Interactive effects of ozone and elevated carbon dioxide on the growth and physiology of black cherry, green ash, and yellow-poplar seedlings

Loats, Ken V.; Rebbeck, Joanne

doi:10.1016/s0269-7491(99)00069-x

Cited by 26 publications

(18 citation statements)

References 55 publications

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“…Measurements were taken over 3 days with one treatment replicate completed per day. Since yellowpoplar photosynthetic rates were determined to be saturated at 800 mmol m 2 s 1 PAR (photosynthetically active radiation) (Loats and Rebbeck 1999;Rebbeck and Loats 1997), leaves were illuminated with an artificial light (GE Cool-Beam PAR Lamp Model 300PAR 56/2WFL) when ambient light dropped below saturating conditions. Leaves were measured at the CO 2 concentration at which they were grown.…”

Section: Treatment and Seasonal Effectsmentioning

confidence: 99%

Foliar physiology of yellow-poplar ( Liriodendron tulipifera L.) exposed to O 3 and elevated CO 2 over five seasons.

Rebbeck

Scherzer

Loats

2004

Trees - Structure and Function

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The chronic effects of ozone (O 3 ) alone or combined with elevated carbon dioxide (CO 2 ) on the foliar physiology of unfertilized field-grown yellowpoplar (Liriodendron tulipifera L.) seedlings were studied from 1992 to 1996. Within open-top chambers, juvenile trees were exposed to the following: charcoal-filtered air (CF); 1 ambient ozone (1XO 3 ); 1.5 ambient ozone (1.5XO 3 ); 1.5 ambient ozone plus 700 ppm carbon dioxide (1.5XO 3 +CO 2 ); or chamberless open-air (OA). Seasonal 24-h mean ambient O 3 concentrations ranged from 32 to 46 ppm over the five seasons. Averaged over 5 years, midseason net photosynthesis at saturating light (A sat ) was reduced by 14% (P=0.029) and stomatal conductance (g s ) was reduced, albeit non-significant, by 13% (P =0.096) in upper canopy foliage exposed to 1.5XO 3 -air relative to CF controls. There were no significant differences over the 5 years in A sat and g s between trees grown in 1XO 3 -and 1.5XO 3 -air. Our results support the hypothesis that the magnitude of O 3 effects on A sat and g s decreases as saplings age. When averaged over the five seasons of exposure, total chlorophyll concentration (chl) was not significantly affected by exposure to elevated O 3 ; however, in 1.5XO 3 +CO 2 -air, foliar chl was reduced by 33% relative to all others (P<0.001). In 1.5XO 3 +CO 2 -air, A sat was 1.4-1.9 times higher (P<0.001) and g s was 0.7 times lower (P=0.022) than all others. O 3 uptake in juvenile trees exposed to elevated O 3 plus elevated CO 2 (1.5XO 3 +CO 2 -air) was most comparable to trees exposed to ambient air (1XO 3 ) throughout the study. These findings suggest that elevated CO 2 may minimize the negative effects of O 3 by reducing O 3 uptake through decreased stomatal conductance.

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Section: Treatment and Seasonal Effectsmentioning

confidence: 99%

Foliar physiology of yellow-poplar ( Liriodendron tulipifera L.) exposed to O 3 and elevated CO 2 over five seasons.

Rebbeck

Scherzer

Loats

2004

Trees - Structure and Function

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“…More recently, rising tropospheric O 3 has been recognized as a possibly potent modifier of forest ecosystem responses to elevated atmospheric CO 2 (Bortier et al 2000). The few OTC studies that have examined the interaction of elevated CO 2 and O 3 on woody perennial biomass (Dickson et al 1998;Volin et al 1998;Loats and Rebbeck 1999) show that elevated CO 2 tends to ameliorate the negative effects of O 3 on photosynthesis and growth (or conversely that O 3 decreased the stimulation due to elevated CO 2 ), but this is not always the case (Kull et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Fine-root biomass and fluxes of soil carbon in young stands of paper birch and trembling aspen as affected by elevated atmospheric CO2 and tropospheric O3

