As human populations expand and have increasing access to technol ogy, two general environmental concerns have arisen. First, human pop ulations are having increasing impact on the earth system, such that we are altering the biospheric carbon pools, basic processes of elemental cycling and the climate system of the earth. Because of time lags and feedbacks, these processes are not easily reversed. These alterations are occurring now more rapidly than at any time in the last several million years. Secondly, human activities are causing changes in the earth's biota that lead to species extinctions at a rate and magnitude rivaling those of past geologic extinction events. Although environmental change is potentially reversible at some time scales, the loss of species is irrevo cable. Changes in diversity at other scales are also cause for concern. Habitat fragmentation and declines in population sizes alter genetic di versity. Loss or introduction of new functional groups, such as nitro gen fixers or rodents onto islands can strongly alter ecosystem processes. Changes in landscape diversity through habitat modification and frag mentation alter the nature of processes within and among vegetation patches. Although both ecological changes altering the earth system and the loss of biotic diversity have been major sources of concern in recent years, these concerns have been largely independent, with little concern for the environmental causes the ecosystem consequences of changes in biodiversity. These two processes are clearly interrelated. Changes in ecological systems cause changes in diversity.

Autorentext
Christian Körner was born in 1949 in Salzburg, Austria, got his academic degrees from the University of Innsbruck, and became professor of botany at the University of Basel, Switzerland in 1989. He published over 300 scientific articles on plant-environment interactions and authored and coauthored numerous scientific books, including the leading plant science textbook Strasburger.

Klappentext

This book provides a synthesis of the patterns, causes and consequences of biodiversity in cold-dominated ecosystems.The first chapters document patterns and causes of genetic and species diversity of plants and animals emphasizing the interaction between historical and contemporary factors in governing biodiversity. The second section addresses how biotic diversity has changed in the past, how it is currently changing, and how it will likely respond to future changes in climate and land use. The third section treats both the conceptual basis and the evidence that biodiversity influences the functioning of arctic and alpine ecosystems. Also included are the implications of terrestrial patterns of biodiversity for landscape patterns and for patterns of diversity in aquatic ecosystems.

Inhalt
I: Patterns and Causes of Diversity.- 1 Patterns and Causes of Arctic Plant Community Diversity.- 2 Causes of Arctic Plant Diversity: Origin and Evolution.- 3 Patterns and Causes of Genetic Diversity in Arctic Plants.- 4 Alpine Plant Diversity: A Global Survey and Functional Interpretations.- 5 Origin and Evolution of the Mountain Flora in Middle Asia and Neighbouring Mountain Regions.- 6 Diversity of the Arctic Terrestrial Fauna.- 7 Animal Diversity at High Altitudes in the Austrian Central Alps.- II: Past, Present, and Future Changes in Diversity.- 8 Arctic Tundra Biodiversity: A Temporal Perspective from Late Quaternary Pollen Records.- 9 Effects of Mammals on Ecosystem Change at the Pleistocene-Holocene Boundary.- 10 Palaeorecords of Plant Biodiversity in the Alps.- 11 Implications for Changes in Arctic Plant Biodiversity from Environmental Manipulation Experiments.- 12 Patterns and Current Changes in Alpine Plant Diversity.- 13 Anthropogenic Impacts on Biodiversity in the Arctic.- III: Ecosystem Consequences of Diversity.- 14 Plant Functional Diversity and Resource Control of Primary Production in Alaskan Arctic Tundras.- 15 Direct and Indirect Effects of Plant Species on Biogeochemical Processes in Arctic Ecosystems.- 16 Causes and Consequences of Plant Functional Diversity in Arctic Ecosystems.- 17 Ecosystem Consequences of Microbial Diversity and Community Structure.- 18 Diversity of Biomass and Nitrogen Distribution Among Plant Species in Arctic and Alpine Tundra Ecosystems.- 19 The Plant-Vertebrate Herbivore Interface in Arctic Ecosystems.- 20 Insect Diversity, Life History, and Trophic Dynamics in Arctic Streams, with Particular Emphasis on Black Flies (Diptera: Simuliidae).- 21 Land-Water Interactions: The Influence of Terrestrial Diversity on Aquatic Ecosystems.- IV: A Synthesis.- 22 Patterns, Causes, Changes, and Consequences of Biodiversity in Arctic and Alpine Ecosystems.