辽宁省冰砬山森林立地分类的研究

森林立地的研究是人工林集约经营的基础,正确地选择宜林地,科学造林,真正做到适地适树,必须进行森林立地分类。森林立地分类应是以现代森林生态学和生态系统理论为依据,研究植被(立木、下木、地被物)和地形、植被与土壤以及地形和土壤的关系。在揭     

森林立地指数的地统计学空间分析

森林生态系统立地质量的评估是森林生态系统经营管理和造林营林的重要理论基础与规划方法,也是研究森林生态系统生产力的重要内容。森林立地指数是一种已被普遍接受的评价森林立地质量的方法,然而由于技术所限,传统的森林立地指数调查方法因其耗时长、花费大,很难大面积的对森林立地指数进行估测和空间分析,地统计学结合地理信息系统技术为研究森林立地及空间格局提供了一条新的途径。以杉木人工林为研究对象,地统计学及地理信息系统技术为手段,根据江西省景德镇枫树山林场杉木立地指数空间分布特点,选取合适的变异函数理论模型,对其森林立地指数进行了估测和空间分析,并在精度验证的基础上对结果进行了评价。研究结果表明,江西省枫树山林场杉木人工林立地指数有中等程度的空间相关。通过模型模拟结果和实测结果对比,K-贝塞耳函数(K-Bessel)模型有较好的拟合效果和较高的精度,说明地统计学在森林立地指数的估测和空间分析中有一定的应用价值。     

森林生态系统立地指数的遥感分析

森林生态系统立地指数分析和立地质量的评估是森林生态系统经营管理和造林营林的重要理论基础与规划方法,也是研究森林生态系统生产力的重要内容.由于技术的限制,迄今为止,还没有实现森林生态系统立地空间分布格局的分析和开展立地条件随时间动态变化的研究.卫星遥感为大面积研究森林生态系统的生产力及其空间分布格局和动态提供了一条重要的途径.以云杉为对象,利用卫星遥感为研究手段,在岷江上游的四川西北部松潘镇江关流域研究森林生态系统立地指数的空间分布特点,探索有关遥感反演模型的建立,并通过有关精度的评估分析这种高技术应用的价值和潜力.研究结果表明,遥感植被指数NDVI和TNDVI与野外实测云杉立地指数（SI）基本为线性相关.通过对模型模拟结果和实际测定结果的比较研究,发现在1：1比例的分析图中,NDVI和TNDVI的遥感反演模型都有很好的拟合效果与较高的精度,说明通过遥感植被指数的方法测定森林立地指数具有较高的实用价值.     

我国林业基础研究刍议

自然科学基础研究是整个科学技术研究的重要组成部分,是应用研究及高技术研究的奠基石。作为自然科学中的一个组成部分,林业科学亦不例外,其应用研究和开发研究的成功和发展在很大程度上依赖于林业基础研究的深化,即对森林自然现象的认识和了解。林业基础研究在宏观方面,主要是揭示森林发生、发育的客观规律及原理,包括森林生物间相互依存、相互制约的机理研究,森林生物多样性的研究,森林生态系统的研究,森林群体遗传规律的研究,林业基本科学数据的收集、整理及分类研究,森林病虫害发生规律的研究,森林与外界环境的相互关系研究,森林资源动态变化规律以及森林经营活动中的自然规律研究。     

森林生态系统中土壤微生物的作用与应用

土壤微生物作为森林生态系统的重要组成部分,在林业可持续发展中扮演重要角色．本文就土壤微生物在森林生态系统中的作用作了综述．内容包括：土壤微生物区系及生物量在林业可持续发展中的作用、菌根在林业可持续发展中的作用、植物病原微生物对林业可持续发展的影响、PGPR在林业可持续发展中的作用．并对其今后的发展趋势及应用前景等问题作了探讨,提出了今后应进一步开展的研究方向．     

