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Title: Responses of mature loblolly pine trees to elevated CO[sub 2] concentrations

Conference · · Bulletin of the Ecological Society of America; (United States)
OSTI ID:6396655
;  [1]
  1. Univ. of Georgia, Athens (United States)

The direct responses of mature loblolly pine (Pinus taeda) foliage to increasing atmospheric CO[sub 2] were investigated in six 18-year-old loblolly pine trees using the branch-chamber technique. On each tree, six main branches were randomly selected and each enclosed in one of six chambers. Each branch received one of the following six treatments: ambient CO[sub 2]/ambient temperature (1), 1.5 x ambient CO[sub 2] ambient temperature (2), 2.0 x ambient CO[sub 2]/ambient temperature (3), ambient CO[sub 2]/2.0[degrees]C + ambient temperature (4), 1.5 x ambient CO[sub 2]/2.0[degree]C + ambient temperature (5) and 2.0 x ambient CO[sub 2]/2.0[degree]C + ambient temperature (6). A/C, curves were run and P- (photosynthetic rate at saturating light) of the current year, first flush needles was measured at each respective treatment CO[sub 2] level for treatments 1, 2 and 3 using the Li-cor 6200 photosynthesis system. Both elevated CO[sub 2] concentrations significantly increased the photosynthesis of the foliage of the mature loblolly pine trees. However, comparison of the slopes of the initial linear part of the A/C[sub 1], curves suggested no reduction in the rubisco carboxylation activity. Additionally, there was no indication of photosynthetic acclimation to elevated CO[sub 2].

OSTI ID:
6396655
Report Number(s):
CONF-930798-; CODEN: BECLAG
Journal Information:
Bulletin of the Ecological Society of America; (United States), Vol. 74:2; Conference: 78. annual Ecological Society of America (ESA) meeting, Madison, WI (United States), 31 Jul - 4 Aug 1993; ISSN 0012-9623
Country of Publication:
United States
Language:
English