| dc.description.abstract | In this thesis, several aspects of the water regulation of plants will be studied and discussed. The focus is on biophysical properties of the system, especially on the dynamics and qualitative mechanistics. Following this introductory chapter is an instrumentation overview in Chapter 2, where experimental setups and technologies used are discussed. Chapter 3 will deal with some transient behavior of the water regulation of plants and present some simulations performed with two well-known models of the system. The rest of the thesis is concerned with oscillatory behavior, starting with a short general introduction into period doubling in the system in Chapter 4. Period doubling is a transition or bifurcation from a simple sinusoidal oscillatory pattern with period T to a pattern with two main frequency components, T and 2T, in some cases more generally used to describe a doubling of the number of main frequency components. Chapter 5 treats the oscillatory, sometimes very complicated, behavior of the plant water regulatory system in a general manner, pointing to its similarity with other oscillating systems and processes. A possible route to chaos is also discussed. Chapter 6 presents some results from the use of a relatively new technique in plant physiology: infrared imaging. This chapter studies the spatial coupling between small cell systems both during stable and oscillatory transpiration behavior and presents results which were outside the grasp of scientists just a few years ago. The thesis ends with Chapter 7, which examines two models of the water regulatory system in relation to the complex behavior demonstrated in the previous chapters. Phase locking or entrainment regions where an intrinsic oscillator locks on to an external or added oscillator will be studied and discussed both in relation to experimental results and recent discoveries within the plant cell sciences.
The first chapter of this thesis will provide a general background for this research field. At the end of this chapter there is a short summary of the different chapters of the thesis and some suggestions for further work. The main reference is Willmer and Fricker (1996), but other references are cited when necessary. | nb_NO |