基于结构方程模型分析森林生态安全的影响因素

森林生态安全是维持国家生态安全的重要基础,也是人类生存的必要环境。森林不仅为人类提供木材和其他林副产品等实物价值,还具有美化环境、固碳释氧、涵养水源、防风固沙等生态服务价值,对维持生态平衡有重要作用。生态安全的相关研究多集中在构建评价指标评价森林生态安全,研究内容相对单一,而针对林业生态-产业共生关系的研究,并没有对林业产业类型进行区分,其次,林业产业发展对森林生态安全的影响研究较少。针对上述问题,在考虑产业分类的基础上,基于PSR理论和狭义的森林生态安全定义,利用31个省(市、自治区)3年的林业统计数据,运用PLS结构方程模型分析林业产业发展、森林生态保护对森林生态安全的影响及影响的大小,并分析了各地区森林生态保护的响应活动,为林业产业发展和森林生态保护的政策制定提供依据,从而促进林业的可持续发展。基于上述分析得出如下结果:(1)林业产业发展对森林生态安全无显著影响,但有部分子产业有森林生态安全有影响;(2)林业一产发展对森林生态安全有显著地直接影响,路径系数为0.175,间接影响不显著;(3)林业二产和三产发展对森林生态安全的直接影响和间接都不显著;(4)三类产业对林业产业发展的影响均显著,影响的大小分别为林业二产(0.636)、林业一产(0.204)、林业三产(0.151);(5)森林生态保护对森林生态安全有显著地直接影响,路径系数为0.619;(6)相对于其他地区,西部的森林生态保护活动积极性不高。由此得出如下结论:林业产业发展及林业二产、林业三产对森林生态安全未形成压力,只有林业一产发展对森林生态安全产生了正压力,需进一步加强林业产业结构的调整;加大保护响应力度对森林生态安全的影响大于合理利用的正压力;加强西部区域的森林生态保护力度,提高森林生态安全。     

辽东山区核桃楸人工林立地类型数量分类的研究

辽宁东部山区是我国用材林基地之一,该区气候湿润,土壤肥沃,适于核桃楸生长。为了在经营管理上做到“适地适树”,我们做了核桃楸林立地类型数量分类的研究。首先,选定与立类型密切相关的立地因子,建立多变量数学模型,计算其线性组合函数值,即主分量。用第一主分量与第二主分量作两维排序,再分别进行两维聚类,划出核桃楸立地类型。 为使用方便起见,以信息量最多的第一主分量,编制核桃楸立地类型上层林分高表,应用于林业生产实际。     

关于森林基础设施属性的探讨

分析了生态基础设施概念的由来和发展,国际社会对森林功能和作用的认识过程,森林对我国经济建设和生态安全的重要性,以及当前林业生态建设的形势和所面临的问题,提出应将森林定位为现代社会国民经济和社会发展的基础设施,强调了森林基础设施定位对转变当前林业生态建设方式的重要作用．在综合分析森林生态系统特点的基础上,认为森林基础设施属性具有一定的特殊性,即主体由活体的生物材料构成,权属带有明显的多元性质,所以林业生态建设的模式和管理体制既要遵循基础设施的基本原则,又应考虑到森林的特殊性．提出了当前开展林业生态建设的4点建议：发展以人与自然和谐为核心的现代生态观;建立长期稳定的林业生态建设投资渠道;按照基础设施建设的原则实施林业生态建设工程;按照基础设施管理的原则经营森林．     

GPS定位仪在林业资源管护中的应用

经济正在不断发展,科技正在不断进步,在林业领域采用先进的科学技术对林业的发展具有非常重要的作用。GPS技术作为一项新兴的科学技术,在我国具有广泛的应用。我们把先进的GPS技术引入到林业领域中,对森林资源进行监测,对森林灾害预警,使我国林业有了更好的发展。     

