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295篇 您的检索式:作者名="Gadow"
    题名 作者 年代 出处 被引量
1一个新的林分空间结构参数——大小比数显示文摘提出了模拟林分空间结构的大小比数。该结构参数量化了参照树与其相邻木的关系,以大于参照树的相邻木数占所考察的全部相邻木的比例表示。大小比数是对直径分布和至今所延用的描述相邻木关系的大小分化度的完善和补充,它能准确地判断出参照树是否比其相邻木大。其优点在于。惠刚盈 Klaus von Gadow Matthias Albert 1999林业科学研究1999,12,1:298
2线性规划、模拟退火和遗传算法在杉木人工林可持续经营中的应用和比较显示文摘以杉木人工林为例 ,介绍了线性规划、模拟退火和遗传算法在编制森林经营方案过程中的应用和比较 ,同时介绍了一种通用的可以处理绝大多数的森林经营模型。采用Hui(1997)的生长和间伐模型来模拟林分的生长、间伐和发展过程。线性规划、模拟退火和遗传算法三者适用于不同的场合。当约束条件都比较宽松时 ,线性规划也有可能得出整数解 ,但不一定就能够避免林分分割经营 (整数解 )。要获得整数解 ,尤其是在林分数目很大的时候 ,可以采用模拟退火和遗传算法。如果允许林分分割 ,线性规划的结果一般可以获得最好的目标方程值。陈伯望 惠刚盈 Klaus von Gadow 2004林业科学2004,40,3:8
3Designing near-natural planting patterns for plantation forests in China显示文摘Background: China has a long tradition of managing planted forests. Different species of Populus, Eucalyptus, Larix, Cunninghamia and Pinus are planted to satisfy the local demand for wood products and provide ecological services at the same time. Evidence of the greater resilience of natural forests provides the motivation to develop asymmetric planting patterns, which is the focus of this study. We present a new method for designing plantation patterns that follow those observed in natural ecosystems and to maintain some regularity for operational convenience. Methods: Based on the uniform angle index, we analyzed the spatial structure of six natural forests in different regions of China. The uniform angle index describes the degree of spatial uniformity of the n nearest neighbors of a given reference tree. Accordingly, we identified all possible patterns of a neighborhood group within a regular planting pattern and developed a method to optimize planting point arrangements that contain some randomness as well as a minimum degree of regularity. Results:(1) There are 13 types of structural units in a regular planting, including seven random units, five even units and one cluster unit;(2) Five near-natural arrangements are presented with a minimum proportion of 50% of random units. These five arrangements represent a combination of regularity for operational convenience and asymmetry. Conclusions: The new planting patterns developed in this study are expected to increase the asymmetric competition and resilience of these important ecosystems. Some experimental plantings, based on our findings, have already been established, e.g., in Pinus tabulaeformis plantations in Tianshui, Gansu Province, and in a Populus deltoides plantation in Fangshan near Beijing.Gongqiao Zhang Gangying Hui Yanbo Hu Zhonghua Zhao Xiuling Guan Klaus von Gadow Ganggang Zhang 2019Forest Ecosystems2019,6,3:6
4用于干形描述的2个少参数削度函数(英文)显示文摘以修正的Brink函数和Pain函数拟合尾巨桉干形曲线。材料来源于南非暖温带花岗岩低地草原地区桉树工业用材林53块标准地的153株尾巨桉干形测定数据。2个削度方程均能对调查数据进行很好地拟合,只是在不同的相对高度时有小的偏差。参数少的方程具有十分好的应用前景,因为从理论上来说,可以用参数预估的方法建立一个广义的干形模型。参数预估不能运用于修正的Brink函数,但在Pain函数的基础上建立参数预估模型是可能的甚至是必要的,因为Pain函数是把绝对树干直径描述为相对树干高度的函数。为此,对参数预估模型是否能描述的树形差异或者仅仅是大小的差异作了测度评价。应用结果表明,参数预估模型未必能用于描述树形的差异。Khalid A. Hussein Matthias Schmidt Heyns Kotze Klaus von Gadow 2008林业科学2008,44,6:4
