人工云杉群体直径和树高生长的灰色代数曲线模型（GAM）

利用舟曲沙滩林场人工云杉解析木材料，建立人工云杉群体直径和树高生长灰色曲线模型，预测其单株生长量，进而预估林分生长量，可提高预报准确性，其中直径生长模型为：Ｘ（ｔ）＝－１．４３６５＋３．１７１ｔ－１．３０４１ｔ＾２＋０．４５４８ｔ＾３－０．０３０５ｔ＾１，树高模型国：Ｘ（ｔ）＝－０．１３９８＋０．６１５１９ｔ＋０．１０４９ｔ＾２＋０．０２５２ｔ＾３－０．０００８ｔ＾４。     

浙江庆元杉木种子园产量预测模型

以浙江省庆元县庆元林场杉木种子园１３ａ种子产量系列和影响杉木种子园产量的生物因（Ｘ１～Ｘ３）、气象因子（Ｘ６～Ｘ１４）及产地因子（Ｘ４～Ｘ５）等资料为依据,在应用回归分析方法筛选构成影响产量主导因子的基础上,分别研建了杉木种子园产量的多元线性模型：杉木种子园年度单位面积种子平均产量Ｙ１＝６０．０４７４６＋０．００１６７Ｘ７（年降水量）－０．１１６９５Ｘ８．９（开花期低温指数）－０．０１５７９Ｘ１０     

毛竹林丰产年龄结构模型与应用研究

从南岭山脉以南的各毛竹产区中收集１３３０块高产林标准地,分别调查各度竹株数、胸径等测树因子与林分、环境因子,以用材林的竹秆产量,笋用林的笋产量为因变量,建立了产量模型：材用林Ｙ１＝－６２６９５．２４５＋６．５４１３Ｎ＋７０１２．５１９５Ｄ＋８．４５４８Ｘ１＋１１．０８７０Ｘ２＋１４．１５２０Ｘ３＋８．９９６９Ｘ４＋１４．５１５６Ｘ５笋用林Ｙ２＝６９７．５５６９＋０．２０５２Ｎ＋１．８５１４Ｄ－０．６４１４Ｘ１＋１．２４９３Ｘ２＋０．７６３６Ｘ３＋０．３７９０Ｘ４－０．８８３３Ｘ５（Ｒ１＝０．９８,Ｒ２＝０．９６）并结合生产要求,提出约束条件八组。应用该模型研究毛竹林最优化年龄结构,可以得到不同竹林质量、立竹量、立地条件、经营水平下最适宜年龄结构。能显著地提高林分的竹材和笋产量。     

杨树不同无性系叶面积模型的选择及其建立

应用Ｌｉ－３０００Ａ叶面积仪测定了８个无性系的叶型及叶面积指标，选择了８个模型，以叶片主脉长（Ｌ）和最大宽（Ｗ），以及两者乘积（Ｌ×Ｗ）为三个变量作与叶面积的相关关系分析，筛选出复相关系数均达０．９５以上的最佳模型为：（１）与两者乘积的叶面积模型：ｌｇＹ＝ａ＋ｂｘ＋ｂ＋ｃｌｇｘ，（２）与最大宽度的模型：Ｙ＝ａ＋ｂｘ＋ｃｘ２。但与叶片主脉长模拟效果较差。此外，还得出了杨树无性系的叶面积通用模型，即：Ｙ＝—０．４５０８２６十０．０００７１Ｘ＋０．９７６３３５ｌｇｘ（ｘ为Ｌ×Ｗ），和Ｙ＝—１．６９７３８７十０．７３３４９７ｘ—０．００１２５３ｘ２（ｘ为Ｗ）。上述８个无性系及杨树通用的模型的建立为叶面积的计算、预测等生理生态研究提供了科学依据，使得叶面积测定更加省时、可靠和方便。     

