A Brief Analysis of the Non-commercial Forest Compensation System in China

The non-commercial forest is an important natural resource protecting the environment and contributing to the sustainable development of a nation. Due to its crucial positive external effects, it is inevitable policy that non-commercial forestry should be invested by government, thereby formulates the non-commercial forestry compensation system. This paper first discusses the theoretical basis of non-commercial forestry compensation system and the process of establishment of non-commercial forestry compensation system in China, and then analyzes the deficiency in the current compensation system.

Empirical Analysis of Factors Influencing Compensation for Non-commercial Forests under CVM

Based on non-commercial forests in Kunming City,this article conducts survey of 506 households in Kunming City to evaluate their willingness to pay ecological benefit of non-commercial forests,using Contingent Valuation Method(CVM);to analyze factors influencing their willingness to compensate for non-commercial forests,using multivariate statistical analysis method.The results show that income,educational level, housing ownership,outdoor exercise time,whether to be concerned about environmental problems,frequency of obtaining forest-related information monthly and whether understanding non-commercial forests or not,are the most principal factors influencing willingness to pay.

A Study on Compensation for Management and Protection Expenses of Non-commercial Forests

This paper analyzes the compensation nature of non-commercial forests under different ownership from two aspects, namely, whether the property right is limited and whether the management and protection expense has been incurred: there are no economic loss compensation problems caused by changes and limitation of property rights for the state-owned non-commercial forests with only the compensation on management and protection expense; but for the non-commercial forests owned by collectives or individuals, double compensation for both the economic loss and management expense exists because of limitation on the property right. In addition, an inframarginal economic analysis framework has been built for the management and protection compensation problems faced by non-commercial forests under different ownership in the perspective of the division of labor. Research results show that: the compensation standard for the management and protection expenses of non-commercial forests shall fall in between the "completely self-sufficient forestry economic structure U(Ayz)" and the "completely specialized productive structure of non-commercial forests U(B1)".

Web service based spatial forest information system using an open source software approach

For technical and other reasons there is a dilemma that data providers cannot find an appropriate way to redistribute spatial forest data and data users who need spatial data cannot access and integrate available forest resources information. To overcome this dilemma, this paper proposed a spatial forest information system based on Web service using an open source software approach. With Web service based architecture, the system can enable interoperability, integrate Web services from other application servers, reuse codes, and shorten the development time and cost. At the same time, it is possible to extend the local system to a regional or national spatial forest information system. The growth of Open Source Software （OSS） provides an alternative choice to proprietary software for operating systems, web servers, Web-based GIS applications and database management systems. Using open source software to develop spatial forest information systems can greatly reduce the cost while providing high performance and sharing spatial forest information. We chose open source software to build a prototype system for Xixia County, Henan Province, China. By integrating OSS packages Deegree and UMN MapServer which are compliant to the OGC open specifications, the prototype system enables users to access spatial forest information and travelling information of Xixia County which come from two different data servers via a standard Web browser and promotes spatial forest information sharing.

Code Reviewer Intelligent Prediction in Open Source Industrial Software Project

Currently, open-source software is gradually being integrated into industrial software, while industry protocolsin industrial software are also gradually transferred to open-source community development. Industrial protocolstandardization organizations are confronted with fragmented and numerous code PR (Pull Request) and informalproposals, and differentworkflowswill lead to increased operating costs. The open-source community maintenanceteam needs software that is more intelligent to guide the identification and classification of these issues. To solvethe above problems, this paper proposes a PR review prediction model based on multi-dimensional features. Weextract 43 features of PR and divide them into five dimensions: contributor, reviewer, software project, PR, andsocial network of developers. The model integrates the above five-dimensional features, and a prediction model isbuilt based on a Random Forest Classifier to predict the review results of PR. On the other hand, to improve thequality of rejected PRs, we focus on problems raised in the review process and review comments of similar PRs.Wepropose a PR revision recommendation model based on the PR review knowledge graph. Entity information andrelationships between entities are extracted from text and code information of PRs, historical review comments,and related issues. PR revisions will be recommended to code contributors by graph-based similarity calculation.The experimental results illustrate that the above twomodels are effective and robust in PR review result predictionand PR revision recommendation.

