Size inequality in regenerating yellow birch stands is reduced by elevated CO[sub 2] atmospheres

Conference · Wed Jun 01 04:00:00 EDT 1994 · Bulletin of the Ecological Society of America; (United States)

OSTI ID:7162031

Wayne, P W; Bazzaz, F A ^[1]

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1. Harvard Univ., Cambridge, MA (United States)

Dense stands of yellow birch (Betula alleghaniensis) seedlings comprised of equal numbers of three maternal families were established in forest soil profiles in low (350 [mu]l l[sup [minus]1]) and high (700 [mu]l l[sup [minus]1]) CO[sub 2] atmospheres in a glasshouse. In both CO[sub 2] treatments, seedling size inequality (% CV) within stands increased through time with total with total stand biomass. However, while stands in high CO[sub 2] maintained greater final above and below ground biomass than stands at low CO[sub 2], inequalities in total seedling mass, shoot height, and leaf area were significantly lower in high CO[sub 2] throughout the growing season. This effect of elevated CO[sub 2] on stand development differs from the effects of other resources additions (e.g. light, nutrients) which generally increase inter-individual size inequality. Lower size inequalities in high CO[sub 2] may have occurred because sub-canopy plants in low light exhibited greater proportional responsiveness to elevated CO[sub 2] than did canopy plants in high light. Other studies with yellow birch suggest CO[sub 2]-induced photosynthetic and growth enhancements are proportionally greater at low vs. high light. Hypothesis which may explain greater CO[sub 2] enhancements at low light are presented. Strong correlations were found between individuals' final positions in stand size hierarchies and seedlings' initial sizes and abilities to preempt light and soil nutrients. The three maternal lines differed in their responsiveness to elevated CO[sub 2], and thus contributed differently to total stand biomass in the two CO[sub 2] treatments.

• OSTI ID: 7162031
• Report Number(s): CONF-940894--
• Conference Information: Journal Name: Bulletin of the Ecological Society of America; (United States) Journal Volume: 75:2
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
BIRCHES
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
ECOLOGICAL CONCENTRATION
GROWTH
MAGNOLIOPHYTA
MAGNOLIOPSIDA
OXIDES
OXYGEN COMPOUNDS
PLANT GROWTH
PLANTS
SEEDLINGS
TREES