Table Of ContentEcological Studies, Vol. 137
Analysis and Synthesis
Edited by
M. M. Caldwell, Logan, USA
G. Heldmaier, Marburg, Germany
O. L. Lange, Wurzburg, Germany
H. A. Mooney, Stanford, USA
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Ecological Studies
Volumes published since 1992 are listed at the end ofthis book.
Springer-V erlag Berlin Heidelberg GmbH
F. Roda J. Retana C. A. Gracia J. Bellot (Eds.)
Ecology of Mediterranean
Evergreen Oak Forests
With 84 Figures and 60 Tables
Springer
Ferran Roda
Javier Retana
Carlos A. Gracia
Center for Ecological Research and Forestry Applications (CREAF)
Autonomous University of Barcelona
08193 Barcelona
Spain
Juan Bellot
Department of Ecology
Faculty of Sciences
University of Alicante
PO Box 99
03080 Alicante
Spain
ISSN 0070-8356
ISBN 978-3-642-63668-4
Library of Congress Cataloging-in-Publication Data
EcologyofMediterranean evergreen oak forests / F. Roda ... [et al.), (eds.) p. cm. (Ecological studies /
Analysis and synthesis, 0070-8356; voI. 137) Includes bibliographical references and index.
ISBN 978-3-642-63668-4 ISBN 978-3-642-58618-7 (eBook)
DOI 10.1007/978-3-642-58618-7
1. Forest ecology - Mediterranean Region. 2. Holm oak - Ecol-
ogy - Mediterranean Region. 3. Forst ecology - Spain - Catalonia. 4. Holm oak - Ecology - Spain -
Catalonia. 5. Plant ecophysiology - Mediterranean Region. 6. Biogeochemistry - Mediterranean Re
gion. 7. Plant ecophysiology - Spain - Catalonia. 8. Biogeochemistry - Spain - Catalonia. 1. Roda, F.
(Ferran), 1953 - II. Series: Ecological studies; v. 137.
Q314.5.E36 1999; 577.3'09182'2-dc21; 98-44830
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Preface
Broadleaved evergreen forests where holm oak (Quercus ilex 1.) is almost
the only canopy tree are a distinctive ecosystem of the Mediterranean Basin.
Biogeographically, these forests lie between cool-temperate deciduous forests
to the north and drier shrublands to the south. In a more general view, they
are ecologically intermediate between these deciduous forests and humid
warm-temperate evergreen forests, such as the laurisilva of the Macarone
sian islands or the broadleaved evergreen forests of eastern Asia. Holm oak
forests are characterized by small-stature trees (usually 5 to 12 m tall), which
are slow growing, cast a deep shade, and have small, evergreen, sclerophyl
lous leaves. Summer drought is the major environmental constraint.
Mediterranean broadleaved evergreen forests have been underrepre
sented in the open literature. For example, The Woodlands Data Set of the
International Biological Program (IBP) contained data from just one holm
oak forest plot, Le Rouquet in southern France (Reichle 1981). Also, some
models of European forests consider just two major forest types, broad
leaved deciduous and evergreen conifers, forgeting the extensive forests and
woodlands of holm oak and cork oak (Quercus suber 1.), which are the ma
jor evergreen oak tree species in the Mediterranean Basin. The extensive lit
erature on Mediterranean-type ecosystems has also largely neglected these
forests, being centred mostly on Mediterranean-type shrublands.
To bridge this gap in knowledge, a research programme on the ecology of
holm oak forests was started in 1978 under the direction of Ramon Margalef,
Jaume Terradas, and Antoni Escarn~. This programme brought together re
searchers from three Spanish universities: the University of Barcelona, the
Autonomous University of Barcelona, and the University of Alicante.
The programme was originally intended to obtain a functional under
standing of holm oak forests, combining three approaches: catchment budg
ets, plot-level analyses of the distribution and cycling of matter, and eco
physiological studies. Its inception was inspired by the IBP plot studies, par
ticularly those conducted by Maurice Rapp in Montpellier (France) and by
P. Duvigneaud and Simone Denaeyer-De Smet in Belgium, and by the
catchment ecosystem studies pioneered by F. Herbert Bormann and Gene E.
Likens at Hubbard Brook (USA). The programme later evolved to include
also demographic approaches to forest dynamics.
