February 28, 2007
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A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 11, NUMBER 7, JULY 1998
IMPACTS OF ELEVATED CO2
"Growth and Nitrogen Uptake in an Experimental Community of Annuals
Exposed to Elevated Atmospheric CO2," G.M. Berntson
(Biolog. Labs., Harvard Univ., 16 Divinity Ave., Cambridge MA 02138), N.
Rajakaruna, F.A. Bazzaz, Global Change Biol., 4(6),
607-626, Aug. 1998.
Studied experimental communities of 11 co-occurring annuals common to
disturbed seasonal grasslands in the southwestern U.S. The most dominant
species showed reduced enhancement and the smaller species showed
increased enhancement, suggesting that through time, elevated CO2
may lead to significant changes in community composition. Results also
support the hypothesis that plant N uptake is largely regulated by
"Effects of Elevated CO2 and O3 on the Rate and Duration
of Grain Growth and Harvest Index in Spring Wheat (Triticum aestivum
L.)," B.J. Mulholland (Horticulture Res. Intl., Warwick CV35 9EF, Uk;
e-mail: barry.mulholland @hri.ac.uk), J. Craigon et al., ibid.,
Experiments with open-top chambers show that the presence of elevated CO2
does not protect against substantial O3-induced yield losses resulting
from its direct deleterious impact on reproductive processes.
"Growth Dynamics and Genotype Variation in Tropical, Field-Grown
Paddy Rice (Oryza sativa L.) in Response to Increasing Carbon
Dioxide and Temperature," T.B. Moya, L.H. Ziska (USDA-ARS, 10300
Baltimore Ave., Beltsville MD 20705; e-mail: firstname.lastname@example.org) et
al., ibid., 645-656.
Reports on studies at the International Rice Research Institute intended
to remedy the paucity of in situ studies on long-term impacts of
CO2 on tropical paddy rice, which represents the bulk of world
rice production. For all cultivars, the combination of increasing CO2
and air temperature resulted in reduced grain yield and declining harvest
index compared to increased CO2 alone, indicating that
simultaneous exposure to elevated temperature may negate the CO2
"Long-Term Growth at Elevated Carbon Dioxide Stimulates Methane
Emission in Tropical Paddy Rice," L.H. Ziska (address above),T.B.
Moya et al.,ibid., 657-665.
Field experiments over three consecutive growth seasons suggest that as
atmospheric CO2 concentration increases, methane emissions
from tropical paddy rice could increase above current projections.
"Do Slow-Growing Species and Nutrient-Stressed Plants Respond
Relatively Strongly to Elevated CO2?" H. Poorter (Dept.
Plant Ecol., Utrecht Univ., POB 800.84, 3508 TB Utrecht, Neth; e-mail:
email@example.com), ibid., 693-697.
Based mainly on a simulation model, Lloyd and Farquhar (1996) predicted
that inherently slow-growing species and nutrient-stressed plants would
show a relatively strong growth response to increased CO2.
This compilation of published experiments indicates, however, to the
"A Meta-Analysis of Elevated CO2 Effects on Woody Plant
Mass, Form, and Physiology," P.S. Curtis (Dept. Plant Biol., Ohio
State Univ., Columbus OH 43210; e-mail: firstname.lastname@example.org), X. Wang, Oecologia,
113(3), 299-313, 1998.
Summarizes and interprets more than 500 reports of effects of elevated
CO2 on woody plant biomass accumulation and partitioning, gas
exchange, and leaf N and starch content. Both total biomass and net CO2
assimilation increased significantly at about twice ambient CO2,
regardless of growth conditions. Found no consistent evidence for
photosynthetic acclimation to CO2 enrichment except in trees
grown in pots, and no effect on stomatal conductance. Results provide
robust, statistically defensible estimates against which new results may
be compared, or for use in forest and climate model parameterization.
"Elevated Atmospheric [CO2] Promotes Frost Damage in
Evergreen Tree Seedlings," J.L. Lutze (Biolog. Sci., Australian Natl.
Univ., Canberra, ACT 0200 Australia; e-mail: email@example.com), J.S.
Roden et al., Plant, Cell & Environ., 21(6), 631-635,
Spring frost damage promoted by elevated CO2 in snow gum,
one of the most frost tolerant of eucalypts, has major implications for
agriculture, forestry and vegetation dynamics. An increase in frost
sensitivity may reduce potential gains in productivity from CO2
fertilization, and may affect predictions of vegetation change based on
"Effects of Carbon Dioxide and Nitrogen on Growth and Nitrogen Uptake
in Ponderosa and Loblolly Pine," D.W. Johnson (Desert Res. Inst., POB
60220, Reno NV 89506; e-mail: firstname.lastname@example.org), R.B. Thomas et al.,J.
