In its first English-language edition, this book introduces the many-faceted interactions of animal populations with their habitats. From soil fauna, ants and termites to small and large herbivores, burrowing mammals and birds, the author presents a comprehensive analysis of animals and ecosystems that is as broad and varied as all nature. Chapter 2 addresses the functional role of animals in landscape ecosystems, emphasizing fluxes of energy and matter within and between ecosystems, and the effects of animals on qualitative and structural habitat change. Discussion includes chapters on the role of animal population density and the impacts of native herbivores on vegetation and habitats from the tropics to the polar regions. Cyclic mass outbreaks of species such as the larch bud moth in Switzerland, the mountain pine beetle and the African red-billed weaver bird are described and analyzed. Other chapters discuss Zoochory - the dispersal of seeds by ants, mammals and birds - and the influence of burrowing animals on soil development and geomorphology. Consideration extends to the impact of feral domestic animals. Chapter 5 focuses on problems resulting from introduction of alien animals and from re-introduction of animal species to their original habitats, discusses the effects on ecosystems of burrowing, digging and trampling by animals. The author also addresses keystone species such as kangaroo rats, termites and beavers. Chapter 6 addresses the role of animals in landscape management and nature conservation, with chapters on the impact of newcomer species such as animals introduced into Australia, New Zealand and Europe, and the consequences of reintroduction of species to original habitat. It also discusses the carrying capacity of natural habit, public attitudes toward conversation and more. The final section ponders the effects of climate on interactions between animals and their habitats.

For more than 40 years I have been engaged in timberline research. Thus, one could suppose that writing this book should not have been too difficult. It was harder, however, than expected, and in the end I felt that more questions had arisen than could be answered within its pages. Perhaps it would have been easier to write the book 30 years ago and then leave the subject to mature. Lastly it was the late Prof. Heinz Ellenberg who had convinced me to portray a much needed and complete picture of what we know of the timberline with special respect to its great physiognomic, structural and ecological variety. The first version of this book was p- lished in the German language (Holtmeier, 2000). Nevertheless, I was very delighted when Prof. Martin Beniston encouraged me to prepare an English edition for the series 'Advances in Global Change Research', which guaranteed a wider circulation. Timberline is a worldwide and very heterogeneous phenomenon, which can only be presented by way of examples. My own field experience is necessarily limited to certain timberline areas, such as the Alps, northern Scandinavia, northern Finland and many high mountain ranges in the western United States and Canada. However, my own observations and the results of my and my previous collaborators research were essential for developing the concept of the book and became integrated into the picture of timberline that is presented in the following chapters.

For more than 40 years I have been engaged in timberline research. Thus, one could suppose that writing this book should not have been too difficult. It was harder, however, than expected, and in the end I felt that more questions had arisen than could be answered within its pages. Perhaps it would have been easier to write the book 30 years ago and then leave the subject to mature. Lastly it was the late Prof. Heinz Ellenberg who had convinced me to portray a much needed and complete picture of what we know of the timberline with special respect to its great physiognomic, structural and ecological variety. The first version of this book was p- lished in the German language (Holtmeier, 2000). Nevertheless, I was very delighted when Prof. Martin Beniston encouraged me to prepare an English edition for the series 'Advances in Global Change Research', which guaranteed a wider circulation. Timberline is a worldwide and very heterogeneous phenomenon, which can only be presented by way of examples. My own field experience is necessarily limited to certain timberline areas, such as the Alps, northern Scandinavia, northern Finland and many high mountain ranges in the western United States and Canada. However, my own observations and the results of my and my previous collaborators research were essential for developing the concept of the book and became integrated into the picture of timberline that is presented in the following chapters.