共查询到20条相似文献，搜索用时 421 毫秒
1.
Tong S.-P. Liang Z.-W. Guan F.-C. Zong X.-C. Zhang Y.-F. Huang L.-H. Wang M.-M. 《草地学报》2019,(1):22-27
In order to explore the effect of Leymus chinensis transplanting on the biodiversity and productivity of saline alkali grassland in Songnen Plain,a comparative experiment was conducted in the transplanting Leymus chinensis grassland. The results showed that the transplanting of Leymus chinensis enhanced plant species and the density of the grassland community. The total plant density under the transplanting of Leymus chinensis was 566.20 plant·m-2,6.85 times as much as that in the control (82.60 plant·m-2),and the difference between the treatments was significant (P<0.05),and the transplanting of Leymus chinensis increased the diversity index of Shannon-Wiener,the evenness index of Pielou and the richness of Margalf species. The total biomass of the community was higher than that in the control. In addition,the total biomass of the transplanting of Leymus chinensis was 357.77 g· m-2,2.14 times as much as that in the control (167.34 g·m-2),and the difference between the treatments was significant (P<0.05),which indicated that the transplanting Leymus chinensis increased the productivity of the plant community,and greatly increased the grassland output benefit, The total income was 3938.00 yuan·hm-2 for the transplanting of Leymus chinensis,7.37 times higher than that in the control (534.40 yuan·hm-2),and the difference between treatments was very significant (P<0.01).Transplanting technology of Leymus chinensis not only improved the biodiversity of the system,but also doubly increased the biomass and economic benefits,So it was a technical model which was worth of popularizing and applying in the saline alkali area of the Western Songnen Plain. © 2019 China Agricultural University. All rights reserved. 相似文献
2.
In this study，SCoT molecular markers were used to analyze the genetic diversity and construct DNA fingerprints of three species of Elymus on the Qinghai-Tibet Plateau to provide a theoretical basis for identification of the different species in collection material. Among 80 SCoT primers， 22 primers were selected for PCR amplification，and a total of 290 bands were amplified，of which 254 were polymorphic with the percentage of polymorphic bands（PPB）of 87.59%. The average values of the Shannon diversity information index（I），Nei’s gene diversity index （H），the observed number of alleles （Na），and an effective number of alleles （Ne） were 0.5411，0.3643，1.9856，and 1.6270，respectively. Cluster analysis results showed that the genetic similarity coefficient ranged from 0.50 to 0.80. At a genetic similarity coefficient of 0.53，46 collections could be divided into 2 groups，and the results of the principal coordinate analysis were consistent with those of cluster analysis. At the same time，the DNA fingerprints of 46 materials were constructed by using 4 SCoT primers. The SCoT molecular marker was suitable for genetic diversity analysis and DNA fingerprint construction of Elymus germplasm resources. This study provides fundamental information for germplasm identification，high-quality character mining，and breeding practice for wild Elymus. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
3.
Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems. 相似文献
4.
5.
Based on measured data from 7 stations on the Qinghai-Tibetan Plateau,the ground surface soil heat flux （G0） was calculated,and the diurnal and seasonal variations were analyzed. Combining this data with a MODIS,1 km resolution all-weather surface temperature data set for Western China and a China regional surface meteorological element driven data set,the Ma model was used to retrieve the ground surface soil heat flux of Qinghai-Tibetan Plateau from 2003 to 2018,and the differences in surface soil heat fluxes of different grassland types were analyzed. It was found that：1） The soil heat flux G0 in the surface layer was greater than that in the subsurface layers. The diurnal curve of G0 showed an inverted“U”shape,and the flux was relatively gentle at night compared with that during the day. 2） The seasonal amplitude of soil heat flux,G0 in the surface layer ranked summer>spring> autumn>winter. The average value of G0 in spring and summer was typically positive,while the average value of G0 in autumn and winter was basically negative. The ground surface soil heat flux in the northwest of the plateau in summer is higher than that in the southeast,while the opposite occurs in winter. 3） The soil heat flux of plateau grassland ranged between 40 and 80 W·m−2. The highest average value of G0 among all categories of grassland in the 16 years surveyed was 76. 557 W·m−2 for the‘desertification’category of temperate grassland,and the lowest was 46. 118 W·m−2 for the alpine meadow category. 4） The G0 of plateau grassland increased and then decreased through any one calendar year and seasonally was ranked summer>spring>autumn>winter. The lowest G0 in spring and summer occurred in alpine meadow,while the highest in spring was in‘desertification’temperate grassland and the highest in summer was in the temperate grassland category; The highest G0 in autumn and winter was in the warm shrub grassland,while the lowest was in the alpine deserts steppe. The above results can provide reference data for the study of surface energy balance of plateau grassland. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
6.