基于地铁客流与建成环境映射关系的新线车站分类方法

科学合理的车站分类对于客流特征研究预测、车站设施布局优化以及周边土地开发建设具有重要意义。针对新线开通前新建车站客流数据未知而导致车站分类不准的问题,提出一种基于地铁客流与建成环境映射关系的新线车站分类方法。首先,从客流角度选取组合聚类指标对既有车站进行聚类,形成各类车站的客流特征区间。其次,从建成环境角度计算既有车站的土地混合熵、不同POI(Point of interest)数量、度和介数等特征,利用随机森林(Random forest,RF)重要度指标筛选和对数变换拟合确定建成环境特征与地铁客流特征的映射关系表达式。最后,输入新线车站的建成环境特征,依据上述映射关系计算新线车站的客流特征值,结合既有车站的客流特征区间进行新线车站客流特征归类,实现客流数据缺失条件下的新线车站分类。为验证方法有效性,采用北京地铁数据进行案例验证。研究结果表明:基于地铁客流与建成环境映射关系的分类方法能够实现新线车站开通前的车站类型提前划分,具有较好的分类结果;进一步分析发现工作日车站与周末车站分类存在的差异与通勤行为特性、土地开发程度有关;研究方法在不同线路数据集上都表现出较好的分类效果,具有较强的适用性。研究结果可为缺失数据条件下的车站分类和新线开通期地铁运营组织提供新的思路和方法。

基于灰狼算法改进随机森林算法的爆破振动速度预测研究

为改善露天矿爆破作业过程中的峰值质点速度在采用传统经验公式和单一仿生算法时预测精度不够的问题,引入灰狼算法(GWO)优化了随机森林算法(RF)中决策树的棵数和层数2个超参数,成功构建了基于灰狼算法改进的GWO-RF爆破振动速度预测模型。结合某爆破工程69组爆破监测数据,以爆心距、最大段药量、总装药量、微差时间、炮孔数、孔距、孔深及排距为输入参数,运用GWO-RF预测模型和RF模型进行爆破振动峰值速度预测对比。结果表明:GWO-RF组合算法能够考虑更多符合实际的爆破振动速度影响因素,GWO-RF组合算法误差率比RF算法提高了37.83百分点;GWO-RF组合算法的爆破振动速度预测精度达到97.72%。说明GWO成功优化了RF中决策树的2个超参数,也证明GWO-RF组合算法能很好进行露天矿爆破振动速度预测。

露天煤矿排土场不同林龄沙棘林下土壤质量变化

以鄂尔多斯满来梁露天煤矿排土场不同林龄沙棘林土壤为试材,排土场无植被样地为对照,以时间代替空间的方法对不同林龄林下沙棘土壤进行采样,对比分析土壤容重、土壤含水率、土壤孔隙度、有机质、土壤pH、速效氮、速效磷、速效钾,研究了不同林龄沙棘对土壤质量的影响,以期为露天煤矿排土场植被恢复提供参考依据。结果表明:不同沙棘样地内土壤物理性质存在差异性,其中土壤含水率、土壤孔隙度变化较为显著,分别上升了1.658%、4.140%。通过种植沙棘土壤化学性质总体来说得到了一定程度改善,其中速效氮、速效钾较为明显,分别提高了8.36、11.93 mg·kg^(-1)。通过土壤质量指数(SQI)计算可得,土壤质量随着沙棘林龄增长升高了0.05,土壤质量在一定程度上得到了有效改善。

上海市开放休闲林地建设现状与建设需求调研分析

采用问卷调研、实地调研和访谈调研相结合的方法,从区域分布、服务功能、建设规模、设施配套、周边资源等方面对上海市开放休闲林地建设现状和市民需求进行调研、分析。结果表明,开放休闲林地建设现状在区域分布、服务功能、配套设施、周边资源和养护管理方面与市民需求存在差异,尚不能完全满足市民需求,存在着区域分布不均,配套设施不足等问题。提出规划引领,加强资源整合,规划项目流程等提高开放休闲林地建设水平和养护质量的建议。

Natural regeneration characteristics of Pinus sylvestris var. mongolica forests on sandy land in Honghuaerji, China

Natural regeneration in Mongolian pine, Pinus sylvesttis var. mongolica, forest at Honghuaerji of China （the original of the natural Mongolian pine, forest on sandy land） was studied in 2004. The total mean values of regeneration indexes were higher in mature stands （more than 80% individual stems were older than 50 years）, the maximum of regeneration index reached 29 seedlings, m^ 2, with lowest values in the younger stand, e.g., in 32-year old and 43-year old stands. The stand age was an important factor determining the natural regeneration, which was the best in the older stands in this investigation （e.g. about 80-year old）. The regeneration index seemed not to be closely in relation to canopy openness although Mongolian pine is a photophilic tree species. In each type of gaps, natural regeneration was very well. Regeneration indexes were satisfactory at the south and east edges in the circle gaps; and at the east edge of the narrow-square gaps. Results indicated that Mongolian pine, seedlings could endure shading understory, but it would not enter the canopy layer without gap or large disturbance, e.g., fire, wind/snow damage or clear cutting etc. These results may provide potentially references to the management and afforestation of Mongolian pine, plantations on sandy land in arid and semi-arid areas. Researches such as the comprehensive comparisons on regeneration, structure and ecological conditions and so on between natural Mongolian pine, forests and plantations should be conducted in the future.

