Concerns have been raised with respect to the state of high-altitude and high-latitude treelines, as they are anticipated to undergo considerable modifications due to global changes, and especially due to climate warming. As high-elevation treelines are temperature-limited vegetation boundaries, they are considered to be sensitive to climate warming. As a consequence, in this future, warmer environment, an upward migration of treelines is expected because low air and root-zone temperatures constrain their regeneration and growth. Despite the ubiquity of climate warming, treeline advancement is not a worldwide phenomenon: some treelines have been advancing rapidly, others have responded sluggishly or have remained stable. This variation in responses is attributed to the potential interaction of a continuum of site-related factors that may lead to the occurrence of locally conditioned temperature patterns. Competition amongst species and below-ground resources have been suggested as additional factors explaining the variability in the movement of treelines. This Special Issue (book) is dedicated to the discussion of treeline responses to changing environmental conditions in different areas around the globe.

Concerns have been raised with respect to the state of high-altitude and high-latitude treelines, as they are anticipated to undergo considerable modifications due to global changes, and especially due to climate warming. As high-elevation treelines are temperature-limited vegetation boundaries, they are considered to be sensitive to climate warming. As a consequence, in this future, warmer environment, an upward migration of treelines is expected because low air and root-zone temperatures constrain their regeneration and growth. Despite the ubiquity of climate warming, treeline advancement is not a worldwide phenomenon: some treelines have been advancing rapidly, others have responded sluggishly or have remained stable. This variation in responses is attributed to the potential interaction of a continuum of site-related factors that may lead to the occurrence of locally conditioned temperature patterns. Competition amongst species and below-ground resources have been suggested as additional factors explaining the variability in the movement of treelines. This Special Issue (book) is dedicated to the discussion of treeline responses to changing environmental conditions in different areas around the globe.

Alpine treelines mark the low-temperature limit of tree growth and occur in mountains world-wide. Presenting a companion to his book Alpine Plant Life, Christian Körner provides a global synthesis of the treeline phenomenon from sub-arctic to equatorial latitudes and a functional explanation based on the biology of trees. The comprehensive text approaches the subject in a multi-disciplinary way by exploring forest patterns at the edge of tree life, tree morphology, anatomy, climatology and, based on this, modelling treeline position, describing reproduction and population processes, development, phenology, evolutionary aspects, as well as summarizing evidence on the physiology of carbon, water and nutrient relations, and stress physiology. It closes with an account on treelines in the past (palaeo-ecology) and a section on global change effects on treelines, now and in the future. With more than 100 illustrations, many of them in colour, the book shows alpine treelines from around the globe and offers a wealth of scientific information in the form of diagrams and tables.

The alpine treeline ecotone (ATE) is an area of transition high on mountains where closed canopy forests from lower elevations give way to the open alpine tundra and rocky expanses above. Alpine tundra is an island biome and its ecotone with forest is subject to change, and like oceanic islands, alpine tundra is subject to invasion – or the upward advance of treeline. The invasion of tundra by trees will have consequences for the tundra biome as invasion does for other island flora and fauna. To examine the invasibility of tundra we take a plant’s-eye-view, wherein the local conditions become extremely important. Among these local conditions, we find geomorphology to be exceptionally important. We concentrate on aspects of microtopography (and microgeomorphology) and microclimate because these are the factors that matter: from the plant’s-eye-view, but we pay attention to multiple scales. At coarse scales, snow avalanches and debris flows are widespread and create “disturbance treelines whose elevation is well below those controlled by climate. At medium scales, turf-banked terraces create tread-and-riser topography that is a difficult landscape for a tree seedling to survive upon because of exposure to wind, dryness, and impenetrable surfaces. At fine scales, turf exfoliation of the fronts of turf-banked risers, and boulders, offer microsites where tree seedlings may find shelter and are able to gain a foothold in the alpine tundra; conversely, however, surfaces of needle-ice pans and frost heaving associated with miniature patterned ground production are associated with sites inimical to seedling establishment or survival. We explicitly consider how local scale processes propagate across scales into landscape patterns. The objective of this book is to examine the controls on change at alpine treeline. All the papers are focused on work done in Glacier National Park, Montana, USA. Although any one place is limiting, we are able to examine the alpine treeline here in some detail – and an advantage is that the treeline ecotone in Glacier National Park is quite variable in itself due to the underlying variability in geomorphology at multiple scales. This book will provide insights into an important ecological phenomenon with a distinctly geomorphic perspective. The editors collectively have over 100 years of experience in working in geomorphology, biogeography, and ecology. They also have each worked on research in Glacier National Park for several decades. The book will be a reference for a variety of professionals and students, both graduate and undergraduate, with interests in Physical Geography, Geomorphology, Ecology, and Environmental Science. Because of the importance of the alpine treeline ecotone for recreation and aesthetic interests in mountain environments, wildland and park managers will also use this book. * Subject matter: geomorphology at alpine treeline* Expertise of contributors: each editor brings over 25 years of experience in studies of ecotones and geomorphology, and collectively over 100 years of experience in Glacier National Park* Changing alpine treeline examines climate change

The European Arctic and Alpine regions are experiencing large environmental changes. These changes may have socio-economic effects if the changes affect the bioproduction, which form the basis for the marine and terrestrial food chains. This uniquely multidisciplinary book presents the various aspects of contemporary environmental changes in Arctic and Alpine Regions.

Originally published in 1974, Arctic and Alpine Environments examines, the relatively simple ecosystems of arctic and alpine lands that still occupy extensive areas little disturbed by modern technology. The book argues that there is a necessity for carefully controlled development of the resources of these regions and suggests that there is a risk of irreversible disturbance without full understanding of these regions. This book provides a detailed documentation of cold-stressed arctic and alpine terrestrial environments and systematically deals with the present and past physical environment – climate, hydrology and glaciology; biota – treeline, vegetation, vertebrate zoology, and historical biogeography; abiotic processes – geomorphological and pedological and the role of man – bioclimatology, archaeology and technological impact, including radioecology. The book will appeal to academics and students of environmental and biological science, as well as providing a significant source for conservationists’, government agencies and industrial organizations.