Table Of ContentDisturbance in Grasslands
Geobotany 10
Series Editor
M.l.A. WERGER
Disturbance in Grasslands
Causes, effects and processes
edited by
J. VAN ANDEL, J.P. BAKKER AND R.W. SNAYDON
1987 DR W. JUNK PUBLISHERS
a member of the KLUWER ACADEMIC PUBLISHERS GROUP
DORDRECHT / BOSTON / LANCASTER
Distributors
jor the United States and Canada: Kluwer Academic Publishers, P.O. Box 358,
Accord Station, Hingham, MA 02018-0358, USA
jor the UK and Ireland: Kluwer Academic Publishers, MTP Press Limited,
Falcon House, Queen Square, Lancaster LAI lRN, UK
jor all other countries: Kluwer Academic Publishers Group, Distribution Center,
P.O. Box 322, 3300 AH Dordrecht, The Netherlands
ISBN-13: 978-94-010-8300-3 e-ISBN-13: 978-94-009-4055-0
DOl: 10.1007/978-94-009-4055-0
Copyright
© 1987 by Dr W. Junk Publishers, Dordrecht.
Sof'tcover reprint of the hardcover 1st edition 1987
All rights reserved. No part of this publication may be reproduced, stored in a
retrieval system, or transmitted in any form or by any means, mechanical,
photocopying, recording, or otherwise, without the prior written permission of
the publishers,
Dr W. Junk Publishers, P.O. Box 163, 3300 AD Dordrecht, The Netherlands.
PREFACE
This volume is the result of a Symposium, held in October, 1985, to celebrate the Silver Jubilee of the De
partment of Plant Ecology of the University of Groningen.
The Department of Plant Ecology was founded by Professor Dingeman Bakker and has, since its incep
tion, been involved with studies of grasslands, and especially with the effects of human interference on
grassland communities. It has been especially involved in an almost unique enterprise to convert areas of
grassland from intensive agricultural production to nature reserves. With over-production of most food
commodities in the EEC, and increasing interest in various types of 'set aside' schemes, this initiative now
seems to be remarkably prescient.
The Netherlands have a long history of human manipulation of the environment. Indeed, the Dutch en
vironment is probably more man-made than that of any other country. In view of this, and the Laborato
ry's interest in managed grasslands, it is not surprising that 'Disturbance in Grasslands' was selected as
the topic for the Laboratory's Jubilee Symposium. Although both the Symposium and the resulting vo
lume, have a strong Dutch component, the organisers invited a number of contributors from Europe and
elsewhere to provide key chapters. The result is a volume which covers many aspects of disturbance in a
variety of grasslands. Disturbance is considered at both the community and the population level, and the
principles and processes underlying those responses are explored. A variety of disturbances are consider
ed, though the main emphasis is on those factors of particular interest to the Department of Plant Eco
logy, especially defoliation, soil fertility, drainage and salinity.
The organisers of the Symposium would like to thank the Royal Netherlands Academy of Arts and
Sciences, the Faculty of Mathematics and Natural Sciences and the Subfaculty of Biology of the Univer
sity of Groningen for their financial support of this Symposium, C. W. Biewenga for assisting with the or
ganisation, and Dr. R.W. Snaydon for his contribution towards the editing of this volume.
