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1.
Ger Boedeltje Alfons J.P. Smolders Jan G.M. Roelofs Jan M. Van Groenendael 《水产资源保护:海洋与淡水生态系统》2001,11(6):453-471
An Erratum has been published for this article in Aquatic Conservation: Marine and Freshwater Ecosystems 12(2), 2002, 251
- 1. In recent decades shallow zones have been constructed along navigation canals in the Netherlands which form a potential new habitat for aquatic macrophytes and helophytes absent from traditional canals.
- 2. The aim of this study was to examine the relationships between the aquatic plant vegetation that becomes established and the physical and chemical characteristics of water and sediment, in order to find the determinants of species composition and the changes therein. Data were collected in 1998 and 1999 from 80 plots in bank zones at varying stages of development since construction along two navigation canals.
- 3. Plots 3–5 years old were partly dominated by rooting submerged macrophytes such as Potamogeton pectinatus, Elodea nuttallii and Potamogeton pusillus; locally non‐rooting species occurred such as Ceratophyllum demersum, Lemna minor and Spirodela polyrhiza. Older plots contained Phragmites australis, locally mixed with free‐floating species. Hydrological isolation from the eutrophic canals was indicated by the presence of Chara vulgaris.
- 4. Characteristics of both water layer and sediment could explain the variation in vegetation composition. Rooting submerged macrophytes predominantly occurred in sites with a thin (<2 cm) layer of sediment with relatively low concentrations of organic matter; moreover, ammonium concentrations in the water layer and sediment pore water were relatively low. Stands of non‐rooting macrophytes and of Phragmites australis were characterized by a relatively thick sediment layer and high ammonium levels in the pore water. Light limitation in turbid water, associated with navigation and eutrophication, may also play a role.
- 5. Although submerged aquatic macrophytes persist for a relatively short time, shallow zones nevertheless function as a habitat for helophyte communities and contribute to a higher aquatic biodiversity than is associated with traditional banks along navigation canals.
2.
Cardé RT Roelofs WL Harrison RG Vawter AT Brussard PF Mutuura A Munroe E 《Science (New York, N.Y.)》1978,199(4328):555-556
Electrophoretic analyses of the (Z) and (E) pheromone-attracted males of Ostrinia nubilalis (Hübner), the European corn borer, in an area of coexistence indicate that these strains are not freely interbreeding. Although the populations are morphologically indistinguishable, studies of allozyme, pheromone, and hybridization suggest that the (Z) and (E) entities are genetically differentiated, perhaps to the status of semi- or sibling species. 相似文献
3.
Nojima S Schal C Webster FX Santangelo RG Roelofs WL 《Science (New York, N.Y.)》2005,307(5712):1104-1106
The sex pheromone of the German cockroach, Blattella germanica, has been characterized as gentisyl quinone isovalerate. This cockroach is a major cause of allergic disease and serves as a mechanical vector of pathogens, making it one of the most important residential and food-associated pests worldwide. The sex pheromone-producing gland in adult females was identified in 1993, but thermal instability of the pheromone made characterization difficult. Now, using a new preparative gas chromatography approach coupled with electroantennographic detection, we have isolated and characterized the pheromone, which we term blattellaquinone, and confirmed the identification by chemical synthesis. The synthetic pheromone was active in behavioral assays and highly effective in field trapping tests, which suggest that it may provide a new tool in cockroach population detection, monitoring, and control. 相似文献
4.
