Table Of Content

Springer-Verlag Berlin Heidelberg GmbH Alpine Plant Life Professor Dr. CHRISTIAN KoRNER Institute of Botany University of Basel SchonbeinstraBe 6 4056 Basel Switzerland [email protected] Cover illustation: Variation in slope, exposure, relief and substrate type over a short distance are keys to understanding alpine plant life (Central Swiss Alps with Finsterahorn, 4200 m in the background) Left: Culcitium ni vale, 4600 m, Cayambe, Ecuador ISBN 978-3-540-00347-2 Library of Congress Cataloging-in-Publication Data Korner, Christian, 1949- Alpine plan! life : functional plan! ecology of high mountain ecosystems 1 Christian Kilrner. - 2nd ed. p. cm. lncludes bibliographical references (p. ). ISBN 978-3-540-00347-2 lSBN 978-3-642-18970-8 (eBook) DOI 10.1007/978-3-642-18970-8 L Mountain plants-Ecology. 2. Mountain plants - Ecophysiology. !. Title. This work is subject to copyright. Ali rights reserved, whether the whole or part of the material is con cerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publica tion or parts thereof is permitted only under the provisions of the German Copyright Law of Septem ber 9, 1965, in its current version, and permission for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. http:l/www.springer.de © Springer-Verlag Berlin Heidelberg 1999,2003 Originally published by Springer-Verlag Berlin Heidelberg New York in 1999, 2003 Soflcover reprint of the hardcover 2nd edition 1999, 2003 The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant pro· tective laws and regulations and therefore free for general use. Cover design: Design & Production, Heidelberg "IYPesetting: SNP Best-set "IYPesetter Ltd., Hong Kong 31/3150Wl-5 4 3 2 1 O-Printed on acid-free paper Preface to the second edition Recent years have seen renewed interest in the fragile alpine biota.The International Year of Mountains in 2002 and numerous international programs and initiatives have contributed to this. Since nearly half of mankind depends on water supplies originating in mountain catchments, the integrity and functional significance of the upland biota is a key to human welfare and will receive even more attention as water becomes an increasingly limited resource.Intact alpine vegetation,as the safeguard of the water towers of the world,is worth being well understood.This new edition ofAlpine Plant Lifeis an update with over100new references,new diagrams,revised and extended chapters (particularly 7,10,11,12,16,17) and now also offers a geographic index.My thanks go to the many careful readers of the first edition for their most valuable comments,in particular to Vicente I.Deltoro (Valencia) and Johanna Wagner (Innsbruck). Basel,April 2003 Christian Körner Preface to the first edition One of the largest natural biological experiments,perhaps the only one replicated across all latitudes and all climatic regions,is uplift ofthe landscape and exposure of organisms to dramatic climatic gradients over a very short distance,otherwise only seen over thousands of kilometers of poleward traveling.Generations ofplant scientists have been fascinated by these natural test areas,and have explored plant and ecosystem responses to alpine life conditions.Alpine Plant Lifeis an attempt at a synthesis. This book has roots in a century ofresearch into alpine ecology at the Insitute ofBotany in Innsbruck,Austria.Anton Kerner pioneered the field in the late 19th century.Arthur Pisek founded modern comparative and experimental ecology of alpine plants,and was the first to systematically combine field with controlled environment studies.Walter Larcher introduced the ecosystem approach,the question ofscale.During my doctoral project with him on alpine plant water relations, he stimulated my interest in links between plant structure and function and in plant devel- opmental processes. My former senior colleague Alexander Cernusca introduced me to environmental physics and thanks to him I began to think in terms offluxes and pools.This text could not have been written without these influences. Privileged to grow up in a green environment,my interest in biology was stimulated by my parent’s fascination in plants and landscape gardening, their painting and photography, and their strong feel for natural aesthetics.Alpine vegetation is often like a garden, a mosaic of beauty,a small-scale multitude of ways of coping with life,attractive to both the naturalist and the scientist.Perhaps the reader will also find some morsels ofthis fascination between the lines ofthis scientific text. Essential contributions to this volume were the patience and help by my wife Raingard and the graphical work,help with literature and laboratory analysis by Susanna Pelaez-Riedl.I am grateful to J Arnone,E Beck,MM Caldwell,T Callaghan,FS Chapin,M Diemer,B Holmgren,S Pelaez-Riedl, F Schweingruber, J Stöcklin and H Veit for commenting on drafts of various parts ofthe text.A number ofcolleagues helped with information, plant samples or unpublished data,namely WD Bowman,J Gonzalez,S Halloy,W Larcher,G Miehe,J Paulsen,H Reisigl,R Siegwolf,M Sonesson, RC Sundriyal,U Tappeiner andP Volko.R Guggenheim and his team pro- duced the scanning electron micrographs in Chap.9and16.H Schneider VIII Preface to the first edition assisted with electronic treatment ofphotographs.The University ofBasel provided an ideal environment for research and