In the 1970s, closed-canopy holm oak forests were still considered the
paradigm of the natural, undisturbed ("climacic") vegetation in those parts
VI Preface
of the Mediterranean Basin receiving enough rainfall. Later findings pointed
out that the prevalence of holm oak was closely related to it being favoured
by humans from about 5000 years B.P. This raises the question of what would
be the contribution of deciduous oaks and pines to the natural landscape. To
some extent, our own programme reflected such changing views. We started
selecting plots and catchments that appeared as homogeneous and undis
turbed as possible. Very soon it became obvious that these holm oak forests
bore the imprint of past cultivation or coppicing and that their present
structure, often characterized by high-density stands of stool resprouts, was
bound to change as a result of abandonment or shifts in forest management.
In later studies we therefore placed more emphasis on the effects of distur
bance and forestry practices, and on the relationships between holm oak and
pines in mixed forests.
The present book brings together and summarizes what we have learnt
about the ecology of Mediterranean evergreen forests dominated by holm
oak in Catalonia, northeast Spain. Some results have been published before,
either in international publications of scattered disciplines, or in sources or
languages little available to foreign audiences. Nonetheless, most chapters of
this book present new material, and attempt a new synthesis of the involved
topics. Also, data have been often updated through increased temporal and
spatial coverage.
Chapter 1 introduces holm oak and holm oak forests, particularly for
those readers that are unfamiliar with Mediterranean forests. Chapter 2 de
scribes our two major experimental areas (Montseny and Prades) where
most of the results of this book were obtained. Chapters 3 and 4 describe the
range of stand structures found in holm oak forests and analyze the patterns
of above- and belowground biomass and production of our experimental
sites. Chapters 5 to 7 deal with the ecology of resprouts, seeds, and seedlings
of holm oak. Chapter 8 integrates the information on the above recruitment
processes and formulates a demographic model of stand dynamics of mixed
holm oak-Aleppo pine forests. Chapters 9 to 11 take an ecophysiological
view to light and water use by holm oak leaves and canopies. Chapter 12 in
tegrates the above knowledge into a water-driven model of ecosystem func
tioning. Chapters 13 to 18 focus on the distribution and cycling of matter at
the stand level. Chapters 19 to 21 summarize water and element budgets at
the catchment scale, and attempt to model the ecosystem functioning. The
effects of fire and of experimental forestry practices are treated in Chapters
22 and 23. Finally, Chapters 24 and 25 outline the ecology of two major ani
mal groups in the holm oak forest: soil arthropods and birds.
This book was made possible through the efforts of many people and in
stitutions. We would like to express our gratitude to those investigators who
were deeply involved in the first research phase, particularly: LIuis Fem~s
who studied the biomass, primary production, and plant nutrient contents in
the permanent plot at Montseny; Claret Verdu who studied litterfall and lit
ter decay at the same site and other forest types; and Luis Lopez-Soria who
Preface VII
in 1978 devised the first application of dimensional analysis for our studies.
We are also grateful to F.H. Bormann, George Hornberger, and Keith Beven
for their early advice on catchment studies, to Carles Gene for his collabora
tion in fieldwork and data analysis, and to Alicia Bernabe for her contribu
tion in data analysis.
We are grateful to the former Institute of Nature Conservation (lCONA) of
the Spanish Ministry of Agriculture, and to the Department of Agriculture,
Livestock and Fisheries of the Catalan government, who throughout these
years have made possible the continued use of the experimental areas at
Montseny and Prades for research. Our work was funded by the US-Spanish
Joint Committee for Science and Technology, the European Commission
DGXII, the Spanish Ministry of Education through the former CAICYT and
then the CICYT, the Spanish Ministry of Agriculture through the INIA and
the former ICONA, the Catalan government through the CIRIT and IRTA,
and the government of the Valencian Autonomous Community through the
Center of Environmental Mediterranean Studies (CEAM).
