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Title: Reproductive allocation and output in herbaceous annuals of the genera Polygonum, Ipomoea, and Cassia in elevated CO[sub 2] environments

Conference · · Bulletin of the Ecological Society of America; (United States)
OSTI ID:7272387
;  [1]
  1. Harvard Univ., Cambridge, MA (United States)

In assessing the capacity of plants to adapt to rapidly changing global climate, we must elucidate the impacts of elevated carbon dioxide on reproduction, fitness and evolution. We investigated how elevated CO[sub 2] influenced reproduction and growth of plants exhibiting a range of floral displays, the implications of shifts in allocation for fitness in these species, and whether related taxa would show similar patterns of response. Three herbaceous, annual species each of the genera Polygonum, Ipomoea, and Cassia were grown under 350 or 700 ppm CO[sub 2]. Vegetative growth and reproductive output were non-destructively measured throughout the full life span, and biomass calibrated with a subsample harvest at first flowering. Viability and germination studies of seed progeny were conducted to more precisely characterize fitness. Timecourse and numbers of floral buds, flowers, unripe and abscised fruits differed between CO[sub 2] treatments. Genera differed significantly in their phenological responses to elevated CO[sub 2], Polygonum and Cassia species (but not Ipomoea) showed accelerated, enhanced reproduction. Elevated CO[sub 2] ameliorated trade-offs between vegetative and floral production. However, seed [open quotes]quality[close quotes] and fitness were not always directly correlated with quantity produced. Species within general responded more consistently to CO[sub 2], indicating that phylogeny and life form may be general predictors of performance under global change.

OSTI ID:
7272387
Report Number(s):
CONF-940894-; CODEN: BECLAG
Journal Information:
Bulletin of the Ecological Society of America; (United States), Vol. 75:2; Conference: Annual Ecological Society of America (ESA) meeting: science and public policy, Knoxville, TN (United States), 7-11 Aug 1994; ISSN 0012-9623
Country of Publication:
United States
Language:
English