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在多因素、多指标的林业选优试验中,正确分析试验结果,找出最优的因素水平搭配是非常关键时问题。本文根据多目标决策观点,提出了一个多指标林业选优试验的综合分析方法。通过互比各指标的试验结果,将参试方案评价排序,并给予量化,以优序值作为综合评价的单数量指标,进行统计分析,并把定量指标与定性指标从评价方法上统一起来。 相似文献
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根据多目标决策观点，对多指标林业选优试验提出了综合分析方法。通过构造合理的评价函数，使多指标转化为单指标分析，从而找出试验因素的主次关系及最优的因素水平搭配。 相似文献
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规定了林业项目社会评价指标体系的基本原则,以及评价指标的范围和内容。内容包括社会经济、生态环境、其他社会因子三方面,各方面又包含若干因素。详述了社会评价基本指标的设置与计算公式。还提出了建立某些社会评价指标判别参数的设想。 相似文献
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多指标评价中指标权重的计算方法研究 总被引：1，自引：0，他引：1
在林业科学的多指标评价中,权值是各指标相对重要程度的一种主观评价和客观反映的综合度量,确定权重是综合评价的关键。本文应用层次分析法给出一种计算权重的方法,简便易行,分析合理,能全面的反映决策者的判断。 相似文献
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<正> 在林业科研工作中,试验是一种重要的手段,通过试验取得数据资料,利用数理统计方法度量或检验关于各种差异的假设,从而认识事物的内在规律。对试验结果的数据分析,常用的方法是方差分析,它能较精确地估计试验误差。检验出各试验因素对试验指标影响的大小,或进而通过多重比较选取较好的水平条件。但作方差分析要计算一系列平方和,工作量大,在缺少计算工具的条件下应用不便。由于在同处理下重复试验数据间的极差反映了试验误差,同因素各水平 相似文献
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用微机进行林业工业普查的数据处理,在我省尚属首次.全省林业工业普查工作数据最大(60多万个数据)、统计指标多(400多个统计指标)、报表类型多且数量大(1200份之多).用人工统计处理,要花费大量的人力和时间;多数统计指标数值很大(达1百多亿,即10~(11)次方),难以用人工进行统计处理.即使部分数据可用人工进行统计处理,但处理速度也很慢,数据处理结果容易产生差错,造成不必要的经济损失,影响企业的经营管理,无法为企业的经济活动分析和经济决策提供可靠的数据,管理部门也难于全面了解、掌握各林业企业的生产情况.为此,四川省林业厅工业普查办公室委托四川省林科所研制《四川省林业工业普查数据处理及其应用软件》管理系统. 相似文献
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《内蒙古林业调查设计》2017,(2):82-84
文章应用层次分析法对内蒙古国有林区林业企业综合效益的评价指标模型进行研究,分析各指标,并进行重要性排序,对研究结论进行分析,旨在为今后国有林区林业企业综合效益的评价及决策提供必要的理论支持。 相似文献
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在山西庞泉沟自然保护区选取典型森林群落5类,设置15块样地,采用Rao指数和CWM指数计算群落的功能多样性指数,分析了不同森林群落功能多样性指数及其生态学意义。研究结果表明:不同群落类型群落功能Rao指数和CWM指数表现一致,基本排序为:华北落叶松混交林>云杉混交林>油松混交林>阔针混交林>阔叶树混交林,群落内不同层次间排序为:乔木层>灌木层>草本层。群落功能多样性指数与物种多样性指数呈显著正相关,并与群落生产力等功能特性密切相关。 相似文献
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Kenneth J. Stadt Carolyn Huston K. David Coates Zhili Feng Mark R. T. Dale Victor J. Lieffers 《Annals of Forest Science》2007,64(5):477-490
A series of conventional distance-independent and distance-dependent competition indices, a highly flexible distance-dependent crowding index, and two light resource estimation indices were compared to predict individual tree diameter growth of five species of mature trees from natural-origin boreal mixed forests. The crowding index was the superior index for most species and ecosites. However, distance-independent indices, such as basal area of competing trees, were also effective. Distance-dependent light estimation indices, which estimate the fraction of seasonal photosynthetically-active radiation available to each tree, ranked intermediate to low. Determining separate competition indices for each competitor species accounted for more variation than ignoring species or classifying by ecological groups. Species’ competitive ability ranked (most competitive to least): paper birch ≈ white spruce ≈> trembling aspen > lodgepole pine > balsam poplar. Stratification by ecosite further improved model performance. However, the overall impact of competition on mature trees in these forests appears to be small. 相似文献
