See this on the BBC Four: A Blooming History for a clearer picture when using with students.

This video clip from the BBC (from the TV series Botany: A Blooming History) introduces the idea of limiting factors in photosynthesis, and the way in which plants are adapted to their environments. 

Modern technology allows us to watch how plants grow. We know they take in carbon dioxide and convert it into sugars and starch, using this as a source of energy for growth. However we do not yet know everything about photosynthesis. As plants cannot move around, they must be adapted to many different living conditions, and be able to respond to their environment. In some places they will have limited light, in others they will have limited water. The fact that without being adapted to their habitat, the plants will die, is emphasised.

This is a good introduction to the idea of limiting factors. Students can watch the clip and pick out the factors which would limit the rate of photosynthesis. This can then lead to experimental work looking at the effect of light intensity, temperature and carbon dioxide levels on the rate of photosynthesis. It is also possible to do other experimental work on the rate of transpiration in relation to humidity, wind speed and temperature. Students can also look at adaptations in leaf structure, observing the adaptive structures in xerophytes. At a higher level, it is possible to look at differences in leaf structure using the light microscope or electron micrographs. A-level students may look at the adaptations of C4 plants.