This book is the unique attempt to combine current knowledge of theoretical and experimental plant physiological causes of isotope fractionations with the most recent understanding of the natural variability of isotopes in tree rings. Based on these fundamentals the application of tree-ring isotopes to climate and palaeoclimte studies is discussed including problems of ongoing pollution effects which complicate calibration studies. Since many investigations require large numbers of samples sampling strategies are addressed carefully in order not to lose any options for later analyses. A final chapter on recent technological developments in the treatment and measurement of isotopes completes the book.