An easy,accurate and efficient procedure to create forest fire risk maps using the SEXTANTE plugin Modeler

To prevent, detect, and protect against forest fires, forest personnel need to define rules for determining forest fire risk. In Portugal, all municipalities must annually produce forest fire risk （FFR） maps. To produce more reliable FFR maps more easily, we developed an open source model using the Modeler plugin of SEXTANTE in the program QGIS version 2.0 Dufour. The model provides all the maps involved in the FFR model （susceptibility map, hazard map, vulnerability map, economic value map, and potential loss map） and was produced according to Portuguese Forest Authority＇s （AFN, Autoridade Florestal Nacional） rules for determining the FFR. This model was tested for the Portuguese municipality Santa Maria da Feira, where 40 % of the total municipality area falls in the category ＂very high＂ or ＂high＂ fire risk. The ＂very high＂ fire risk area is mainly classified as broad-leaved forest and has the steepest slopes （〉15 %）. The distance of burned areas to roads was also analyzed; the proportion of burned areas increased with increasing distance to the main roads. In addition, 92.6 % of the ＂high＂ and ＂very high＂ risk zones were located in areas with lower elevation. These results confirmed that forest fire is strongly influenced not only by environmental factors but also by anthropogenic factors. The procedure implemented here was compared with our open source application already available in QGIS and also to the same procedure implemented in GIS pro- prietary software. Although the results were obviously the same, the model developed here presents several advan- tages over the other two approaches. Besides being faster, it is easy to change the model parameters according to user needs （i.e., to the rules of different countries）, and can be modified and adapted to other variables and other areas to create risk maps for different natural phenomena （e.g., floods, earthquakes, landslides）. The model is easy to use and to create risk and hazard maps rapidly in a free, open source environment that does not require any programming knowledge.

Exploring Factors Influencing Species Natural Regeneration Response Following Harvesting in the Acadian Forests of New Brunswick

In the Acadian Forest Region of northeastern North America, forest managers are under increasing public pressure to restore the forest to a more historic, natural condition by reducing in clearcutting and promoting partial-cut treatments that more closely emulate historic, local natural disturbance regimes. However, although numerous studies on the effects of partial-cutting on forest regeneration response have been conducted in surrounding temperate and boreal forest ecosystems, there are few studies that directly explore responses to various forms of harvesting within the Acadian Forest ecosystem, with its unique mixture of northern hardwoods and boreal forest species. Here, we conducted one of the first retrospective studies on forest regeneration following a variety of harvesting methods in the Acadian Forest using univariate and multivariate regression trees to assess regeneration response in 50 naturally-regenerating, harvested forest sites in New Brunswick, Canada. Our study shows that regeneration was highly influenced by harvest type, overstory composition, and environmental conditions as reflected by ecoregion classification. Canopy opening size (as controlled by harvest method) significantly influenced the dominance of regenerating species. The presence of conspecific overstory trees increased the likelihood of their regeneration following disturbance, supporting the direct-regeneration hypothesis, especially for species with limited seed dispersal (e.g., sugar maple (Acer saccharum Marsh.) and American beech (Fagus grandifolia Ehrh.). Despite reported problems elsewhere in eastern North America, neither American beech nor balsam fir (Abies balsamea (L.) Mill.) constituted significant competition for the desired species on a broad scale, but the presence of beech was a significant deterrent for yellow birch (Betula alleghaniensis Britt.).

