Drought—CO2 interactions in trees observations and mechanisms

摘要: summary It is sometimes assumed that because increases in atmospheric CO2 concentration usually enhance water use efficiency per unit leaf area, there will be a tendency for plants to show greater drought tolerance as well increased biomass the future. A critical examination of responses elevated three temperate tree species shows this assumption might incorrect case two them. Both beech (Fagus sylvatica L.) and birch (Betula pubescens Ehrh.) display minimal stomatal closing CO2, F. control transpiration area appears unable compensate development area. By contrast, stomata oak (Quercus robur close appreciably an extent which sufficient increase total simple model controls on supply consumption whole suggests potential height attainment given sapwood decrease rises. The conclusions drawn from experimental data modelling are supported by field observations made UK 1995, when responded very differently severe drought. We suggest progressive over past 200 yr have accentuated differences sensitivity between these species.