Sex pheromone of the winter moth, a geometrid with unusually low temperature precopulatory responses
Roelofs WL Hill AS Linn CE Meinwald J Jain SC Herbert HJ Smith RF 《Science (New York, N.Y.)》1982,217(4560):657-659
The sex pheromone for the winter moth, Operophtera brumata (L.), has been identified as the novel compound (Z,Z,Z)-1,3,6,9-nonadecatetraene. The male moths respond to the pheromone at low temperatures (4 degrees to 15 degrees C) and exhibit an upper response limit that coincides with the lower response limit for other reported moth sex pheromone systems. The pheromone attracted two other geometrid species, O. bruceata (Bruce spanworm) and O. occidentalis. 相似文献
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J. A. A. R. Schuurkes I. C. C. Heck P. L. G. M. Hesen R. S. E. W. Leuven J. G. M. Roelofs 《Water, air, and soil pollution》1986,31(1-2):267-272
In a greenhouse, seven identical mini-ecosystems, simulating soft water ponds, were exposed to different types of artificial rain water. The effects of rain water containing H2SO4 and nitrate, and rain water containing ammonium sulphate on water quality and vegetation were studied and compared. Causal relations were established between rain water quality, water chemistry and changes in floristic composition. Ammonium sulphate deposition, particularly, strongly affected water quality and vegetation development. Although ammonium sulphate deposition was only slightly acid, due to nitrification it acted as an important acid source, causing acidification to pH=3.8. Under acidified conditions, ammonium sulphate deposition lead to a luxuriant growth ofJuncus bulbosus andAgrostis canina. In the mini-ecosystems, H2SO4 deposition with a pH of 3.5 only decreased the pH of the water to 5.1 within 1 yr. The acidification of water appeared to be coupled with changes in alkalinity, sulphate, Al, Cd, Ca, Mg, K and inorganic-N. It is concluded that in NH3-affected regions in The Netherlands, the high atmospheric deposition of ammonium sulphate probably contributes to a large extent in the acidification, eutrophication and floristic changes of oligotrophic soft waters. 相似文献
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Sex pheromone specificity is the only obvious reproduction isolating mechanism for two tortricid species and two gelechiid species. Pheromones of the gelechiid species are cis-9-tetradecenyl acetate and trans-9-tetradecenyl acetate. Male response of one gelechiid species is inhibited by the pheromone of the other species. This could be important for sympatric evolutionary saltation. 相似文献
9.
Global air pollution crossroads over the Mediterranean 总被引：3，自引：0，他引：3
Lelieveld J Berresheim H Borrmann S Crutzen PJ Dentener FJ Fischer H Feichter J Flatau PJ Heland J Holzinger R Korrmann R Lawrence MG Levin Z Markowicz KM Mihalopoulos N Minikin A Ramanathan V De Reus M Roelofs GJ Scheeren HA Sciare J Schlager H Schultz M Siegmund P Steil B Stephanou EG Stier P Traub M Warneke C Williams J Ziereis H 《Science (New York, N.Y.)》2002,298(5594):794-799
The Mediterranean Intensive Oxidant Study, performed in the summer of 2001, uncovered air pollution layers from the surface to an altitude of 15 kilometers. In the boundary layer, air pollution standards are exceeded throughout the region, caused by West and East European pollution from the north. Aerosol particles also reduce solar radiation penetration to the surface, which can suppress precipitation. In the middle troposphere, Asian and to a lesser extent North American pollution is transported from the west. Additional Asian pollution from the east, transported from the monsoon in the upper troposphere, crosses the Mediterranean tropopause, which pollutes the lower stratosphere at middle latitudes. 相似文献
10.
Effects of NH4
+ on the growth and K+ (86Rb) uptake of various ectomycorrhizal fungi in pure culture
As a result of considerable deposition of ammonium sulphate on vegetation and soil the NH4/K ratios in the soil water extracts of pine forests in the Netherlands are increasing. Increasing the NH4/K ratio from 1 to 40 in the solid nutrient medium of isolated ectomycorrhizal fungi will in general result in a 60 to 80% inhibition of the lateral growth. On increasing the NH4/K ratio the biomass of most of the fungi examined shows a maximum at ratios of approximately 10 to 20, although the colony diameter at those ratios remains rather small. NH4 + also exerts a pronounced effect on the uptake rate of Rb+ inRhizopogon luteolus.At low Rb concentrations the inhibitory effect of NH4 + is maximal, whereas on increasing the Rb+ concentration the inhibitory effect of NH4 + is abolished. This means that NH4 + competitively inhibits the Rb+ uptake inR. Iuteolus. 相似文献