Friday, February 3, 2012

Why do evergreen trees like holly tend to transpire less than tomato plants?

Evergreen needles have far less surface area than broad leaves like those on a tomato plant. Plants transpire through holes (stomata) on their leaves. You will find they are much more dense on the tomato plant.





This creates an ability to rapidly produce energy on warm sunny days in tomato plants....and it is also why the tomato plant cannot survive through a cold winter like the holly. The holly, with it's slow transpiration and evergreen needles will continue to produce food for itself any time the temperature is above freezing...giving it the edge in a cold climate.





Hope this helps.

Why do evergreen trees like holly tend to transpire less than tomato plants?
Evergreens have needles, which are basically a vasuclar bundle surrounded by very little tissue. It has a thick resinous cuticle to retard water loss, fewer stomata since the surface is smaller (water is lost through stomata) and stomata are embedded in cripts below the surface so that wind does not cause evaporation. Many grow in cooler climates so transpiration is less in any case.


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