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Snow resisting capacity of Caragana microphylla and Achnatherum splendens in a typical steppe region of Inner Mongolia,China

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Journal of Arid Land 2020年第2期12卷 294-302页

作者： YAN Min ZUO Hejun WANG Haibing DONG Zhi LI Gangtie Key Laboratory of Aeolian Physics and Desertification Control Engineering Inner Mongolia Autonomous RegionCollege of Desert Control Science and EngineeringInner Mongolia Agricultural UniversityHohhot 010018China Forestry College Shandong Agricultural UniversityTai'an 271018China

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.

关键词： herb shrub snow cover snow resisting capacity field observation steppe

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Features on N/P ratio of plants with different functional groups between two types of steppe in semi-arid area

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Research in Cold and Arid Regions 2019年第5期11卷 371-381页

作者： YueDan Zhao XingDong He Lei Chen XinFeng Ding MengQi Li PingYi Xu YuBao Gao College of Life Sciences Nankai University

The differences in nitrogen/phosphorus(N/P)ratios of different functional groups in ecology are more helpful in explaining species competition and community dynamics.Based on the functional groups of plant growth type,carbon metabolism pathway,root type and phylogenetic type,we analyzed characteristics of leaf N/P ratios of 77 species in Sanggendalai(typical grassland zone)of Zhenglan Banner,Inner Mongolia,China and 91 species in the Habahu National Nature Reserve(desertified grassland zone)in Yanchi County of Ningxia,China.The results show that the N/P ratio(16.91)of C3 plants in the desertified steppe was significantly larger than that(12.72)in the typical steppe,but there was no significant difference between the N/P ratios of C4 plants in the two zones.There was no significant difference in N/P ratios between C3 plants and C4 plants in the same zone.Similarly,the N/P ratio(16.60)of dicotyledons in desertified steppe were significantly higher than that(12.98)in typical steppe,while differences in N/P ratios between monocotyledonous plants of the two zones was not significant,and there existed no significant difference in N/P ratios between dicotyledonous and monocotyledonous plants in the same zone.The N/P ratio had significant difference between gramineous and non-gramineous plants in the typical steppe but not in the desertified steppe,but there existed no significant difference in N/P ratios among different root types of perennial herbaceous plants in the same type of steppe or between two types of steppe.Thus,different features on the N/P ratios of C3 plants and dicotyledonous plants between typical steppe and desertified steppe may lead to different growth status of plants,and the N/P ratio stoichiometric of the same plant functional group may be a foundation of the changes of a plant community.

关键词： semi-arid region plant N/P ratio plant functional groups desertified steppe typical steppe

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Impact of Climate and Grazing on Biomass Components of Eastern Russia Typical steppe

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Journal of Integrative Agriculture 2014年第6期13卷 1183-1192页

作者： Ubugunov Leonid Rupyshev Yuriy Ubugunov Vasiliy HOU Xiang-yang Vishnyakova Oxana Lavrentieva Irina Ubugunova Vera REN Wei-bo DING Yong Institute of General and Experimental Biology Siberian Branch of Russian Academy of Sciences Grassland Research Institute Chinese Academy of Agricultural Sciences

Spatial and structural characteristics of plant communities in the steppe ecosystems of the Baikal region, Russian Federation have been researched in connection with climate change and grazing. The present study, based on a total of 15 typical steppe sampling plots, investigated above-ground biomass （AGB）, below-ground biomass （BGB）, total biomass （TB） and root：shoot ratios （R：S） and their relationships with climatic factors and grazing. All biomass components varied widely depending on the climatic parameters and the degree of grazing affected transformation. A strong negative correlation between mean annual temperature （MAT） and total plant biomass was revealed for all study area. Mean annual precipitation （MAP） signiifcantly affected communities productivity increasing only in the south of the region. Due to the large and mountainous territory, the inlfuence of latitude and elevation （mountain） factors on the components of the biomass were studied. Although all studied plant steppe communities were transformed by uncontrolled grazing, their productivity is signiifcantly reduced only at plots with maximum digression. Vegetation shift is an indicator of climate change, as well as providing a diagnostic tool to build predictive models. Based on the complex index of effective precipitation, it was revealed that at the end of last century in the steppes of the Baikal region the structural and production processes will be affected by an arid climate trend.

