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Title: Photosynthesis and pigment production in Liquidambar styraciflua - developmental and UV-B radiation effects

Conference · · Bulletin of the Ecological Society of America; (United States)
OSTI ID:6144881
; ;  [1]
  1. Univ. of Maryland, College Park (United States)

Leaf expansion is very sensitive to different environmental stresses. This study describes ontogenetic changes in leaf size and physiology of Liquidambar styraciflua seedlings grown under UV-B irradiance levels simulating 0% (control), 16% (low) and 25% (high) stratospheric ozone reductions. Leaf size, light- and CO[sub 2]-saturated rates of O[sub 2] evolution (A[sub max]), and concentration of chlorophylls (chl), and UV-B absorbing pigments were measured over a 4-week period. Specific leaf weight, A[sub max] and chl concentration increased with leaf age, except for a peak in A[sub max] at early development. Chlorophyll b concentration increased at a slower rate than chl a. Recently unfurled leaves has the greatest concentration of UV-B absorbing pigments. The effect of UV-B radiation on leaf growth and physiology were small and not dose-dependent. Expansion of leaves exposed to low UV-B was slightly delayed compared to controls (1.663 vs. 1.90 cm[sup 2]/day), but final leaf size was unaffected by UV-B radiation. Physiological effects were less pronounced during the rapid expansion period. High UV-B tended to promote, while low UV-B inhibited accumulation of chl, especially chl a. In contrast, concentration of UV-B absorbing compounds was promoted only by low UV-B. The small inhibitory effects of UV-B on leaf growth and physiology suggests a high tolerance of the species to damaging UV-B radiation.

OSTI ID:
6144881
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