落叶松褐锈病防治指标与测报技术的研究

落叶松褐锈病对林木当年生长无明显影响,但对第二年生长影响显著。连年发病损失量剧增;不同病情指数（Ｘ）每公顷材积生长损失量为Ｙ＝１９４／１＋ｅ５４９３３７－００６８９３Ｘ;该病为害指标———病情指数为３６。立木林价、防治效果和成本分别为Ｃ、Ｑ、Ｅ时,防治指标方程为：１９４Ｃ［１／１＋ｅ５４９３３７－００６８９３Ｘ－１／１＋ｅ５４９３３７－００６８９３（１－Ｑ）Ｘ］－Ｅ＝０;前一年９月份降水量（Ｘ３）、当年５月份平均气温（Ｘ１）和８月份相对湿度（Ｘ２）为测报因子。预测区域平均病情指数Ｙ＝５１８５＋３２５９６Ｘ１－０４２１０５Ｘ２＋００８６２７Ｘ３±６９。     

云南松纵坑切梢小蠹成虫发生量预测预报研究

１９９２～１９９５年在玉溪市北城镇刺桐关办事处石狗头村，对云南松纵坑切梢小蠹进行了系统的调查及试验研究，得出小蠹成虫发生量的预测预报方法，即应用有效虫口基数法测报下一代小蠹成虫发生量，准确率达８５％以上。并初步建立了小蠹发生量的曲线回归测报模型：Ｙ＝０．１２９４０８８６４Ｘ０．９８７９１６５４２，相关因子为云南松受害株率，用于测报越冬代及下一代成虫发生量；多元回归测报模型：Ｙ＝－７９．０５２６＋０．４５０４Ｘ１＋５．３３６７Ｘ２＋０．１７１８Ｘ３±０．２５，相关因子是越冬虫口基数，４月上旬温度、雨量，用于测报下一代成虫发生量：二元回归测报模型：Ｙ＝－０．６２８２＋０．０４１５Ｘ１＋０．１１９２Ｘ２±１．５，相关因子是林木受害株率，用于测报越冬代及下一代小蠹成虫发生量。上述模型准确率均达８０％以上，具有较好的实用价值，为进行综合治理提供可靠的科学依据     

竹缺爪螨危害对毛竹生理生化影响的初步研究

本文报道毛竹上重要害螨一竹缺爪螨ＡｐｏｎｙｃｈｕｓｃｏｒｐｕｚａｅＲｉｍａｎｄａ）危害对毛竹生理生化影响。研究表明：毛竹叶片受害程度与叶绿素含量,还原糖含量,总糖含量,含水量呈明显负相关关系。其数学模型分别为：Ｙ叶绿素＝１．５－０．２１８５Ｘ（Ｒ＝－０．９７）;Ｙ总糖＝４．５８６－０．８１Ｘ（Ｒ＝－０．９８）;Ｙ还原糖＝３．１４３－０．３８６８Ｘ（Ｒ＝－０．９４）;Ｙ含水量＝３０．４９－５．１５Ｘ（Ｒ＝－０．９０）。并对综合治理提出对策。     

大袋蛾危害对泡桐生长量的影响

１９９０－１９９２年在安徽省阜阳市和利辛县测定了大袋蛾Ｃｌａｎｉａ ｕａｒｉｅｇａｔａＳｎｅｌｌｅｎ危害兰考泡桐Ｐａｕｌｏｗｎｉａ ｅｌｎｇａｔａ的损叶量和人工模拟危害对泡桐生长量的影响。泡桐的蓄叶量Ｔ（ｃｍ＾２）与胸径Ｄｃｍ）呈直线关系：Ｔ＝４４５０３．３３６Ｄ－２７２６２７．０４３。大袋蛾幼虫对泡桐的平均损叶量为４７０．９３６ｃｍ＾２。摘叶量在５０％及其以下时，泡桐生长量没有受到显著影响，摘叶     

白杨透翅蛾幼虫空间分布型及抽样技术的研究

通过频次分布χ２检验和９种分布型指数的测定，白杨透翅蛾幼虫的空间分布型为一般负二项分布，空间分布的基本成分是疏松的个体群，个体群的分布为聚集型。当ｔ＝１，Ｄ＝０．２５时的理论抽样数为：ｎ＝２０．８０６４／Ｘ＋１０．９０４，在防治指标为０．１０头／株时，最大抽样数为２２０株。序贯抽样的累积虫量界限为：Ｔｏ（Ｎ）＝：０．１０Ｎ±０．３６９５Ｎ。该幼虫的田间简单随机抽样以平行线法为最佳。     

