Plant Pheno-morphological Studies in Mediterranean Type Ecosystems

400 Pages·1988·24.317 MB·English

by  Gideon Orshan (auth.), Gideon Orshan (eds.)

Plant Pheno-morphological Studies in Mediterranean Type Ecosystems
Geobotany 12
Series Editor
M.J.A. WERGER
Plant Pheno-morphological Studies
in Mediterranean Type Ecosystems
edited by
GIDEON ORSHAN
Kluwer Academic Publishers
Dordrecht I Boston I London
Library of Congress Cataloging in Publication Data
Plant pheno-morphologlcal studies In Mediterranean type ecosystems /
edited by Gideon Drshan.
p. em. -- (Geobotany ; 12)
1. Botany--Medlterranean Reglon--Ecology. 2. Plant
phenornorphology--Medlterranean Region. 3. Mediterranean climate.
4. Growth (Plants)--Medlterranean Region. 5. Plant phenomorphology.
6. Plants--Development. 7. Growth (Plants) I. Orshan, Gideon.
II. Title, Plant phenomorphologlcal studies In Mediterranean type
ecosystems. III. Title, Mediterranean type ecosyste.s. IV. Serles.
QK314.5.P53 1988
574.5"264'091822--dc19
ISBN-13: 978-90-6193-656-5 e-ISBN-13: 978-94-010-7897-9
DOl: 10.1007/978-94-010-7897-9
Published by Kluwer Academic Publishers,
P.O. Box 17, 3300 AA Dordrecht, The Netherlands.
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All Rights Reserved
© 1989 by Kluwer Academic Publishers
Softcover reprint of the hardcover 1s t edition 1989
No part of the material protected by this copyright notice may be reproduced
or utilized in any form or by any means, electronic or mechanical
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Table of Contents
List of contributors vii
1. Introduction
byG.Orshan 1
2. Description of plant annual cycles 7
2.1. France
by CR. Floret, M.J. Galan, E. Le Floc'h, F. Leprince and F. Romane
2.1.1. Location and description of sites 9
2.1.2. Annual cycles of single species 17
2.1.3. Seasonality of phenophases 94
2.1.4. Duration of phenophases 95
2.1.5. Life duration of assimilating organs 96
2.1.6. Vegetative growth and flowering as related to climate 97
2.2. Israel
by G. Orshan
2.2.1. Location and description of sites 99
2.2.2. Annual cycle of single species 105
2.2.3. Seasonality of phenophases 155
2.2.4. Duration of phenophases 156
2.2.5. Life duration of assimilating organs 157
2.2.6. Vegetative growth and flowering as related to climate 157
2.3. South Africa
by A. Le Roux, P. Perry and X. Kyriacou
2.3.1. Location and description of sites 159
2.3.2. Annual cycle of single species 163
2.3.3. Seasonality of phenophases 342
2.3.4. Duration of phenophases 345
2.3.5. Life duration of assimilating organs 345
2.3.6. Vegetative growth and flowering as related to climate 345
2.4. Chile
by G. Montenegro, G. Avila, M.E. Aljaro, R. Osorio and M. Gomez
2.4.1. Location and description of sites 347
2.4.2. Annual cycle of single species 355
2.4.3. Seasonality of phenophases 384
2.4.4. Duration of phenophases 386
2.4.5. Life duration of assimilating organs 387
2.4.6. Vegetative growth and flowering as related to climate 387
3. General synthesis
by G. Orshan, Ch. Floret, E. Le Floc'h, A. Le Roux, G. Montenegro and F. Romane
3.1. Comparison between sites and continents 389
3.2. Phenomorphology as related to growth forms 394
3.3. Phenomorphological types 396
3.4. Phenomorphological types as related to summer drought 398
4. References 401
VI
List of Contributors
Aljaro, Maria Ester: Botanical Laboratory, Catholic University of Chile, Santiago, Chile
Avila, Guacaldo: Botanical Laboratory, Catholic University of Chile, Santiago, Chile
Floret, Christian: C.E.P.E. Louis Emberger, CNRS, B.P. 5051, 34033 Montpellier Cedex, France
Galan, Marie-Jose: C.E.P.E. Louis Emberger, CNRS, B.P. 5051,34033 Montpellier Cedex, France
Gomez, Miguel: Botanical Laboratory, Catholic University of Chile, Santiago, Chile
Kyriacou, Xenia Sophia: Department of Botany, Cape-Town University, Cape-Town, South Africa
Le Floc'h, Edouard: C.E.P.E. Louis Emberger. CNRS, B.P. 5051, 34033 Montpellier Cedex, France
Leprince, Frederic: Quartier du Termes, Charleval13640, Le Roque D'Antheron, France
Le Roux, Annelise: Jonkershoek Nature Conservation, Stellenbosch, 7600, South Africa
Montenegro, Gloria: Botanical Laboratory, Catholic University of Chile, Santiago, Chile
Orshan, Gideon: Department of Botany, The Hebrew University, Jerusalem, Israel
Osorio, Rodemiro: La Serena University, Chile
Perry, Pauline Lesley: Campton Herbarium, Kirstenbosch Gardens, P.O.B. X7, Clermont 7725, South
Africa
Romane, Fran«ois: C.E.P.E. Louis Emberger, CNRS, B.P. 5051,34033 Montpellier Cedex, France
GIDEON ORSHAN
1. Introduction
Phenomorphology of flowering plants deals with starts growing, how long it grows and what happens
the study of temporal changes in the morphology of to it when it stops growing. Is it being dispersed like
plants and plant organs during their whole life diaspores, does it die eventually like leaves, or does
span. It is in fact the study of the visible life history it remain alive as part of the plant body during the
of each of the vegetative and generative organs of whole lifespan of the plant or during part of it, and
the plant. Consequently it combines the use of finally what is its life duration. Generally only the
phenology, which deals with the seasonality of phe life history of leaves, stems, flowers and fruits was
nophases (Linnaeus 1751), and of morphology, followed. The following phenophases are de
since the morphological changes of the plant as a scribed: vegetative growth, flower bud formation,
whole and of its individual organs within and be fruiting, dispersal of diaspores, and leaf shedding.
