Canadian Forest Service Publications

Air pollution and forest health: toward new monitoring concepts. 2004. Percy, K.E.; Ferretti, M. Environmental Pollution 130: 113-126.

Year: 2004

Issued by: Atlantic Forestry Centre

Catalog ID: 24210

Language: English

Availability: Order paper copy (free), PDF (download)

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It is estimated that 49% of forests (17 million square km) will be exposed to damaging concentrations of tropospheric ozone by 2100. Global forest area at risk from sulpher deposition may reach 5.9 million square km by 2050, despite sulphur dioxide emission reductions of 48% in North America and 25% in Europe. Although sulpher dioxide levels have decreased, emissions of oxides of nitrogen are little changed, or have increased slightly. In some regions, the molar SO4/NO3 ratio in precipitation has switched from 2/1 to near 1/1 during the past two decades. Coincidentally, pattern shifts in precipitation and temperature are evident. A number of reports suggest that forests are being affected by air pollution. Yet, the extent to which such effects occur is uncertain, despite the efforts dedicated to monitoring forests. Routine monitoring programmes provide a huge amount of data. Yet in many cases, these data do not fit the conceptual and statistical requirements for detecting status and trends of forest health, nor for cause-effect research. There is a clear need for a re-thinking of monitoring strategies.