植物DNA甲基化研究进展

植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。     

Armillaria ostoyae in managed coniferous forests in Kastamonu in Turkey

Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m². One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites.     

林木远缘杂交育种现状及研究进展

远缘杂交是拓宽种内遗传资源、扩大基因库和弥补近源杂交局限性的重要手段, 目前在林业生产上已取得了重要成果。然而, 由于生殖隔离的存在, 远缘杂交往往具有一定的不亲和性, 对育种进程造成了较大的阻碍。文中对远缘杂交育种的发展历史、原理、育种策略及在林业上的研究成果进行了综述, 并对远缘杂交育种过程中存在的困难及解决办法进行了分析, 以期为远缘杂交育种在林业上的应用提供参考。     

Variation in photosynthetic light-use efficiency in a mountainous tropical rain forest in Indonesia

Photosynthetically active radiation (Q)-use efficiency (epsilon) is an important parameter for deriving carbon fluxes between forest canopies and the atmosphere from meteorological ground and remote sensing data. A common approach is to assume gross primary production (P(g)) and net primary production (P(n)) are proportional to Q absorbed by vegetation (Q(abs)) by defining the proportionality constants epsilon(Pg) and epsilon(Pn) (for P(g) and P(n), respectively). Although remote sensing and climate monitoring provide Q(abs) and other meteorological data at the global scale, information on epsilon is particularly scarce in remote tropical areas. We used a 16-month continuous CO(2) flux and meteorological dataset from a mountainous tropical rain forest in central Sulawesi, Indonesia to derive values of epsilon(Pg) and to investigate the relationship between P(g) and Q(abs). Absorption was estimated with a 1D SVAT model from measured canopy structure and short wave radiation. The half-hourly P(g) data showed a saturation response to Q(abs). The amount of Q(abs) required to saturate P(g) was reduced when water vapor saturation deficit (D) was high. Light saturation of P(g) was still evident when shifting from half-hourly to daily and monthly time scales. Thus, for a majority of observations, P(g) was insensitive to changes in Q(abs). A large proportion of the observed seasonal variability in P(g) could not be attributed to changes in Q(abs) or D. Values of epsilon(Pg) varied little around the long-term mean of 0.0179 mol CO(2) (mol photon)(-1) or 0.99 g C MJ(-1) (the standard deviations were +/- 0.006 and +/- 0.0018 mol CO(2) (mol photon)(-1) for daily and monthly means, respectively). In both cases, epsilon(Pg) values were more sensitive to Q(abs) than to daytime D. These findings show that the current epsilon-approaches fail to predict P(g) at our tropical rain forest site for two reasons: (1) they neglect saturation of P(g) when Q(abs) is high; and (2) they do not include factors, other than Q(abs) and D, that determine seasonality and annual sums of P(g).     

Structure of aquatic insect communities in tank-bromeliads in a East-Amazonian rainforest in French Guiana

Tank-bromeliads are discrete habitats which contain distinct aquatic communities, and which commonly occur in the neotropics. Because they span a broad range of ecological gradients in terms of habitat structure and amount of resources, researchers study the associations between the biodiversity of communities and these gradients in rainforests, where the very high species richness and densities within other continuous habitats makes it difficult to quantify animal communities. We analysed the diversity of aquatic insect communities in relation to different tank-bromeliad species in a primary rainforest (French Guiana) using artificial intelligence and complex optimization techniques to classify communities and model their determinants. First, the self-organizing map (neural network) was used to classify 158 bromeliads according to the quantitative structure of the insect communities. Catopsis berteroniana and Guzmania lingulata formed separate clusters of plants on the virtual map, while Vriesea splendens, Vriesea pleiosticha and Aechmea melinonii were grouped together in the remaining clusters. Some insect taxa occurred in all bromeliads, while other taxa were specific to a given species. Second, general linear modelling allowed us to specify the influence of the bromeliad species; water volume and volume of fine particulate organic matter inside of the tank; elevation above the ground; and sampling site on taxonomic richness and insect abundance. The number of taxa and individuals per plant increased with greater water volume, but the slope of the relationships depended on the bromeliad species. The significant influence of bromeliad species suggested that at similar water volumes different plant species had different taxon richness and insect abundance. Greater amounts of fine particulate organic matter were detrimental to community diversity in the tanks, probably because they decreased available space by clogging it and/or affected oxygen concentrations. The influence of tank-bromeliad species on the aquatic insect community was primarily related to their physical (and probably chemical) features rather than to species-specific associations sensu stricto. The classification of bromeliads with respect to animal species is likely to provide referential schemes for those biodiversity patterns to be expected under certain conditions, and may help to target model communities for subsequent experimental research.     

