Communities and Ecosystems

420 Pages·1975·30.219 MB·English

by  Robert H. Whittaker

Robert H. Whittater Second Edition
Communities and
Ecosystems

!
B6/h "^s^f^B-e^dt
mcE^±^ZT SAVE
^
—
OUR r s~
f
price TREE
ANOTHER USED BOOK FROM
F L L E T T ' S
MICHIGAN BOOK STORE
i

:
The Primary Production of the Earth (from Chapter 5).
The energy of sunlight reaching the earth averages 700 cal/cm2/day for all wave
lengths outside the atmosphere, about 5.5 X 105 kCal/m2/yr in the visible range
A
at the earth's surface. fraction of this energy is absorbed by chlorophyll and
used in photosynthesis and primary productivity, the amounts of which vary
widely in different kinds of communities.
NetPrimaryProductivity WorldNet
per UnitArea Primary
Ecosystem Type Area NormalRange Mean Production
106kmz dryg/m2/yr 109 dryXIyr
Tropical forest 24.5 1000-3500 2000 49.4
Temperate forest 12.0 600-2500 1250 14.9
Boreal forest 12.0 400-2000 800 9.6
Woodland and shrubland 8.5 250-1200 700 6.0
Savanna 15.0 200-2000 900 13.5
Temperate grassland 9.0 200-1500 600 5.4
Tundra and alpine 8.0 10-400 140 1.1
Desert and semidesert 42.0 0-250 40 1.7
Cultivated land 14.0 100-3500 650 9.1
Swamp and marsh 2.0 800-3500 2000 4.0
Lake and stream 2.0 100-1500 250 0.5
Total continental 149.0 773 115
Open ocean 332.0 2-400 125 41.5
Continental shelf, upwelling 27.0 200-1000 360 9.8
Algal beds, reefs, estuaries 2.0 500-4000 1800 3.7
Total marine 361.0 152 55
World total 510.0 333 170
The energy content of organic matter averages 4.26 kCal/g of dry matter in
land plants, 4.9 kCal/g in open-ocean plankton, and 4.5 kCal/g in other algae.
Some mean values (excluding freshwater from land and estuaries from oceans)
On Land In the Forthe
Only Oceans World
Mean net primary productivity 780 147 336 g/m2/yr
Mean energy of NPP 3300 720 1500 kCal/m2/yr
Chlorophyll/surface area 1.5 0.05 0.48 g/m2
NPP
Efficiency of
Dry matter/visible sunlight 1.42 0.27 0.61 mg/kCal
Dry matter/chlorophyll 510 3000 700 g/g/yr
Energy/chlorophyll 2200 15,000 3100 kCal/g/yr
Energy/visible sunlight 0.60% 0.13% 0.27% kCal/kCal
Gross primary productivity should average (approximately) 2.7 X NPP on
land, 1.5 x NPP in the oceans, and 2.3 x NPP for the world.
Digitized by the Internet Archive
2014
in
http://archive.org/details/communitiesecosOOwhit
COMMUNITIES AND ECOSYSTEMS
^^HITTAICER
«
Cornell University
Communities
and SECOND EDITION
Ecosystems
MACMILLAN PUBLISHING CO., INC.
New York
COLLIER MACMILLAN PUBLISHERS
London
To Clara
Cover photo is of the southern Oregon coast at Gold Beach in the redwood belt,
from The Last Redwoods by Francois Leydet, published by the Sierra Club. [Re-
produced by permission of Philip Hyde, Box 220, Taylorsville, California.]
Copyright © 1975, Robert H. Whittaker
Printed in the United States of America
All rights reserved. No part of this book may be reproduced or
transmitted in any form or by any means, electronic or mechanical,
including photocopying, recording, or any information storage and
retrieval system, without permission in writing from the Publisher.
©
Earlier edition copyright 1970 by Robert H. Whittaker.
Macmillan Publishing Co., Inc.
866 Third Avenue, New York, New York 10022
Collier-Macmillan Canada, Ltd.
Library of Congress Cataloging in Publication Data
Whittaker, Robert Harding, (date)
Communities and ecosystems.
Includes bibliographies and index.
1. Ecology. L Title.
QH541.W44 1975 574.5'24 74-6636
ISBN 0-02-427390-2
Printing: 1 2 3 4 5 6 7 8 Year: 5 6 7 8 9