灌排方案对避雨番茄需水特性与产量的影响

为了实现南方地区番茄节水、优质、高效生产,在避雨栽培条件下,研究了不同灌排方式对番茄需水特性与产量的影响.研究结果表明:各亏缺灌溉处理土壤含水率随时间总体呈下降趋势,暗管埋深08 m的处理较埋深06 m处理,土壤含水量下降更快但不明显.番茄不同生育阶段的蒸发蒸腾量差别较大,表现为始花坐果期>果实成熟与采收期>苗期.随着番茄的生长,其日蒸发蒸腾量大体呈逐渐上升的趋势.在不同灌排模式和避雨措施条件下,苗期的日蒸发蒸腾量变化范围为107～271 mm／d,始花坐果期日蒸发蒸腾量变化范围为160～309 mm／d,果实成熟与采收期日蒸发蒸腾量变化范围为178～335 mm／d.在相同的排水措施,不同灌溉条件下,番茄果实产量随着灌水量的减少而减少,水分利用率和灌溉水利用率却随着灌水量的减少而增大.研究可为南方避雨栽培下番茄灌排方式的选择及其节水、优质、高产提供参考.     

欧亚种葡萄避雨栽培主要生物学特性研究

通过对意大利、黑玫瑰等13个欧亚种葡萄(Vitis vinifera L．)品种在避雨栽培下的生长结果习性、物候期、果实经济性状及抗病性等方面的田问鉴定，结果表明：早中熟品种的京秀、森田尼无核、矢富罗莎及晚熟品种意大利、秋黑等5个品种综合性状表现良好。而美人指等品种存在着成花难、裂果等一些问题，推广应慎重。并对欧亚种葡萄在南方避雨下栽培出现的一些问题进行了讨论。     

三北防护林的建设与指导原则解析

本文介绍了三北防护林的建设目的与重要作用,并从资金、林地修复与技术更新三个角度对 三北工程的指导原则开展解析,提出了开拓个人、金融企业与国际援助等集资渠道。同时,针对不同 原因造成林地退化的修复办法和技术创新手段进行探究,旨在促进我国三北工程顺利开展,加快我国 生态文明建设。     

典型荒漠农田防护林对棉田土壤水盐动态的影响

[目的]研究典型荒漠农田防护林对棉田土壤水盐动态的影响.[方法]以新疆石河子150团棉田-防护林体系为研究对象,测定0.1H、0.25H、0.5H、1H、2H、3H地段与林地的水盐含量及蒸发量,分析防护林对周围棉田土壤的水盐变化特征.[结果](1)防护林的浅根系在其0.25H范围内同棉株争夺水分.(2)棉田防护林下的土...     

防护林对科尔沁沙地耕地土壤理化性质的影响

为了探究防护林对不同地貌类型耕地的影响,选择科尔沁沙地奈曼旗境内坨耕地和甸耕地,对比分析了在有、无防护林情况下坨耕地和甸耕地土壤理化性质及其变化特征。结果表明：① 有防护林耕地土壤理化性质优于无防护林耕地;② 防护林对坨耕地的影响大于甸耕地,其影响在样点1、样点2和样点3都有显现,且在样点1和样点2较为突出,而防护林对甸耕地的影响只在样点1较为明显。     

苏北海堤基干林带刺槐林生长及种群竞争特征研究

研究沿海防护林种群生长竞争规律对营建高效沿海防护林具有重要意义。对苏北海堤不同栽植密度下12 a生刺槐人工林进行生长情况调查,研究种群生长的空间及竞争特征。结果表明,随着密度的增加,刺槐平均胸径(DBH)呈下降趋势,3 m×3 m密度下刺槐平均胸径为13.3cm,单株刺槐生长量最大,而1 m×1 m密度下单位面积刺槐生物量最高。高密度下种内竞争激烈,死亡率高。刺槐胸径的空间分布规律存在差异,随着栽植密度的增高,刺槐胸径的空间变异性增大。因此,营建刺槐防护纯林密度不宜过高,不同栽植密度下刺槐种群竞争规律及机制还有待进一步研究。     

福建东山岛防护林景观格局研究

运用景观生态学原理,借助地理信息系统技术,选取斑块密度、边缘密度、分维数、景观多样性、景观优势度和均匀度指数等指标,对东山岛防护林景观格局进行研究,结果表明,人类活动对东山岛防护林景观格局产生巨大影响,必须加强防护林保护建设。     

Is light the key factor for success of tube shelters in forest restoration plantings under Mediterranean climates?