PROLOGUE
The importance of disturbance Defining disturbance
Disturbance, both man-induced and natural, has There are several underlying difficulties in consi
received increasing attention from ecologists in dering disturbance in plant communities and po
the last decade. This interest has culminated in pulations. The first of these is the difficulty of
several recent books (e.g. Cairns et aI., 1977; nomenclature. The early stages of most develop
Mooney & Godron, 1983; Pickett & White, 1985) ing fields of science are marked by a prolifera
and reviews (e.g. White, 1979; Sousa, 1984; Rap tion of jargon; studies of disturbance in communi
port et aI., 1985). The increasing interest in dis ties and populations are no exception. The pro
turbance has probably been stimulated by a re blem is heightened by the fact that most of the
cognition, sometimes perhaps not conscious, that jargon (e.g. disturbance, perturbation, and
more can be learned about the functioning of stress) has been borrowed from everyday speech,
communities and populations by studying their often with subtle changes in meaning. In the first
response to disturbance than by studying these two chapters of this volume, the authors tackle
systems in equilibrium. Such studies may be of this problem and, largely as a result of discussions
systems that have been naturally disturbed, unin at the symposium, opt to simplify the nomencla
tentionally disturbed by man, or intentionally dis ture by dispensing with synonyms, or terms which
turbed by man. Ideally, studies should be made of were used inconsistently. Simplifying the nomen
systems that have been experimentally disturbed, clature, however, does not overcopJe the ·difficul
where the treatments have been imposed after ties of defining disturbance per se. It is extremely
careful consideration, and a valid experimental difficult to distinguish disturbance from normally
design has been used with replication. These occurring variation in environmental conditions.
ideal conditions are ra~ely achieved, and we may At one extreme, a disturbance may occur that has
be forced to observe the effects of some previous never previously existed, e.g. the application of a
ly imposed, unreplicated disturbance; sometimes novel man-made herbicide; in this case adapta
there may not be even a valid control treatment tion will not have already occurred but, as the
with which to compare the disturbed community example of herbicides indicates, adaptation may
or population. In spite of the fact that we may of still occur as a result of intense selection for mu
ten be forced to study far from ideal situations, tants. At the other extreme, environmental varia
disturbance is still a valuable tool in ecological tion may be such an important attribute of the ha
and genecological study, allowing us to study the bitat, that communities and populations are fully
underlying processes at work within communities adapted to the variation, and their very survival
and populations. may depend .u pon it. Between these extremes
there is a complete spectrum.
VIII
Another difficulty is that of measuring distur Various types of disturbance have been studied
bance or even, in some cases, recognising its oc in the context of grasslands. The most common,
currence. In theory, like most biological proces and those widely considered in this volume, can
ses, disturbance can be recognised, and perhaps be broadly categorised into particular changes in
measured, by its causes or by its effects. Indeed, soil conditions, and defoliation regime. Distur
disturbance is normally defined in terms of either bance in soil conditions might include: (i) in
its cause or its effects, and is commonly recogni crease or decrease in nutrients supply (e.g. in
sed by its effects; changes in composition or struc crease or decrease in application of fertilizer); (ii)
ture of communities and/or populations are pro increase or decrease in soil water content (e.g.
bably the most effective way of finding whether drainage or flooding, or change in tidal pattern);
disturbance has occurred. While the recognition (iii) change in soil salinity (e.g. change in tidal
of disturbance is difficult, the processes of res pattern). Disturbance of the defoliation regime
ponse to disturbance are even more difficult to may include: (i) change in frequency, intensity or
discover. Although most of the papers in this vo seasonality of defoliation; (ii) change in the type
lUme deal with the causes and effects of distur of defoliation (e.g. cutting versus grazing). Most
bance, many also attempt to define the processes of these forms of potential disturbance are consi
of response to disturbance. dered at least once in this volume.
The response to disturbance can be measured
at each level of biological organisation from the
Disturbance in grasslands cellular level to the ecosystem level. Here we are
concerned with levels from the individuals up
The are several advantages in studying distur wards. The volume is broadly divided into res
bance in grasslands. Firstly, the responses to dis ponses at the community level (parts II and III),
turbance in grassland are usually rapid, so that with some consideration of the ecosystem level,
experiments can be carried out in reasonably and responses at the level of the individual and
short time spans. Whereas responses to distur population (part IV). Chapters 1 and 2 consider
bance may take decades, or even centuries, to de the general principles relating to those two grou
velop in woodlands, they can often be detected pings.
within weeks in grasslands, and a new equilibrium
may be reached in a few years. The reasons for
this rapid response are twofold: (i) individuals of References
most species in grassland are phenotypically very
plastic, so that changes in plant sizes or form are Cairns, J., Dickson, K.L. & Hendricks, E.E. (1977) Recovery
usually apparent in a few weeks; (ii) individuals and Restoration of Damage to Ecosystems. Charlottsville,
of most grassland species are usually short-lived, University Press of Virginia.
