Population structure and spatial pattern analysis of Quercus aquifolioides on Sejila Mountain,Tibet,China

Understanding population structure provides basic ecological data related to species and ecosystems.Our objective was to understand the mechanisms involved in the maintenance of Quercus aquifolioides populations.Using a 1 ha permanent sample plot data for Q.aquifolioides on Sejila Mountain,Tibet Autonomous Region(Tibet),China,we analyzed the population structure of Q.aquifolioides by combining data for diameter class,static life table and survival curve.Simultaneously,the spatial distribution of Q.aquifolioides was studied using Ripley’s L Function in point pattern analysis.The results showed:(1) Individuals in Q.aquifolioides populations were mainly aggregated in the youngest age classes,that accounted for94.3% of the individuals; the older age classes had much smaller populations.Although the youngest age classes(ClassesⅠ and Ⅱ) had fewer individuals than Class Ⅲ,the total number of individuals in classes Ⅰ and Ⅱ was also greater than in classes Ⅳ to Ⅸ.In terms of tree height,fewsaplings,more medium-sized saplings and few large-sized trees were found.The diameter class structure of Q.aquifolioides populations formed an atypical ‘pyramid’type; the population was expanding,but growth was limited,tending toward a stable population.(2) Mortality of Q.aquifolioides increased continuously with age; life expectancy decreased over time,and the survivorship curve was close to a Deevey I curve.(3) The spatial distribution pattern of Q.aquifolioides varied widely across different developmental stages.Saplings and medium-sized tree showed aggregated distributions at the scales of 0–33 m and 0–29 m,respectively.The aggregation intensities of saplings and medium-sized trees at small scales were significantly stronger than that of large-sized trees.However,large-sized trees showed a random distribution at most scales.(4) No correlation was observed among saplings,medium-and large-sized trees at small scales,while a significant and negative association was observed as the scale increased.Strong competition was found among saplings,medium-and large-sized trees,while no significant association was observed between medium-and largesized trees at all scales.Biotic interactions and local ecological characteristics influenced the spatial distribution pattern of Q.aquifolioides populations most strongly.

Bibliometric Analysis on Pennisetum Sinese Roxb. in China during 2006-2016

The development prospect of Pennisetum Sinese Roxb. is receiving much concern of domestic researchers. In this paper,literature of Pennisetum Sinese Roxb. was taken as basis,and bibliometric analysis method was used to make statistics of distribution of years,research institutions,authors,and research fields. The results showed that research fields of Pennisetum Sinese Roxb. in China were mainly ecological restoration,accounting for 13. 27% of the total literature; the research took on dynamic and diversified cooperation trend. In recent 5 years,the number of papers significantly increased,accounting for 93. 04% of the total literature. The distribution of authors and regions were relatively concentrated,but the overall level of research is low.

Application of Ecological Footprint

Ecological footprint is a method of measuring how much we use the natural resources and how much the nature provides services for human beings. This paper summarized the application of ecological footprint at different scales and in different fields and different ecological types at home and abroad,analyzed the advantages and disadvantages of ecological footprint method,and made a prediction of the application of ecological footprint.

Phenotypic Diversity of Different Populations of Paeonia ludlowii in Nyingchi of Tibet

