利用地理信息系统进行伐区采伐作业调查设计

为实现资源数据与图面资料的系统管理,利用森林资源管理与监测地理信息系统,经过一定的组织和定期的统一更改,实现数据和林相图的更新以及在此基础上的伐区调查设计工作.伐区设计、伐区生产管理与地理信息系统及GPS定位相结合,实现图形库与档案库的互查互动,全面掌握伐区情况.伐区设计的图文材料一次完成,形成从采伐许可、组织伐区作业到伐区验收一整套严格的采伐作业管理程序.     

人工林抚育采伐作业中的几个问题探析

分析目前在人工林抚育采伐中普遍存在着林分密度不均,各地块采伐强度不一,作业设计与实际脱节,林分抚育滞后,欠帐过大等问题.藉此提出重视后续资源培育,加强森林抚育工作,在作业设计中灵活应用森林采伐作业规程等建议.     

三亚市林木采伐现状分析

以三亚市为研究区,比较2019年至2021年林木采伐总体、起源结构和林种结构对林木采伐结构进行了现状与动态变化分析。结果表明,2019年至2021年三亚市林木采伐面积在536.98hm²～631.87hm²之间,采伐蓄积量在21845.92m³～36185.96m³之间,采伐出材量在15879.17m³～26037.58 m³之间。采伐天然林面积、蓄积量和出材量远远低于人工林,以经济林的采伐面积、蓄积量和出材量最高。近三年的林木采伐面积呈下降趋势,蓄积量和出材量呈先上升后下降趋势。建议加强设计人员的业务知识水平、林业信息化技术培训和监督管理,以期为森林资源的可持续发展提供保障。     

开鲁县林木采伐"阳光作业"

林木采伐是社会普遍关注的热点，开鲁县林木采伐审批，县、乡、村一律推行政务公开，“阳光作业”，做到公开、公平、公正。     

我国林木采伐管理对策研究

保护发展森林资源,是改善生态环境、维护生态安全的主要手段,也是实现森林资源"越采越多、越采越好、青山常在、永续利用"经营目标的具体措施。从我国国情林情出发,《中华人民共和国森林法》确定了限额采伐和凭证采伐两项基本制度,从源头上保护了森林资源。林木采伐管理,是实现森林资源可持续经营的重要手段。新形势下,应根据伐区具体情况科学设定采伐限额,加强采伐作业设计管理,优化林木资源管理手段,为森林资源科学发展和永续利用夯实基础。     

商品材采伐作业设计和流通管理的研究

控制商品材适度消耗是采伐限额管理的重要内容,由于毗邻县林业经营政策不一,税费不同,造成林区商品材非法外流严重,促使了林区乱砍滥伐。经研究认为：只要在林区进行采伐作业设计,经采伐验收后发给商品材流通票,凭流通票进行收购、加工、经营、运输商品材,利用木材检查站查验木材运输证和流通票,即可解决上述问题。     

林木采伐调查设计技术流程探讨

指出了林木采伐调查设计是又脏、又累、又苦的一项调查,调查人员往往需要翻山越岭,对设计人员的素质要求比较高。设计过程繁琐,需要注意的细节比较多。只有不断加强学习提高自身业务水平,才能有效保证设计质量。探讨了设计原则,讨论了设计程序,探索了每一个步骤注意事项,为今后采伐设计提供参考。     

Excel软件在林木采伐作业设计角规样地中的应用

利用Excel软件的函数功能,建立林木采伐作业设计角规样地表,操作规程为:1填写树种名和形高、出材率代码;2录入树种、径阶、断面积、平均高等调查数据;3填写采伐小班面积,其它数据可自动生成并进行汇总计算。通过Excel软件解决了角规样地调查内业查表、计算等工作繁琐、容易出错等问题。     

林木采伐权的制度设计

通过对林木采伐权的性质界定,关于林木采伐的规定及其缺陷分析,提出了完善林木采伐权法律制度的具体对策。     

Morphological acclimation and growth of ash (Fraxinus pennsylvanica Marsh.) advance regeneration following overstory harvesting in a Mississippi River floodplain forest

Stand-level growth responses and plant-level patterns of biomass accumulation and distribution were examined to learn how stand structure influences morphological acclimation and growth of green ash (Fraxinus pennsylvanica Marsh.) advance regeneration following overstory harvesting. Nine, 20-ha plots that received clearcut harvesting (100% basal area removal), partial harvesting (50% basal area removal), or no harvesting (control) were sampled to measure height, root-collar diameter, leaf, stem and root biomass, and leaf mass ratio (LMR), stem mass ratio (SMR) and root mass ratio (RMR) of ash regeneration. Six years after treatment, plot-level analyses indicated that ash growth was greatest in plots receiving clearcut harvesting, and least in control plots. Examination of LMR, SMR and RMR revealed that this growth response was not associated with acclimation that altered plant morphology. Total biomass ranged 275-fold among sampled plants, and much of this variation was accounted for by measurements of stand leaf area index (LAI). Along the gradient of stand LAI, values greater than 2 inhibited biomass accumulation. Stand LAI values less than 1.5 promoted ash biomass accumulation which reached a maximum where LAI values approached 0.7 and tapered above or below this value. Our findings indicate that green ash regeneration can be managed beneath light canopy cover, and the ability of seedlings to establish and persist beneath closed canopies and vigorously respond to release without having to endure prolonged morphological acclimation provides flexibility in developing regeneration protocols.     