Agro-pastoral ecotone is an important ecological barrier in China,and its ecological environment problems are becoming increasingly prominent. In this study,61 species of plants in 27 grassland plots in the agro-pastoral ecotone of Inner Mongolia and Liaoning border were collected for calorific value analysis under the random sampling condition. The changes of calorific value of plants in different types of functional groups were explored to provide scientific data and research support for energy fixation and rational use of grassland resources in the agro-pastoral ecotone. The results showed that:The average calorific value of 61 species was 17.14 KJ·g-1. Among them,Salsola collina had the lowest calorific value (12.82 KJ·g-1),the caloric value of Polygala tenuifolia was the highest (20.07 KJ·g-1),and the total calorific value was normal distribution. Comparing the caloric values of different life-type functional groups,the caloric value of annuals and biennials was significantly lower than perennial grasses and shrubs (P<0.05),which had no significant difference with sub-shrubs and perennial forbs. There was no significant difference among perennial grasses,shrubs,perennial weeds and semi-shrubs (P>0.05). There was no significant difference in caloric value between different water ecological functional groups (P>0.05). The plant caloric mean value of the Xero-mesophytes was slightly lower than other groups. There was no significant difference in calorific value among Liliaceae,Leguminosac,Gramineae,Compositae and Rosaceae,and the caloric value of Chenapodiaceae was significantly lower than other families (P<0.05). There was a significant positive correlation between plant calorific value and carbon content (P<0.05). © 2019 China Agricultural University. All rights reserved. 相似文献
7.
This research studied the effects of sowing date and cutting prior to sowing on establishment of the leguminous forage，alfalfa（Medicago sativa），in a lightly degraded Leymus chinensis meadow and investigated the sowing date×cutting interaction. The factorial experiment comprised four sowing dates（May 1，June 1，July 1，August 1）and cutting treatment（cut or uncut）prior to sowing，and evaluated the establishment performance of alfalfa and the ecological mechanisms related to establishment. It was found that soil moisture during emergence of alfalfa was the greatest when sowing occurred on July 1，and clipping prior to sowing significantly decreased the plant height of L. chinensis during emergence and seedling growth of alfalfa. There was a significant sowing date×cutting interaction effect on alfalfa establishment. Clipping prior to sowing significantly increased the emergence percentage of alfalfa through reducing the plant height of L. chinensis and associated above-and below-ground competition，and the seasonal soil moisture change resulted in a 20% higher（P<0. 05）alfalfa emergence rate when sowing occurred on July 1. With cutting，the number of surviving alfalfa seedlings and seedling survival rate were greatest（83 plants· m−2 and 53%，respectively）when sowing occurred on July 1. For later sowing，owing to the shortened growing time，the development and overwintering survival rates of alfalfa seedlings were significantly reduced. Cutting prior to sowing significantly increased the overwintering rate of alfalfa seedlings through improving their development. In the cutting treatment，the number of overwintered alfalfa seedlings（22 plants·m−2）when sowing was on July 1 was significantly higher than for other reseeding dates. In the second year，a botanical composition measurement showed that clipping prior to reseeding significantly increased the alfalfa biomass within the meadow，and the alfalfa biomass was significantly greater than in other treatments when sowing occurred on July 1 after cutting. Cutting prior to sowing also significantly increased the crude protein content of forage. Based on these research results，normal production practice should include cutting when alfalfa is sown into L. chinensis meadow. Combined with cutting，a sowing date around July 1 is the most favorable for the establishment of alfalfa. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved. 相似文献
8.