应用正交旋转设计确定银中杨最佳施肥量试验

采用回归旋转设计进行田间配方施肥试验结果的统计分析，建立了银中杨施肥效应回归方程：Ｙ＝５．２５１６＋０．２３１０Ｘ１＋０．２５１３Ｘ２－０．２１８８Ｘ１Ｘ２－０．１３６２Ｘ２１＋０．１３９７Ｘ２２，确定在本地区，磷肥是林木生长土壤肥力的限制因子，增施磷肥补施氮肥，并注意其配比是该区促进林木丰产的重要措施。经济最佳施肥量为Ｎ３６２ｇ／株，Ｐ２Ｏ５１７４ｇ／株，氮和磷的最佳配比为Ｎ：Ｐ２Ｏ５＝１∶０．４８。     

日本龟蜡蚧在枣树上的发生与危害

１９９６年８月￣１９９７年６月，在陕西大荔县八鱼乡西营村和蒲支县平路庙乡直杜村调查了日本龟蜡蚧在枣树上的分布与危害。结果表明，单叶幼虫数随枣树受害程度的增加而增加，单果重随枣树爱害程度的增加而减少，越冬雌虫的危害造成每股的抽吊数减少，吊长显著变短，每吊的刺树数减少，幼虫和雌成虫在树冠上的分布是阳面（南面）大于阴面（北面），其中树冠中部虫量分布的最多。     

A Mechanistic Approach for Evaluating the Role of Wind Dispersal in Tree Population Dynamics

Abstract

We observed seed (or diaspore) dispersal of six species (4 species of Betulaceae, 2 species of Aceraceae) for 5 years in a species-rich deciduous broad-leaved forest (Ogawa Forest Reserve, central Japan), and explained the observed patterns with a mechanistic model of dispersal. The model involves three parameters which can be biologically interpreted; terminal seed velocity (F), tree height (H), and amount öf dispersed seed per reproductive individual (Q).The relationship between dispersed seed density and distance from a single seed source were explained well by the model. Two dimensional distribution of seed density dispersed from multiple seed sources was approximated by the model. We evaluated the dispersal success in reaching safe sites as the gap area covered by a given seed density, and discussed the adaptive meaning of the dispersal traits based on the model and empirical data. While Fdid not vary greatly among the species, Qshowed greater variation among the species in this forest. The species with large Qdescended more slowly (H/F)in this forest. The traits which were related to the enlargement of dispersal area tended to compensate for the low survival-of seedlings.     

Effects of tree shading on maize crop within a Poplar-maize compound system in Hexi Corridor oasis,northwestern China

Effects of tree shading on crop within agroforestry system in the oasis regions or under irrigation agriculture are poorly understood. Objective was to determine maize yield variation and its reasons when tall Poplar trees (Populus gansuensis) were grown in western and eastern margins of the crop field in Hexi Corridor desert oasis in northwestern China. Maize growing among the 50 m alley space were divided into five regions, including shading region in western side (W-S), non-shading region in western side (W-NS), middle region (M), shading region in eastern side (E-S) and non-shading region in eastern side (E-NS), for all measurements. Measurements of leaf area expansion were carried from seeding to flowering stage, photosynthetic physiological parameters and microclimate characteristics were measured at booting stage, grain yield and other harvest parameters were obtained at harvest time. We found that tree shading reduced the crop yield by 27 and 22% in western and eastern regions, respectively, and also, mean crop yield for western side was 23% lower than eastern side. The direct reason of yield variation was transpiration rate (E) variation at booting stage, that is, maize which had higher daily mean E would obtained higher yield. Moreover, changes of incident photosynthetically active radiation (PARi), air temperature (T _a) and CO₂ concentration (C _a) were the basic reasons of yield variation among different regions. Because higher PARi, higher T _a and lower C _a, which caused by the tree shading, would all led to higher E and finally higher crop yield.     

