26 Overview: Perspectives in Ecophysiological
Research of Photosynthesis
E.-D. Schulze and M.M. Caldwell
26.1 Introduction: A Historic Perspective
The beginning of the ecophysiology of photosynthesis is generally associated
with Lundegardh (1929), Boysen-Jensen and Muller (1929), Harder et al.
(1931), Stocker (1929, 1935), and others who used the weighing method for
transpiration and CO2 absorption by KOH for assessing photosynthesis in
the Sahara desert, the Scandinavian tundra, and in a Javan tropical forest.
However, it was the invention of the infrared-gas analyzer (Egle and Ernst
1949) that propelled this field of study into an active area of research. The
on-line measurements of photosynthesis by Tranquillini (1957) on Pinus
cembra, by Mooney et al. (1964) on Pinus aristata, and by Lange et al.
(1968) on lichens were pioneer pieces of research. Much of the initial work
was devoted to technical problems of gas exchange chamber environments,
etc. (Sestak et al. 1971). The methodological workshop of the International
Biological Program held in Trebon, Czechoslovakia, centered around questions such as whether physiological or meteorological approaches were more
appropriate (Malek 1970).
Following this "methodological age" in the ecophysiology of photosynthesis, measurements of gas exchange became an almost routine undertaking in the 1970s. Nearly all major plant types in most of the world's
biomes have been enclosed in chambers or porometers at one time or
another to test their gas exchange characteristics. Much of this was summarized in the Encyclopedia of Plant Physiology 12 (Lange et al. 1982).
Screening for response curves and daily courses of gas exchange lost much
of its momentum in the 1980s since ecophysiology was taking different, and
very divergent, courses pursuing: (1) molecular bases of photosynthetic
response to the environment such as accommodation of excessive light, (2)
whole-plant phenomena including controls exerted by and of root/shoot
hormonal signals, carbon allocation, storage, and interactions with mineral
nutrition, (3) characterization of photosynthetic behavior elucidating major
plant groups, such as aquatic plants, poikilohydric plants, and C 3 or C 4
species. In this endeavor, use of stable isotopes has become a powerful tool
in extending our understanding of relationships between CO 2 and water
vapor exchange to more expansive scales of time and geographical dis-
Research of Photosynthesis
E.-D. Schulze and M.M. Caldwell
26.1 Introduction: A Historic Perspective
The beginning of the ecophysiology of photosynthesis is generally associated
with Lundegardh (1929), Boysen-Jensen and Muller (1929), Harder et al.
(1931), Stocker (1929, 1935), and others who used the weighing method for
transpiration and CO2 absorption by KOH for assessing photosynthesis in
the Sahara desert, the Scandinavian tundra, and in a Javan tropical forest.
However, it was the invention of the infrared-gas analyzer (Egle and Ernst
1949) that propelled this field of study into an active area of research. The
on-line measurements of photosynthesis by Tranquillini (1957) on Pinus
cembra, by Mooney et al. (1964) on Pinus aristata, and by Lange et al.
(1968) on lichens were pioneer pieces of research. Much of the initial work
was devoted to technical problems of gas exchange chamber environments,
etc. (Sestak et al. 1971). The methodological workshop of the International
Biological Program held in Trebon, Czechoslovakia, centered around questions such as whether physiological or meteorological approaches were more
appropriate (Malek 1970).
Following this "methodological age" in the ecophysiology of photosynthesis, measurements of gas exchange became an almost routine undertaking in the 1970s. Nearly all major plant types in most of the world's
biomes have been enclosed in chambers or porometers at one time or
another to test their gas exchange characteristics. Much of this was summarized in the Encyclopedia of Plant Physiology 12 (Lange et al. 1982).
Screening for response curves and daily courses of gas exchange lost much
of its momentum in the 1980s since ecophysiology was taking different, and
very divergent, courses pursuing: (1) molecular bases of photosynthetic
response to the environment such as accommodation of excessive light, (2)
whole-plant phenomena including controls exerted by and of root/shoot
hormonal signals, carbon allocation, storage, and interactions with mineral
nutrition, (3) characterization of photosynthetic behavior elucidating major
plant groups, such as aquatic plants, poikilohydric plants, and C 3 or C 4
species. In this endeavor, use of stable isotopes has become a powerful tool
in extending our understanding of relationships between CO 2 and water
vapor exchange to more expansive scales of time and geographical dis-