خيارات البحث
النتائج 321 - 329 من 329
Air pollution effects on crops and forests, January 1984 - December 1989
1990
Gates, Jane Potter
Eutrophication along the french coasts النص الكامل
1990
Menesguen, Alain
The French coasts exhibit two kiruJs of eutrophicati.on; the prolif erati.on of green macroa/gae (Ulva sp.) affects the very shallow Mediterranean /agoons as we/1 as a lot of widely open beaches in Brittany, whereas phytoplanktonic mass blooms are to be f ound in front of the large estuaries and in some Atlantic -embayments. Bath these types of eutrophicati.on seem to have increased during the fast twenty years, probably in relation with the increase of the nutrients /oadings from agriculture and sewage. However, the severity of eutrophicati.on is not on/y related to the absolute amount of /oadings. The local residence time of the waters, deduced from hydrodynamics, is a crucial parameter; numerica/ mode/s have highlighted the raie of tidal residua/ circulation. Reduction of eutrophicati.on requires a precise knowledge of the in-situ limiting nutrient. If green macroalgae are c/early nitrogen limited, phytoplankton may be either phosphorus or nitrogen limited. Ecological numerical mode/s may help to quanti/y the effects of various strategies of lowering the loadings of nutrients.
اظهر المزيد [+] اقل [-]Review of potentially harmful substances: choosing priority organochlorines for marine hazard assessment
1990
Review of potentially harmful substances: Nutrients
1990
The state of the marine environment
1990
Screening methods for groundwater pollution potential from pesticide use in Colorado agriculture
1990
Durnford, Deanna S.
Report of the twentieth session (of GESAMP)
1990
Protection et gestion des oceans: principes sous-jacents et elements de la protection et de la gestion des milieux marin et cotier.
1990
Rapport. Groupe Mixte d' Experts OMI/FAO/UNESCO/OMM/OMS/AIEA/ONU/PNUE Charge d' Etudier les Aspects Scientifiques de la Pollution des Mers. Sess. 20.
1990
