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81.
神农架地区珍衡植物沿河岸带的分布格局   总被引:2,自引:0,他引:2  
Due to the importance of riparian zone in maintaining and protecting regional biodiversity, increasingly more ecologists paid their attentions to riparian zone and had been aware of the important effects of riparian zone in basic study and practical management. In this study, 42 sampling belts (10 m×100m) parallel to the bank of Xiangxi River at different elevations in Shennongjia Area were selected to investigate the riparian vegetation and rare plants. 14 species of rare plants were found distributing in riparian zone, accounting for 42.4% of the total rare plant species in Shennongjia Area. The main distribution range of the 14 rare plant species was the evergreen and deciduous mixed broadleaved forest at elevation of 1200–1800 m, where, species diversity of plant community was the maximum at the moderate elevation. The analysis of TWINSPAN divided the 14 rare species into 3 groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation species group. The analysis of DCA ordination showed similar results to that of TWINSPAN. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out that the important function of riparian zone on rare plant species protection. Foundation item: This project was supported by National Natural Science Foundation of China (NSFC39970123), and Changbai Mountain Open Research Station, Chinese Acadamy of Science. Biography: JIANG Ming-xi (1965-), male, associate professor in Wuhan Institute of Botany, Chinese Academy of Sciences, Wuhan 430074, P. R. China Responsible editor: Chai Ruihai  相似文献   
82.
The historical formation and development of the abandoned channel of the Yellow River is reviewed and its causes of formation and present condition of prevention and control are analyzed in this paper. Based on this analysis, some ideas about control, critical problems and countermeasures in the next period are proposed with two typical control models as examples. We suggest that in preventing and controlling the wind-drift sandy lands in the region, the emphasis should be to develop, with a greatly expanded effort, a recycling economy. This should realize a combination of two ideas, i.e. integrate combating desertification with a structural adjustment of agricultural and an increase in the income of farmers.  相似文献   
83.
霍林河是松嫩平原西部地区科尔沁、向海和查干湖湿地的重要补给水源,其洪泛作用对流域洪泛区环境系统的景观维系起着决定作用。选取流域3个代表测站近50年来的年最大洪峰流量序列,分析流域洪水径流演变的规律及驱动机制,包括自然和人为干扰两方面,可以为流域防洪减灾及洪水资源化利用提供理论依据。霍林河洪水以雨洪型为主,洪水多发于降雨...  相似文献   
84.
宁夏黄河灌区农业非点源污染损失估算   总被引:2,自引:0,他引:2  
以宁夏黄河灌区为研究区,在充分利用JOHNES输出系数法计算灌区非点源污染负荷的基础上,应用环境经济学中的恢复防护费用法对灌区农业非点源污染产生的负荷转化为经济损失进行估算.结果表明:宁夏黄河灌区禽畜养殖产生的污染负荷最高,占灌区污染负荷的41.27%,其中全氮排放占整个区域污染负荷的37.25%,全磷排放占整个区域污...  相似文献   
85.
石羊河流域主要作物的需水量及需水规律的研究   总被引:3,自引:0,他引:3  
试验于2008年在甘肃武威进行,采用水量平衡法在充分灌溉的条件下研究了石羊河流域春小麦、春玉米、制种油葵、色素辣椒、小麦/玉米带田等5种作物的需水量及需水规律,并根据作物生育期需水规律提出了适宜的灌溉制度.试验结果表明,春小麦全生育期需水量为480.5 mm,需水关键期为拔节期和抽穗开花期;春玉米需水量为569.0 m...  相似文献   
86.
季节性河道渗漏野外试验研究   总被引:1,自引:0,他引:1  
为研究季节性河流大沽河河道的渗漏规律,以包气带水分运动理论为基础,在大沽河上、中游建立有代表性的试验场,进行野外现场入渗试验,研究不同包气带岩性下河道的入渗能力.结果表明:干涸河道入渗过程可分为非稳定入渗和稳定入渗两个阶段;包气带的水理性质影响着河床的入渗规律,大沽河河道上游的入渗率比中游的入渗率大,上游和中游南沙梁村...  相似文献   
87.
对于降雨稀少的内陆干旱区,露水具有重要的生态学意义.在黑河中游的张掖市临泽县平川镇,于2008年6~9月利用人造面板法对露水进行了连续90d的观测,发现:①只有当露水收集板的温度低于露点时,露水才能生成;②观测期间河岸带共生成露水52次,总生成量为4.26 nn,绿洲内共生成34次,总生成量为1.52 mm,戈壁共生成...  相似文献   
88.
以黄河兰州段11个不同采样点3种多环芳烃的临测浓度及其对6~38种水生生物的LC50为基础资料,分别应用商值法、概率密度函数重叠面积和联合概率曲线3种风险浮价方法对黄河兰州段苯并(a)芘、荧蒽、芘的生态风险进行了评价.结果表明:黄河兰州段3种PAHs残留具有一定的生态风险.其中低暴露风险条件下(受威胁生物不超过1%),...  相似文献   
89.
通过选取新疆艾比湖湿地国家级自然保护区阿其克苏河东大桥管护站至塌桥子管护站15km为研究区域,野外分两次采样:在研究区内中德合作项目胡杨样地及垂直河道胡杨、柽柳混交林处采挖地下水测点,在典型植被芦苇、梭梭、柽柳及出露的泉水处采挖地下水测点,分别采集水样。实验室实测地下水矿化度及主要离子(K^+、Na^+、Ca^2+、M...  相似文献   
90.
One of the requirements for the forest restoration of soils disturbed by the oil‐exploitation industry is that saplings be able to endure soil‐adverse conditions. In this study, saplings of 20 species susceptible to be used in reforestation programs were evaluated for their ability to grow on substrates derived from soils disturbed by petroleum extractions in the Ecuadorian Amazon. Seeds of each species were planted in germination trays. Once seedlings reached 5 cm in height they were transplanted to plastic bags with three treatment substrates: two derived from petroleum‐exploitation activity (soils from mud and drill cutting cells and from areas surrounding oil wells) and a control soil. Plant survival rate, stem height, and diameter were measured on a weekly basis until 14 weeks after transplantation, when we harvested the plants and also measured plant biomass and calculated the Dickson quality index for each species. Oil‐exploitation by‐product substrates impaired the performance of many saplings, with the substrate from mud and drill cutting cells being the one that most affected plant performance. Only saplings of five native species in the Amazon basin—Apeiba membranaceae, Cedrelinga cateniformis, Inga densiflora, Myroxylon balsamum, and Pouroma cecropiifolia—exhibited high or similar Dickson quality index values in all soil treatments and performed better than the rest. The use of these five species in remediation of soils disturbed by petroleum extraction in the Amazon basin could prove important because of their high potential to adapt to these disturbed sites. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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