授粉树的选配

怎样选择与配置授粉树是某些树种（品种）提高坐果率的基本手段。由于雌雄异株树木（如银杏、猕猴桃、香榧、杜仲等）、自花不结实的树种或品种（如梨、李、梅、柚）和自花结实少的树种或品种（如荔枝、龙眼、枇杷、桃、枣、油茶等），合理地选择和配置授粉树，是提高其坐果率，取得丰产稳产的重要措施。     

怎样选配授粉树

怎样选择与配置授粉树是其些树种（品种）提高坐果率的基本手段：对于雌雄异株树木（如银杏、猕猴桃、香诬、杜仲等）．自花不结实的树种或品种（如苹果、梨、李、梅、柚）和自花结实少的树种或品种（如荔枝、龙眼、枇耙、桃、枣、油茶等）．合理地选择和配置授粉树，是提高其坐果率．取得丰产稳产的重要措施。     

授粉树与花粉活力对板栗结实率和坐果率的影响

以北京市怀柔区3个板栗主栽品种为授粉母树,采用9个不同种源的良种作为父本,进行授粉试验,研究授粉树与花粉活力对板栗结实率和坐果率的影响。结果表明：东陵明珠和石丰是燕山红粟的最佳授粉树;遵玉和紫珀是怀九的最佳授粉树;紫珀和东陵明珠是怀黄的最佳授粉树;花粉活力在盛花期时最高,对任何品种而言,盛花期都是最佳的授粉期。     

苹果梨不同授粉方法的坐果率比较试验

黑龙江省东宁县于1958年从吉林省延边自治洲引进苹果梨,经过40多年发展,到2002年苹果梨面积达到8万亩,占全县果树总面积的62％,其中20世纪70年代末前苹果梨3万亩,主要以客发梨、南果梨、谢花甜作为授粉树,经过多年实践证明,南果梨比苹果梨早开花4～5天,授粉时间很短、授粉效果差,谢花甜和客发梨由于商品价值低,也不适合作苹果梨的授粉树,到20世纪70年代以后,全县     

梨树授粉品种的配置

梨树是异花授粉植物,绝大多数品种自花授粉结实率很低,有的甚至接近于零.梨自花授粉结实率低甚至不实的原因,据国内外专家研究,是授粉不亲和或亲和力差所致.     

怎样提高花木授粉率

花木授粉率的高低与其结实率紧密相关。只有提高授粉受精率，才能获得较多的种子进行繁殖。     

油茶家养蜂授粉研究与应用现状

油茶是重要木本油料植物，油茶产业是维护国家粮油安全的新兴力量，因花粉限制原因其出现了低产低效瓶颈问题，授粉是缓解该问题的根本途径。基于油茶为有毒蜜源植物，油茶林下养蜂技术要求高，本研究综述了油茶的粉蜜特性、引起家养蜂中毒的主要成份、家养蜂授粉预防中毒技术；探讨了家养蜂油茶授粉研究重点方向，旨在为生产中利用家养蜂油茶授粉提供科学依据。     

2001莱果适宜授粉品种选择的初步研究

对太行山区栽培的2001苹果的5个授粉品种进行初步研究的结果表明，2001自花不育；藤牧1号、金冠与2001花期相遇，在自然传粉下，以金冠、藤牧1号作授粉品种，花序坐果率达73．88％、58．19％，花朵坐果率分别为39．77％和23．22％，果实品质较好，可溶性固形物含量分别为14．88％、14．19％；在人工授粉条件下还可以用红星、王林品种的花粉；同时各授粉处理的2001果实均具有良好的耐贮性。     

2001苹果适宜授粉品种选择的初步研究

对太行山区栽培的 2 0 0 1苹果的 5个授粉品种进行初步研究的结果表明 ,2 0 0 1自花不育 ;藤牧 1号、金冠与 2 0 0 1花期相遇 ,在自然传粉下 ,以金冠、藤牧 1号作授粉品种 ,花序坐果率达 73 88%、 5 8 19% ,花朵坐果率分别为 39 77%和 2 3 2 2 % ,果实品质较好 ,可溶性固形物含量分别为 14 88%、 14 19% ;在人工授粉条件下还可以用红星、王林品种的花粉 ;同时各授粉处理的 2 0 0 1果实均具有良好的耐贮性     

