The decreasing demand for pitrops [pitwood] since 40 years
1997
Wegener, H.J. (Forstliche Forschungsanstalt Eberswalde e.V., Waldsieversdorf (Germany). Inst. fuer Angewandte Forstpflanzenzuechtung)
This article describes the historical development of pitrops which were significant in former times. The pitrops began to flourish around 1870 and their rise was closely connected to coal-mining. The demand for pitrops started to decrease with the structural change in mining 40 years ago. In 1974 more than 30 solid meters of pitrops were needed for every 1000 tons of coal mined. In 1961 it was 18.5 solid meters, in 1980 five solid meters and by now only two solid meters of pitrops are needed for mining 1000 tons of coal.
اظهر المزيد [+] اقل [-]الكلمات المفتاحية الخاصة بالمكنز الزراعي (أجروفوك)
المعلومات البيبليوغرافية
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