teaching alpine ecology to students and permitted the needed work-leave. I thank the Abisko Research Station in N-Sweden for hosting me during much of the literature and text work. I also gratefully acknowledge the fruitful cooperation with the Springer team throughout this project.In particular,I would like to thank S Bunker, D Czeschlik,A Schlitzberger,K Matthias,and K-H Winter. Alpine Plant Lifewas written for a broad readership.This has made it necessary to start several chapters with rather general introductions.On the other hand,I have tried to cover the bulk ofscientific findings.In trying to cover as many relevant topics as possible,the reader will often only be given a reference to find answers elsewhere.There is no way to treat this field ofscience exhaustively in a single volume like this.Hence,the product is a compromise,which hopefully will interest the specialist as well as a wider audience. Basel,February 1999 Christian Körner Contents 1 Plant ecology at high elevations ......................... 1 The concept oflimitation ............................... 1 A regional and historical account ........................ 3 The challenge ofalpine plant research .................... 7 2 The alpine life zone.................................... 9 Altitudinal boundaries........ ......................... 9 Global alpine land area ................................ 12 Alpine plant diversity .................................. 13 Origin ofalpine floras.................................. 16 Alpine growth forms .................................. 18 3 Alpine climate ........ ............................... 21 Which alpine climate? .................................. 21 Common features ofalpine climates ...................... 21 Regional features ofalpine climates ...................... 26 4 The climate plants experience ........................... 31 Interactions ofrelief,wind and sun....................... 31 How alpine plants influence their climate.................. 38 The geographic variation ofalpine climate ................ 45 5 Life under snow:protection and limitation ................ 47 Temperatures under snow .............................. 47 Solar radiation under snow ............................. 48 Gas concentrations under snow .......................... 52 Plant responses to snowpack ............................ 54 6 Alpine soils .......................................... 63 Physics ofalpine soil formation.......................... 63 The organic compound................................. 70 The interaction oforganic and inorganic compounds ....... 74 7 Alpine treelines ....................................... 77 About trees and lines .................................. 77 Current altitudinal positions ofclimatic treelines ........... 78 X Contents Treeline-climate relationships ........................... 80 Intrazonal variations and pantropical plateauing of alpine treelines........................................ 86 Treelines in the past ... ................................ 87 Attempts at a functional explanation oftreelines ........... 88 A hypothesis for treeline formation....................... 95 Growth trends near treelines ............................ 97 Evidence for sink limitation ............................. 99 8 Climatic stress ........................................ 101 Survival oflow temperature extremes..................... 102 Avoidance and tolerance oflow temperature extremes ....... 106 Heat stress in alpine plants.............................. 111 Ultraviolet radiation – a stress factor? .................... 114 9 Water relations ....................................... 121 Ecosystem water balance ............................... 121 Soil moisture at high altitudes ... ....................... 126 Plant water relations – a briefreview ofprinciples .......... 133 Water relations ofalpine plants .. ....................... 134 Desiccation stress ..................................... 143 Water relations ofspecial plant types ..................... 145 10 Mineral nutrition ..................................... 149 Soil nutrients ......................................... 150 The nutrient status ofalpine plants....................... 152 Nutrient cycling and nutrient budgets ..... ............... 155 Nitrogen fixation ...................................... 160 Mycorrhiza .......................................... 163 Responses ofvegetation to variable nutrient supply ......... 165 11 Uptake and loss ofcarbon .............................. 171 Photosynthetic capacity ofalpine plants................... 171 Photosynthetic responses to the environment .............. 180 Daily carbon gain ofleaves ............................. 186 The seasonal carbon gain ofleaves ....................... 186 C4and CAM photosynthesis at high altitudes .............. 189 Tissue respiration ofalpine plants........................ 190 Ecosystem carbon balance .............................. 196 12 Carbon investments ................................... 201 Non-structural carbohydrates ........................... 201 Lipids and energy content .............................. 209 Carbon costs ofleaves and roots ......................... 211 Whole plant carbon allocation........................... 214 13 Growth dynamics and phenology ........................ 221 Seasonal growth ...................................... 221