Background: Brain size may affect the probability of invasion of urban habitats if a relatively larger brain entails superior ability to adapt to novel environments. However, once urbanized urban environments may provide poor quality food that has negative consequences for normal brain development resulting in an excess of individuals with small brains.Methods: Here we analyze the independent effects of mean, standard deviation and skewness in brain mass for invasion of urban habitats by 108 species of birds using phylogenetic multiple regression analyses weighted by sample size.Results: There was no significant difference in mean brain mass between urbanized and non-urbanized species or between urban and rural populations of the same species, and mean brain mass was not significantly correlated with time since urbanization. Bird species that became urbanized had a greater standard deviation in brain mass than non-urbanized species, and the standard deviation in brain mass increased with time since urbanization. Brain mass was significantly left skewed in species that remained rural, while there was no significant skew in urbanized species. The degree of left skew was greater in urban than in rural populations of the same species, and successfully urbanized species decreased the degree of left skew with time since urbanization. This is consistent with the hypothesis that sub-optimal brain development was more common in rural habitats resulting in disproportionately many individuals with very smal brains.Conclusions: These findings do not support the hypothesis that large brains promote urbanization, but suggest that skewness has played a role in the initial invasion of urban habitats, and that variance and skew in brain mass have increased as species have become urbanized. 相似文献
9.
Tong T. Zhang K.-D. Wu Y.-J. Suo-Langda Yang F. Chen Y.-L. Yang Y.-X. Yang Y.-X. 《草地学报》2019,(1):104-111
This experiment was conducted in Nima County,Nagqu region,Tibet,to investigate the effects of seasonal changes on pasture nutrients and the feeding preferences of Tibetan cashmere goats,and estimate grassland yield and livestock carrying capacity. The results showed that the nutrient content in pasture showed regular changes with the seasons. The weight of crude protein (CP) and dry matter (DM) showed an inverted "V" shape with the increase of season,neutral,but the change in the content of detergent fiber (NDF) and acid detergent fiber (ADF) was in verse. Compared with autumn,there was a significant change in the eating degree of Tibetan cashmere goats on forages such as Stipa purpurea,Potentilla bifurca, Anaphalis xylorrhiza, Cirsium souliei and Leontopodium pusillum in summer (P<0.05),which was significantly correlated with the total coverage of forage (P< 0.05). The NDVI extracted from the TM remote sensing image of alpine meadow grassland showed linear and logarithmic relationship with fresh grass biomass and biomass,and the correlation coefficients were 0.8108 and 0.7970,respectively. At the same time,it found that there was overgrazed throughout the year. © 2019 Ｊｏｕｒｎａｌ ｏｆ Ｒｅｆｒｉｇｅｒａｔｉｏｎ. All rights reserved. 相似文献
10.