et al. 2001

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Rising atmospheric CO may stimulate future forest productivity, possibly increasing carbon storage in terrestrial ecosystems, but how tropospheric ozone will modify this response is unknown. Because of the importance of fine roots to the belowground C cycle, we monitored fine-root biomass and associated C fluxes in regenerating stands of trembling aspen, and mixed stands of trembling aspen and paper birch at FACTS-II, the Aspen FACE project in Rhinelander, Wisconsin. Free-air CO enrichment (FACE) was used to elevate concentrations of CO (average enrichment concentration 535 µl l) and O (53 nl l) in developing forest stands in 1998 and 1999. Soil respiration, soil pCO, and dissolved organic carbon in soil solution (DOC) were monitored biweekly. Soil respiration was measured with a portable infrared gas analyzer. Soil pCO and DOC samples were collected from soil gas wells and tension lysimeters, respectively, at depths of 15, 30, and 125 cm. Fine-root biomass averaged 263 g m in control plots and increased 96% under elevated CO. The increased root biomass was accompanied by a 39% increase in soil respiration and a 27% increase in soil pCO. Both soil respiration and pCO exhibited a strong seasonal signal, which was positively correlated with soil temperature. DOC concentrations in soil solution averaged ~12 mg l in surface horizons, declined with depth, and were little affected by the treatments. A simplified belowground C budget for the site indicated that native soil organic matter still dominated the system, and that soil respiration was by far the largest flux. Ozone decreased the above responses to elevated CO, but effects were rarely statistically significant. We conclude that regenerating stands of northern hardwoods have the potential for substantially greater C input to soil due to greater fine-root production under elevated CO. Greater fine-root biomass will be accompanied by greater soil C efflux as soil respiration, but leaching losses of C will probably be unaffected.

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“…O 3 , on the other hand, inhibits the growth of plants (Heath 1994;Pell et al 1997) by decreasing stomatal conductance and photosynthesis, decreasing the content and activity of Rubisco, decreasing the content of chlorophyll and inducing accelerated senescence (Darrall 1989;Pell et al 1992;Landry and Pell 1993;Pell et al 1994;Karnosky et al 1996;Nali et al 1998). While the individual effects of CO 2 and O 3 on plants are rather well known, their interactive effect on plant growth and metabolism is still a matter of active discussion (Polle et al 1993; Barnes et al 1995;Rao et al 1995;Kull et al 1996;Lippert et al 1997;McKee et al 1997a;Dickson et al 1998;Grams et al 1999;Loats and Rebbeck 1999). It was first assumed that the contrasting effects of elevated CO 2 and O 3 might simply cancel each other out, and for several members of the Gramineae family there are experimental data to support this view (Rao et al 1995;McKee et al 1997b).…”

Section: Introductionmentioning

confidence: 99%

The effect of elevated carbon dioxide and ozone on leaf- and branch-level photosynthesis and potential plant-level carbon gain in aspen

Noormets

McDonald

Dickson

et al. 2001

Trees

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Two aspen (Populus tremuloides Michx.) clones, differing in O 3 tolerance, were grown in a freeair CO 2 enrichment (FACE) facility near Rhinelander, Wisconsin, and exposed to ambient air, elevated CO 2 , elevated O 3 and elevated CO 2 +O 3 . Leaf instantaneous light-saturated photosynthesis (P S ) and leaf areas (A) were measured for all leaves of the current terminal, upper (current year) and the current-year increment of lower (1-year-old) lateral branches. An average, representative branch was chosen from each branch class. In addition, the average photosynthetic rate was estimated for the short-shoot leaves. A summing approach was used to estimate potential whole-plant C gain. The results of this method indicated that treatment differences were more pronounced at the plant-than at the leaf-or branch-level, because minor effects within modules accrued in scaling to plant level. The whole-plant response in C gain was determined by the counteracting changes in P S and A. For example, in the O 3 -sensitive clone (259), inhibition of P S in elevated O 3 (at both ambient and elevated CO 2 ) was partially ameliorated by an increase in total A. For the O 3 -tolerant clone (216), on the other hand, stimulation of photosynthetic rates in elevated CO 2 was nullified by decreased total A.

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Interactive effects of ozone and elevated carbon dioxide on the growth and physiology of black cherry, green ash, and yellow-poplar seedlings

Cited by 26 publications

References 55 publications

Foliar physiology of yellow-poplar ( Liriodendron tulipifera L.) exposed to O 3 and elevated CO 2 over five seasons.

Foliar physiology of yellow-poplar ( Liriodendron tulipifera L.) exposed to O 3 and elevated CO 2 over five seasons.

Fine-root biomass and fluxes of soil carbon in young stands of paper birch and trembling aspen as affected by elevated atmospheric CO2 and tropospheric O3

The effect of elevated carbon dioxide and ozone on leaf- and branch-level photosynthesis and potential plant-level carbon gain in aspen

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