect of annual atmospheric N deposition on ecosystem stability,suggesting that to better evaluate the influence of N deposition in temperate grasslands,both field experiments and global modeling should consider not only the annual N load but also its seasonal dynamics.Moreover,further studies should pay more attention to the alteration in the ecosystem temporal deviations,which might be more sensitive to human-induced environmental changes. | Yuqiu Zhang Zhengru Ren Haining Lu Xu Chen Ruoxuan Liu Yunhai Zhang | 2023 | Fundamental Research2023，3，2： | 0 |
| 19 | Effects of Main Climatic Factors on Plant Community Characteristics of a Meadow Steppe Under Different Grazing Intensities显示文摘This experiment studies the influence of main climatic factors on the structure of grassland plant community under different grazing intensities, determines the influence of climatic factors on the quantitative characteristics of meadow steppe community structure changes, and explores the response and adaptation of meadow steppe biodiversity and ecosystem functions to climate changes, so as to provide a reference and basis for rational utilization and management of natural grassland and prediction of development trend of meadow steppe under global climate changes. The results showed that the correlations between grassland community characteristic index and different climatic factors were significantly different under different grazing intensities. The average temperature and annual precipitation in the critical period were the main climatic factors affecting the changes in meadow steppe community characteristics, and the sensitivity of community indexes to the changes in average temperature of the critical period was greater than that to the changes in annual precipitation. The aboveground biomass of zero grazing and moderate grading was positively correlated with the average temperature and annual precipitation during the critical period, and the correlations between aboveground biomass and environmental factors were no significant under heavy grazing. | ZHAO Jianguo LIU Cunqi LI Hongbo LUO Ning MENG Shujin ZHANG Zhihui WANG Jianghua | 2019 | Journal of Landscape Research2019，11，2： | 0 |
| 20 | Wind farm potential is higher in prime habitat for uncommon soil crust lichens显示文摘Introduction:Biotic soil crust communities contribute valuable ecosystem services and biodiversity in steppe ecosystems.The uncommon crust lichens Acarospora schleicheri,Fuscopannaria cyanolepra,Rhizocarpon diploschistidina,and Texosporium sancti-jacobi are associated with fine-textured soils along rivers of the Columbia Basin.A.schleicheri and R.diploschistidina indicate late-successional habitat and may serve as indicators for other rare or cryptic species associated with similar habitats.Much of the most favorable habitat for these species has been lost to urban and agricultural development.We sought to overlay favorable habitats with wind farm development potential to assess whether these species are likely to be affected by renewable energy development.Methods:We overlaid habitat models for four lichen species on land use and wind farm potential maps.Using a sample of 5,000 points,we determined whether there were differences in probability of occurrence among wind farm potential classes within developed and natural lands using Multi-Response Permutation Procedures.Sites with modeled probability of occurrence greater than 60%were considered“favorable”habitats;for these,aχ2 test allowed us to determine whether favorable habitats were associated with wind farm potential categories.Results:Sites that are developed for agriculture or have higher wind farm potential coincide with more favorable habitats for uncommon soil crust lichens.Of the favorable habitats for the four focal lichens,28–42%are already affected by development or agriculture;5–14%of favorable habitats remain in natural vegetation and are considered sites with fair or good potential for wind farms.Conclusions:Development of wind energy has the potential to negatively impact uncommon soil crust lichen species because favorable sites coincide with especially good habitat for these species.However,as these renewable energy resources are developed,we have the opportunity to ensure that valuable soil crust functions and diversity are maintained by surveying before construction and planning new facilities such that disturbance to existing habitat is minimized. | Heather T Root Myrica McCune Bruce McCune | 2013 | Ecological Processes2013，2，1： | 0 |
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