Effects of exposure to ozone and water stress on the following season's growth of beech (Fagus sylvatica L.)

Abstract

SliMMARYBud break and growth of beech trees were measured durmg the growing season of 1992. The trees had previously been exposed, through the growing season of 1991, to one of four treatments: (1) episodic ozone for 128 d, total dose = 46-3 ppm h; (2) air purified by filtration through Purafil and charcoal; (3) ozone together with a period of water shortage; (4) filtered air with a period of water shortage.Despite uniform growth conditions during 1992, the previous water stress treatment caused bud break to begin slightly earlier, but the rates of shoot growth and the length of the first fiush branches were reduced (40"i,)-In v.'eU-watered plants ozone caused a reduced rate of shoot growth during the first week after bud break. The total amount of growth during 1992 was shown to be reduced (36'"'o) by the previous water stress treatment. In the case of the well-watered trees, exposure to ozone in the previous year reduced the amount of new growth by 17"t,, which was the result of reduced internodal expansion. When ozone was combined with water stress, there was no further reduction in the amount of new growtb, but tbere was a fall in the number of internodes relative to waterstressed plants grown in filtered air.Ozone and water stress applied singly reduced growth. A combination of the two stresses, however, caused no additional reduction in growth, but reduced tbe number of internodes. The possible implications of the aftereffects of these stresses are discussed in relation to reduced productivity and canopy structure.

Responses to ozone in 12 provenances of European beech (Fagus sylvatica): genotypic variation and chamber effects on photosynthesis and dry‐matter partitioning

“…Reduced root growth at elevated O $ may be caused by reductions in available C from photosynthesis (Saxe, 1991) ; an increased C demand for aboveground repair or replacement mechanisms (Kelly et al, 1993 ;Pearson & Mansfield, 1994) ; and\or by impaired phloem functioning (Spence et al, 1990 ;Matyssek et al, 1992). In our study, at least part of the declining root : shoot ratio in the 12 provenances could have been caused by a decline in photosynthesis, though the decline of A max became significant only late in the second season.…”

Impacts of ozone on forests: a European perspective

“…Commonly, growth reductions or premature senescence are reported within one exposure season (birch, Matyssek et al (1992, Pa$ a$ kko$ nen, Holopainen & Ka$ renlampi (1995 a, 1997 a), Pa$ a$ kko$ nen et al (1995 b, 1996) ; American aspen (Populus tremuloides), Keller (1988) ; hybrid poplar (Populus euramericana), Matyssek et al (1993), Mooi (1980)). European beech is also O $ -sensitive, and growth reductions and premature senescence have been detected in several recent studies (Ku$ ppers et al, 1994 ;Pearson & Mansfield, 1994 ;Braun & Flu$ ckiger, 1995 ;Krause & Ho$ ckel, 1995 ;Steingro$ ver et al, 1995 ;Mikkelsen & Jorgensen, 1996 ;Mortensen, Bastrup-Birk & Ro-Poulsen, 1996). Amongst the most widely planted conifers, Sitka spruce (Picea sitchensis) showed reduced growth after two 13-wk seasons of O $ exposure and this negative effect was still detectable in the third year, in which there was no O $ exposure .…”

Effects of ozone exposure on growth and photosynthesis of beech seedlings (Fagus sylvatica)

“…As for other tree species, the following common effects of ozone stress have been reported for beech : acceleration of leaf senescence (Mikkelsen & HeideJorgensen, 1996), visible damage, reduced photosynthetic performance (Pearson & Mansfield, 1993 ;Lippert et al, 1996 ;Dixon et al, 1998), and reduced growth rates (Pearson & Mansfield, 1994 ;Braun & Flu$ ckiger, 1995 ;Krause & Ho$ ckel, 1995 ;Mortensen et al, 1995).…”