农田防护林带对小麦气孔阻抗的影响

<正> 一前言当气流通过或越过林带时,林带迫使气流结构改变,引起一系列生态环境因子变化,进而对作物生长和产量有所影响,这方面已有很多的研究。而结合作物生理机制研究农田防护林带对作物生长发育和产量的影响,还是不多的。     

四川盆地丘陵区坡地农林复合系统内部结构和系统综合效能的研究

针对四川盆地丘陵区农林生产特点和坡地农林复合系统特征,对其内部结构进行综合研究。分析了林带对农作物的正,负效应,依据林带间散射辐射分布规律、农地水土流失特征和农作物产量分布格局等方面与林带间距离的相互关系,提出了坡地林带间距离应不小于３倍林带平均高,才能保证农作物不至于减产;同时,对建成的坡地农林复合系统模式进行综合效能分析,表明,与农地系统对比,坡地农林复合系统提高了土地生产力、能量转化率、营养     

林带对春大麦产量的影响

关于防护林带下春大麦的产量,据报道在遭受干热风影响的1982年,赫尔松斯克省叶里萨韦特格拉斯茨县阿尔布琴斯克乡卡灭罗瓦特林带间农田的产量为1050kg/hm~2,而空旷地的产量每公顷只有225～300kg。在风调雨顺的1902年,接近林缘的春大麦的产量比调查地的中间地块少。在遭受干旱的1955年,在捷尔库斯林区的防护下,每公顷收获春大麦1890kg,即比每公顷空旷地超产350kg。甚至在大旱的1954年,据乌克兰南部林区的调查资料,林带内农地的产量每公顷也增加了200kg。 1962～1968年,在基洛沃格勒斯克省马罗维斯科夫斯克地区胜利国营农场,防护林带下春大麦每公顷收获2540kg,而紧靠着处于相同土壤气候条件的空旷地块每公顷少收     

栗园防护林生态效应及效益研究初报

根据大田作物防护林带的研究成果，从生态角度出发，研究了防护林带与栗园之间的关系，分析防护林带调节栗园小气候，对栗树生长发育和产量等方面的影响，调查其防护效应和胁地效应，具体分析了风速、空气温度、空气湿度、光照及日照投影方面的变化规律，研究了叶片含水量、植株蒸腾量等水分生理方面的反应，测定株高、冠幅、干径、新梢生长量等栗树生长发育指标以及株产量方面的变化，为建园、防风林配套设计及生产提供理论依据。     

农田防护林提高粮食质量研究初报

<正> 国内外的研究表明,在风沙干旱地区营造农田防护林可以通过对农田小气候的改善而明显地提高农作物的产量,增产幅度随作物品种和天气条件而变动。一般谷类作物可增产20—30%。随着人们对粮食成分要求的提高,防护林带影响农作物质量的研究,特别是分析粮食的营养物组成受到越来越大的重视。国外已有不少报道,我国李德毅在六十年代初曾作过林带对棉花衣脂、籽脂的防护效果分析。此外,有关方面的研究则不多。为了查明防护林带对粮食质量的影响,我们在1979年对防护林带保护下的玉米进行了产量调查和蛋白质、糖含量分析,现将结果报告如下: 材料和方法试材取于辽宁省法库县丁家房公社西方田N0 8林带后玉米田,玉米品种系丹玉6号。该     

河岸农田防护林“两大效益”调查研究

河岸农田防护林不仅能有效控制洪水和风沙危害,增加土壤肥力,调节气候,而且能提高作物产量,防护林带还可作为速生丰产林进行开发利用,经济效益突出,生态、经济“两大效益”十分可观。     

油茶低产林改造效应的研究：II.低产林改造相关分析

采用相关分析和典型相关分析方法，对油茶低产林改造中效应因子间及其与产量间的相关关系进行分析，表明：叶绿素含量，叶片中磷含量，单株果数，地面相对光强和土壤容重与产量关系密切；生态效应因子是通过影响生长效应因子，生长效应因子又是通过影响结实效应因子，进而影响油茶产量的，还采用灰色局势决策方法，对低改措施组合进行决策，结果是综合改造效应最显著，增产最明显。     