中国热带森林植被类型研究历史和划分探讨

热带森林是我国森林植被的重要组成部分,明确其森林植被类型分类对于生物多样性维持机制研究和保护管理等都具有重要意义。该文以中国热带森林植被分类研究中存在的问题为出发点,通过阐述我国各省区植被类型分类的研究历史,在综合考虑多种生物和非生物影响因素的基础上,提出一个新的热带森林植被类型分类框架以供探讨。结果表明:(1)尽管针对我国热带森林的分布范围和群落特征等都已开展了诸多研究,但对我国热带森林植被类型的划分依据和分类体系仍存在争议。(2)尽管我国的热带森林都处于季风气候区带内,但许多热带地区的森林植被类型并不只是受季风影响,而是气候带、关键气候因子、地形、土壤反馈和物种适应等多种因素共同作用的结果。(3)我国的热带森林植被包括5个植被型,即非典型性热带雨林、热带季雨林、热带山地雨林、热带山顶苔藓矮林(热带云雾林)和热带针叶林,其中热带季雨林植被型包含4种植被亚型[热带落叶季雨林、热带半落叶(半常绿)季雨林、热带常绿季雨林和热带石灰岩(石山)季雨林]。(4)阐明了上述热带森林植被型和植被亚型在我国各省区的分布情况,并提出未来有必要对人工恢复后的热带森林进行评估和植被类型划分。综上所述,该文提出一个新的热带森林植被类型分类框架,以期为今后基于不同地区开展热带森林比较研究提供参考。     

西藏鲁朗森林立地分类的初步研究

采用主成分分析法对西藏鲁朗森林立地66个标准地调查实测材料分析,选取海拔高度、坡度、坡向、土层厚度、土壤质地、石砾含量、土壤有机质含量7个因子,共划分出8个森林立地类型.结果表明,在西藏高山峡谷林区以此方法划分森林立地类型较适宜.     

Cellulose hydrolysis in evolving substrate morphologies I: A general modeling formalism

We develop a general framework for a realistic rate equation modeling of cellulose hydrolysis using non‐complexed cellulase. Our proposed formalism, for the first time, takes into account explicitly the time evolution of the random substrate morphology resulting from the hydrolytic cellulose chain fragmentation and solubilization. This is achieved by integrating novel geometrical concepts to quantitatively capture the time‐dependent random morphology, together with the enzymatic chain fragmentation, into a coupled morphology‐plus‐kinetics rate equation approach. In addition, an innovative site number representation, based on tracking available numbers of β(1,4) glucosidic bonds, of different “site” types, exposed to attacks by different enzyme types, is presented. This site number representation results in an ordinary differential equation (ODE) system, with a substantially reduced ODE system size, compared to earlier chain fragmentation kinetics approaches. This formalism enables us to quantitatively simulate both the hydrolytically evolving random substrate morphology and the profound, and heretofore neglected, morphology effects on the hydrolysis kinetics. By incorporating the evolving morphology on an equal footing with the hydrolytic chain fragmentation, our formalism provides a framework for the realistic modeling of the entire solubilization process, beyond the short‐time limit and through near‐complete hydrolytic conversion. As part I of two companion papers, the present paper focuses on the development of the general modelling formalism. Results and testable experimental predictions from detailed numerical simulations are presented in part II. Biotechnol. Bioeng. 2009; 104: 261–274 © 2009 Wiley Periodicals, Inc.     

Deciphering common recognition principles of nucleoside mono/di and tri‐phosphates binding in diverse proteins via structural matching of their binding sites

