خيارات البحث
النتائج 1 - 3 من 3
[Surveillance of the condition of Danish forests by colour infrared aerial photography and satellite pictures]
1988
Olesen, H.H.
Air Pollution and Forest Condition in Central Europe
1993
Kandler, O. (University of Munich, Munich (Germany).Botanical Institute of University of Munich)
Depending on their concentrations, air pollutants are dangerous to forests. With the exception of some industrial areas in the east, concentrations of air pollutants in Central Europe are below the damaging threshold as shown by the records of the monitoring stations.
اظهر المزيد [+] اقل [-]Forests in Virumaa
2000
Ratas, R. (Estonian Agricultural Univ., Tartu (Estonia). Inst. of Environment Protection) | Ratas, J. (Tallinn Technical University, Tallinn (Estonia))
Virumaa has the richest forest resources in Estonia. The area covered with forests in Virumaa amounts to 51.3 per cent (total in Estonia 49 per cent). Pine, birch and spruce forests dominate. A large part of forests are under technogenous pressure (oil-shale mining, power engineering etc.). The total amount of all the fellings in 1999 was 1.061 million cubic metres (in Estonia totally 6.704 mln. cubic metres). The volume of fellings has reached the critical level close to the annual increment of forests. Therefore, the volume of cutting down forests should not be increased
اظهر المزيد [+] اقل [-]