Influence of site in the wood quality of Eucalyptus in plantations in Brazil

Genetic materials interact with the environment in specific ways, therefore their responses in wood need to be better understood. The present study sought to evaluate the influence of different climatic conditions in Minas Gerais, Brazil on Eucalyptus grandis × Eucalyptus urophylla wood. Two six-year-old clones were cultivated in Belo Oriente, Ferros, Santa Bárbara, Itabira and Peçanha. Five trees from each clone were sampled from the base to top direction. Wood density, heartwood/sapwood ratio, vessels, fibres, and extractive and lignin contents were determined, as well as their correlation with environmental variables. Vessel diameters, heartwood/sapwood ratio, and extractive and lignin contents all increased due to higher water availability in Santa Bárbara and Itabira. In both genetic materials, the variables linked to growth and wood quality were related to environmental factors.     

科尔沁沙地盐碱地造林技术研究

通过多年对科尔沁沙地西部盐碱地提高造林成活率技术措施的研究，结果表明：采用开沟造林技术是适合当地特点的成功造林措施：造林成活率达到85％以上，林木生长量比一般整地造林方式高一倍。在地下水位浅、土壤盐渍化程度严重的地区，采用筑台地造林，其成活率可高达90％，造林5年后即可郁闭成林，林木生长量为一般造林地的2倍：采用上述2种整地造林技术，可有效改善土壤中养分和水分状况，同时土壤含盐量和pH值均明显下降，在沙地盐渍化轻度地区可采用穿透碱隔深穴造林措施。     

Decreased morphogenetic potential in peach palm stem-like cells in long-term in vitro conditions

Peach palm(Bactris gasipaes Kunth)has been micropropagated from pre-procambial cells that provide stem-like cell niches,(i.e.,pre-procambial cells),multipotent,pluripotent and totipotent for direct vascularization,adventitious buds and somatic embryogenesis,respectively.The direct induction of adventitious buds and somatic embryogenesis reduces the frequency of mutations when compared to indirect morphogenesis.Long-term in vitro cultivation of perennial species such as peach palm cause the clones to age and deteriorate;however,the consequences for morphogenesis potential are not fully clear.The morphogenic potential of peach palm clones established and in vitro cultivated for 8 years(regeneration of adventitious buds without callus formation)was investigated in leaves,roots and stem bases using histological and histochemical analyses.Data from long-term cultures(8-years-old)was compared to data from short-term cultures(1-year-old).Morphogenic pathways monitoring for direct induction of somatic embryos and adventitious buds revealed a strong morphogenic reduction potential in the pre-procambial cells,parenchyma cells in the proximal region of stem bases,and external cells of leaf sheaths.Initial cells of shoot apical meristems and pre-procambial cells commit cell reprogramming to the undifferentiated state and subsequent acquisition of cellular competence.These results are applicable in the micropropagation of peach palm,with consideration to obtaining clones and their long-term in vitro culture.     