Mooney, H.A. & Godron, M. (1983) Disturbance and Eco
so that changes in the structure of both popula
systems. Berlin, Verlag-Springer.
tions and communities can occur in a few years.
Pickett, S.T.A. & White, P.S. (1985) The Ecology of Natural
The second advantage of studying disturbance in Disturbance and Patch Dynamics. New York, Academic
grassland is that a great diversity of grassland ty Press.
pes is available for study, ranging from natural to Rapport, D.J., Regier, H.A. & Hutchinson, T.C. (1985) Eco
system behaviour under stress. American Naturalist, 125,
man-made, from botanically simple to botanically
617-640.
complex, and in a diversity of habitats varying,
Sousa, W.P. (1984) The role of disturbance in natural commu
for example, from semi-arid to water-logged. In nities. Annual Review of Ecology and Systematics, 15,
addition, grasslands are abundant, easily accessi 353-391.
ble and, because of their agricultural importance, White, P.S. (1979) Pattern, process and natural disturbance in
vegetation. Botanical Review, 45, 229-299.
have been widely studied.
Table of contents
Preface........................................... V PART THREE: VEGETATION RESPONSE
Prologue ......................................... VII TO DEFOLIATION AND PATHOGENS
List of contributors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XI
9. The herbivore as prisoner of its food supply
by R.H. Drentl H.H.T. Prins. . . . . . . . . . . . . . . . . .. 131
10. Ecological modeling of short-term plant commu
PART ONE: DISTURBANCE IN
nity dynamics under grazing with and without dis
PERSPECTIVE
turbance
by L.F.M. Fresco I H.P.M. van Laarhoven I
1. Disturbance of grasslands - Outline of the theme M.J.J.E. Loonen IT. Moesker. . .. ... .. .. . ...... 149
byJ. van AndeIlJ.P. vandenBergh ............. 3 11. Modelling the structural changes in vegetation un
2. Population responses to environmental disturbance der different grazing regimes
byR.W. Snaydon............................. 15 by D.C.P. Thalen I H. Poorter I L.A.P. Lotz I P.
Oosterveld. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 167
12. Restoration of species-rich grassland after a period
of fertilizer application
by J.P. Bakker. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 185
PART TWO: VEGETATION RESPONSE TO
13. The function of plant pathogenic fungi in natural
CHANGING SOIL CONDITIONS
communities
by J .C. Zadoks ............................... 20)
3. Soil variation caused by plants: a mechanism of flo
ristic change in grassland?
byJ. Miles .................................. . 37
PART FOUR: POPULATION AND SPECIES
4. Soil fertility and the composition of semi-natural
grassland RESPONSES
byD.M. Pegtel .............................. . 51
5. Hybridization of the habitat in disturbed hay mead 14. Population differentiation in grassland vegetation
ows by W.H.O. Ernst ............................. 213
by A.P. Grootjans I G.J .R. Allersma I C. Kik ..... 67 15. Population responses in Agrostis stolonifera to se-
6. Disturbances in transplanted grasslands and wet lective forces in inland and coastal habitats
lands byC. Kik .................................... 229
by F. KI6tzii ................................. . 79 16. A physiological analysis of genotypic variation in
7. Vegetation responses to changes in tidal inunda relative growth rate: Can growth rate confer eco-
tion of salt marshes logical advantage?
byW.G. Beeftink ............................ . 97 by H. Lambers/P. Dijkstra .................... 237
8. Vegetation development from denuded ground to 17. Ecological significance of size variation within pop-
grassland ulations
by A. Fischer ................................ . 119 byA. Biere .................................. 253
x
18. Population responses of Rhinanthus angustifolius Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 303
to disturbance of grassland communities Subject index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 307
byP.C. de Hullu I A.P. Grootjans ............... 265 Species index..................................... 311
19. Pollination and pollen flow disturbed by honeybees Communities index................................ 317
in bumblebee-pollinated Rhinanthus populations?
