一种基于Python与ARCGIS模型构造器的小班四至坐标提取及编号方法探讨

探讨了小班四至坐标提取、四至坐标的编号排序方法,基于ARCGIS模型构造器,使用Python脚本语言实现小班四至坐标的快速自动提取以及坐标编号排序,为开展林业调查规划设计工作节省大量人力,较大幅度地提高了林业调查规划设计的成图效率。     

基于Arcpy数据的林地小班自动排序编号

以重庆黑山国家森林公园林地资源数据为例,通过ArcGIS软件中集成的Python窗口调用Arcpy实现自动识别林地小班并依据林班(村)赋值小班号,达到林地小班自动编号的目的。认为该方法简明可行,将跨平台的操作整合,实现了林地小班自动排序,特别是避免了人为编号漏排、误排、错排等失误,大大提高了林地小班编号的效率,也为林业资源数据的自动化管理提供了新思路。     

ArcGIS10．0与Excel2007相结合实现林业小班自动编号的探讨

运用ArcGIs软件绘制森林资源规划设计调查成果图和林业专题图后,进行手工小班编号是一件费时、费力的工作,且易出错,编号过程中一旦失误或疏漏,经常会出现前功尽弃的情况。运用ArcGIS10．0与Excel 2007相结合,借助ArcGIS10．0的优点和Excel 2007的操作简易性,实现林业小班编号的自动化,提高工作效率。     

基于ARCGIS的林业小班自动排序研究

文章研究ARCGIS和Visual Fox Pro 6.0等软件,以内蒙古辉河国家级自然保护区湿地资源调查小班排序为例,通过在ARCGIS中提取必要的空间位置信息,利用VFP(Visual Fox Pro)进行小班自动排序,再回挂到GIS软件的过程以及利用ARCGIS的Spatial ETL Tools工具排号的方法,通过实践证明,这些方法简单易学,容易掌握,为林业小班自动编号技术另辟蹊径,便于大家按照自己的实际需求进行编号,为林业小班自动编号提供一定的参考,为大家开拓了林业小班自动编号的思路,起到抛砖引玉的效果。     

林地“一张图”小班自动排序编号——基于Python脚本

为提高林地"一张图"小班自动排序编号的效率,以重庆青山湖湿地公园资源数据为例,通过编写Python脚本自动识别小班,并依据林班(村)及小班质心坐标,实现对小班的自动排序编号。该方法独立于软件操作,不仅避免了多步骤、跨平台的操作,也不用通过在Arcmap中集成的Python窗口输入代码,具有更强的通用性、兼容性、拓展性。为林业资源数据的自动化处理提供了新途径。     

巧用Excel函数实现林业小班号自动赋值

在林业调查设计成果图中,要分行政区域从上往下、从左向右对小班编号,费时费力,一旦出错,功亏一篑。巧用Excel函数实现不同区域内小班号按自然数自动赋值,达到事半功倍的效果。     

基于林地“一张图”的小班自动编号探究

以林地一张图小班排序编号为研究对象,基于ArcGIS10.2浮动版,用简单的Python语句求算小班周界横坐标最小值、纵坐标最大值,在查找相同的工具制作表中,图层与表连接,在横坐标最小值与纵坐标最大值相等的相邻小班顺序值字段中输入从左到右顺序值用于排序,导出图层属性表,采用Excel 2010函数countif自动编号,图层与Excel表连接,用VBScript语言字符串函数left表达式格式化小班号,对横坐标最小值与纵坐标最大值相等出现错误的小班编号,手动修改小班号错误。其操作简单,容易理解,实用,可解决极少数小班号编号不准确的问题,使小班自动编号准确,符合林业调查规划小班编号规则。     

Excel与ArcGIS相结合自动编写森林资源规划设计调查小班号方法初探

在ArcGIS平台上,利用电子表格--Excel对森林资源二类调查成果图制作中的小班进行编号,结果表明:Excel与ArcGIS相结合实现了小班编号的自动化,并具有准确、快捷、高效特点,克服了传统小班号编写方法的弊端.     

利用计算机制作地形图与勾绘小班求积的探讨

随着计算机办公的应用和普及,其应用领域不断扩展,但利用计算机制作林业规划作业设计图、计算小班面积缺乏相应的技术应用。通过本人工作中的实践和探索,利用计算机制作林业作业设计图、计算小班面积,从而摆脱了林业各类设计图制作、小班面积计算需大量人工完成的局面,实现电脑操作完成。本文介绍的是在没有专业的相关软件的情况下,利用几个图形处理软件完成林业各类设计图制作、小班面积计算方法,为解决林业各类设计工作提供了新的途径。     

森林小班跨图层编号地理处理模型的设计与实现

森林小班是准确标示到图上的基本区划单位,是森林资源二类调查统计和经营管理的基本单位。在森林地图采集与处理过程中,由于数据来源、采集方式、采集批次及林地类型的不同,采用分层的方式存储数据。而在实际制图过程中,往往需要对森林小班进行跨图层统一编号。传统森林小班编号工作人工参与度高,存在主观性强、效率低,易出现错误、漏号、重号等现象。为提高森林小班编号的效率和准确率,基于ArcGIS Model Builder设计了可嵌入在ArcGIS Desktop运行的符合ESRI空间建模标准的通用模型,实现了在不破坏原图层属性和几何结构情况下跨图层森林小班自动编号功能,解决了南北延伸较长和面积相差较大的小班编号在视觉上的跳跃问题、岛洞型小班的编号重复问题。通过案例数据测试,效果良好,有效提高了工作质量和效率,避免了森林小班编号过程中产生错误、漏号、重号现象,即准确、快捷、高效,还节省大量时间和人力投入,随着数据量的增加,效率提升更明显,有着良好的推广意义。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。