氰氟草酯乳油防除水稻秧田千金子效果及安全性

[目的]明确氰氟草酯的除草效果、适宜的用药量以及对水稻秧苗的安全性.[方法]以50％二氯喹磷酸可湿性粉剂为对照药剂,通过田间药效试验研究了100 g/L氰氟草酯乳油不同剂量(90、120、150、180 g,/hm2)对水稻秧田千金子、稗草等杂草的防除效果及对水稻秧苗生育的安全性.[结果] 100 g/L氰氟草酯乳油用药量150 g/hm2时对水稻秧田抗性杂草——千金子具有很好的防除效果,施药后20 d除治千金子的效果达到98.3％,千金子生物鲜重抑制效果为98.7％,同时对稗草的除治效果为96.2％;100 g/L氰氟草酯乳油不同剂量对水稻生育安全.[结论] 100 g/L氰氟草酯乳油是除治水稻旱育秧田千金子的优良除草剂,并可兼治稗草等1年生杂草.     

Ontogeny and dietary specialization in brown trout (Salmo trutta L.) from Loch Ness, Scotland, examined using stable isotopes of carbon and nitrogen

Abstract – The trophic ecology of many fish species in cold temperate lakes is often characterized by a generalist or opportunist strategy. In this study, the diets of polytrophic brown trout in Loch Ness, Scotland, have been examined using stable isotopes of carbon and nitrogen to complement gut content analyses and aging by otolith annuli counts. Using the stable isotope ratios, it was possible to trace trout ontogeny from parr development in a natal river to piscivory in the pelagic. Potential dilution of maternal isotope signatures from eggs to parr was also demonstrated. Despite the low productivity of the loch, intraspecific variability in isotope ratios suggested dietary specialization, rather than opportunism, in some individuals.     

Mapping serpulid worm reefs (Polychaeta: Serpulidae) for conservation management

• 1. This study describes investigations into mapping of the biogenic reefs produced by the polychaete worm, Serpula vermicularis, for the purposes of conservation management.
• 2. Reef distribution throughout Loch Creran, Scotland, was mapped using a diver transect technique and was found to be restricted to a peripheral band, with a mean upper limit of distribution of 2.7 m. The mean lower limit was found to decrease with distance from the mouth of the loch, with a lower limit of 9.3 m in the lower basin rising to 6.6 m in the upper basin; the likely influence of a corresponding decrease in the upper depth distribution of muds is discussed.
• 3. Through determination of the mean width of the reef band and coastline length, the areal extent of the reef band was estimated as 108 ha, revealing Loch Creran to harbour the most extensive known development of S. vermicularis reef habitat in the world.
• 4. The utility of sidescan sonar in mapping serpulid reefs was examined in four of the major embayments. Reef material appeared as characteristic patterning on the sonargrams, with the morphology of individual larger reefs being discernible.
• 5. Sidescan sonar was found to be particularly valuable for the identification and monitoring of threats to the conservation of serpulid reefs. Sidescan sonar surveying was found to facilitate identification of loss of habitat extent resulting from anthropogenic activities such as moorings, aquaculture installations and dredging and can also be used to monitor the potentially damaging activity of otter trawling. Further improvements in the mode of deployment of sidescan sonar are discussed.

Copyright © 2008 John Wiley & Sons, Ltd.     

不同色光对南板蓝生长的影响

[目的]了解红、绿、蓝3种不同基础色调的光对南板蓝生长的影响。[方法]运用易得到的材料自制滤光设备,采用不同光质的色光照射南板蓝,研究自然日光与红、绿、蓝3种色光对南板蓝生长的影响。[结果]红光最有利于种子发芽,自然日光次之,再次蓝光,绿光最后;生长量总体上以红光照射最大,自然日光次之,蓝光再次,绿光最后;定性比较叶面积大小顺序为自然日光照射、蓝光照射、红光照射、绿光照射;平均总分枝数大小排序为红光照射、蓝光照射、自然日光照射、绿光照射。[结论]不同的色光对植物不同部分的形成和生长影响不同,对植物内部不同的生化反应影响也不同,有针对地根据植物的现状进行光照干预调节,补充实际中自然光照的缺陷,才能促进植物更好地生长。