Photosynthetic pigments and their response to different light levels

[Sandee Anna-Maria Szarka]

Dear all,
	I am currently doing an experiment to determine what changes in 
photosynthetic pigments occur in response to different light levels. 
Unfortunatly the majority of the resources and past papers 
i have found on the subject are more concerned with measuring the 
gas exchange rates as opposed to actual changes in pigment ratios  esp with
respect to carotenoids. If anyone knows of any web sites or papers from journals
that might be of use to me this would greatly be appreciated.
	Kind regards,
		Sandee Szarka