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Cynthia G. Locasio B. G. Lockaby Jon P. Caulfield M. Boyd Edwards M. Keith Causey 《New Forests》1990,4(4):261-269
Diversity of understory vegetation was compared among four intensities of site preparation and an adjacent 50-year-old pine-hardwood forest. The study site was a six-year-old loblolly pine (Pines taeda) plantation in the lower Piedmont of Georgia. Species richness and Shannon diversity indices were used to evaluate vine and woody (trees and shrubs) species diversity. Biomass distribution was compared among four plant categories: vines, forbs, grasses, and woody. Moderate intensity treatments (chainsaw and shear and chop) consistently ranked highest overall in diversity, with the mature pine-hardwood forest ranking lowest. Distribution of the four plant categories was not significantly affected by intensity of site preparation.Alabama Agricultural Experiment Station Series No. 9-892325P. 相似文献
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Twenty-two taxa and five interspecific hybrids of Leucaena, grown together on a site in Houduras, were evaluated in terms
of their potential value as tropical fodder crops. Content of crude protein, organic matter, acid detergent fibre, neutral
detergent fibre, total tannin and condensed tannin (proanthocyanidin), as well as in vitro digestibility, were estimated in
dried leaf samples, and the accessions ranked according to each of these criteria. The relative palatability of thirteen of
the taxa and two of the hybrids was also assessed in a 'cafeteria' trial using fresh leaf material fed to sheep over an 18
day period. Protein, digestibility and palatability estimates, together with previously published yield data, were used to
construct three indices of fodder potential, to allow direct comparisons between taxa. The most promising taxa according to
these criteria included L. shannonii subsp. shannonii, L. collinsii subsp. zacapana and L. multicapitula, all of which achieved
higher scores than the much better-known L. leucocephala subsp. glabrata in the index derived from crude protein and digestibility.
When yield and palatability were included in the indices, the very high palatability of L. leucocephala gave it the highest
score overall. The most unpromising taxa included L. pulverulenta, L. trichandra, L. esculenta (subsp. esculenta and subsp.