tween the phenophases are described. It is hoped that such a study of plant growth and
Man's interest in plant life goes back to prehis development will lead to a better understanding of
toric times. Apart from being a significant compo the growth and development processes of the plant
nent of his environment, plants provide an impor on the one hand, and of plant - environment rela
tant part of his diet, are used as fuel and supply part tionships on the other.
of the materials used for the production of his Seasonal changes in plant growth are decisive in
clothes and shelter. The interest of early man in the determining the plant's adaptation to a seasonally
life cycle of plants markedly increased with the changing environment. Their importance increases
development of early agriculture. The knowledge with the increase of the seasonal variation and the
of the timing of germination, flowering and fruiting intensity of the seasonal stress periods. Since re
became important for reasonably treating his culti duction of the plant body is frequently associated
vars and therefore decisive in determining the suc with seasonal di- or polymorphism of leaves and
cess or failure of his crops. branches, the size and structure of plant organs
In modern times when conservation of man's which develop in different seasons are important
environment tends to become essential for the sur variables in many cases in adaptation of plants to
vival of the human race, a thorough knowledge of the environmental complex when during stress pe
plant life cycle is important, because it helps to riods some factors are limiting.
determine the seasons when the plant is more sus The study of seasonal changes of plant growth is
ceptible or more resistant to the damage caused by especially important in mediterranean type ecosys
man. tems because the mediterranean type climate is
The aim of the present study is to better recog characterised by a dry summer season with some
nise the seasonal cycle of the plants examined and times severe water stress. Vegetative growth oc
to find out where and when each part of the plant curs in most cases when the environmental condi
e.g. leaf, branch, inflorescence, originates and tions are more favourable while leaf and stem shed-
G. Orshan (ed.), Plant Pheno-morphological Studies in Mediterranean Type Ecosystems, pp. 1-4. 1
© 1989 by K1uwer Academic Publishers, Dordrecht
ding, related in many cases to a reduction in the ises mediterranean type ecosystems in different
assimilating parts of the plant body, take place parts of the world is due to convergent evolution
generally during the stress periods (Orshan 1964). which took place under similar environmental con
Plant phenomorphology is closely related to ditions (Di Castri & Mooney 1973, Cody & Moo
growth forms. Seasonality of vegetative growth, of ney 1978). However, so far it is not known whether
flowering and of leaf-and branchshedding, as well the same environmental factors to which the scle
as life duration of these organs are major growth rophyllous mediterranean plants seem to be adapt
form attributes (Du Rietz 1931, Lacza & Fekete ed are also the morphogenetic and phenogenetic
1969, 1972; Fekete & Lacza 1970, 1971; Ellenberg factors causing their particular growth forms (Or
& Mueller-Dombois 1967; Mueller-Dombois & El shan 1938, Berliner & Orshan 1971).
lenberg 1974; Orshan 1953, 1982, 1983, 1986). It was hoped that comparative studies of the
Therefore knowledge of the phenomorphology of phenomorphology of important components of the
the plants investigated is an essential pre-requisite mediterranean type vegetation in different conti
for critical studies of growth forms. In fact the nents with different floristic origins will call atten
present study was undertaken because it turned out tion to the lines through which convergent evolu
that relatively very little is known about the phe tion took place. Consequently the work was car
nomorphology of species dominating the winter ried out in mediterranean type ecosystems in
rainfall plant communities of Chile, South Africa Southern France, Israel, the Cape Province of
and Israel, when it was attempted to analyse them South Africa and Central Chile. Apart from France
for their monocharacter growth form types (Or and Israel, which have more or less the same flo
shan et a1. 1984). ristic stock, the floras of the other regions are hard
Relatively numerous investigations involving the ly related to each other. Hence a comparison of
study of phenology of plants have been carried out plant phenomorphology in the different continents
during the last century (Lieth 1974, Kummerow will hopefully enable us to discover whether con
1983). Investigations related to phenomorphology vergent evolution was achieved through the same
are markedly less numerous. One should mention strategies for adaptation of plants to the mediterra
those of Orshan (1964), Margaris (1975, 1977, nean type environments.