用定量分析方法确定丰宁县红果适生范围

丰宁地处河北北部,属燕山余脉的山区县,1983年以来,该县红果生产取得了很大进展。根据红果对气候条件的基本要求,以六年生红果树株产(效益)为因变量,以影响作物效益的生态条件为自变量,采用多元回归方法,做相关分析和统计检验,以揭示在一定地区内诸生态因子与效益的内在联系和因子间相互关系,从而找出影响作物产量的诸多因子中起关键作用的少数主导因子(即主导适生因素)在此基础上,再进行多元回归分析,用逐步回归直接推导出最优多元回归     

川中浅丘农区坡地林农复合系统的水文效应

本文对坡地林农复合系统水文效应进行的研究结果表明，复合系统中林地土壤非毛管孔隙对降水的有效调蓄能力比荒草坡强；全年除了３月，５月外，复合系统农地土壤含水量均比对应的纯农地略高；采用横坡聚土垄作或土石护坎工程可有效地减少复合系统农地水土养分的流失量。     

桉树人工林复合系统的经济效益研究

文章对桉农复合生态系统中桉树及间作物的经济效益进行分析,用以探索不同大宽行桉树林不同株距、不同密度对桉树生产量和间作物产量的影响。通过对三年生桉树经济产量和间作物的经济产量的各项经济指标进行系统分析,表明桉农间作系统可以达到木材生产和林下农业的双重效益,为林区经济发展找到新的增长点。     

晋中农田防护林建设现状及其效益评述

农田防护林是林业生态体系的重要组成部分，该文通过对晋中地区农田防护林的调查，分析，研究，提出了科学建设农田防护林的对策，并对农田防护林的效益进行了评述。     

半干旱风沙区农田防护林的功能及效益评价

在全面调查、详细观测防护林带结构及其对气象因子作用的基础上，对防护林的功能进行了探讨，提出了在半干旱地区建立防护林的主要依据。     

Predicting maize and soybean production in a sheltered field in the Cornbelt region of North Central USA

Shelterbelts (field windbreaks) are an important tool for farming in semi-arid areas but are not commonly used. An obstacle to the adoption of shelterbelts is the lack of site-specific information about the benefits and costs associated with establishing and maintaining them. A group of researchers has been developing a modeling system that will estimate site-specific effects, benefits, and costs for sheltered fields that produce maize or corn (Zea maize) and soybean (Glycine max) in the U.S. Corn Belt region. Akey component of the modeling system is the use of the CROPGRO-Soybean and CERES-Maize models to simulate yield response to microclimatic changes acrossa sheltered field. In this work, we tested the ability of both models to simulate yield in a sheltered field, evaluated the potential yield increase of shelterbelts based on long-term simulations, and compared the influence of shelter induced changes in temperature and windrun on yield. Both models simulated yield increases due to shelter. The soybean model was more responsive to microclimatic differences than the maize model. Long-term simulations generally showed a field level increase in yield due to shelter for maize and soybeans with an average increase of 4.1 and 3.3, respectively. Change in windrun due to shelter is more important in increasing yield than changes in temperature. The CERES-Maize model seems to be more sensitive to changes in windrun than the CROPGRO-Soybean model.     

风暴袭来 海防林可否抵挡——海防林的喜与忧——中国海防林建设纪实

八月，我参加了中宣部、国家林业局联合组织的“绿色海疆万里行”活动第四小组的采访。在历经十天的奔波中。我们跨越山东、江苏和上海三省市，行程共计万余里。每天五六百公里的路程，不仅是新闻采访团对我国沿海防护林的一次考察，也是海防林对我们这些记者身体和意志的一次考验。胶东半岛的艳阳烈日，江苏海港的涛沱大雨，上海崇岛的微风星夜，给我们太多回想，就连成山林场的小咬，大丰糜鹿苑的蚊子都或多或少地在我们的胳膊和大腿上留下了点“印记”。这印记和回忆是那么的美好和深刻，使得我们时时怀念……     