Photosynthetic response to green crown pruning in young plantation-grown Eucalyptus pilularis and E. cloeziana

The loss of foliage through pruning of live branches may reduce tree growth or it may be compensated by photosynthetic up-regulation of the remaining crown. Here, the changes in light-saturated photosynthesis following pruning to remove 50% of green crown length were examined in 4-year-old Eucalyptus pilularis Sm. and Eucalyptus cloeziana F. Muell. trees. The objectives of the study were to: (1) compare leaf-level physiological (light-saturated photosynthesis (A_max), stomatal conductance (g), transpiration (T), dark respiration (R_d), quantum yield (Φ), light compensation point (Γ), water-use efficiency (WUE), nitrogen-use efficiency (NUE)) traits in species with contrasting crown dynamics and structure, (2) examine the effect of crown position on these traits, and (3) examine the effect of pruning on A_max, g, T, WUE, NUE, leaf N and P concentrations and specific leaf area (SLA). Prior to pruning there were no differences in R_d, Γ and Φ between E. pilularis and E. cloeziana but differences in A_max, T, g, leaf N, leaf P, WUE, NUE and SLA. Whereas the rate of physiological processes (A_max, T, and g) and leaf N and P concentrations increased with crown height, R_d, Γ, Φ and SLA declined along this vertical gradient, except in the upper crown of E. cloeziana where A_max, T and g were not different to the lower crown. No up-regulation of photosynthesis or changes in leaf physiology occurred between 6 and 13 months after pruning in either species. The results provide an important basis for modelling pruning effects in process-based tree growth models.     

Optimum pruning intensity for reducing crop suppression in a <Emphasis Type="Italic">Gmelina</Emphasis>–maize smallholder agroforestry system in Claveria,Philippines

On-farm trials were conducted to assess the effects of four branch pruning levels on maize grain yield, tree growth and stem shape. The experimental plots consisted of Gmelina (Gmelina arborea R.Br.) trees planted at 1 × 10 m with maize intercropped in the 10 m-wide alleys between lines of trees. Pruning levels consisted of retaining a live crown ratio of 60–70% (T ₁), 40–50% (T ₂); 30–40% (T ₃) and of 20–30% (T ₄). At the end of the experiment, the total maize grain yield was highest under the high pruning intensity (T ₄) (18.06 t ha⁻¹) and lowest under T ₁ (14.48 t ha⁻¹). Maize grain yield under the pruning regime T ₂ and T ₃ were 16.08 and 17.21 t ha⁻¹, respectively. Mean annual increment (MAI) in tree diameter was greater (5.0 cm year⁻¹) under T ₁ than those at T ₄ (4.1 cm year⁻¹). Pruning regimes T ₂ and T ₃ resulted in a MAI of 4.7 and 4.5 cm year⁻¹, respectively. Financial analysis showed that maize-tree systems under T ₄ were more profitable than under T ₁ as long as the reduction of the average dbh at harvest were not greater than 1 cm. Pruning trees intensively also generated greater returns from labour than moderate pruning, as the greater maize grain yields under T ₄ compensated for the cost of pruning and the lower timber yield. In the context of resource-poor farmers, intensive branch pruning was a practice that prolonged the period of profitable intercropping and was compatible with commercial timber production.     

南阳市南水北调中线工程水源地乔木林生物量和碳储量初步研究

通过建立不同优势树种生物量与蓄积量之间的回归模型,以树种含碳率作为生物量转换为碳储量的系数,利用2007年河南省森林资源规划设计调查资料,对南阳市南水北调中线工程渠首水源地乔木林生物量和碳储量进行推算。结果表明:水源区总生物量为2 212.25万t,总碳储量为1 103.35万t;阔叶林碳储量占乔木林碳储量的96.5%,其中栎类最多占82.1%;幼龄林碳储量占用材树种的90.9%;研究区乔木林平均碳密度为22.08t/hm2。研究可为当地生态环境改造提供借鉴参考依据。     

