Ecophysiology Of Photosynthesis

In a world of increasing atmospheric CO2, there is intensified interest in the ecophysiology of photosynthesis and increasing attention is being given to carbon exchange and storage in natural ecosystems. We need to know how much photosynthesis of terrestrial and aquatic vegetation will change as global CO2 increases. Are there major ecosystems, such as the boreal forests, which may become important sinks of CO2 and slow down the effects of anthropogenic CO2 emissions on climate? Will the composition of the vegetation change as a result of CO2 increase? This volume reviews the progress which has been made in understanding photosynthesis in the past few decades at several levels of integration from the molecular level to canopy, ecosystem and global scales.

An integrated guide to photosynthesis in an environmentally dynamic context, covering all aspects from basic concepts to methodologies.

In a world of increasing atmospheric CO2, there is intensified interest in the ecophysiology of photosynthesis and increasing attention is being given to carbon exchange and storage in natural ecosystems. We need to know how much photosynthesis of terrestrial and aquatic vegetation will change as global CO2 increases. Are there major ecosystems, such as the boreal forests, which may become important sinks of CO2 and slow down the effects of anthropogenic CO2 emissions on climate? Will the composition of the vegetation change as a result of CO2 increase? This volume reviews the progress which has been made in understanding photosynthesis in the past few decades at several levels of integration from the molecular level to canopy, ecosystem and global scales.

In this translation of the French edition (L'U. de Saint-'etienne, 1999), the author treats the interrelated factors that inform plants' adaptations to their environments. Applying ecophysiological principles to identify mechanisms of dysfunction in ecosystems, he presents data-based cases for: less stressful growing methods (e.g., using cultivars

This handbook covers the most commonly used techniques for measuring plant response to biotic and abiotic stressing factors, including: in vitro and in vivo bioassays; the study of root morphology, photosynthesis (pigment content, net photosynthesis, respiration, fluorescence and thermoluminiscence) and water status; thermal imaging; the measurement of oxidative stress markers; flow cytometry for measuring cell cycle and other physiological parameters; the use of microscope techniques for studying plant microtubules; programmed-cell-death; last-generation techniques (metabolomics, proteomics, SAR/QSAR); hybridization methods; isotope techniques for plant and soil studies; and the measurement of detoxification pathways, volatiles, soil microorganisms, and computational biology.

The Handbook of Plant Ecophysiology Techniques you have now in your hands is the result of several combined events and efforts. The birth of this handbook can be traced as far as 1997, when our Plant Ecophysiology lab at the University of Vigo hosted a practical course on Plant Ecophysiology Techniques. That course showed us how much useful a handbook presenting a bunch of techniques would be for the scientists beginning to work on Plant Ecophysiology. In fact, we wrote a short handbook explaining the basics of the techniques taught in that 1997 course: Flow cytometry to measure ploidy levels, Use of a Steady-State porometer to measure transpiration, In vivo measure of fluorescence, HPLC analysis of low molecular weight phenolics, Spectrophotometric determinations of free proline and soluble proteins, TLC polyamines contents measures, Isoenzymatic electrophoresis, Use of IRGA and oxygen electrode. That modest handbook, written in Spanish, was very helpful, both for the people who attended the course and for other who have used it for beginning to work in Plant Ecophysiology. The present Handbook is much more ambitious, and it includes more techniques. But we have also had in mind the young scientists beginning to work on Plant Ecophysiology. In 1999 François Pellissier leaded a proposal presented to the European Commission in the Fifth Framework Program in the High Level * Scientific Conferences, including three EuroLab Courses about lab and field techniques useful to improve allelopathic research.

Box 9E. 1 Continued FIGURE 2. The C–S–R triangle model (Grime 1979). The strategies at the three corners are C, competiti- winning species; S, stress-tolerating s- cies; R,ruderalspecies. Particular species can engage in any mixture of these three primary strategies, and the m- ture is described by their position within the triangle. comment briefly on some other dimensions that Grime’s (1977) triangle (Fig. 2) (see also Sects. 6. 1 are not yet so well understood. and 6. 3 of Chapter 7 on growth and allocation) is a two-dimensional scheme. A C—S axis (Com- tition-winning species to Stress-tolerating spe- Leaf Economics Spectrum cies) reflects adaptation to favorable vs. unfavorable sites for plant growth, and an R- Five traits that are coordinated across species are axis (Ruderal species) reflects adaptation to leaf mass per area (LMA), leaf life-span, leaf N disturbance. concentration, and potential photosynthesis and dark respiration on a mass basis. In the five-trait Trait-Dimensions space,79%ofallvariation worldwideliesalonga single main axis (Fig. 33 of Chapter 2A on photo- A recent trend in plant strategy thinking has synthesis; Wright et al. 2004). Species with low been trait-dimensions, that is, spectra of varia- LMA tend to have short leaf life-spans, high leaf tion with respect to measurable traits. Compared nutrient concentrations, and high potential rates of mass-based photosynthesis. These species with category schemes, such as Raunkiaer’s, trait occur at the ‘‘quick-return’’ end of the leaf e- dimensions have the merit of capturing cont- nomics spectrum.

Photosynthesis and the Environment examines how photosynthesis may be influenced by environmental changes. Structural and functional aspects of the photosynthetic apparatus are examined in the context of responses to environmental stimuli; particular attention being given to the processing of light energy by thylakoids, metabolic regulation, gas exchange and source-sink relations. The roles of developmental and genetic responses in determining photosynthetic performance are also considered. The complexity of the responses to environmental change is demonstrated by detailed analyses of the effects of specific environmental variables (light, temperature, water, CO2, ozone and UV-B) on photosynthetic performance. Where appropriate attention is given to recent developments in the techniques used for studying photosynthetic activities. The book is intended for advanced undergraduate and graduate students and a wide range of scientists with research interests in environmental effects on photosynthesis and plant productivity.