Forest decline and dieback - A global ecological problem.

Destruction of tropical forests has gained world-wide attention, and the associated depletion of biodiversity has become a growing concern. Almost simultaneously, forest decline and dieback in the developed countries on both sides of the North Atlantic has become an international worry. Industrial pollution has been implicated as the major cause, but the etiology of forest decline and dieback remains largely unresolved. Decline and dieback can also be related to biotic impoverishment in the sense of reduction of canopy species diversity, simplification of structural diversity and biological mining of soil nutrients. Thus, concern over the depletion of biodiversity is highly justified. It links tropical forest destruction to forest dieback in Europe in a way not yet widely realized. At the same time, it does not diminish tge equally justified concern about industrial pollution. A world-wide internationally coordinated research program is suggested which focuses on comparative, interdisciplinary studies in those countries where forest decline and dieback has surfaced as an unresolved problem.