Simulation Study of a Single-grip Harvester in Thinning from Below and Thinning from Above

Abstract

The time consumption and productivity of a single-grip harvester were studied, using a simulation model, when thinning from below and above in eight randomly selected stands. The model estimated the time required for each work element, given machine and tree positions, and tree size. A 2×5 factorial design was used with factors thinning type [from below (T_b) and above (T_a)] and tree size. Trees were subjectively selected for harvest according to thinning type. Total basal area removal was 30% plot^?1. Approximately 50% more trees were harvested in T_b than in T_a Time consumption tree^?1 was higher for T_a than T_b. Time consumption for machine and boom movements decreased with increasing number of harvested trees, and time for felling and processing of trees increased with harvested mean stem volume. Harvester productivity was 36% higher for T_a, since the increase in harvested mean stem volume was higher than the increase in time consumption tree^?1.     

福州地区半常绿及落叶杨树无性系引种试验

杨树（Ｐｏｐｕｌｕｓｓｐｐ．）是重要的速生用材树种,在国内一般认为杨树是北方树种,不注意在南方发展杨树。实际上不少亚热带和热带国家（印度、南非、澳大利亚、巴基斯坦、伊朗、阿根廷和巴西等）都广泛栽培杨树［１,２］。为探讨南方营造杨树工业用材林的可能性,...     

Soil organic matter in European forest floors in relation to stand characteristics and environmental factors

Published data on the quantities of organic matter in the forest floor (SOM_fl) of European forest stands were collated. Studies of SOM_fl were included if the total sampled surface was at least 0.15 m², the surface of a single sample was at least 100 cm², live material was sorted out, and ash or carbon content was determined. Data from 59 forest stands were compared with regard to stand characteristics and environment. Using a single variable, tree genus was most important for the amount of SOM_fl (R ² _adj = 0.34). The amounts in spruce stands (41 × 10³ kg ha^?1) were significantly higher than those in larch, Douglas fir, oak and birch stands (4–11 × 10³ kg ha^?1). The best significant multiple model was genus combined with stand age and basal area (R ² _adj. = 0.72). The importance of litter quantity and quality for differentiating the tree genera is discussed.     

Water Use of Tree Lines: Importance of Leaf Area and Micrometeorology in Sub-Humid Kenya

In this research the relative importance of leaf area and microclimatic factors in determining water use of tree lines was examined in sub-humid Western Kenya. Measurements of tree water-use by a heat-balance technique, leaf area, bulk air saturation deficit, daily radiation, and soil water content were done in an experiment with tree lines within crop fields. The tree species were Eucalyptus grandis W. Hill ex Maiden, Grevillea robusta A. Cunn. and Cedrella serrata Royle, grown to produce poles on a phosphorus-fixing Oxisol/Ferralsol with (+P) or without (−P) phosphorus application. Doubling the leaf area of Cedrella and Grevillea doubled water use in a leaf area (LA) range of 1–11 m² per tree. The response of Eucalyptus water use (W) to increases in leaf area was slightly less marked, with W = LAⁿ, n<1. Transpiration rate per unit leaf area (Tr) was the other important determinant of water use, being affected by both tree species and phosphorus fertilization. A doubling of the saturation deficit (SD) halved the water use of all trees except for Cedrella +P, in which water use increased. A direct effect of soil water content on water use was only found in Grevillea -P, with a small increase (60%) as available water increased from 1.4 to 8.9% above wilting point (32%). This low direct response to soil water content is probably due to the extensive tree-root systems and the deep clayey soils supplying sufficient water to meet the evaporative demand. Indirect responses to soil water content via decreases in leaf area occurred in the dry season. The results showed that water use of tree lines was more determined by leaf area and transpiration rate per unit leaf area than by micro meteorological factors. The linear response of tree water use to leaf area, over a wide range leaf areas, is a specific characteristic of tree line configurations and distinguished them from forest stands. In tree lines light interception and canopy conductance increase with leaf area much more than a similar leaf area increase would have caused in a closed forest canopy.