SEMINAR  I  NATURVITENSKAP

 

TORSDAG   25. NOVEMBER  2004

 

Rom  A – 204,   kl. 14.15

 

Professor Anders Johnsson

 

Institutt for fysikk, NTNU

 

 

Eksperimentelle og teoretiske studier av svingninger i planters transpirasjon  

 

 

Plants often show an oscillatory transpiration and water can be transported through the plants and into the atmopshere with a period of, typically, 40 minutes. The main part of the water regulation occurs in the socalled stomata of the leaves. The surface of the first leaf of the oat plant typically contains about 50 stomates per mm2. These openings are usually synchronized in their opening and closing, forming the overall pattern of the oscillatory transpiration.

 

Measurements of the water transport show that very stable oscillations can be found under some conditions. However, changing the experimental conditions can lead to subharmonic oscillations and to even more complex wave patterns. The system might even be possible to change into a chaotic state.

 

The seminar will discuss experimental techniques to record the oscillations, to study the synchronization of the different parts of the leaf surfaces and show some different types of period doubling etc. Results from analysis of non-linear systems will be used to describe some of the results.

 

 

 

Jan Terje Kvaløy og Per A. Amundsen