New type forest decline
1988
Huettl, R.F. (Forstreferat Kassel (Germany, F.R.))
The present research findings into the 'new type' forest damages observed since the mid 1970s indicate that primary as well as secondary gaseous air pollutants, acid precipitation, nitrogen and heavy metal depositions may play a decisive role in the cause of this phenomenon. In spite of this, a large number of further natural and unnatural stress factors has to be considered when causal mechanisms are discussed in relation to the observed damages. Even though the initial dramatic development seems to be stopped the damages remained at a rather high level since 1984. It can be stated that the new type forest damages are site specific and caused by regional sets of varying stress factors. There is no single causal mechanism that can be named to explain the damages. The new type forest damages are a complex problem. However, a good portion of the forest decline research has been focused on the nutritional status of declining forest ecosystems. These findings show that many damage tapes are associated with nutritional disturbances. In this context it was found that appropriate fertilizer and lime applications can be utilized to revitalize, respectively restabilize declining ecosystems when the damages are associated with nutritional disturbances. Furthermore, various silvicultural techniques exist to stabilize forest ecosystems. Nevertheless, the reduction of air pollutants has to be continued. Finally, it can be concluded that the forests of the Federal Republic of Germany are damaged considerably. But if all activities that have been initiated to counteract this problem proceed and/or are enhanced these forests have a fair chance to survive and provide their many vital functions for future human generations
显示更多 [+] 显示较少 [-]