Creating trust in institutions in Russian forest localities

Russia is a country with a low level of trust. In consequence, companies working in Russia have to emphasize the development and maintenance of trust with all their interest groups. In this paper we study how trust is built up at the local level with municipalities and local communities. Local level interest groups, however, seem to be less significant for companies in contemporary Russian countryside. This paper will provide an analysis of why local level interest groups are weak and what the consequences are. The paper also discusses legislation and regulations affecting social structures in the Russian countryside showing why and how much social responsibility is transferred to companies. In addition, the paper discusses whether private governance regulation, such as forest certification, will help local communities to be heard.The paper applies Douglass North's approach to economic development with formal and informal institutions, and also the literature on trust and the social responsibility of enterprises. Formal institutions such as national legislation and international privately controlled rules of FSC certification are compared with informal practices at the local level.Cooperation with companies and environmental organizations has complemented traditional Russian social responsibility and increased cooperation between the different interest groups. NGOs can also help local communities to be heard, but since companies are more concerned with the trust of their clients, weak municipalities remain humble receivers of aid. Globalization also makes companies pay more attention to their competitiveness, which will exert pressure on the government to arrange social security and strengthen municipalities. Structural changes in Russia will, however, take time, since Russia not only has to tackle the construction of new formal institutions but it must also deal with the increasing effects of globalization as it changes the traditional structures of democracy and a market economy.     

Natural regeneration in patch clear-cutting in Picea abies stands in Southern Finland

Abstract

The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha^–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha^?1), and 36% were at least satisfactory (≥1300 ha^?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting.     

Research advance in wood composites in China

Inthe21stcentury,thewoodsupplyinChinawillcontinLJetobelessthanthedemand,soChinawillneedtousewoodasetfectivelyasPossible.Theuseotwoodcompositesisaveryefficientwaytosavewood.ChinalackssLJfficientforeststomeetitsdemandforwood,especiallyinfinequalitywoods.BecauseofChina'spopulationandfiberdemand,efficientuseofwoocJismoreimportanttoChinathanthattosomeothercoLJntries.However,Chinawasneitherconvincedofthisandnordiditpayattentiontothestudyofwoodcompositesbeforethe1970's.FacingthewoodcrisisChinaf…     

唐山市采煤塌陷区湿地生物多样性调查及评价

湿地生物多样性评价是生物多样性保护和实现可持续发展的基础性工作,本研究采用全面调查、样地设置等多种方法对物种进行调查,运用物种多样性和生态系统多样性的指标体系对唐山市采煤塌陷区湿地生物多样性进行较全面的评价。       

Deposits in heartshakes in wood

Summary Crystalline or almost pure organic compounds can be formed either alone or with two or three related compounds in juxtaposition in shakes in central heartwood. The compounds may not always be present in the more complex extractives formed at the heartwood periphery. The largest amounts of deposits are in the innermost or widest portion of the shake. No evidence could be found of a source of substrate, energy or specific enzymes necessary for the selective biosynthesis of these deposits. They are considered to be formedin situ by an undetermined mechanism during enlargement of the shake.     

Agroforestry preferences in refugee hosting communities in Cameroon

Pressure on natural resources and local infrastructure often increase in areas of refugee settlement, and food and health security can decline as a result. Agroforestry is the use of trees and crops and/or livestock in the same farming system to achieve production and conservation objectives. These polycultures can help improve food security in refugee settlement areas by rendering diverse products while increasing conservation in the face of augmented population pressure. In the past 10 years, 90,000 Central African Republic refugees have crossed into Cameroon and settled in hundreds of villages. This study focused on agroforestry preferences among refugees and host-nationals in six villages in the Adamaoua Region of Cameroon. One-hundred and twenty-two community members participated in the study. Visual methods were used to quantify preferences for eight agroforestry practices and tested for statistically significant differences across gender, ethnicity, and status as refugee or Cameroonian. There were differences in practice preferences as well as preferences for implementation in a group or as a family. Most differences were between refugees and Cameroonians. Refugees were more likely to prefer practices that help meet basic needs and also more likely to prefer group implementation. Open-ended comments also were analyzed to contextualize quantitative results. Overall, results suggest that agroforestry preferences in refugee settings may relate to a greater degree on social class and experience rather than gender or ethnicity. Results also indicate common ground in that refugees and host nationals are likely to share many preferences.     