1981) and especially the work carried out within the
parallel studies of mediterranean type ecosystems
in California and Chile (e.g. Mooney 1977, Monte Method
negro et a1. 1981, Mooneyet a1. 1974, Thrower &
Bradbury 1977). The sites where the phenomorphology of the plants
It is well known that the physiognomy of vegeta has been studied were visited regularly at time
tion and the seasonal changes in the morphology intervals of 3-5 weeks. In exceptional cases, be
and structure of its components are different in cause of technical difficulties, the time intervals
different climates. Broad leaved winter deciduous were extended to 8 weeks. During the visits to the
trees characterise temperate regions with rainfall sites the plants examined were described in detail
distributed throughout the year. Evergreen, scle in the field with the aid of a portable tape recorder.
rophyllous plants characterise the Mediterranean Attention was paid to the different types of
region, stem-succulents - the hot deserts of North branches, different types ofleaves, inflorescences,
and South America, and small shrubs which are flowers and fruits, recording their developmental
absolute or partial summer shedders - the more stages. No attempt was made to measure length or
arid habitats mainly in the Eastern hemisphere width of parts of plants nor even to mark such parts
(Schimper 1903, Walter 1964). except in special cases. The purpose was to first
It had been suggested that the similarity in struc obtain a qualitative knowledge of the seasonal de
ture, seasonal changes and function of the ever velopment and of the plant parts' turnover during
green sclerophyllous vegetation which character- the year. In certain cases an attempt was made,
2
however, to obtain average dimensions of plant March, April and May - spring; June, July and
parts - length of developing branches, or length August - summer; September, October and No
and width of leaves. It was found that the main vember - autumn, and December, January and
growing season could easily be determined with the February - winter.
aid of such examinations. For the Southern Hemisphere the same months
Emphasis was put on collecting herbarium speci are: autumn, winter, spring and summer respec
mens representing typical parts of the plants ob tively.
served. These were found to be invaluable since it The following terminology was used in the de
happens that the beginning of a growth phase or of scription of organs and phenophases:
a shedding one is not noticed while describing the
plant in the field, and therefore omitted from the a. Plant organs
description. Such phenomena could easily be de
tected in the dried specimens. The dried specimens The following terminology was used when describ
were kept as phenological herbaria for each of the ing the organs of flowering plants.
sites examined. Flower - Single flower as distinct from flower head
By these procedures the phenophases were de and inflorescence.
termined to an accuracy of 4 weeks, which was Flower head - Groups of flowers packed tightly
considered to be satisfactory for obtaining the gen together. This term is wider than the capitulum
eral seasonal cycle of the species examined. It is of the Compositae and includes flower heads like
evident that for more detailed phenomorpholog those of Berzelia lanuginosa.
ical studies, e.g. along environmental gradients, Inflorescence - A branching system bearing flow
much shorter time intervals should be used. ers or flower heads. It contains mainly bracts but
The plant was examined at all the sites during at sometimes also a limited number of ordinary
least one year; at some sites it lasted somewhat leaves.
longer. In the latter case it became evident for a Synflorescence - A branching system containing
considerable number of the species that one year is inflorescences arranged in a fixed pattern and
not exactly similar to the other and sometimes, e.g. bearing a considerable number of leaves.
at the Hester Malan Nature Reserve, considerable Brachyblast - A short branch. Orshan (1964) dis
differences were found. At the latter site it was tinguished between absolute brachyblasts, the
evident for some plants that the onset of growth length of which does not exceed a few milli
was triggered by the first effective rains. It seems metres, and partial brachyblasts which may
that these plants are plastic in their capability to reach a length of a few centimetres. It is pro
grow and complete their growth cycle according to posed here to limit their length to 3 em at most.
the distribution of rainfall. It follows therefore, Each of the brachyblast types can be either per
that the study of seasonal growth and development manent, i.e. its length is fixed throughout its life
should be carried out during as many years as pos span, or temporary, i.e. elongating eventually to
sible. form a long branch.
Monthly as well as seasonal distribution of vege Dolichoblast - A long branch, the elongation of
tative growth and flowering was calculated in per which is not arrested.
centages of the relevant number of species exam Mesoblast - A branch with its elongation arrested
ined per site. For the monthly distribution of as compared with that of the dolichoblast. In
growth or flowering each species was counted for many cases it bears flower- or inflorescence
each month in which it was actually growing or bearing brachyblasts. Most of the mesoblasts are
flowering. For the seasonal distribution, on the permanent and die after a few years. Relatively
other hand, it was counted only once for the season few are temporary and elongate to eventually
or seasons-combination during which it was active. form dolichoblasts.
The seasons were defined as follows for the Leaf - A leaf in the morphological sense whether
Northern Hemisphere. simple, trifoliate or compound.
3