Background:Galacto-oligosaccharides(GOS)have been shown to modulate the intestinal microbiota of suckling piglets to exert beneficial effects on intestinal function.However,the modulation of intestinal microbiota and intestinal function by GOS in intestinal inflammation injury models has rarely been reported.In this study,we investigated the effects of GOS on the colonic mucosal microbiota composition,barrier function and inflammatory response of lipopolysaccharides(LPS)-challenged suckling piglets.Methods:A total of 18 newborn suckling piglets were divided into three groups,the CON group,the LPS-CON group and the LPS-GOS group.Piglets in the LPS-GOS group were orally fed with 1 g/kg body weight of GOS solution every day.On the d 14,piglets in the LPS-CON and LPS-GOS group were challenged intraperitoneally with LPS solution.All piglets were slaughtered 2 h after intraperitoneal injection and sampled.Results:We found that the colonic mucosa of LPS-challenged piglets was significantly injured and shedding,while the colonic mucosa of the LPS-GOS group piglets maintained its structure.Moreover,GOS significantly reduced the concentration of malondialdehyde(MDA)and the activity of reactive oxygen species(ROS)in the LPS-challenged suckling piglets,and significantly increased the activity of total antioxidant capacity(T-AOC).GOS significantly increased the relative abundance of norank_f_Muribaculaceae and Romboutsia,and significantly decreased the relative abundance of Alloprevotella,Campylobacter and Helicobacter in the colonic mucosa of LPS-challenged suckling piglets.In addition,GOS increased the concentrations of acetate,butyrate and total short chain fatty acids(SCFAs)in the colonic digesta of LPS-challenged suckling piglets.GOS significantly reduced the concentrations of interleukin 1β(IL-1β),interleukin 6(IL-6),tumor necrosis factor-α(TNF-α)and cluster of differentiation 14(CD14),and the relative mRNA expression of Toll-like receptor 4(TLR4)and myeloid differentiation primary response 88(MyD88)in the LPS-challenged suckling piglets.In addition,GOS significantly reduced the relative mRNA expression of mucin2(MUC2),and significantly increased the protein expression of Claudin-1 and zonula occluden-1(ZO-1)in LPS-challenged suckling piglets.Conclusions:These results suggested that GOS can modulate the colonic mucosa-associated microbiota composition and improve the intestinal function of LPS-challenged suckling piglets. 相似文献
11.
高原鼠兔干扰对高寒草甸植物群落多样性和稳定性的影响 总被引：1，自引：0，他引：1
物种多样性和功能冗余是评价植物群落稳定性的重要内容。采用野外调查方法研究了高原鼠兔干扰对高寒草甸植物群落物种多样性、功能多样性、功能冗余和植物群落稳定性的影响。结果表明:高原鼠兔干扰增加了物种丰富度指数、功能多样性和功能冗余,降低了物种多样性指数、均匀度指数和植物群落稳定性。随高原鼠兔干扰强度增加,植物群落多样性指数、丰富度指数、功能冗余和植物群落稳定性呈先增大后减小的变化趋势,说明高原鼠兔干扰对植物群落物种多样性和稳定性的影响不仅要考虑干扰与否,而且要考虑干扰强度。 相似文献
12.
采用堵洞法设置高原鼠兔干扰区和非干扰区,然后在干扰区和非干扰区内利用样方法研究了高原鼠兔干扰对青海湖流域高山嵩草草甸植物多样性和地上生物量的影响。结果表明,植物物种多样性和不同植物功能群多样性对高原鼠兔干扰的响应并不一致,其中干扰增加了杂类草功能群丰富度指数与物种丰富度指数,降低了物种均匀度指数、莎草科功能群丰富度指数和禾草科功能群均匀度指数(P<0.05)。干扰区内物种均匀度指数、物种丰富度指数和杂类草功能群丰富度指数随干扰强度增加而呈增加趋势,但禾草科功能群均匀度指数却呈显著降低趋势。虽然高原鼠兔干扰显著降低了植物群落总生物量,莎草科、禾草科和豆科功能群生物量(P<0.05),但显著增加了杂类草功能群生物量(P<0.05)。干扰区随干扰程度增加,莎草科功能群和豆科功能群生物量逐渐降低,杂类草功能群生物量逐渐增加,而禾草科功能群生物量则先增加后降低。鉴于高山嵩草草甸植物群落物种多样性和功能多样性对高原鼠兔干扰的响应不一致,植物物种多样性和功能群多样性之间不能互相替代。 相似文献
13.
高原鼢鼠的干扰对高寒草地植物群落物种多样性的影响 总被引：4，自引：3，他引：1
在青藏高原东部的甘南高寒草甸就高原鼢鼠Myospalax baileyi不同干扰强度对草地植被的影响,主要是对植被组成、物种多样性和功能群多样性的影响进行了研究。结果表明,高原鼢鼠干扰对草地植被组成和物种多样性变化有重要影响;物种数在中度干扰时达到最大(32种),依次为轻度干扰(20种)、重度干扰(16种);Shannon-Wiener指数、Simpson指数和均匀度指数均表现出相似的变化趋势;功能群数在各干扰样地中没有变化,但功能群内物种数和功能群内Shannon指数变化显著,各功能群内物种数均在中度干扰时达最大值。 相似文献
14.