by M.M. Kwak ............................... 273
ZO. Disturbance, hybridization and hybrid speciation
by K.M. Urbanska . . . . . . . . . . . . . . . . . . . . . . . . . . .. 285
List of contributors
G.J.R. Allersma, P. Campersingel 65, 9713 AD Groningen, F. Klotzii, Geobotanisches Institut ETH, Stiftung Rubel, ZU
The Netherlands richbergstrasse 38, CH-8044 Zurich, Switzerland
J.P. Bakker, Department of Plant Ecology, University of M.M. Kwak, Department of Plant Ecology, University of
Groningen, Biological Centre, P.O. Box 14, 9750 AA Ha Groningen, Biological Centre, P.O. Box 14, 9750 AA Ha
ren (Gn), The Netherlands ren (Gn), The Netherlands
W.G. Beeftink, Delta Institute for Hydrobiological Research, H. Lambers, Department of Plant Ecology, University of
Vierstraat 28,4401 EA Yerseke, The Netherlands Utrecht, Lange Nieuwstraat 106, 3512 PN Utrecht, The
Netherlands
A. Biere, Department of Plant Ecology, University of Gro
ningen, Biological Centre, P.O. Box 14, 9750 AA Haren M.J.J.E. Loonen, Department of Plant Ecology, University
(Gn), The Netherlands of Groningen, Biological Centre, P.O. Box 14, 9750 AA
Haren (Gn), The Netherlands
P.e. de Hullu, State Forestry Service, Department Flora and
Fauna, P.O. Box 200.20, 3502 LA Utrecht, The Nether L.A.P. Lotz, Institute for Ecological Research, Duinzoom
lands 20a,3233 EG Oostvoorne, The Netherlands
R.H. Drent, Zoological Laboratory, University of Gro J. Miles, Institute of Terrestrial Ecology, Banchory Research
ningen, Biological Centre, P.O. Box 14, 9750 AA Haren Station, Banchory, Kincardineshire, AB3 4BY, UK
(Gn), The Netherlands
T. Moesker, Department of Plant Ecology, University of Gro
P. Dijkstra, Department of Plant Physiology, University of ningen, Biological Centre, P.O. Box 14, 9750 AA Haren
Groningen, Biological Centre, P.O. Box 14, 9750 AA Ha (Gn), The Netherlands
ren (Gn), The Netherlands
P. Oosterveld, Research Institute for Nature Management,
W.H.O. Ernst, Department of Ecology and Ecotoxicology, P.O. Box 46, 3956 ZR Leersum, The Netherlands
Free University, De Boelelaan 1087, 1081 HV Amsterdam,
D.M. Pegtel, Department of Plant Ecology, University of
The Netherlands
Groningen, P.O. Box 14, 9750 AA Haren (Gn), The Ne
A. Fischer, Institut fUr Pflanzenokologie der Justus-Liebig therlands
Universitiit, Heinrich Buff-Ring 38, D,6300 Giessen, BRD
H. Poorter, Department of Plant Ecology, University of
L.F.M. Fresco, Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, 3512 PN Utrecht, The
Groningen, Biological Centre, P.O. Box 14, 9750 AA Ha Netherlands
ren (Gn) , The Netherlands
H.H.T. Prins, Zoological Laboratory, University of Gro
A.P. Grootjans, Department of Plant Ecology, University of ningen, Biological Centre, P.O. Box 14, 9750 AA Haren
Groningen, Biological Centre, P.O. Box 14, 9750 AA Ha (Gn), The Netherlands
ren (Gn), The Netherlands
R.W. Snaydon, Department of Agricultural Botany, Plant
e. Kik, Department of Plant Ecology, University of Gro Science Laboratories, University of Reading, White
ningen, Biological Centre, P.O. Box 14, 9750 AA Haren knights, Reading RG6 2AS, UK
(Gn), The Netherlands
D.C.P. Thalen, Research Institute for Nature Management,
P.O. Box 46,3956 ZR Leersum, The Netherlands
