Seasonal Effects of Changes in the Temperatur and Osmotic Potential of the Root Medium on Photosynthesis and Transpiration in Lodgepole Pine (Pinus Contorta)
The experimental work described here in was carried out using facilities kindly made available by the Forstlichen Bundesversuchsanstalt, Vienna, while the writer was on study leave from the New Zealand Forest Service. Grateful acknowledgement is made to both these institutions. Althouggh much of the work in the present series of experiments, thre are some indications of how environmental changes influence the behaviour of the species under study. The culture solution experiments habe shown that Pinus contorta has the ability to carry on photosynthesis at relatively low levels of root temperature and to make positive photosynthetic gains of some importance not ohnly during winter, when aabove-ground factos favor physiological activity, but during the growing season as well....