December 1998 F. Roda
J. Retana
C.A. Gracia
J. Bellot
References
Reichle DE (ed) (1981) Dynamic properties of forest ecosystems. Cambridge University Press,
Cambridge
Contents
Part 1 Introduction................................................................................ ... ..... 1
1 1 Holm Oak and Holm Oak Forests: An Introduction
J. Terradas................................................................................................. 3
1.1 Biogeography of Holm Oak ................................................................... 4
1.2 History of Holm Oak Forests ................................................................. 5
1.3 Species Composition Patterns in Holm Oak Forests ........................... 5
1.4 Biology of Holm Oak .............................................................................. 6
1.5 Responses of Holm Oak to Environmental Conditions ...................... 9
1.6 Management ............................................................................................ 11
References .................................................................................... ....................... 13
2 Experimental Areas of Prades and Montseny
A. Hereter and J.R. Sanchez .................................................................. :. . 15
2.1 The Montseny and Prades Mountains ................................................... 15
2.2 Experimental Areas at Montseny ........................................................... 16
2.2.1 Experimental Layout ............................................................................... 16
2.2.2 Climate ..................................................................................................... 19
2.2.3 Lithology and Relief ................................................................................ 19
2.2.4 Soils ........................................................................................................... 20
2.2.5 Vegetation ................................................................................................ 20
2.3 Experimental Area at Prades .................................................................. 23
2.3.1 Experimental Layout ............................................................................... 23
2.3.2 Climate ..................................................................................................... 23
2.3.3 Lithology and Relief ................................................................................ 23
2.3.4 Soils ........................................................................................................... 26
2.3.5 Vegetation ................................................................................................ 26
References ........................................................................................................... 27
x
Contents
Part 2 Stand Structure and Dynamics ................................................... 29
3 Stand Structure, Aboveground Biomass and Production
J.J. Ibanez, M.J. Lledo, J.R. Sanchez, and F. Roda ................................... 31
3.1 Introduction ............................................................................................. 31
3.2 The Database ........................................................................................... 32
3.3 Stand Structure ....................................................................................... 34
3.4 Aboveground Biomass ............................................................................ 35
3.5 Stand Dynamics ...................................................................................... 37
3.5.1 Demographic Changes ........................................................................... 37
3.5.2 Tree Growth ............................................................................................. 37
3.6 Aboveground Production ....................................................................... 39
3.7 Structure, Biomass and Production
in Mediterranean Holm Oak Forests ..................................................... 41
References ..................... ,..................................................................................... 43
4 Structure and Dynamics of the Root System
J. Canadell, A. Djema, B. Lopez, F. Lloret, S. Sabate, D. Siscart,
and C.A. Gracia........................................................................................ 47
4.1 Introduction. ............................................................................................ 47
4.2 The Database ........................................................................................... 48
4.3 Structure of the Root System ................................................................. 49
4.4 Lignotubers .............................................................................................. 51
4.5 Allometric Relationships Between Above-
and Belowground Biomass ..................................................................... 52
4.6 Root Biomass ........................................................................................... 53
4.7 Fine Roots ................................................................................................ 54
References ........................................................................................................... 56
5 Resprouting Dynamics
J.M. Espelta, S. Sabate, and J. Retana ...................................................... 61
5.1 Introduction ............................................................................................. 61
5.2 Resprouting Response of Holm Oak after Disturbance ...................... 62
5.3 Main Sprout Features .............................................................................. 64
5.4 Sprout Dynamics in the Stool................................................................ 66
5.5 Consequences of Resprouting Dynamics at the Stand Level .............. 70
References ........................................................................................................... 71
Contents XI
6 Acorn Ecology
D. Siscart, V. Diego, and F. Lloret.......................................................... 75
6.1 Introduction........................................................................................... 75
6.2 Acorn Production.................................................................................. 76
6.2.1 Reproductive Biology of Holm Oak .................................................... 76
6.2.2 Pattern of Acorn Production................................................................ 77
6.3 Acorn Production.................................................................................. 81
6.3.1 Pre-dispersal Predation ........................................................................ 81
6.3.2 Post-dispersal Predation....................................................................... 83
6.4 Abiotic and Biotic Interactions ............................................................ 85
References ........................................................................................................ . 86
7 Seedling Recruitment
J. Retana, J.M. Espeita, M. Gracia, and M. Riba ................................... 89
7.1 Introduction................................................................................. .......... 89
7.2 Variability of Holm Oak Recruitment According
to Environmental Conditions .............................................................. 90
7.3 Responses of Holm Oak Seedlings to Different Light
and Water Levels.................................................................................... 91
7.4 Effects of Disturbance on Seedling Density and Dynamics ............. 95
7.5 The Sapling Stage: Is There a Lack of Recruitment
in Holm Oak Forests under Present Management? ............................ 98
References ......................................................................................................... 101
8 A Model of Stand Dynamics For Holm Oak-Aleppo Pine Forests
M.A. Zavala ............................................................................................ 105
8.1 Introduction. .......................................................................................... 105
8.2 Background ............................................................................................ 106
8.2.1 Models of Forest Dynamics .................................................................. 106
8.2.2 The Case of Mediterranean Forests..................................................... 107
8.3 Top-Down Models of Stand Composition
in Mixed Holm Oak-Aleppo Pine Forests .......................................... 108
8.4 Mechanistic Models of Stand Dynamics
in Mixed Holm Oak-Aleppo Pine Forests .......................................... III
8.5 Conclusions: Theoretical and Practical Implications ........................ 114
References ......................................................................................................... 115
