This PhD thesis comprises basically four chapters, prepared for publication in peer-reviewed international journals. Chapter 1 was already published in 2001, chapter 3 is presently being in press. The chapters 1 and 2 cover methodological aspects of rhizosphere research including the development of a novel rhizobox design and potential artifacts in rhizosphere research. Chapter 3 presents a review on As in the soil-rhizosphere-plant system with emphasis on phytoremediation of As-polluted soils, while chapter 4 describes a experiment conducted to investigate the fate of As in the rhizosphere of a recently discovered As-hyperaccumulator plant.
