女子沙滩排球垫球调整在比赛中的运用对比分析     

杨景淼 《四川畜牧兽医学院学报》2008,(2):118-120

通过文献资料法、录像统计法、观察分析法，以部分世界女子沙滩排球巡回赛、全国女子沙滩排球巡回赛为研究对象，对沙滩排球垫球调整技术在比赛中的运用进行研究分析。认为沙滩排球比赛受自然环境的影响和规则的限制，传球调整容易造成持球和连击，而我国沙滩排球队伍仍然更多采用传球调整技术。重视垫球调整是提高我国沙滩排球技战术水平与世界接轨的发展趋势，也是适应自然条件和适应规则的有效措施。  相似文献   

斑马水塔花的组织培养和快速繁殖     

梁国平  肖三元  杨焱 《热带农业科技》2002,25(4):26-28

试验筛选出斑马水塔花的诱导愈伤组织培养基MS+6-BA1.0mg·L-1+NAA0.2mg·L-1，愈伤组织诱导率达96.7%；继代增殖培养基MS+6-BA2.0mg·L-1+NAA0.2mg·L-1，增殖倍数达8～9倍；生根培养基MS+KT 0.5mg·L-1+NAA0.5mg·L-1，生根率达100%。幼苗经炼苗后，移栽到经菌肥处理的甘蔗渣∶泥炭土∶珍珠岩＝6∶3∶1的基质上，成活率达95%以上。  相似文献   

景洪市砂仁现状调查(一)——阳春砂仁衰老现象初报   总被引：1，自引：0，他引：1  

李荣英  李学兰  里二  管志斌 《热带农业科技》2002,25(3):18-19

经调查，西双版纳阳春砂仁由于种植时间长，植株衰老，即叶、茎变小变细，开花结果少，果千粒重变轻等，是大幅度减产的主要原因。  相似文献   

普通油茶对炭疽病抗性的病理学研究   总被引：8，自引：0，他引：8       下载免费PDF全文

张常青 《林业科学研究》1996,9(4):435-438

普通油茶对炭疽病抗性的病理学研究张常青关键词普通油茶、油茶炭疽菌、抗病类型、孢子萌发与侵入由于油茶炭疽病菌（ＣｏｌｅｔｏｔｒｉｃｈｕｍｃａｍｅｌｉａｅＭａｓｓｅｅ）的危害，使普通油茶（ＣａｍｅｌｉａｏｌｅｉｆｅｌａＡｂｏｌ）大量落花落果，这是严重影响...  相似文献   

Effects of silvicultural activity on ecological processes in floodplain forests of the southern United States: a review of existing reports     

B. G. Lockaby  J. A. Stanturf  M. G. Messina 《Forest Ecology and Management》1997,90(2-3):93-100

Activities associated with timber harvesting have occurred within floodplain forests in the southern United States for nearly two hundred years. However, it is only in the last ten years that any information has become available about the effects of harvesting on the ecological functions of this valuable resource. Hydrology is the driving influence behind all ecological processes in floodplains, and timber harvesting alone usually has little long-term effect on hydroperiod. However, logging roads, built in association with harvest sites, can sometimes alter hydroperiod to the extent that vegetation productivity is raised or lowered. There is no evidence that harvesting followed by natural regeneration represents a threat to ground or surface water quality on flood plain sites, as long as “best management practices” are followed. Harvested floodplains may increase or have little effect on decomposition rates of surface organic matter. The nature of the effect seems to be controlled by site wetness. Data from recently harvested sites (i.e. within the last ten years) suggest that vegetation productivity is maintained at levels similar to those observed prior to harvests. During the early stages of stand development, tree species composition is heavily influenced by harvest method. Similarly, amphibian populations (monitored as bioindicators of ecosystem recovery) seem to rebound rapidly following harvests, although species composition may be different from that of unharvested stands.  相似文献   

Development and ecology of bottomland hardwood sites   总被引：3，自引：0，他引：3  

John D. Hodges 《Forest Ecology and Management》1997,90(2-3):117-125

A basic knowledge of the origin, development, and ecology of bottomland hardwood sites is important for assessing harvesting impacts on those sites. This paper presents an overview of the geologic origin and development of hardwood sites, species-site relationships and the natural patterns of ecological succession on those sites, and the implications of that information for forest management. Bottomland hardwoods occur on floodplain sites primarily in the Atlantic and Gulf Coastal Plains. Past geologic events led to the formation of broad stream valleys in those areas because of the erodible, sedimentary geologic materials. Natural patterns of ecological succession on floodplain sites are influenced by autogenic and allogenic processes in that the sites may undergo constant change because of deposition. Three natural patterns of succession are recognized for floodplain sites of major river bottoms—those occurring on permanently flooded sites, those on low elevation wet sites, and those on higher elevation, better drained sites. Floristic composition and successional patterns are strongly influenced by the hydrologic events on the sites and particularly by rates and types of deposition.  相似文献   

Sedimentation associated with forest road surfacing in a bottomland hardwood ecosystem     

Bob Rummer  Bryce Stokes  Graeme Lockaby 《Forest Ecology and Management》1997,90(2-3):195-200

Access systems are a necessary element of resource production in bottomland hardwood sites. However, road building may have a detrimental effect on hydrologic function of the site. This report describes initial results of a study designed to examine the effect of different road surfacing treatments on water quality.

Four surfacing treatments installed on two test roads included native soil, native soil with vegetative stabilization, 6 cm of gravel, and 15 cm of gravel over geotextile. During the first flooding season periodic sampling measured floodwater suspended sediments and location of erosion and sediment deposition within the road prism. Initial results suggest that sediment movement was confined to the road right-of-way, with no statistically significant sedimentation effects detected beyond the clearing limits of the road. The study is continuing for another field season.  相似文献   

具有广阔发展前景的几种云南天然香料   总被引：1，自引：0，他引：1  

郝立勤  杨永清 《热带农业科技》2001,24(3):31-33

叙述了云南省天然香料资源开发利用简况及生产现状，提出了发展香料产业区域布局的设想。重点论述了香荚兰、肉桂、薄荷的国内外生产动向及在云南的发展现状和前景。  相似文献   

马尾松褐斑病调查研究初报     

乐克辉  张著奎 《福建林业科技》1996,23(4):62-65

松针褐斑病是马尾松的一种新的病害。调查发现在发病严重的湿地松林下及林缘的马尾松幼树已普遍感染松针褐斑病，发病率达６７．１％，个别发病严重的植株已濒临死亡。而在马尾松纯林调查中未发现马尾松褐斑病。马尾松褐斑病发生规律是春季为发病盛期，秋季为新叶发病期；病菌潜育期比湿地松上长一个月以上，病菌子实体产生的数量也比湿地松上产生的数量少的多。可见，马尾松是抗褐斑病较强的树种。  相似文献   

园林树木遮荫功效研究进展     

杨建欣 《湖北林业科技》2022,(4):64-69

摘要：卫星遥感是现阶段测绘领域应用较为成熟的技术,然而在农林业病虫害监测预警方面使用较为迟缓,特别是针对省级管理机构缺乏监管技术和预警能力,本研究探索了利用卫星遥感技术开展异常变色林木监测的应用实践,以服务于区域松材线虫病防控的技术指导和督查。经过3年的应用表明,高空间分辨率卫星遥感技术具有客观、科学和实时的优势,能够为上级管理机构提供决策依据。  相似文献