Nucleoside triphosphate (NTP) ligands are of high biological importance and are essential for all life forms. A pre‐requisite for them to participate in diverse biochemical processes is their recognition by diverse proteins. It is thus of great interest to understand the basis for such recognition in different proteins. Towards this, we have used a structural bioinformatics approach and analyze structures of 4677 NTP complexes available in Protein Data Bank (PDB). Binding sites were extracted and compared exhaustively using PocketMatch, a sensitive in‐house site comparison algorithm, which resulted in grouping the entire dataset into 27 site‐types. Each of these site‐types represent a structural motif comprised of two or more residue conservations, derived using another in‐house tool for superposing binding sites, PocketAlign. The 27 site‐types could be grouped further into 9 super‐types by considering partial similarities in the sites, which indicated that the individual site‐types comprise different combinations of one or more site features. A scan across PDB using the 27 structural motifs determined the motifs to be specific to NTP binding sites, and a computational alanine mutagenesis indicated that residues identified to be highly conserved in the motifs are also most contributing to binding. Alternate orientations of the ligand in several site‐types were observed and rationalized, indicating the possibility of some residues serving as anchors for NTP recognition. The presence of multiple site‐types and the grouping of multiple folds into each site‐type is strongly suggestive of convergent evolution. Knowledge of determinants obtained from this study will be useful for detecting function in unknown proteins. Proteins 2017; 85:1699–1712. © 2017 Wiley Periodicals, Inc.     

One parameter to describe the mechanism of splice sites competition

The choice of a splice site is not only related to its own intrinsic strength, but also is influenced by its flanking competitors. Splice site competition is an important mechanism for splice site prediction, especially, it is a new insight for alternative splice site prediction. In this paper, the position weight matrix scoring function is used to represent splice site strength, and the mechanism of splice site competition is described by only one parameter: scoring function subtraction. While applying on the alternative splice site prediction, based on the only one parameter, 68.22% of donor sites and 70.86% of acceptor sites are correctly classified into alternative and constitutive. The prediction abilities are approximately equal to the recent method which is based on the mechanism of splice site competition. The results reveal that the scoring function subtraction is the best parameter to describe the mechanism of splice sites competition.     

The amino acid sequence and reactive site of a single-headed trypsin inhibitor from wheat endosperm

The sequence of a trypsin inhibitor, isolated from wheat endosperm, is reported. The primary structure was obtained by automatic sequence analysis of the S-alkylated protein and of purified peptides derived from chemical cleavage by cyanogen bromide and digestion withStaphylococcus aureus V8 protease. This protein, named wheat trypsin inhibitor (WTI), which is comprised of a total of 71 amino acid residues, has 12 cysteines, all involved in disulfide bridges. The primary site of interaction (reactive site) with bovine trypsin has been identified as the dipeptide arginyl-methionyl at positions 19 and 20. WTI has a high degree of sequence identity with a number of serine proteinase inhibitors isolated from both cereal and leguminous plants. On the basis of the findings presented, this protein has been classified as a single-headed trypsin inhibitor of Bowman-Birk type.     

Geometric and chemical patterns of interaction in protein--ligand complexes and their application in docking

We present a new method for representing the binding site of a protein receptor that allows the use of the DOCK approach to screen large ensembles of receptor conformations for ligand binding. The site points are constructed from templates of what we called "attached points" (ATPTS). Each template (one for each type of amino acid) is composed of a set of representative points that are attached to side-chain and backbone atoms through internal coordinates, carry chemical information about their parent atoms and are intended to cover positions that might be occupied by ligand atoms when complexed to the protein. This method is completely automatic and proved to be extremely fast. With the aim of obtaining an experimental basis for this approach, the Protein Data Bank was searched for proteins in complex with small molecules, to study the geometry of the interactions between the different types of protein residues and the different types of ligand atoms. As a result, well-defined patterns of interaction were obtained for most amino acids. These patterns were then used for constructing a set of templates of attached points, which constitute the core of the ATPTS approach. The quality of the ATPTS representation was demonstrated by using this method, in combination with the DOCK matching and orientation algorithms, to generate correct ligand orientations for >1000 protein--ligand complexes.     