Tube shelters were designed to protect against browsing, but they improve seedling survival in Mediterranean dry climates. Mechanisms for this response, however, are not fully understood and this knowledge can be useful to help design optimal tube shelters for Mediterranean species and climates. Our objective in this study was to determine if the positive effect of tube shelters is due to enhanced growth during the wet season or to reduced light stress during the dry season. We performed two independent experiments. In the first, we assessed root growth during the wet season in two Mediterranean species with contrasting light tolerance (Quercus ilex L. and Pinus halepensis Mill.) growing in tubes with varying light transmissivity. In the second experiment, we studied the response of a Quercus ilex plantation to different shelter treatments. Root growth during the wet season was reduced with decreasing light transmissivity in the shade intolerant P. halepensis, but not in the shade tolerant Quercus ilex. Survival of Q. ilex shaded by a mesh shelter only during summer was higher than in unsheltered seedlings and similar to the survival in tube and mesh shelters during the whole season. This suggests that shade during the dry period was the main factor explaining survival in this species. This effect could be related to the lower leaf temperature recorded in sheltered seedlings. We conclude that Q. ilex (and perhaps other late successional, shade tolerant Mediterranean species) should be planted in tubes with the currently used light transmissivity because these shelters reduce light stress in summer without impairing root growth in the wet season. However, current tubes impair root growth in P. halepensis (and likely other pioneer, shade intolerant Mediterranean species), so higher transmissivity tubes may be necessary. Optimal transmissivity for tube shelter in Mediterranean climates is species-specific and identifiable as the point that minimizes light stress during summer without impairing root growth in the wet season.     

库布齐沙漠典型防护林土壤养分特征

以库布齐沙漠典型防护林为研究对象,通过测定不同防护林的土壤理化性状,评估该防护林系统的土壤改良效益,为库布齐沙漠防护林的管理与养护提供理论依据.结果 表明:(1)库布齐沙漠防护林营建15年后,在植被改良的作用下,原有的流沙质量发生了明显改变.与流沙环境相比,研究区土壤的碱解氮(AN)、速效磷(AP)、速效钾(AK)、有...     

不同颜色防雨布对杨梅生长发育及果实品质的影响

为提高杨梅综合品质及经济效益,研究延迟杨梅成熟期、降低落果率的技术措施,在杨梅硬核期和转色期分别设置覆盖防虫网及防虫网配合覆盖白、蓝、绿、红、黑色防雨布处理,以无覆盖处理为对照(CK1),测定不同处理对杨梅生长发育及果实品质的影响。结果表明,与CK1相比,绿色和蓝色防雨布有利于降低温度和相对湿度,而红色和黑色防雨布有利于温度升高,所有处理均显著抑制光合速率和枝梢的伸长,光合速率抑制率达30.62%～66.75%,其中转色期覆盖防虫网+绿色防雨布处理的抑制率最高。CK1的果实在成熟时100%脱落,硬核期和转色期进行防虫网单独覆盖和防虫网+黑色防雨布共4个处理的落果率在35.23%～70.49%之间,其他处理能显著降低杨梅果实落果率,落果率在16.44%～19.9%之间;防虫网+绿色防雨布处理、防虫网+蓝色防雨布处理延迟杨梅果实成熟时间最长,达5～9 d。综合分析杨梅果实总糖含量、维生素C含量等品质指标,转色期覆盖防虫网+蓝色防雨布处理的果实综合品质最佳,而覆盖防虫网+黑色防雨布处理的最差。本研究结果为有效利用不同颜色防雨布开展杨梅设施栽培、延迟杨梅供应期提供了理论指导。