[Objectives] To study the differences in fruit traits of different populations of Paeonia ludlowii , and to provide basic data for the identification, protection and utilization of germplasm resources of P. ludlowii .[Methods] Nine fruit traits of three different populations of P. ludlowii in Tibet were tested and analyzed.[Results] The mean values of 9 fruit traits of P. ludlowii were different in different populations;the coefficients of variation of different traits of different populations were also different;there were morphological differences of different sizes among individuals in each population;there were significant differences in 8 traits (pod length, pod width, pod thickness, pod weight, seeds per pod, seed length, seed width, and seed weight) among different populations. Among the 9 traits of the three P. ludlowii populations, the variability of the five traits was higher in the fruit pods, the variation degree of five traits including pod weight, pod thickness, seeds per pod, and seed weight was higher. It is of great significance for the screening and preservation of the germplasm resources of P. ludlowii . According to the principal component analysis (PCA), the seed weight, seed width, and seed length, i.e. the seed traits, were the main factors causing differences in fruit traits among populations. There was a certain correlation between different traits of P. ludlowii . Among the 36 Pearson- related combinations of 9 fruit traits, 11 combinations had extremely significant correlations, and 8 combinations had significant correlations, indicating that there was a certain correlation between fruit traits in the growth and development. Through cluster analysis, three populations of P. ludlowii can be divided into two categories. The BV population was a category, which is characterized by long pods, long seeds, wide seeds, thick seeds and large seed weight. Therefore, the BV population is suitable material for breeding excellent varieties.[Conclusions] This study provides basic data for the identification, protection and utilization of germplasm resources of P. ludlowii .

Estimation of Biodiversity Conservation Value of Forest Ecosystem in Nyingchi Prefecture of Tibet

The estimation was made for the conservation value of forest ecosystem biodiversity in Nyingchi Prefecture of Tibet.The results showed that the annual economic benefits of biodiversity in Nyingchi Prefecture were about 21.4 billion yuan,and the annual economic benefits of global biodiversity were about 3 trillion USD.It indicated that the ecological value of forest ecosystem in Nyingchi Prefecture is high,forest ecosystem has extremely important ecological value.Therefore,in the decision-making process,it is necessary to strengthen the protection of forest ecosystem,with particular emphasis on the restoration of damaged ecosystem.

Study on the Growth Adaptability of Ligustrum L. Plants in Southeast Tibet

In this study,we choose the street green space in Bayi District,Mainling Town of Mainling County and Zhamu Town of Bomê County in Nyingchi City as investigation sites.In each investigation site,we select the undamaged plant communities of moderate density as objects of investigation and record,and establish the investigation database.Based on the habitat records and natural ecological conditions,we analyze the growth adaptability of Ligustrum L.plants in Southeast Tibet and the key influencing factors.It is found that the Ligustrum L.plants introduced in Southeast Tibet mainly include Ligustrum lucidum Ait.,Ligustrum quihoui Carr.and Ligustrum vicaryi.The growth adaptability of Ligustrum lucidum Ait.plants is divided into high level,middle level and low level.According to the investigation results,the frequency of Ligustrum lucidum Ait.plants with good growth status is greater than 65%.In general,the plants are fond of light,and have certain tolerance to cold.They can be cultivated in open field and show good growth adaptability in Southeast Tibet,so these plants can be further applied.

外来入侵物种在青藏高原的入侵性和生态影响不一致

在全球变化背景下,管控入侵物种是一项具有挑战性的工作。这主要由于从入侵物种的入侵性推断它们的生态危害存在很大的不确定性。更确切地说,入侵性和生态危害的关系可能依赖于所研究的生态系统,同时这种关系还没有在像青藏高原这样独特的高寒生态系统中被研究过。在这项研究中,我们在青藏高原东南部的一个样带上调查了32种入侵植物。我们将这些入侵物种的生态危害分解为分布范围(R)、局部丰度(A)和个体对本地植物群落的影响(E)3个组分,并研究了植物性状对这些组分的相对贡献。研究结果表明,入侵植物的入侵性(R×A)和其所产生的危害(R×A×E)没有相关性。这表明这些入侵植物的入侵性不能反映它们对本地群落生态危害的严重性。在青藏高原,R和A共同驱动了入侵性,而R单独驱动了生态危害。植物性状并没有通过这3个组分驱动入侵性和生态危害,只有果实类型(主要是浆果)影响了E。我们的结果表明,驱动入侵性和生态危害的组分的不匹配导致了入侵植物的入侵性不能反映它们的生态危害。因此,关于入侵物种的管控应该优先考虑那些分布广泛的物种或者已经被证实会对本地物种产生负面影响的物种。