Development of plant communities after restoration of the Antaibao mining site,China

To investigate the dynamic changes in the artificial vegetation in an abandoned mining site,we analyzed the relationships among community types,environmental variables and community structure in the process of vegetation restoration in the Antaibao mining site,China by survey of the communities and use of biological dating methods.By means of the quantitative classification method (two-way indicator-species analysis,TWINSPAN) and the ordination technique (de-trended correspondence analysis,DCA; and de-trended canonical correspondence analysis,DCCA),the plant communities were classified into seven groups:community Ⅰ,Robinia pseudoacacia + Pinus tabulaeformis-Caragana korshinskii-Agropyron cristatum; community Ⅱ,Robinia pseudoacacia-Hippophae rhamnoides-Artemisia capillaries; community Ⅲ,Ulmus pumila-Elaeagnus angustifolia-Artemisia capillaries;community Ⅳ,Caragana korshinskii-Agropyron cristatum+Artemisia capillaries;community Ⅴ,Hippophae rhamnoides-Elymus dahuricus;cornrnunity Ⅵ,Elaeagnus angustifolia+Hippophae rhamnoides-Brassica jucea;community Ⅶ,Hippophae rhamnoides+Elaeagnus angustifolia-Salsola collina.We conclude that the community types and diversity are mainly influenced by the succession time and the soil organic matter content.The forest community is more adaptable to the special inhabitation than the shrub community.     

Risk-Based Zoning Strategy for Soil Remediation at an Industrial Site

After determining at an early stage of the project that the future land use of this New Jersey chemical manufacturing site remain industrial in nature, the site was zoned according to risk. The chemicals of concern (COCs) at the site included relatively low levels of mono- and polynuclear aromatic hydrocarbons, chlorinated aliphatics, as well as other volatile and semivolatile compounds. Direct human exposure scenarios were the key to the mitigation of risks related to soils because the groundwater migration pathway was already interrupted using groundwater recovery. A focused remedial strategy was developed to ensure that the exposure pathways (inhalation, ingestion, and dermal contact) are alleviated and the remedial measures are protective to the workers operating and/or maintaining the site. The risk evaluation process included a preliminary risk assessment (Tier 1) based on a comparison with pertinent soil cleanup criteria, a prioritization analysis to rank zones, chemicals and pathways of concern, and an application of the Risk Based Corrective Action (RBCA) approach (Tier 2) for construction worker exposure scenario. The risk assessment identified selected areas that would benefit from remedial actions. Prioritization Analysis classified the site into five high-priority (comprising 97% of the total health-based risk), three medium-priority (contributing to remaining 2 to 3% of the risk), and adequately protected areas. The boundaries and volumes of affected areas were delineated based on confirmatory soil sampling and statistical analyses. The remedial technologies selected for the site have achieved appropriate reduction in risk to comply with all State regulations and include (in addition to the institutional controls): ??Capping the site where only immobilesemivolatile contaminants are present ??Excavation and on-site treatment of the soils impacted by volatile organic com pounds through ex situ low temperature desorption, or alternative “biopile” treatment and natural attenuation, and ??Excavation and off-site disposal of limited volumes of soils This risk-based, integral approach helped identify the real significance of contamination present at the site and facilitated the development of suitable and adequate remedies. Had not it been for this approach, the mere comparison with soil cleanup criteria would have unnecessarily resulted in denoting all areas as nuisance contributors, and thus requiring some actions. New Jersey Department of Environmental Protection (NJDEP) has approved this approach and contributed to its accomplishment.     

Classification of Artificial Forest Site of Larix olgensis in Liaoning Province

Determinant factors influencing growth of Larix olgensis were screenced and interrelationships among topography soil and growth of L. olgensis were studied employing pathway analysis (PA), principal component analysis(PCA) and canonical analysis(CA). The research indicates that determinant factors are exposure soil texture, soil depth, and exposure is closely related to organic matter, soil texture, soil depth. Site classification was made by using a method of ecological forest site classification. 3 groups of site type and 14 main site types were devided for L. olgensis in the East part of Liaoning. Group of site type on shaded slope included 5 site types: thick, moderate silt loam and thick, moderate loam and thick clay loam. Group of site type on half-shaded and half-sunny slope included 6 site types: thick, moderate silt loam and thick, moderate loam and moderate sandy loam soil and thin soil. Group of site type on sunny slope included 3 site types: thick, moderate and thin soil.