5Climate change effects in the Western Himalayan ecosystems of India: evidence and strategies显示文摘Background: The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background information on India's Western Himalayas and reviews evidence of warming as well as variability in precipitation and extreme events.Methods: Understanding and anticipating the impacts of climate change on Himalayan forest ecosystems and the services they provide to people are critical. Efforts to develop and implement effective policies and management strategies for climate change mitigation and adaptation requires particular new research initiatives. The various studies initiated and conducted in the region are compiled here.Results: Several new initiatives taken by the Himalayan Forest Research Institute in Shimla are described. This includes new permanent observational field studies, some with mapped trees, in high altitude transitional zones for continuous monitoring of vegetation response. We have also presented new strategies for mitigating potential climate change effects in Himalayan forest ecosystems.Conclusions: Assessment of the ecological and genetic diversity of the Himalayan conifers is required to evaluate potential responses to changing climatic conditions. Conservation strategies for the important temperate medicinal plants need to be developed. The impact of climate change on insects and pathogens in the Himalayas also need to be assessed. Coordinated efforts are necessary to develop effective strategies for adaptation and mitigation.Vindhya Prasad Tewari Raj Kumar Verma Klaus von Gadow 2017Forest Ecosystems2017,4,3:4
6德国北部挪威云杉林可持续经营中期计划的实例分析显示文摘可持续森林经营理论为中期林业计划和收获调整提供了丰富的模型选择,其不同的方法可应用于各种特定的场合和不同经营类型。本文简要回顾了传统的森林计划方法,一种称为“多林分发展”的概念可以用于任意的经营系统,这个概念把森林看作由一系列林分组成,在每一个林分中可以预先制定多种经营措施的选项,每种选项都可以通过木材或其它产品以及消耗的资源计算出一个目标值。这种简单的概念可以应用到大量的不同森林经营场合,它为森林经营者制定切实可行的森林措施和评价森林经营计划提供方法。在本研究中,以德国北部一片包括21个小班的挪威云杉林班的一个中期计划为例,说明“多林分发展”这一经营系统在实际生产中的应用。每个小班具有不同的初始状态,每个小班预设了若干经营选项,根据小班的初始状态、生长模型为各种选项计算各时期的木材产出。在林班的水平上,经营目标方程包括两个组成部分:净现值和均衡木材收获值。用模拟退火的方法来优化总体目标方程值。优化的总体解决方案在为每个小班选定合适的经营选项的同时,在全林的水平上获得最优的经济和均衡产出组合。陈伯望 Klaus.von Gadow Frantiek Vilko Sofía Sánchez Orois 2006林业科学研究2006,19,5:4
7德国北部挪威云杉林可持续经营计划中空间目标的优化显示文摘根据德国北部挪威云杉林相邻林分间的特定地理关系,包括林分重心间的距离和共同边界的长度,建立了德国北部挪威云杉林经营的一个空间优化模型,该模型是一种新的空间优化方法。地理数据从G IS中获得并保存到数据库中,数据库还包括林分选项和相应的目标方程值等内容。首先使用了一个由41个林分组成的林班,每个林分21个选项,采用模拟退火的方法来分别和综合优化经济模型、均衡产出模型和空间模型,并将它们的结果方案与具最大净现值的方案进行比较。当均衡产出和空间2个组成部分逐一加入到目标方程后,它们显著地改进了结果方案,而经济目标只有中等程度的下降。陈伯望 Klaus von Gadow 2008林业科学研究2008,21,3:3
8Tabu搜索法在森林采伐量优化问题中的应用显示文摘介绍了一种新颖高效的启迪式搜索方式———Tabu搜索法。以一个杉木人工林采伐量方案的优化为例,介绍了Tabu搜索法的基本原理和应用方法,并把Tabu搜索法与线性规划、模拟退火和遗传算法处理同一森林采伐量优化方案例子获得的结果进行了比较。结果表明,禁忌搜索法在解决一般森林采伐量优化问题时有快速高效的特点,尤其是在移动产生的相邻解数目有限且差异较大的情况下,可以很快获得模拟退火和遗传算法多次重复计算也较难达到的高目标方程值。禁忌周期对Tabu搜索法的影响比较小,寻找好的移动方式和排序方式是影响Tabu搜索法效率的关键。陈伯望 惠刚盈 Klaus von Gadow 2003林业科学研究2003,16,1:3
9超音速火焰喷涂气缸内壁涂层及其固有孔隙的益处显示文摘按照内燃机的新规定和规范,需要降低其油耗和排放。超音速火焰喷涂可以用来喷涂耐磨涂层,这一工艺具有很大潜力。热喷涂涂层能提高内燃机的效率,减少发动机气缸壁的损耗,提高持久性和耐磨性,从而达到促进发动机减耗的目的。热喷涂工艺同样可以达到耐腐蚀的要求,如使用合金和陶瓷粉末,就可以在现代的内燃机里使用生物燃料。此外,热喷涂涂层的特殊表面结构,包括其多孔性,可以让气缸保持在润滑摩擦的状态,甚至是在相对移动量较小处也可以减小摩擦,如顶部和底部的正中心处。另外,表面开放孔隙可以减少油耗,从而减少内燃机的污染物排放。运用HVOF和HVSFS工艺可以喷涂各种材料,包括最最新的纳米级粉末。经过喷涂的气缸和引擎由于其摩擦系数,磨损和油耗等重要因素,被认为是现代化的部件。Manzat A Killinger A Gadow R 鲍君峰 2012热喷涂技术2012,4,2:2