关键词： steppe productivity climate grazing transformation Baikal region

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Trait complementarity between fine roots of Stipa purpurea and their associated arbuscular mycorrhizal fungi along a precipitation gradient in Tibetan alpine steppe

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Journal of Mountain Science 2019年第3期16卷 542-547页

作者： ZHANG Jing WANG Ping XUE Ka HAO Yan-bin WANG Yan-fen CUI Xiao-yong College of Life Sciences University of Chinese Academy of Sciences College of Forestry Beijing Forestry University College of Resources and Environment University of Chinese Academy of Sciences

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 steppe. The complementarity between fine root and mycorrhizal fungi of S. purpurea is mediated by precipitation in Tibetan alpine steppe.

关键词： Arbuscular mycorrhizal fungal colonization Root diameter Trait complementarity Precipitation Stipa purpurea Alpine steppe

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Stipa tenacissima Does not Affect the Foliar δ^(13)C and δ^(15)N of Introduced Shrub Seedlings in a Mediterranean Semi-arid steppe

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Journal of Integrative Plant Biology 2006年第8期48卷 897-905页

作者： Fernando T.Maestre Susana Bautista Jordi Cortina Departamento de Ecologia Universidad de AlicanteApartado de correos 9903080 AlicanteSpain Department of Biology Duke UniversityPhytotron BuildingScience DriveBox 90340DurhamNorth Carolina 27708-0340USA Centro de Estudios Ambientales del Mediterraneo C/ Charles Darwin 1446980 PaternaSpain

Recent studies have shown that the tussock grass Stipa tenacissima L. facilitates the establishment of late-successional shrubs, in what constitutes the first documented case of facilitation of woody plants by grasses. With the aim of increasing our knowledge of this interaction, in the present study we investigated the effects of S. tenacissima on the foliar δ13C, δ15N, nitrogen concentration, and carbon ： nitrogen ratio of introduced seedlings of Pistacia lentiscus L., Quercus coccifera L., and Medicago arborea L. in a semi-arid Mediterranean steppe. Six months after planting, the values of δ13C ranged between -26.9‰ and -29.6‰, whereas those of δ15N ranged between -1.9‰ and 2.7‰. The foliar C ： N ratio ranged between 10.7 and 53.5, and the nitrogen concentration ranged between 1.0% and 4.4%. We found no significant effect of the microsite provided by S. tenacissima on these variables in any of the species evaluated. The values of δ13C were negatively correlated with predawn water potentials in M. arborea and were positively correlated with relative growth rate in Q. coccifera. The values of δ15N were positively correlated with the biomass allocation to roots in the latter species. The present results suggest that the modification of environmental conditions in the are surrounding S. tenacissima was not strong enough to modify the foliar isotopic and nitrogen concentration of shrubs during the early stages after planting.

关键词： facilitation Medicago arborea Pistacia lentiscus Quercus coccifera stable isotopes steppe Stipa tenacissima.

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Effects of Main Climatic Factors on Plant Community Characteristics of a Meadow steppe Under Different Grazing Intensities

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Journal of Landscape Research 2019年第2期11卷 104-106页

作者： ZHAO Jianguo LIU Cunqi LI Hongbo LUO Ning MENG Shujin ZHANG Zhihui WANG Jianghua Green Development Institute Hebei Provincial Academy of Environmental Sciences College of Life Science Hebei University Hengshui Environmental Monitoring Center Xingtai Environmental Monitoring Center Baoding Environmental Protection Institute

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.

