Adaptation responses of crops to climate change

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:249768

Seino, Hiroshi ^[1]

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1. National Inst. of Agro-Environmental Sciences, Tsukuba, Ibaraki (Japan)

Appreciable global climatic responses to increasing levels of atmospheric CO{sub 2} and other trace gases are expected to take place over the next 50 to 80 years. Increasing atmospheric concentrations of carbon dioxide and other greenhouse gases are producing or will produce changes in the climate of the Earth. In particular, numerous efforts of climate modeling project very substantial increase of surface air temperature. In addition to a general warming of the atmosphere, the possibility of increased summer dryness in the continental mid-latitudes has been suggested on the basis of both historical analogues and some General Circulation Model (GCM) studies. There are three types of effect of climatic change on agriculture: (1) the physiological (direct) effect of elevated levels of atmospheric CO{sub 2} on crop plants and weeds, (2) the effect of changes in parameters of climate (e.g., temperature, precipitation, and solar radiation) on plants and animals, and (3) the effects of climate-related rises in sea-level on land use. The direct effects of elevated CO{sub 2} are on photosynthesis and respiration and thereby on growth, and there are additional effects of increased CO{sub 2} on development, yield quality and stomatal aperture and water use. A doubling of CO{sub 2} increases the instantaneous photosynthetic rate by 30% to 100%, depending on the other environmental conditions, and reduce water requirements of plants by reducing transpiration (per unit leaf area) through reductions in stomatal aperture. A doubling of CO{sub 2} causes partial stomatal closure on both C{sub 3} and C{sub 4} plants (approximately a 40% decrease in aperture). In many experiments this results in reductions of transpiration of about 23% to 46%. However. there is considerable uncertainty over the magnitude of this in natural conditions.

• Research Organization: National Science Foundation, Washington, DC (United States). Committee on Earth and Environmental Sciences
• OSTI ID: 249768
• Report Number(s): CONF-930285--; ON: DE96008736
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
55 BIOLOGY AND MEDICINE
BASIC STUDIES
CARBON DIOXIDE
CLIMATIC CHANGE
CROPS
EARTH ATMOSPHERE
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL EFFECTS
ENVIRONMENTAL TRANSPORT
GLOBAL ASPECTS
RESPONSE FUNCTIONS