10Competition effects in an afrotemperate forest显示文摘Background:Information about competition responses is mainly available for monospecific stands or mixed stands with a small number of species.Studies on complex multi-species and highly structured forest ecosystems are scarce.Accordingly,the objective of this study was to quantify competition effects and analyse competition responses in a species-diverse afrotemperate forest in South Africa,based on an observational study with mapped tree positions and long-term diameter increment records.Methods:The sensitivity to competition was analysed for individual species and involved the calculation of the slope of the linear relation between the value of a competition index(CI) and diameter growth as a measure of sensitivity.In a next step different competition indices were combined and tree diameters were grouped in three classes as surrogates for canopy status and ontogenetic stage.Results:Five competition indices were found to be effective in showing sensitivity to competition for a number of canopy and sub-canopy species.Significant linear regressions were fitted for 18 of a total of 25 species.Species reactions varied significantly in their sensitivity to the different CIs.The indices were classified as belonging to two groups,those that responded more to local crowding and those that are more sensitive to overtopping,which revealed species-specific sensitivities to both factors.The analysis based on diameter classes revealed that species clearly changed their sensitivity to crowding or overtopping depending on diameter.Canopy and sub-canopy species showed distinct differences in their reactions.Conclusions:The application of multiple CIs brought novel insights relating to the dynamics of afrotemperate forests.The response patterns to different competition indices that focus on crowding and overtopping are varied and tree diameter dependent,indicating that oversimplified assumptions are not warranted in the interpretation of CI- growth relations.Thomas Seifert Stefan Seifert Armin Seydack Graham Durrheim Klaus von Gadow 2014Forestry Studies in China2014,16,3:2
11Strukturentwicklung eines buchen-fichten-mischbes-tandes显示文摘Gadow K 1997Allg Foxst-a J-Ztg1997,168,67:1
12Das Winkelmass: Theoretische tl berlegungen zum optimalen Standardwinkel显示文摘Hui G Y Gadow K 2002Allgemeine Forst und Jagdzei- tung2002,173,9:1
13Zur Modellierung personens-pezifacher durchforstungen in ungleichaltrigen mischbestaenden显示文摘Daume S Fueldner K Gadow K 1998Allg Forst-a J-Ztg1998,169,:1
14Das winkelmass-theoretische tiberlegungen zum optimalen standardwinke显示文摘Hui G Y von Gadow K 2002Allgemeine Forst und Jagdzeitung2002,173,9:1
15Zur bestandesbeschreibung in der forsteinrichtung显示文摘Von Gadow K 1993Forest und Holz1993,48,21:1
16An analysis of spatial forest structure using neighborhood-based variables 显示文摘AGUIRRE O HUI G Y GADOW K V 2003Forest Ecology and Management2003,183,:1
17Das Winkelmass-Theoretische Uberlegungen zum optimalen Standardwinkel 显示文摘Hui G Y Gadow K V 2002Allgemeine Forst- Und Jagdzei- tung2002,173,:1
18An analysis of spatial forest structure using neighborhood-based variables 显示文摘Aguirre O Hui G Y Gadow K V 2003For Ecol Manage2003,183,:1
19Das Winkelmass-Theoretische uberlegungen zum optimalen Standardwinkel 显示文摘Hui G Y Gadow K V 2002Allg Forst-u J-Ztg2002,173,:1
20A generalized height-diameter model including random components for radiata pine plantations in northwestern Spain显示文摘Castedo Dorado F Diéguez-Aranda(U) Barrio Anta M Sánchez Rodríguez M Gadow KV 0,,:1
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