三江源区高寒草甸植物多样性的海拔分布格局 总被引：1，自引：0，他引：1
三江源地区是我国受气候变化影响最大且最敏感的区域之一。研究高寒草甸植物多样性海拔分布格局及其与环境的关系,能为预测气候变化对植物多样性的影响和响应提供科学依据。本研究以青海三江源地区的6个样地/海拔梯度共78个样方的高寒草甸样地为研究对象,了解高寒草甸植物多样性和群落结构,分析海拔分布格局及其与环境的关系,旨在以空间替代时间的实验系统来揭示植物对气候变化的响应。统计分析发现,6个高寒草甸样地共有植物21科、51属、74种,且在中海拔和高海拔地区,高寒草甸以藏嵩草、高山嵩草、矮嵩草等莎草科植物占优势,低海拔地区高寒草甸则以针茅、早熟禾、垂穗披碱草等禾本科植物为优势种群。方差分析表明,随着海拔的降低,高寒草甸群落的物种多样性和物种丰富度均呈“单峰”分布格局,而均匀度指数逐渐升高。DCA分析发现,高寒草甸植物群落沿着海拔梯度呈现有规律的变化,具有从高寒草甸向高寒草原化草甸的逐渐过渡的特征,海拔梯度明显的影响了植物群落结构和多样性。此外,CCA结果表明,土壤pH值是影响高寒草甸植物群落分布格局的主要因素,土壤含水量、土壤温度、土壤有机碳、碱解氮含量与全钾含量是影响植物群落分布格局的关键因子。综上所述,我们推测气候变化极有可能影响三江源地区高寒草甸植物群落结构与分布格局。 相似文献
15.
海拔梯度对藏北高寒草地生产力和物种多样性的影响 总被引：2，自引：0，他引：2
草地群落物种多样性和生产力在海拔梯度的变化规律及其关系, 以及不同功能群的变化一直是热点问题, 目前尚未得出一般性规律。本研究通过藏北地区那曲县日参波山样线的高寒草地样方调查实验, 分析各海拔梯度(4485~4635 m)植物群落生产力、结构和物种多样性的变化。结果表明, 随着海拔升高, 高寒草地植物群落生产力先增加后降低, 并在海拔4535~4585 m左右达到最佳;莎草类在群落由相对优势变为绝对优势, 禾草类和杂草类的重要值以不同幅度下降, 豆科类的重要值先上升后下降;物种丰富度、Shannon-Weiner 多样性指数、Simpson多样性指数和E.Pielou均匀度指数均呈现“单峰”型格局, 物种多样性指数与地上生物量呈正相关关系, 但只能作为部分解释地上生物量变化的因素。 相似文献
16.
以甘肃天祝和玛曲为例,研究了青藏高原东北缘和东缘地区高寒草甸植物群落特征和多样性的分异性。结果显示,青藏高原东北缘和东缘地区高寒草甸植物群落的优势种均为高山嵩草（Kobresia pygmaea）;东缘地区植物群落高度和盖度大于东北缘地区;植物群落均表现为双层垂直结构。东缘和东北缘地区高寒草甸植物群落的物种丰富度指数差异不显著（P>0.05）;物种均匀度指数、α多样性指数、β多样性指数和地上生物量均表现为东缘地区显著大于东北缘地区。本研究结果说明,青藏高原周边地区高寒草甸群落特征、植物多样性和草地初级生产力具有较大分异性,因此,制订经营策略时应因地制宜,以维持高寒草甸的稳产和保育植物多样性。 相似文献
17.
