Page:Brundtland Report.djvu/181

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.

A/42/427
English
Page 181


A forest is an ecosystem that exists under certain environmental conditions, and if you change the conditions, the system is going to change. It is a very difficult task for ecologists to foresee what changes are going to be because the systems are so enormously complex.

The direct causes behind an individual tree dying can be far removed from the primary pressure that brought the whole system into equilibrium. One time it might be ozone, another time it may be SO2, a third time it may be aluminium poisoning.

I can express myself by an analogy: If there is famine, there are relatively few people who die directly from starvation; they die from dysentery or various infectious diseases. And in such a situation, it is not of very much help to send medicine instead of food. That means that in this situation, it is necessary to address the primary pressures against the ecosystem.

Alf Johnels
Swedish Museum of Natural History
WCED Public Hearing
Oslo, 24-25 June 1985

known, but all theories include an air pollution component. Root damage[1] and leaf damage appear to interact, affecting the ability of the trees both to take up water from the soil and to retain it in the foliage, so that they become particularly vulnerable to dry spells and other stresses. Europe may be experiencing an immense change to irreversible acidification, the remedial costs of which could be beyond economic reach.[2] (See Box 7–3.) Although there are many options for reducing sulphur, nitrogen, and hydrocarbon emissions, no single pollutant control strategy is likely to be effective in dealing with forest decline. It will require a total integrated mix of strategies and technologies to improve air quality, tailored for each region.

38. Evidence of local air pollution and acidification in Japan and also in the newly industrialized countries of Asia, Africa, and Latin America is beginning to emerge. China and the Republic of Korea seem particularly vulnerable, as do Brazil, Colombia, Ecuador, and Venezuela. So little is known about the likely environmental loading of sulphur and nitrogen in these regions and about the acid-neutralizing capacity of tropical lakes and forest soils that a comprehensive programme of investigation should be formulated without delay.[3]

39. Where actual or potential threats from acidification exist, governments should map sensitive areas, assess forest damage annually and soil impoverishment every five years according to regionally agreed protocols, and publish the findings. They

/…
  1. Tyler, G., et al. (1983). Metaller i Skogsmark : Deposition och omsättning. PM 1692. Solna, Sweden: Statens naturvårdsverk. ISBN 9789175901305. OCLC 808729421. 
  2. 'Neuartige Waldschäden', 1983, op. cit; Paces, 'Weathering Rates', op. cit.
  3. Rodhe, op. cit.