四川长宁楠竹(Phyllostachys Pubescens)竹干形状规律及材积测定公式的初步研究

为更精确地评定竹干材积,研究了竹干形状的特性。形率按直径的分布趋于正态分布。胸高直径与形率的相关、胸高直径与形数的相关,直径与形高的相关都已作了研究,作为结论八个测定竹干材积的公式提了出来,划分为四个类型,其标准差都小于±5％。另一方面,对实积仔数也进行了研究、实积仔数随直径的增大而减小。竹产资源的计量单位,目前我国尚无统一的标准,有以重量为单位、有以株数为单位、也有以竹干材积为单位。就楠竹而论,由于竹干形体相差甚大,用株数计不能正确评定竹产资源和竹干材积,用重量计则又称量不便,加之含水率对竹干重量影响甚大,正确测定竹干含水率不是每一生产单位都很方便和可能的。比较一致的意见是赞同以材积作为评定单位较合理可行。为此有必要对楠竹干形及求积式进行研究。长宁是四川楠竹的主产区,历年来大量地提供国家建设所需的竹材。我们根据400余株标准竹和计算竹的实侧资料,对该地竹干形状进行探讨,在此基础上提出了八个竹干材积测定公式,供生产单位试用检验。     

Carbon stocks and greenhouse gas balance of harvested wood products: focus on the Asia-Pacific Partnership countries vis-à-vis the European Union

With the analytical tool, Frankfurt Harvested Wood Products Model, FPM, the carbon stocks and carbon stock changes of Harvested Wood Products, HWP, either in USE or in LANDFILLS L-F, have been evaluated, each separately, from the readily available statistical data base of the FAO, FAOSTAT, on the wood commodities: “Sawnwood and Wood-based Panels, SWP” and the paper commodities, “Paper and Paperboard, PAP”. The focus was on the newly founded Asia-Pacific Partnership countries for Clean Development and Climate (in short AP6), including Canada, which wants to join the AP6, in relation to the countries of the European Union EU-25. It could be shown that the stocks and stock changes of the HWP in USE follow a simple algorithm of the annual consumption or production and their mean annual growth, for the categories SWP and PAP, provided the mean residence times of the HWP in USE can be estimated. With the information on the fraction of residues entering the landfills and their estimated residence times an equivalent simple expression has been derived for stocks and stock changes of the HWP in LANDFILLS L-F. Their values have been calculated to be approximately 0.5 to 0.7 times smaller than those of the HWP in USE. Still, all stock changes of the HWP in L-F were positive and thus accumulating carbon. However, when methane outgasing within the HWP in L-F had been considered, the calculated Greenhouse Gas Balance was zero or negative under the estimated parameters thus to at least partly compensate the positive storage of carbon in HWP in USE. The percentage of CO₂ removed by the HWP in USE in comparison to the annual greenhouse gas emissions varied from 0.3 to 1.7%, with a mean value of 0.8% for the AP6 countries including Canada, in contrast to 1.0% of the EU-25 countries. Despite of the relative small magnitude in relation to the total emission of all GHG this contribution should not be neglected in the GHG Budget of a country.     

雅安地区土地资源的特点及开发利用对策探讨

在参与雅安地区土地详查和土地利用总体规划编制的基础上 ,分析了雅安地区土地资源的特点与利用现状特征 ,提出了雅安地区今后土地资源合理开发利用的对策和措施。     

“3S”技术在森林资源中的应用

本文对近年来"3S"技术在森林资源中的应用加以总结,进而分析其在森林资源中的应用优势和目前存在的问题,对未来"3S"技术在森林资源中应用的发展方向提出意见和建议。     

日本梅品种引种试验

从日本引入的3个梅品种以“白加贺”和“鸳宿”表现较好。它们的果重20克左右,含糖量约1.5％,含酸量约50.％,丰产,花期迟;6月中、下旬成熟,白加贺的单株产量略高于莺宿,但在钙质土“白加贺”更易生理缺铁。两品种可在亚热带湿润气候区推广。     

Dry matter yield and water use efficiency of five perennial subtropical grasses at four levels of water availability

The effect of four levels of water availability on the yield and water use efficiency (WUE) of five subtropical perennial grasses was evaluated in a small plot trial under a rain shelter. The soil profiles were brought to 100% (W4 = the control), 75% (W3), 50% (W2) and 25% (W1) of field capacity on a weekly basis. Under W4 (control) and W3 conditions, yields did not differ significantly from each other. Where water became less available (W2 and W1), yields were significantly reduced, in comparison with the control (W4). Buffel grass, a drought-tolerant species, produced yields (11.7–20.0t ha^?1) under moderate to severe water restriction (W1, W2 and W3), which were comparable with yields obtained with adequate water (W4) for traditionally-irrigated grasses such as couch grass (12.0–15.8t ha^?1) and kikuyu (5.6–11.8t ha^?1). All five grass species tended to use water more efficiently under moderate to severe water-limiting conditions (W1 and W2) than under control conditions (W4). These results also indicate that traditionally drought-tolerant grass species should not be overlooked when identifying species for use under irrigation.     

四川土地资源的现状及问题分析1.四川土地资源的现状

以四川（不含重庆市）历年统计资料为基础,利用土壤普查和部分土地利用现状详查资料,进行系统分析,从土地资源学的角度阐明了四川土地资源的现状、问题及应采取的对策。其现状和问题可概括为土地资源总量大,人多地少,人地矛盾十分突出;优势地貌类型占有量小;土地资源的数量结构失衡、地域差异明显;优质地类比重不大、光温潜力和土地生产潜力的发挥不够;宜农耕地后备资源贫乏,难利用土地比重大;土地开发利用程度和土地生产力水平较低。     

川西山区土壤资源的开发利用与保护

川西山区自然资源丰富,生产潜力大,具有开发利用价值。山区土壤的开发利用是建立在对土壤类型及其特征特性的深刻认识以及合理评价的基础上的,而水土保持是开发利用山区土壤的前提和关键,经济植物土宜的研究则为土壤合理开发利用提供有效途径。本文对上述四个方面的研究结果作了简要的论述。     

四川水牛杂交改良研究

四川于1971年开始引进摩拉种公牛杂交改良本地水牛,至1985年已约有杂交水牛55,000头。杂交一代水牛在体格、役用能力、产肉力及产乳力上均优于本地水牛。第一代杂交母水牛第一胎泌乳期产奶置为1096.65公斤,含脂率8.5％,相当于1842.37公斤标准奶,而本地母水牛仅产奶441.41公斤,含脂率9.75％,相当于812.19公斤标准奶,杂交一代母水牛第一泌乳期产奶量较本地母水牛高127‰故水牛为一种潜在的遗传资源,杂交育种是向乳用方向改良本地水牛的有效方法。     

川西南山地区土地资源的特点及生产潜力评价

在分析川西南山地区土地资源特点的基础上 ,结合当地生产实际 ,指出了当前土地利用上存在的问题 ,并对耕地、林地、草地进行了生产潜力评价 ,提出了实现其潜力的对策和措施