杨梅授粉与花粉直感研究

选择20年生的荸荠种、东魁杨梅和水晶种3个杨梅品种雌株各3株,21年生实生雄优株、21年生荸荠种雌雄同株杨梅和12年生实生东魁雄杨梅进行3a授粉试验,研究杨梅授粉坐果的特性及若干果实性状的花粉直感规律.结果表明:杨梅花粉生活力较强,9d后仍达75.8％以上;杨梅坐果率与花粉生活力不成正比.雄株花粉对坐果率的花粉直感效应明显,即雄株花粉以实生东魁杨梅雄株花粉坐果率最高,平均21.47％;品种以水晶种坐果率最高,平均22.47％;年份以2008年坐果率最高,平均16.43％;雄株花粉与杨梅品种之间存在交互作用.人工授粉与自然授粉的坐果率趋势一致,各品种套袋后人工授粉的坐果率略低于自然授粉,套袋不授粉的不结果.不同雄株对不同杨梅品种成熟期和果实品质(如色泽、果实大小、风味等)的花粉直感现象不明显.     

规则人工林的随机行调查法

森林调查是一项重要的资源管理和经营的手段。常规的调查法有着他们的适用性，但也同时具有其局限性。随着人工林面积的不断扩大，提出一种适用于人工林的特殊调查法十分必要。规则人工林的随机行法具有高效性和精确性，与面积单元线性测量法构成了完整的人工林调查体系。     

红松优树自由授粉子代测定的数据分析

以吉林省三岔子林业局国家红松良种基地的红松29a生子代测定林为材料,对树高和胸径生长性状进行测定和数据分析,结果表明:在41个参试家系中,家系间树高和胸径生长均值在0.05水平上差异显著。树高均值超过对照的家系有31个,占家系总数75.6%,胸径均值超过对照的家系有29个,占70.7%;树高均值超过对照10%的家系有1个,占家系总数2.4%,超过对照5%的家系有8个,占19.6%;胸径均值超过对照10%的家系有4个,占9.8%;超过对照5%的家系有8个,占19.6%;42#和75#家系的树高与胸径生长均大于对照5%以上。以树高和胸径生长超过对照5%为入选标准,入选率为19.6%。树高和胸径生长最优家系分别为57#与75#,一般配合力分别为1.788与6.902。树高和胸径遗传力分别为0.393与0.363;遗传增益分别为2.9%与4.5%。     

Fire sensitivity of broadleaf tree species in plantations of Kurdistan,Iran

To better manage wildfires and plantations in Kurdistan, native tree species commonly used in planting and reviving forests such as Quercus brantii Lindl., Q. infectoria Olivier, Q. libani Olivier, Pistachio atlantica Desf., Fraxinus rotundifolia Vahl, and Robinia pseudoacacia L. were evaluated and compared in terms of fire sensitivity and fire resistance. To determine fire sensitivity, indices such as the fl ammability index, ignition time, fl ame durability, moisture content, carbonized surface, mass reduction, bulk density, as well as dry weight of wood, bark, and leaves were used. The data were subjected to ANOVA. The means obtained, after examining homogeneity or heterogeneity of the variances, were compared using parametric and nonparametric comparison tests. There was a significant difference at the level of 5%. Based on the analysis of these indices, the species could be divided into three groups: species sensitive to fire such as Robinia pseudoacacia, species moderately sensitive to fire such as F. rotundifolia, and species relatively resistant to fire, including Q. brantii, Q. libani, Q. infectoria, and P. atlantica.     

Evaluation of leaf display of evergreen broadleaved tree species and deciduous tree species in warm temperate conifer plantations

We investigated the sapling leaf display in the shade among trees of various leaf lifespans co-occurring under the canopy of a warm-temperate conifer plantation. We measured leaf-area ratio (aLAR) and morphological traits of saplings of evergreen broadleaved tree species and a deciduous tree species. Although we found large interspecific and intraspecific differences in aLAR even among saplings of similar size in the homogeneous light environment, we did not find a consistent trend in aLAR with leaf lifespan among the species. While deciduous trees annually produced a large leaf area, some evergreen broadleaved trees retained their leaves across years and had aLAR values as high as those of deciduous trees. Among leaf-level, shoot-level, and individual-level morphological traits, aLAR was positively correlated with current-year shoots mass per aboveground biomass in deciduous trees, and with the area of old leaves per aboveground mass in evergreen broadleaved trees. Thus, tree-to-tree variation in the degrees of annual shoot production and the accumulation of old leaves were responsible for the interspecific and intraspecific variations in aLAR.     

