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What are the effects of climate change on plants?Future climate will have changes in temperature and rainfall, but also the future environment will have an increased concentration of carbon dioxide. All these changes affect (benefit or detrimet) the production of plants that are used for food. The final effect is the combination of changes in temperature, rainfall, and carbon dioxide. |
Temperature increase.High temperatures produce heat stress in the plants, they grow less, and they produce less. In some cases, the plants do not produce at all since excessive heat causes sterility of the pollen (the masculine reproductive part of the flowers). A temperature increase may be beneficial in some areas that are very cold at present and plants cannot be grown during the frozen winters. For example, in Siberia or northern Europe it would be possible to grow crops for a longer period of the year, and even grow fruits that now are only found in warm areas. This example is illustrated in the maps in Unit 1, where you learnt about the distribution of crops depending on climate zones. On the other hand, the soils in the Northern regions may not be adequate for plant growing as they have been bearing very hard conditions that make them have a different structure to those in Southern regions. This means that even if climate would be the appropriate to grow the crops, the soil might be the limiting factor. Climate change implies extremely quick temperature change, so vegetation and crops will have to adapt to the new conditions in an unusually short time. This may cause additional problems with the vegetation.
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1. Fields of corn
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Drought (less rainfall)Water affects directly the growth and production of plants. The pictures above show corn fields in Africa during normal conditions and during drought (no production at all). In most parts of Africa there is not enough water even in normal conditions. In contrast, in the USA, corn is grown with enough water and the picture shows the clear difference between corn in the USA and in Africa. |
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Increased rainfall.Excessive rainfall results in floods. Floods can damage plants as we saw in the first unit because the roots cannot breath and they die. The picture shows a field that was flooded and plants were not able to grow any more.
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Increased rainfall without floods may rsult beneficial in very dry areas, this would be the case of a place like the one we just saw in the pictures above from Zimbabwe. One of the main concerns about a change in climate is not only these variations in tempertaure and distribution of precipitations around the world, which can be either good or bad for different regions, it is the severity that these rains or droughts can reach what is most important and what can have large and devastating impacts.
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Carbon dioxide increase.The increase of CO2 derived from burning fossil fuels has a fertilizing effect on most plants, since CO2 is a component of photosynthesis (the biochemical mechanism of plant growth). Photosynthesis converts water and carbon dioxide into glucose. Light is the energy that powers this reaction. The basic equation of the process of photosynthesis is:
hv is energy needed to complete this reaction, this energy is naturally obtained from solar radiation.
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Scientists measure plant production in fields or growth chambers with an increase in atmospheric CO2. In the experiment shown in the figure the scientists are measuring the effect of CO2 on wheat production.
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Related pages: How do humans influence climate change?: |
1. Scientific reviewer: Alex de Sherbinin - CIESIN, Columbia University - USA 2. Scientific reviewer: Lily Parshall - Goddard Institute for space studies, Columbia University - USA Educational reviewer: Emilio Sternfeld - Colegio Virgen de Mirasierra - España Last update: 12/05/2004 |