关键词： Climatic factors Meadow steppe Community characteristics RDA analysis

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Degradation induces changes in the soil C:N:P stoichiometry of alpine steppe on the Tibetan Plateau

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Journal of Mountain Science 2019年第10期16卷 2348-2360页

作者： ZHANG Zhen-chao HOU Ge LIU Miao WEI Tian-xing SUN Jian School of Soil and Water Conservation Beijing Forestry UniversityBeijing100083China Synthesis Research Centre of Chinese Ecosystem Research Network Key Laboratory of Ecosystem NetworkObservation and ModellingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy ofSciencesBeijing100101China State Key Laboratory of Urban and Regional Ecology Research Center for Eco–environmental SciencesChineseAcademy of SciencesBeijing100085China Department of Ecology Evolutionand Natural ResourcesSchool of Environmental and Biological SciencesRutgersUniversityNew BrunswickNew Jersey08901USA

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 susta

关键词： Tibetan Plateau Alpine steppe Degradation Soil stoichiometry C/N C/P N/P

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C:N:P stoichiometry of perennial herbs’ organs in the alpine steppe of the northern Tibetan Plateau

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Journal of Mountain Science 2019年第9期16卷 2039-2047页

作者： MA Xing-xing HONG Jiang-tao WANG Xiao-dan College of Geographical Sciences Shanxi Normal University Linfen 041000 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China

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.

关键词： Shoot tissues Chemical elements Biogeochemical process Alpine steppe Tibet Plateau

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The Relationship Between Plant Community Characteristics and Soil Organic Matter Content of Sedentary Grazing Pastures in a Typical steppe

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Journal of Landscape Research 2019年第1期11卷 57-60,64页

作者： SARULA SAIXIYALATU CHUN Feng ZHANG Weiqing College of Geographical Science Inner Mongolia Normal University

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.

关键词： Stipa krylovii steppe Plant community characteristics Soil organic matter content Sedentary grazing

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Analysis of Grassland Vegetation of the Southwest Heilongjiang steppe （China） Using the Power Law

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Journal of Integrative Plant Biology 2005年第8期47卷 917-926页

作者： Mikinori TSUIKI Yu-Sheng WANG Yiruhan Michio TSUTSUMI Masae SHIYOMI Faculty of Agriculture lwate University Morioka 020-8550 Japan National Northeast Agricultural University Harbin 150030 China Environmental Engineering Department College of Science and Engineering Jinan University Guangzhou 510630 China National Institute of Livestock and Grassland Science Ecology Department Tochigi 329-2724 Japan Faculty of Science lbaraki University Mito 310-8512 Japan

In 1997, we conducted a vegetation survey in three semi-arid natural grasslands （steppes） with different livestock grazing intensities in Southwest Heilongjiang Province, China, The dominant grassland species was the grass Stipa baicalensis Roshev. Grasslands with light, intermediate, and heavy grazing intensities were located 10, 5, and 2 km from a village, respectively. Villagers use the steppe to raise cattle, horses, sheep, and goats. Each of the three grasslands was surveyed by placing 100 quadrats （50 cm×50 cm） along a 50 m line transect. Each quadrat was divided into four equal areas （25 cm×25 cm; S-quadrats） and all plant species occurring in each of these smaller areas were identified and recorded. These data were summarized into frequency distributions and the percentage of S-quadrats containing a given species and the variance of each species were estimated. The power law was applied to these estimates. The power law was used to evaluate the spatial heterogeneity and frequency of occurrence for each species in the grassland community. The lightly grazed grassland exhibited high spatial heterogeneity （caused by large plant size）, the highest species diversity, and a high occurrence of S. baicalensis. In contrast, the heavily grazed grassland exhibited high spatial heterogeneity （caused by patchy populations of small plant size）, low species diversity, and a low occurrence of S. baicalensis. We judged that the heavily grazed grassland was overgrazed and exclusion of livestock from the degraded areas is necessary for recovery.

关键词： degradation grazing intensity Heilongjiang （China） spatial heterogeneity species diversity steppe Stipa baicalensis.

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