Environ. Qual., 27(2), Mar.-Apr. 1998.
Greenhouse and open-top chamber studies show that (1) N deficiency is a
continuum rather than a step function; (2) responses to elevated CO2
vary across this continuum; and (3) elevated CO2 greatly
enhances growth response to N additions when N is initially in the
extremely deficient range.
"Impacts of Rising Atmospheric Carbon Dioxide on Model Terrestrial
Ecosystems," T.H. Jones (NERC Ctr. Population Biol., Imperial
College, Ascot, Berkshire SL5 7PY, UK; e-mail: email@example.com), L.J.
Thompson et al.,Science, 280(5362), 441-442, Apr. 17,
In model terrestrial ecosystems maintained at elevated CO2
for three plant generations, increases in photosynthetically fixed carbon
were allocated below ground, raising concentrations of dissolved organic
carbon in soil. These effects were then transmitted up the decomposer food
chain. Results have implications for long-term feedback processes in soil
ecosystems subject to rising global CO2.
"N-Poor Ecosystems May Respond More to Elevated [CO2]
than N-Rich Ones in the Long Term. A Model Analysis of Grassland,"
M.G.R. Cannell (Inst. Terr. Ecol., Bush Estate, Penicuik, Midlothian EH45
0QB, UK; e-mail: firstname.lastname@example.org), J.H.M. Thornley, Global Change Biol.,
4(4), 431-442, Apr. 1998.
Used the Hurley Pasture Model to examine the short and long-term
response of grazed grasslands in the British uplands to elevated CO2
and inputs ranging from 5 to 100 kg N/ha/yr. A startling conclusion is
that nutrient-limited ecosystems may be responding proportionally much
more to elevated CO2 than nutrient rich ones.
"Enriched Atmospheric CO2 and Defoliation: Effects on
Tree Chemistry and Insect Performance," S. Roth (Dept. Entomol.,
Univ. Wisconsin, Madison WI 53706; e-mail: email@example.com), R.L.
Lindroth et al., ibid., 419-430.
Studied effects of forest tent caterpillars on quaking aspen over a
two-year period. In this study, the impact of defoliation on tree
chemistry and insect performance was not affected by CO2
"Water and Nutrient Deficits, Crop Yields, and Climate Change,"
K.R. Reddy (Dept. Plant & Soil Sci., Box 9555, Mississippi State
Univ., Mississippi State MS 39762), A.R. Reddy et al.,World Resource
Review, 10(1), 23-43, Mar. 1998.
Reports results of cotton plants grown in naturally-lit chambers in
which temperature, CO2, water, and nutrients were varied
systematically. Draws general conclusions: crops produced primarily for
grain or fruit may not benefit from additional growth in a high CO2
environment. Crops produced largely for foliage or wood are expected to
benefit from high CO2, even in seasons in which temperatures
are above optimum for growth.
"Impact of Elevated Atmospheric CO2 Concentration on Soil
Microbial Biomass and Activity in a Complex, Weedy Field Model Ecosystem,"
C. Kampichler (Inst. Soil Ecol., Ingolstadter Landstrasse 1, D-85764
Neuherberg, Ger.; e-mail: firstname.lastname@example.org), E. Kandeler et al., Global
Change Biol., 4(3), 335-346, Mar. 1998.
At the end of two experimental runs lasting 4.5 and 9 months,
respectively, root dry weight and quality showed contradictory responses
to elevated CO2 concentrations. However, no significant
differences in microbial biomass or activity were detected. Concludes that
the response of complex communities to elevated CO2 cannot be
predicted on the basis of oversimplified experimental setups.
"Interactions Between Elevated CO2 Concentration,
Nitrogen and Water: Effects on Growth and Water Use of Six Perennial Plant
Species," W.J. Arp (Dept. Environ. Sci., Wageningen Agric. Univ.,
Bornsesteeg 69, 6708 PD Wageningen, Neth.; e-mail:
email@example.com), J.E.M. van Mierlo et al., Plant, Cell &
Environ., 21(1), 1-11, Jan. 1998.
Greenhouse experiments over one season showed a positive effect of CO2
on growth only at high N concentrations, but plants used much less water
at low N concentrations. Potentially faster growing species appeared to
respond better to high CO2 when supplied with a high level of
N; inherently slow-growing species were more successful at low N
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