Relative Importance of Increasing Atmospheric CO2, N Deposition and Temperature in Promoting European Forest Growth : Causes and Consequences of Accelerating Tree Growth in Europe. Proceedings of the International Seminar

1999

S. 25-41

zahlr. Lit

Unselbständiges Werk

200058994

This paper sets out some of the arguments and counter-arguments for and against increasing atmospheric CO2, N deposition and temperature as potential drivers of the observed increase in growth rate of European forests. Some of the arguments are summarized in Tables 1, 2 and 3. The author's evaluation of the evidence is that there has been a positive, non-zero effect of increasing CO2 on the growth of European forest this century, possible increasing NPP by as much as 10-15%. It is also highly likely that N deposition has amplified the CO2 effect (or vice versa) in areas where forest growth is N-limited, although N deposition on its own is unlikely to have accounted for more than 10-15% increases in forest growth. Increasing temperatures may have had a smaller effect than might be deduced from site studies. But all three factors will not account for the 50%+ increases in forest growth observed in some parts of Europe, which must also be due to changes in land use practices and improvements in forest management.