期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
圆斑弯叶毛瓢虫对湿地松粉蚧的控制作用 被引量:3
1
作者 李莹 田明义 +1 位作者 刘永康 梁铭生 《武夷科学》 2002年第1期120-124,共5页
圆斑弯叶毛瓢虫是湿地松粉蚧的本地捕食性天敌 ,本论文通过林间散放圆斑弯叶毛瓢虫评价其对湿地松粉蚧的控制作用。结果表明 ,通过散放瓢虫的成虫和幼虫 ,增加林间瓢虫的数量 ,能较好地抑制湿地松粉蚧的增长。散放瓢虫 5 0多天后 ,在散... 圆斑弯叶毛瓢虫是湿地松粉蚧的本地捕食性天敌 ,本论文通过林间散放圆斑弯叶毛瓢虫评价其对湿地松粉蚧的控制作用。结果表明 ,通过散放瓢虫的成虫和幼虫 ,增加林间瓢虫的数量 ,能较好地抑制湿地松粉蚧的增长。散放瓢虫 5 0多天后 ,在散放成虫区 ,湿地松粉蚧的对照存活率达 0 .2 8,即控制效果为 72 % ;在散放瓢虫幼虫区 ,粉蚧的对照存活率为 0 .10 ,即控制效果达 90 %。从持续作用和控制效果比较 ,散放幼虫较好 ,且以瓢虫幼虫与粉蚧雌成虫益害比为 2 :5时对湿地松粉蚧的控制效果最好。 展开更多
关键词 圆斑弯叶毛瓢虫 湿地松粉蚧 控制作用
下载PDF
雨季和旱季暴雨湿地营养物滞留特性 被引量:1
2
作者 邱训平 岳兵 《水利水电快报》 2012年第6期37-41,共5页
构建了一个0.23 hm2的湿地试点,以研究一个面积7.42 hm2的韩国农业小流域控制非点源(NPS)污染的效率。该湿地在基流和暴雨径流的条件下运行,并进行了长达4 a(2006~2009年)的监测。雨季,湿地在高水力负荷率(HLR,日均0.78 m)下运行,进水... 构建了一个0.23 hm2的湿地试点,以研究一个面积7.42 hm2的韩国农业小流域控制非点源(NPS)污染的效率。该湿地在基流和暴雨径流的条件下运行,并进行了长达4 a(2006~2009年)的监测。雨季,湿地在高水力负荷率(HLR,日均0.78 m)下运行,进水平均氮浓度为9.8 mg/L,而在旱季大约为11.6mg/L。由于雨季水力停留时间(HRT)短,湿地氮滞留量很少,只有6.1%;而旱季湿地对氮滞留的效率较高,约为17.9%。湿地在雨季对总磷(TP)的滞留量比较高,平均效率达68.3%,同时总悬浮物(TSS)的去除率也达到84.7%。但是在旱季,湿地对可溶性正磷酸盐(SRP)的滞留效率大于TP。监测还发现湿地内各处营养水平不同。此外,为获得更好的效果,对湿地设计提出了建议。 展开更多
关键词 雨季和旱季 湿地控制 非点源污染 试点研究 韩国
下载PDF
Control of Agricultural Nonpoint Source Pollution by Natural Wetland Management 被引量:1
3
作者 F.D. Shields Jr C.W. Pearce 《Journal of Environmental Science and Engineering》 2010年第4期62-70,共9页
Reduction ofnonpoint source pollutants, principally sediment and nutrients moving from cultivated fields to surface waters, is a major challenge. Remnants of once-extensive natural wetlands occur across the agricultur... Reduction ofnonpoint source pollutants, principally sediment and nutrients moving from cultivated fields to surface waters, is a major challenge. Remnants of once-extensive natural wetlands occur across the agricultural landscape, and it has been suggested that these areas might be managed to yield improved wetland function in terms of trapping and retention of nonpoint source pollutants. An existing wetland in a severed meander bend cut off in the 1940s from the Coldwater River in Tunica County, MS, USA was modified by the construction of weirs equipped with water control structures. The wetland was a segment o fold river channel about 500 m long and 20 m wide. Inputs to the wetland cell included sporadic flows due to runoff events from about 350 ha of cultivated fields and less frequent but larger flood events from the river. This type of flood event occurred only once during the study. Concentrations of sediment and nutrients in water were generally lower at the downstream end of the wetland cell than in the major inflow, an ephemeral slough. Mean values of turbidity, suspended sediment concentration, and concentrations of filterable and total phosphorus were 25% to 40% lower at the wetland cell discharge weir than in the slough. Mean concentrations of ammonia were 38% lower, but mean nitrate and nitrite concentrations were essentially unchanged by the wetland cell. Comparison of estimated input and output loads during periods when the wetland cell was not flooded by the river indicated that the wetland cell retained about 18% of input suspended sediment, 24% of phosphorus, and 29% of nitrogen input from cultivated fields. Wetland cell sediment and nutrient retention efficiency was treater for drier months, and declined durin~ wetter periods with frequent runoff events. 展开更多
关键词 AGRICULTURE NUTRIENTS SEDIMENTS WETLANDS ecological engineering.
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部