植物群落多样性及稳定性对草地生态系统功能的稳定发挥至关重要。本研究以青藏高原高寒湿地草甸、高寒草甸、高寒草原和高寒荒漠草原为研究对象,基于480个野外样方调查及实验分析,运用显著性分析、回归分析和结构方程模型等方法,探究不同草地类型植物多样性与稳定性之间关系及其影响因素。结果表明：高寒草原植物多样性显著高于其他3种草地类型;高寒草甸群落稳定性最高。高寒草地中,不同的物种多样性指标与群落稳定性的关系不同,4种草地类型均匀度与群落稳定性显著负相关;高寒草甸和高寒荒漠草原中Shannon-Wiener多样性与群落稳定性显著负相关,在高寒湿地草甸和高寒草原中丰富度与稳定性显著正相关。降水量是影响高寒草地植物多样性和群落稳定性的主要因素,土壤有机碳、pH以及铵态氮含量也能通过影响植物多样性进而影响群落稳定性。综上,在高寒草地生态系统的管理过程中,需充分考虑气候和土壤因子的变化,根据草地类型制定不同的管理措施。 相似文献
18.
旅游干扰对喀纳斯景区草地植物多样性的影响 总被引：6，自引：1，他引：5
研究喀纳斯景区旅游干扰下草甸草地群落的植物多样性,利用主要物种重要值、α多样性、功能群重要值和β多样性比较分析不同干扰后群落植物多样性及结构功能的变化。结果表明:随着干扰强度的增加,群落物种组成从以不耐旅游干扰的物种为主逐渐发展到以耐旅游干扰的物种为主,群落的重要值有向少数物种集中的趋势;Patrick丰富度指数和Shannon-Wiener指数均随着干扰强度的增加而呈下降趋势,均匀度指数则在中度干扰下最大,生态优势度的变化与α多样性的变化存在一定的负关联;功能群丰富度在中度干扰下最高;中度-重度干扰阶段群落间的物种替代速率最快。喀纳斯景区草甸草地群落稳定与群落自身的物种多样性、功能群功能特性及结构特点密切相关。 相似文献
19.
河北省森林草原区草本植物物种多样性和功能多样性 总被引：2，自引：0，他引：2
理解物种多样性和功能多样性之间的关系以及分析它们对环境变化的响应,有利于揭示生物多样性的影响因素。本研究以塞罕坝地区不同植被类型(草地、灌木林和天然次生林)的草本群落为研究对象,分析了物种多样性(物种丰富度、Shannon-Wiener多样性和Pielou均匀度)和功能多样性测度指标(功能丰富度、功能均匀度和功能离散度)之间的相互关系,并采用相似性分析检验(ANOSIM)和冗余度(RDA)分析等方法研究了它们随植被类型和环境因子的变化规律。结果表明,草地中草本植物物种丰富度、Shannon-Wiener多样性指数显著高于灌木林和天然次生林中的草本群落(P<0.05),而功能丰富度指数在草地中最低(P<0.05),功能均匀度和功能离散度在灌木林中最低(P<0.05),Pielou均匀度指数在不同植被类型间差异不显著(P>0.05);功能丰富度与物种丰富度、Shannon-Wiener多样性指数显著负相关(P<0.01),功能离散度与物种均匀度显著正相关(P<0.01),而功能均匀度与所有物种多样性指数均不相关(P>0.05);影响物种多样性的主要因子有土壤含水量、土壤有机质、土壤pH值、土壤全氮含量和坡向,影响功能多样性的主要因子有土壤有机质、土层深度、土壤含水量和海拔。物种多样性和功能多样性分布主要受土壤因子的影响,分别占到总解释变异的29.1%和29.8%。本研究结果表明研究区草本植物物种多样性和功能多样性变化相对独立,物种多样性可能主要是由资源可利用程度决定,而功能多样性可能是生态位分化即环境筛选和物种间相互作用共同决定。 相似文献
20.
不同海拔高度的高寒草甸植物群落多样性的研究 总被引：2，自引：0，他引：2
具有江河源头的青海,位于青藏高原的东部,地形复杂,群落类型众多.对生物多样性的研究和保护是一项重要的任务.本文对互助县松多乡高寒草甸植物群落多样性进行调查,着重分析了高山蒿草草甸植物群落的丰富度、生态优势度、多样性指数和相对多度与海拔的关系.结果表明：随着海拔梯度的逐渐升高,其生态优势度逐渐减小,多样性指数和均匀度在增加,丰富度先增加后减小. 相似文献