Question

Какихе листья быстрее завядают при почвенной засухе - верхние или нижние? С чем это связанно?

Answer 1

Верхние листья засыхают первыми

Answer 2

The Effect of Soil Drought on Leaf Withering

When it comes to the effect of soil drought on leaf withering, there are several factors to consider. One important factor is the location of the leaves on the plant, specifically whether they are upper or lower leaves.

In general, lower leaves tend to wither faster than upper leaves in response to soil drought. This is because lower leaves are closer to the ground and are therefore more exposed to the drying effects of the soil. They also receive less sunlight compared to upper leaves, which can further contribute to their faster withering.

The withering of lower leaves is primarily due to the plant's natural defense mechanism to conserve water during periods of drought. When the soil becomes dry, the plant reduces the flow of water to the lower leaves in order to prioritize the survival of the upper leaves and other vital parts of the plant. This process is known as "leaf abscission" and helps the plant conserve water and energy.

On the other hand, upper leaves are generally better positioned to receive sunlight and are less exposed to the drying effects of the soil. They are often able to maintain their water content for a longer period of time compared to lower leaves. However, it's important to note that the exact response of upper and lower leaves to soil drought can vary depending on the specific plant species and environmental conditions.

Conclusion

In summary, lower leaves tend to wither faster than upper leaves in response to soil drought. This is because lower leaves are more exposed to the drying effects of the soil and receive less sunlight compared to upper leaves. The withering of lower leaves is a natural defense mechanism of plants to conserve water during periods of drought. However, it's important to consider that the response of leaves to soil drought can vary depending on the plant species and environmental conditions.