我国农业的一次思想革命——林农牧渔副新排列次序论引发的思考

作者介绍了林农牧渔副新排列次序的论点，认为这个新论，点将唤起全社会重新思考森林的作用和加强林业的意识；纠正小农业思想和做法，认真推行大农业发展战略；重视山区建设，解决水利命脉问题；改变我国农民只会耕田，不会耕山的传统习惯，学会合理经营山区和草原。     

影响森林细根分解的机理研究进展

细根是森林地下生态系统的重要组成部分,其生产、周转和分解构成土壤与生物间的物质循环,是陆地生态系统C和养分循环的重要环节。细根分解的影响因素总体来讲包括植物本身和环境因素,每个影响因子各自独立成体系,又彼此紧密联系。以往的研究基本上都是各因素相互独立的研究。本文根据国内外近几十年来树木细根分解的研究现状,对细根分解所受的影响因子进行了综述,旨在进行纵向比较,得出细根分解目前的研究进展和动态,探讨影响细根分解因素的作用机理;总结当前存在的问题,并对细根分解研究方向进行了展望,为我国细根分解研究的深入开展提供良好借鉴。     

Biomass harvesting in Eucalyptus plantations in Western Australia

Australia is at an early stage of exploring the use of forest biomass to generate energy. This study evaluated the biomass yield and the productivity rates of equipment for harvesting biomass in a poor-quality eucalypt plantation. The operation consisted of a tracked feller-buncher, grapple skidder and mobile chipper. Time study methods were used to measure the harvesting operation. A multiple regression model was constructed to predict skidding productivity. Biomass production was 63.9 t ha^?1 based on the recorded load weight of eight trucks. Delays were documented and analysed. The average delay for all equipment was about 30% of working time. The study results will help guide biomass harvesting managers to estimate productivity and cost of similar operation sites.     

浅谈鹤北林业局伐区生产工艺的复杂化和对应措施

鹤北林业局由于多年的大量采伐，带来了伐区生产的艰难性和复杂性，针对这种情况，为了确保伐区木材生产的安全，本文作者提出了具体的措施。     

桂林市寺庙园林植物应用探究

寺庙园林历史底蕴深厚 , 文化内涵丰富，园内的植物更是其独特内涵的体现。以唐代岭南佛教中心桂林的寺庙园林为例 ,研究其中植物景观的种类特点与配置结构。结果发现：11 处寺庙园林共有园林植物 75 种，隶属 52 科 67 属，其中桑科榕属 Ficus植物和天门冬科植物是最主要的组成部分；并且有些园林植物 ( 如桂花Osmanthus fragrans 、樟Cinnamomum camphora 等）既蕴含佛教内涵又体现了壮族文化。总体而言，桂林寺庙园林植物景观建设不仅体现了独特的山水特征，也包含着壮族文化底蕴。     

中国玉兰嫁接繁殖技术研究进展

玉兰是我国常见的绿化观赏树种，在生产实践中玉兰优良无性系常以嫁接方式进行扩大繁殖。近年来市场需求不断扩大，玉兰苗木供应短缺的问题开始出现。文中概述了植物嫁接的基本原理、玉兰嫁接育苗生产中的常用砧木和不同嫁接方法、影响玉兰嫁接成活率的主要因素等方面的研究进展，可为提升玉兰嫁接育苗效率、嫁接苗质量提供参考；此外，针对目前玉兰嫁接研究中存在的不足，建议在今后研究中从解剖学、生理学、分子生物学等方面深入探讨玉兰嫁接繁殖的调控机理，从而建立完善的嫁接繁殖技术体系，提高玉兰嫁接繁殖的效率，以促进玉兰品种资源的保存、推广及开发应用。