Influence of Environmental Variables on the Natural Regeneration of a Forest under Restoration after Bauxite Mining and in a Reference Ecosystem in Southeastern Brazil

The shrub-tree floristic composition of the natural regeneration stratum of a bauxite mine in the process of restoration and in a reference ecosystem(remnant of a preserved secondary Seasonal Semi-Deciduous Forest)were analysed to evaluate forest restoration conditions after five years of planting.The influence of canopy openness,accumulated leaf litter and soil attributes in the regeneration stratum were also investigated in both the forests.The floristic composition of the regeneration stratum in the forest under restoration(16 species and 5,083 individuals ha-1)and in the reference ecosystem(58 species and 26,250 individuals ha-1)are distinct due to the difference in the environmental variables.Results showed that the reference ecosystem favours the presence of species that tolerate environments with greater shading and higher aluminium and organic matter content in the soil like Psychotria carthagenensis Jacq.,while the forest under restoration favours the presence of species adapted to fertile soils and those that tolerate greater luminosity like Vernonanthura phosphorica(Vell.)H.Rob.

基于SMA算法优化随机森林的PPV预测模型

爆破振动速度峰值(Peak Particle Velocity,PPV)的准确预测是有效控制爆破工程振动危害的前提。为了提高爆破振动速度峰值的预测精度,提出将黏菌算法(Slime Mould Algorithm,SMA)对随机森林(Random Forest,RF)中的树的个数和最小叶子点数2个超参数进行优化。以某露天爆破工程实例中收集的具有4个输入参数(最小抵抗线r、高差H、最大段药量Q_(max)、水平距离W)和1个输出参数(PPV)的23个样本的数据集为依据,将4种参数组合(Q_(max)-H-W-r、Q_(max)-H-r、Q_(max)-W-r、Q_(max)-r)作为随机森林算法中的输入参数,确定最优的参数组合。随后对SMA-RF模型、未优化RF模型和国内外常用的6组经验公式的预测结果进行比较,结果表明SMA-RF模型取得了最优的预测效果,因此在工程实践中推荐使用SMA-RF模型预测爆破振动速度峰值。

日本落叶松种子园和人工林优树自由授粉家系试验林比较

【目的】为日本落叶松持续遗传改良提供应用材料和初级无性系种子园去劣疏伐提供依据。【方法】在甘肃小陇山沙坝国家落叶松/云杉良种基地,采用完全随机区组试验设计,在日本落叶松采伐迹地营造了30个优树自由授粉家系(Ⅰ)和25个日本落叶松种子园自由授粉家系(Ⅱ)试验林,试验林Ⅰ和Ⅱ均为15个区组,区组内家系株数2株×2株配置,株行距1.5 m×1.5 m。【结果】种子园自由授粉家系试验林胸径、树高、材积平均达到(6.474±1.474)cm、(6.429±0.885)m、(1.274±0.599)×10^(-2) m^(3),显著高于人工林优树自由授粉家系试验林胸径、树高、材积的13.99%、9.18%和26.94%(P>0.05)。种子园自由授粉家系胸径、树高、材积的表型变异系数和遗传变异系数为13.76%、22.76%、47.02%和4.52%、1.96%、9.54%,家系遗传力和单株遗传力为0.729、0.544、0.735和0.214、0.156、0.210;优树自由授粉家系胸径、树高、材积的表型变异系数和遗传变异系数是21.92%、26.82%、60.03%和4.36%、2.91%、9.76%;家系遗传力和单株遗传力依次为0.645、0.626、0.598和0.169、0.175、0.148;优树自由授粉家系试验林胸径、树高、材积性状的遗传变异比种子园自由授粉家系更加丰富。种子园自由授粉家系子代测定回向选择指导初级无性系种子园去劣疏伐升级1.5代种子园,入选单株直接无性繁殖利用或作为高阶育种应用材料,种子园自由授粉家系按照40%的入选率,入选10个家系,入选家系平均胸径、树高、材积为6.6148 cm、6.8420 m、0.0143 m^(3),在家系选择的基础上,选择50个单株,单株入选率3.58%,入选单株平均胸径、树高、材积达到9.16 cm、7.60 m、0.026 m^(3);入选家系和单株材积的平均遗传增益达到9.39%和22.09%。优树自由授粉家系和单株入选率为30%和3.01%。【结论】种子园自由授粉家系试验林入选单株预期遗传增益为22.09%,可作为高世代种子园营建和进一步遗传改良的应用材料,并直接进行无性系繁殖利用,使育种早见成效。优树自由授粉家系试验林入选单株预期遗传增益为20.66%,补充遗传改良材料,不断丰富和拓展遗传改良材料的遗传基础,确保长期稳定的遗传增益和持续遗传改良。