Microclimate modification and response of wheat planted under trees in a fan design in northern India

The presence of trees in fields may help overcome the physiological stress that happens to late sown wheat (Triticum aestivum L.) in subtropical India. Wheat was planted in an agroforestry system with Eucalyptus tereticornis trees on 7 January 1998 in a fan design that provided different combinations of tree row spacing and orientations. Crop profile microclimatic conditions and the resulting growth responses of the intercropped wheat were studied to explore the potential of agroforestry systems to influence late sown wheat yields under different tree row spacing and orientations. Agroforestry treatments exhibited a potential to optimize the microclimatic conditions for seedling emergence, tillering and earhead emergence at some tree row orientations and distances from the crop. The net radiation distribution at three stages of crop growth indicated that the radiation availability was lower in all the agroforestry treatments than for the sole crop. The tree row orientation and distance influence the growth behavior of the crop but the effect of sun angle (which changes with season) can change their influence over time. The deterioration or amelioration of microclimatic conditions in agroforestry with the passage of time should be expected because of altered interaction patterns between sunrays and tree canopy resulting from changing solar elevation and angle of sunrays. Statistically similar harvest indices in all the treatments despite lower total biological yields in agroforestry treatments revealed that microclimatic conditions under agroforestry were more favorable for wheat growth attributed to reduction in heat load during the post anthesis period. This revised version was published online in June 2006 with corrections to the Cover Date.     

吉林省三北地区农防林更新方式

吉林省三北地区农防林的更新方式主要有半带更新、全带更新、隔带更新、全面更新、加带更新、改带更新。本文对其更新方法、更新顺序进行了详细介绍。并对乡（镇）农田防治森工程的更新轮伐进行了论述。     

论辽宁沿海防护林体系工程的建设

阐述了辽宁沿海防护林体系建设的意义，提出海防林体系建设的目标和布局，建设重点是基干林带、湿地保护和恢复、城乡绿化美化、绿色通道。     

木麻黄优良无性系营建农田防护林试验

利用速生、抗性强的木麻黄P10-33优良无性系,采其小枝经水培出根后培育容器苗,结合配套的造林技术,在平潭县营建农田防护林试验,取得较好的效果。重点介绍营建木麻黄优良无性系农田防护林的技术和初步成效,旨在为将营建农田防护林的单位提供一些借鉴。     

斯文秀才——江苏沿海防护林

江苏沿海地区地处我国海岸带中部。是我国经济发展战略的重要部位。全省沿海海岸线全长967公里。北起连云港市赣榆县绣针河口，南抵长江口，属黄海区域。沿海多为滩涂地带，拥有海涂面积978万亩。占全国四分之一以上。并且以每年4～5万多亩的速度在继续扩展。     

Effect of shelter on temperate crops: a review to define research for Australian conditions

The fact that the shelter created by windbreaks can have a significant, positive effect on crop production is supported by eight decades of research from many countries around the world. Although the concept of planting windbreaks to enhance crop production has general currency in Australia, the practice is not as wide as it could be. This review of the last decade of windbreak literature defines the research needed to encourage wider utilisation of windbreak technology. After outlining the principal mechanisms behind the effect of shelter on temperate crops, the review discusses relevant literature of the past decade especially that from Australia. The main mechanisms discussed are: the protection of crops from physical damage; soil conservation; the direct augmentation of soil moisture; and the alteration of the crop energy balance and plant water relations. Also discussed are the elusiveness of the shelter effect, competition from windbreak trees, and the modelling of windbreak systems. Suggestions for future research in Australia include: quantifying the competition of various windbreak species and the effect of root pruning on both crop and tree; a model of crop energy and water relations at the tree-crop interface; an economic model and a farmer-oriented decision support tool. This revised version was published online in June 2006 with corrections to the Cover Date.