Effects of the second-generation larch plantations onsoil fertility and tree growth

Larch is one of the most important plantation species in the northeast region of China. After clear cutting of larch plantations it is the urgent problem to besolved that whether the second generation is continuously plant6d, whether the soil fertility is decreasing and the plantstion is how to be managed onthe forestry produCtion. In odder tO realize the secondgenerahon Of larch plantstions and to provide thetheoretical base and the reasonable managementmeasures, we inventoried the groWth o…     

Shade tolerance and suitability of tree species for planting in rubber plantations

The rapid increase in rubber monoculture in Xishuangbanna has resulted in extensive damage to its local ecosystem. To decrease the negative effects, the concept of the ecological-economic rubber plantation (EERP) system was proposed. The EERP entails intercropping rubber plants with other economically significant plants, which would not only decrease the ecological impact of the rubber plantation, but also maintain and potentially increase its profitability compared with rubber monocultures. In order to select the appropriate species and intercropping pattern in the EERP system, we compared the photosynthetic parameters of five economically important trees (Swietenia mahagoni, Coffea arabica, Mesua ferrea, Myristica yunnanensis and Paramichelia baillonii) under four irradiance levels. The optimal irradiance intensity of C. arabica and M. yunnanensis was approximately 40%, and these species can be planted in the understory of an 8- to 15-year-old rubber forest. Adult S. mahagoni, M. ferrea and P. baillonii grow taller than the rubber trees, and their seedlings also show superior performance in 100% irradiance than in other irradiances. Thus, in an EERP, these valuable trees could be planted adjacent to rubber plantations but on sites that are economically and environmentally marginal for rubber production.     

多效唑对大石早生李幼树生长的影响

对大石早生李进行土施或叶面喷施多效唑 ,均有控制新梢加长和加粗生长、降低树体高度、缩短节间长度、增加短果枝和花束状果枝比例、降低长果枝和中果枝比例、促进花芽分化、提高单株产量的效果 ;对单果重没有明显作用 ,对果实硬度有增强趋势 ,而对座果率和果实可溶性固形物含量有降低趋势。分析认为 ,以土施 0 5g/m2和喷施 10 0 0mg/kg× 2效果为好     

Application of high-resolution airborne data using individual tree crowns in Japanese conifer plantations

We investigated conifer plantation management in Japan using high-resolution airborne data based on an individual tree crown (ITC) approach. This study is the first to apply this technique to Japanese forests. We found that forest resources can be measured at the level of a single tree. We also produced a tree-crown map for a test site with Chamaecyparis obtusa, Pinus densiflora, Larix kaempferi, Cryptomeria japonica, other conifers, and broadleaved trees, with a classification accuracy of 78%. Forest-stand polygons with tree-cover types were generated from this map, a tree-density map, and a crown-occupied-area map. Forest information for the stand polygons was extracted automatically and compared with detailed field-survey data. The error between our ITC estimates and the field-survey data ranged from 0.3 to 30.2%, depending on tree crown size, density, and other factors. Errors were highest for high-density stands with mixed compositions and tree crown diameters ≤5.0 m. However, the error for stands with crown diameters ≥6.2 m was 11.6% or less. Therefore, this technique is best suited to pure Japanese conifer plantations without multiple layers or high-density stands.     

Impact of native tree plantations on mine spoil in a dry tropical environment

This study describes the impact of young high-density plantations of two native leguminous (Albizia procera and A. lebbeck) and one non-leguminous timber tree (Tectona grandis) species on the soil redevelopment process during the early phase of mine restoration in a dry tropical environment. There was a general improvement in soil properties due to establishment of plantations. Highest soil organic C values were found in A. lebbeck plantations and lowest in T. grandis plantations. Both A. lebbeck and A. procera substantially increased levels of nitrogen in soil. However, A. procera, with slow decomposing litter, was not as effective in raising N levels in the soil as A. lebbeck, indicating that all N fixers may not be equally efficient in raising soil N levels. Soil microbial biomass and N mineralization rates were always higher in plantations of N-fixer species. A continued increase with age in microbial C:total C ratio indicates these plantations have yet to reach steady state.