The mining industry, in terms of ore excavation and metal production, is and has been important to the Swedish economy. In connection with the ore excavation process, large amounts of partly sulphidic waste are produced. When the metal sulphides are exposed to air and water they are eventually oxidised, which leads to the formation of acidic water with high concentrations of metal cations and sulphate ions, so called Acid Mine Drainage (AMD). This water may reach the nearest surroundings and cause negative environmental effects. By covering the waste with soil or water, the oxidation process can be minimised. At the Rävlidmyran mine in the county of Västerbotten open pit mining took place between 1951 and 1991.

Nature conservation has for a long time been founded on the assumption that high ecological values depend on low human impact. In Sweden this has led to forests with these characteristics being strictly protected from human influences. However, it is also known that historical land-use can enhance ecological values in forests. Mountainous forests in Sweden, which have not been affected by modern forestry, have for a long time been considered as untouched by people. However, forest history research has in recent years shown that even these areas have been used by people for a long period of time.

Unwanted vegetation on the land of electric transforming stations is a problem, in the sense that it contributes to higher fire risks and also constitutes an obstacle for people performing maintenance operations at the station. Such unwanted vegetation is controlled using herbicides and mechanical measures. Since the use of herbicides implies environmental hazards, there is a need to find alternative ways of fighting the unwanted vegetation. Investigation into suitable plants for ground cover, trials in the greenhouse, trials in the field, soil analyses and compilation of experiences from similar trials are parts of this work. The paper also contains analyses of possible environmental benefits and economical gains. There is also a final discussion of some proposals regarding alternative weed controlling methods.

SAMMANFATTNINGMastit är den vanligaste och mest kostsamma sjukdomen hos mjölkkor. Enligt statistik från Svensk Mjölk har cirka 65 % av alla kor i Sverige mastit någon gång under en laktation. Subklinisk (utan märkbara symtom) mastit utgör det största problemet. De är svåra att upptäcka då även mjölken ser normal ut, vilket resulterar i att den hamnar i tanken och levereras till mejeriet. Mjölk från kor med mastit har ett ökat celltal samt försämrad kvalitet och sammansättning vilket i slutändan medför sämre betalt för lantbrukaren.