Preface

Human activities cause the degradation of innumerable ecosystems. In particular, forest degradation leads to far-reaching nutrient cycle changes throughout all environments. Reversible and irreversible degradation processes cause ecosystem self-regulation to decline. While reversible processes tend to be a structural simplification and a decrease in native forest biodiversity under the preservation of the ecosystem's abiotic components, irreversible processes alter the character of the potential natural vegetation due to climate change, acidification, eutrophication, and soil erosion. Subsequent secondary ecosystems already affect global change processes in an uncertain way. The book discusses the irreversible degradation processes of forests worldwide.

This book is organized into three parts on general, climatic, and land-use degradative effects. Global environmental change involves a related sequence of the biophysical, ecosystem, and socioeconomic alterations that damage the life-sustaining abilities of the planet. Current global change is caused by the human transformation of the natural environment, but also by the reaction of human communities to the induced modifications. Human transformations of the natural environment are concentrated in a critical zone. The most vulnerable part of the terrestrial critical zone is composed of soil (pedosphere), which includes interfaces among the atmosphere, hydrosphere, lithosphere, and biosphere.

The most serious soil damage is due to land-use modifications after deforestation. While mere forest felling only gives rise to reversible changes in ecosystem functions, the combination of forest felling with soil erosion or conversion for the need of subsequent management utilization generates irreversible ecosystem degradation. Deforestation is instantly followed by declining evaporation and soil loss. The imminent consequences of deforestation are gradually leading to regional climate change, the loss of ecosystem recoverability, and uninhabitable landscapes. Ultimately, landscape uninhabitability is caused by uncontrollable soil erosion because of surface exposure to wind and landslides of weathered rocks impoverished from organic binders. Thus, this book discusses characteristics of human activities that disrupt the landscape and highlights the need to restore wildlife.

> **Pavel Samec** Faculty of Forestry and Wood Technology, Department of Geology and Soil Science, Mendel University, Brno, Czech Republic

Section 1