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.     

Using the LANDIS model to evaluate forest harvesting and planting strategies under possible warming climates in Northeastern China

The Small Khingan Mountains in northeastern China provide most of the timber and wood products in the country. Evaluating the long-term effects of harvesting and planting strategies is important especially as the climate changes. In this study, we evaluated the effects of the projected climate warming on potential changes in species’ coverage (percent cover), area harvested (percentage of the study area) and species harvested, using the LANDIS model. Our evaluation was based on the harvest and planting plans specified in Natural Forest Protection Project (NFPP). Our simulated results show that the coverage of southern species such as Korean pine (Pinus koraiensis) and ribbed birch (Betula costata) increases, whereas the coverage of northern species like larch (Larix gmelinii), Kingan fir (Abies nephrolepis), spruces (Picea koraiensis and P. jezoensis) and Dahur birch (Betula davurica) decreases under the warming climate in the region. The species harvested primarily consist of the southern species, especially deciduous species under the warming climate. The warming climate leads to 11.2% increase in area harvested compared to that under the current climate, when planting is not simulated. When planting is simulated, tradeoffs between planting and area harvested are complex. The area harvested only increases in places where moderate planting is implemented, and decreases in places with both low (≤5% area planted) and high (≥30%) planting percentage. This is because when the planting percentage is low, the rate of increase of harvestable species due to planting is lower than the rate of decrease of warming-declining species. When the planting percentage is high, the rate of increase of planted species is higher than the rate of colonization of warming-adapted deciduous species, and the planted species delay the establishment of the warming-adaptable species that have short harvest rotations (due to lower harvestable ages). Our results suggest that the management strategy with planting area of 20% is the best among all the scenarios simulated. Under this warming climate, moderate planting area (e.g. 20%) increases the area harvested to about 43%, which is still less than that (58%) designated in the NFPP. These results have important implications for forest managers designing sustainable forest harvest and reforestation strategies for the landscape under the warming climate.     

Using landscape metrics and topographic analysis to examine forest management in a mixed forest,Hokkaido, Japan: Guidelines for management interventions and evaluation of cover changes

In this study, we identified the distribution characteristics of a mixed forest of coniferous and broad-leaved trees (a typical forest type in Hokkaido, Japan) using landscape metrics and topographic factors, and attempted to apply this knowledge to examine forest management. This approach provides a new perspective (i.e., the landscape structure) on forest management, which traditionally has been determined on the basis of individual forest stands. We first created a cover type map of the study area by means of aerial photo interpretation. The characteristics of each cover type identified from the photographs were determined using landscape metrics for each cover class. We digitized a forest administrative map (1:20,000 scale) using 20-m contours, and imported this into GIS software to produce a terrain model; on this model, we overlaid the cover types. Our examination of landscape metrics showed that most of the natural forest could be managed similarly. However, our examination of topographic characteristics revealed exceptions (e.g., areas that are difficult to regenerate) that will require particular attention when managing the natural forest. Based on the information we obtained, we proposed a guideline for sustainable forest management. From the land cover map, we proposed an “improved” cover type map to illustrate the development of a high growing stock of forest based on forest management. We compared the current cover map with the “improved” cover map and demonstrated that the improved form would have more significant effects on fauna that do not recognize differences in the proportion of the dominant species types than on those that can recognize these differences. Our results show how the information obtained using landscape metrics and terrain models is an essential tool for various stages of forest management planning.     

Application of an airborne laser scanner to forest road design with accurate earthwork volumes

In this study we developed a forest road design program based on a high-resolution digital elevation model (DEM) from a light detection and ranging (LIDAR) system. After a designer has located the intersection points on a horizontal plane, the model first generates the horizontal alignment and the ground profile. The model precisely generates cross-sections and accurately calculates earthwork volumes using a high-resolution DEM. The model then optimizes the vertical alignment based on construction and maintenance costs using a heuristic technique known as tabu search. As the distance between cross-sections affects the accuracy of earthwork volume calculations, the results were examined by comparing them with the exact earthwork volume calculated by the probabilistic Monte Carlo simulation method. The earthwork volumes calculated by the Pappus-based method were similar to those calculated by the Monte Carlo simulation when the distance between cross-sections was within 10m. The model was applied to a high-resolution DEM from the LIDAR of Capitol Forest in Washington State, USA. The model generated a horizontal alignment, length 827m, composed of five horizontal curves. We examined the number of grade change points. The results indicated that tabu search found the best solution ($61.42/m) with five grade change points. This was composed of two vertical curves that almost followed the ground profile. As the accuracy of a high-resolution DEM from LIDAR increases, the model would become a useful tool for a forest road designer because it eliminates or at least reduces the time-consuming process of road surveys.