基于随机森林二分类器的模块化多电平换流器子模块开路故障检测方法

随着模块化多电平换流器(modularmultilevel converter,MMC)应用领域的日益扩展,其子模块的开路故障引起了更多关注。为了诊断子模块开路故障,该文提出一种基于机器学习(machinelearning,ML)的故障检测和定位策略。根据开路故障特性,文中选择子模块电容器电压作为故障检测的关键指标,然后引入一种从电压数据中提取时域特征的方法,以构造用于有监督学习分类器的样本。在对随机森林的分类器进行样本训练后,检测策略实时电压数据的特征量判断每个子模块的工作状态。所提出的策略可快速准确地定位故障子模块,而无需添加额外的传感器或构建电路的数学模型。最后,通过三相MMC实验平台验证所提出的开路故障检测策略的有效性。

格氏栲天然林植物功能性状与系统发育对林窗大小的响应

为探究植物功能性状与系统发育对不同林窗大小的响应,以格氏栲天然林为研究对象,采用简单线性回归探讨格氏栲天然林的叶功能性状和功能多样性随林窗大小的变化规律,并运用Pearson相关分析研究系统发育多样性与功能多样性的相关性,结合系统发育树和功能性状树揭示物种适应策略。结果表明:格氏栲天然林的比叶面积随林冠开度的增大而极显著减小(P<0.01),叶干物质含量随林冠开度的增大而显著降低(P<0.05),叶片氮含量随林冠开度的增大而极显著降低(P<0.01),叶片厚度随林冠开度的增大显著增大,叶绿素含量和叶片磷含量随林冠开度的增大显著升高(P<0.05)。增大林冠开度,格氏栲天然林的功能均匀度、功能分歧度和功能离散度具有显著降低的趋势(P<0.05),而功能丰富度和Rao二次熵系数无明显的变化趋势。格氏栲天然林的系统发育结构和系统发育多样性与功能多样性之间的相关性较弱,仅系统发育多样性指数与功能丰富度呈现极显著正相关(P<0.01)。格氏栲天然林的叶功能性状均未检测到显著的系统发育信号(P>0.05),且许多亲缘关系较远的物种具有功能相似性,表现出对外部环境的性状趋同。格氏栲天然林林窗更新过程中,植物叶功能性状具有趋同适应特性,生境过滤主导群落构建与物种共存。

基于PCA-RF的边坡稳定性预测

随着露天矿山开采深度的增大,高陡边坡数量也越来越多,边坡灾害发生频次逐年上升,为减少边坡灾害的发生,有必要开展边坡稳定性预测研究。通过对机器学习算法的对比和筛选,提出了一种将主成分分析(PCA)与随机森林模型(RF)相结合的露天边坡稳定性预测模型,边坡实例预测结果显示,该模型预测准确率达100%;通过6折交叉验证法评估发现,该模型的预测精度高达94.44%。将该模型应用于拉拉铜矿东部露天采场终了边坡的稳定性预测,结果表明,边坡东帮、西帮、南帮、北帮均处于稳定状态,该预测结果可为矿山实际生产提供参考。

单相触树接地故障引燃特性及模型分析

针对单相触树引燃植被进而引发森林火灾问题,为明确植被的引燃特性与温升机理,搭建试验平台对导线接触松木进行研究,分析导线触树引燃植被过程中的引燃现象与温度变化。分析发现植被引燃分为初始接触、水分蒸发、炭化通道、蔓延贯穿4个阶段;同时,泄漏电流受温度影响也呈现出明显的4个发展阶段特点;植被温度升高的热量来源于电流热效应与物体传热。根据热量作用途径与温升机理,提出计算燃点-时间的温升模型,对植被蔓延至不同位置的明火时间进行预测分析。验证结果表明,计算模型具有较高的准确性,对指导线路引发森林火灾防治工作具有重要意义。

Changes in snow parameterization over typical vegetation in the Northern Hemisphere

季节性降雪对气候变化很敏感,常被当作气候变化的信号.由于其局地特征差异显著,不同下垫面类型的积雪过程也不尽相同.北半球中高纬度的典型下垫面(开阔灌丛,常绿针叶林和混交林)在积雪覆盖率和雪深之间有着独特的关系曲线,这种关系不仅代表了积雪过程和融雪过程的特征变化,更能用于模式进行积雪预测.研究发现,北半球中高纬度的增温改变了积雪参数化关系,进一步影响了局地能量和水循环,造成开阔灌丛的北缩和常绿针叶林及混交林的扩张.然而,目前模式中的积雪参数化并不能很好地再现全球变暖影响下融雪阶段出现的加速融化过程,并且进一步影响对春季融雪的生态影响的理解.