Surviving the Consequences of Climate Change—Drought

March 3rd, 2014 BY ChrisD | No Comments
dead tree drought

As scientists delve more deeply into climate change, one thing remains certain. The effects will not be uniform across the planet. As a consequence of the mild winter, the lower 48 states are experiencing an increase in drought conditions that has boosted over 60 percent of them into abnormally dry conditions.

Winners and Losers
The next question is which plants can survive these conditions and which will perish? A study by Northern Arizona University may shed some light on what may be expected. Researchers found that drought-like conditions can initially cause a spurt in plant growth.

Flora responded positively to the increase in the growing season and availability of nitrogen. However, the effects were short-lived. After 10 years of slow deterioration, plant growth essentially disappeared. If desert plants cannot survive, what does this portend for other ecosystems?

Survival Adaptations
To live under these conditions, desert plants have several adaptations to prevent excess water loss. Plants are often succulent to store water. They may have smaller leaves or spines. Others may open the stomata or pores of their leaves as night to avoid evaporation.

A study by UCLA offers additional insight on plant survival. Plant cells differ from animal cells by the presence of cell walls. They provide protection and help plants maintain their internal water pressure or turgor. The researchers found, however, that this characteristic alone is not sufficient for survival.

Plants that have stiff cell walls in addition to a high salt concentration are more drought tolerant and able to survive under these stressful conditions. This combination allows plants to maintain their turgor and avoid shrinking in arid environments.

Surprisingly, these characteristics are contrary to what one may think of as the ultimate in desert survival in the form of cacti and yuccas. The former are more likely to survive these extreme conditions. The UCLA study provides a means for measuring drought tolerance that can be easily done.

This ability can add to the growing body of evidence of the consequences of climate change by identifying the plants that are most vulnerable to its effects. It can also provide a more complete picture of the dangerous consequences of climate change.

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