matudae), and L. greggii.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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The leaf area index (LAI) of 16 sample plots was estimated based on terrestrial three-dimensional laser scanning. The point-cloud data of stand canopy were first scaled and projected onto a hemisphere according to Lambert azimuthal equal-area projection or stereographic projection, and the resulting hemispherical point-cloud images were used to extract the canopy porosity coefficients. Then, single-angle inversion and Miller formula inversion methods were used, respectively, to calculate the effective leaf area indices with canopy porosity coefficients. Results showed that the effective LAIs estimated by single-angle inversion method with Lambert projection and stereographic projection were within the range of 2.14~5.36 and 1.83~4.67, respectively. The effective LAIs obtained by Miller formula inversion method with Lambert projection and stereographic projection were within the range of 1.84~4.67 and 1.68~4.34, respectively. As a comparison, the LAI measured with a fish-eye camera ranged from 1.55 to 3.87. The LAI values estimated with four different calculation methods were linearly correlated with those measured by a fish-eye camera. The highest coefficient of determination (R2) 90.28% was obtained by the Miller formula inversion method combined with stereographic projection, and Duncan’s new multiple range test also further showed that this method had a relatively higher precision compared to other three methods. 相似文献
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DRIS-based fertilization efficiency of young hybrid poplar plantations in the boreal region of Canada 总被引：1，自引：0，他引：1
In order to maximize early growth and establishment of planted hybrid poplars in the boreal region of Eastern Canada, growth response of four clones to fertilization was tested in two plantations. The first two fertilization treatments were based on Diagnosis and Recommendation Integrated System (DRIS), a method based on nutrient ratios: DRIS I was based on previously established norms from a study that had been conducted in the same area, and DRIS II was based on DRIS norms developed from hybrid poplars in northern Ontario, Canada. Nutrient status and growth of trees under these 2 treatments were compared to unfertilized trees and to trees under standard (STD) fertilization treatment (40 N–20P–20 K). Leaf nutrient concentrations and DRIS indices showed that fertilization treatments, and especially DRIS I corrected N deficiencies but failed to correct P deficiencies. Fertilization increased volume relative growth rate by 7.51, 4.76 and 13.25 % on average at the agricultural site for DRIS I, DRIS II and STD treatments respectively, compared to no fertilizer application. At the forest site, fertilization treatments based on DRIS indices (DRIS I and DRIS II) increased growth rates (6.67 %) slightly more than the standard treatment (5.80 %). Overall, although DRIS-based fertilization treatments generally increased growth rates, they were often equal to or less efficient than the STD treatment, and may not be as practical as using a standard fertilization recipe. 相似文献
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Analysis of reflectance can be used to estimate foliar concentrations of photosynthetic pigments, thus providing information on the physiological status of green plants. We compared several methods of reflectance analysis for the capacity to differentiate among effects of fertilization treatments across different irradiances on seedlings of Engelmann spruce (Picea engelmanii Parry ex Engelm.). Seedlings were grown in two light treatments (0 and 60% shade) and three nitrogen (N) treatments (10, 25 and 100 mg N l-1) for one growing season, after which foliar reflectance of the needles was measured. Five indices were tested: R550 (% reflectance at 550 nm); red edge position; the ratio R698:R760; the structure independent pigment index (SIPI); and the photochemical reflectance index (PRI). Both the light and nutrient treatments significantly affected foliar chlorophyll a and b and carotenoid concentrations. Among the indices tested, R550, red edge position and R698:R760 ratio were related to chlorophyll concentration, and were significantly affected by both light and N treatments. Both SIPI and PRI were related to chlorophyll and carotenoid concentrations. Among these relationships, PRI was affected by both treatments, whereas SIPI was sensitive to N treatment but not to light treatment. All five indices were weakly but significantly correlated with growth as measured by dry weight. 相似文献
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以3月生、5个来源不同桐花树母株的子代苗为研究对象,分析比较了不同桐花树母株其子代苗的苗高、分枝数和存活率的差异,探讨不同母株对子代苗生长适应性的影响.结果表明:桐花树5个母株子代苗苗高均值为22.5cm,单株苗高变异比较大,总的变异系数37.2％,母株子代苗高平均值大小依次为:母株1＞母株3＞母株4=母株2＞母株5;母株1的子代苗的分枝数最多(BN=3.6枝),而母株2子代苗的分枝数最少(BN=2.9枝),总平均为3.3枝.保存率总平均值为81.4％,变异程度在3个指标中最大(47.9％),其中来源母株1的苗保存率最大(SR=89.7％),而母株3苗的保存率最小(SR=74.6％),而母株2和母株5相差不大.因子分析表明:桐花树子代苗的苗高在区组重复之间差异显著(P＜0.01),在分枝数上,母株因子效应显著(P＜0.01),苗高和分枝数在区组与母株之间均存在显著的交互作用.对桐花树生长以及适应性指标综合评估表明,以母株1子代苗生长适应性面表现优良,其次为母株5,母株3在排名靠后. 相似文献