Kirschbaum, M.U.F. (1999). The impacts of climate change on the growth and ecology of tropical forests. In: “Proceedings of the International Conference on Tropical Forests and Climate Change: Status, Issues and Challenges”, University of the Philippines, Laguna, Philippines, pp. 19-44.

Abstract. Tropical forests are the most species rich of all terrestrial ecosystems, and ecological effects of climate change on these forests are of particular importance. There are many different aspects of climate change, and while some are likely to be detrimental to plant growth, others can be beneficial. Increasing CO2 concentration can increase photosynthetic rates. Increases are especially pronounced in C3 plants, at higher temperatures and under water-limited conditions. Increasing temperature has direct effects on plant growth by changing photosynthesis and respiration rates. However, plants have a considerable ability to adapt to changing conditions and can tolerate even extremely high temperatures, provided sufficient water is available. Increasing temperature is likely to increase vapour pressure deficits of the air, and thereby increase transpiration rates from most plant canopies. Effects are likely to vary between plant communities, with forests generally experiencing greater increases in transpiration rates than grasslands, and relative effects being somewhat smaller in regions that are already hot than in regions with more moderate temperatures.

All these factors interact strongly so that for different combinations of increases in temperature and CO2 concentration, and for systems primarily affected by water or nutrient limitations, different overall effects on plant productivity can be expected. Responses can be negative in some circumstances and positive in others, but on balance, there appears to be no reason to expect dramatic overall changes in plant growth.

However, ecological consequences are potentially more serious. The distribution of many species tends to be limited to a narrow range of environmental conditions. With climate change, conditions over much of a species’ current natural range may change to become completely unsuitable for that species. This may cause the loss of a large number of the many unique species that currently inhabit the World’s tropical forests. These ecological and ecophysiological factors described here add additional impacts to tropical forests that are already being impacted by a range of other direct and indirect anthropogenic factors

[Miko Kirschbaum’s home page] [Back to Climate Change Studies]