ITALIAN HABITATS. The Mediterranean maquis

Transcription

1 ITALIAN HABITATS The Mediterranean maquis 6

2 Italian habitats Italian Ministry of the Environment and Territory Protection / Ministero dell Ambiente e della Tutela del Territorio Friuli Museum of Natural History / Museo Friulano di Storia Naturale Comune di Udine ITALIAN HABITATS Scientific coordinators Alessandro Minelli Sandro Ruffo Fabio Stoch Editorial commitee Aldo Cosentino Alessandro La Posta Carlo Morandini Giuseppe Muscio "The Mediterranean maquis Evergreen coastal formations" edited by Alessandro Minelli Texts Giuseppe Carpaneto Gaudenzio Paola Simonetta Peccenini Margherita Solari In collaboration with Luca Lapini Mirca Zocchi English translation Gabriel Walton Illustrations Roberto Zanella Graphic design Furio Colman The Mediterranean Maquis Evergreen coastal formations Photographs Archive INFS (Valter Trocchi) 139 Archive MFSN (Ettore Tomasi) 36/2, 37, 39, 48/2, 50, 60 Mauro Arzillo 128, 129 Paolo Audisio 8 Pietro Baccino 12, 15, 20/1, 22, 24, 32, 35/1, 36/1, 38/1, 38/2, 41/1, 41/2, 42, 44/1, 44/2, 47/2, 51, 64/1, 64/2, 64/3, 69, 78, 132/1, 132/2, 133, 150, 151 Enrico Benussi 116/1 Eugenio Busetto 18/1, 26, 34 Giuseppe Carpaneto 11, 33/2, 35/2, 44/3, 47/1, 70, 71, 80, 87, 88/1, 88/2, 89/1, 102, 107, 109, 110/1, 110/2, 111, 112/1, 112/2 Ulderica Da Pozzo 67, 134 Vitantonio Dall Orto 74 Dario Ersetti 19/3, 33/1 Maurizio Fabbri 93, 95/1 Luca Facchinelli 10 Gabriele Fiumi 90/1, 90/2, 90/3, 94, 95/3, 96, 97, 98 Giovanni Gobbi 84, 89/2, 99, 101, 104, 114/1, 126 Gianluca Governatori 18/2, 18/4, 19/2, 82, 148 Luca Lapini 81, 110/3, 122, 140 Daniele Macale 95/2, 103 Paolo Maltzeff 90/4 Maurizio Rizzotto 77 Ugo Mellone 18/3, 83, 130 Giuseppe Muscio 28 Michele Panuccio 86, 108, 120 Gaudenzio Paola 25, 43, 48/1, 54, 56, 62, 142, 144 Roberto Parodi 40, 113, 114/2, 115/1, 115/2, 116/2, 116/3, 117, 118, 119, 135 Silvia Sebasti 123, 137, 138 Paola Sergo 19/1 Pino Sfregola 20/2 Margherita Solari 147 Mido Traverso 52/1, 52/2, 53/1, 53/2 Roberto Zucchini Museo Friulano di Storia Naturale, Udine, Italy 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, without the prior permission in writing of the publishers. ISBN Cover photo: low maquis with thyme and ever-lasting flowers (photo by Margherita Solari) MINISTERO DELL AMBIENTE E DELLA TUTELA DEL TERRITORIO MUSEO FRIULANO DI STORIA NATURALE COMUNE DI UDINE

3 Of the various environmental aspects which may be found in Italian territory, many are familiar to the traveller's eye, and are commonly accepted as an expression of naturalness. They are in fact the result of centuries-long interactions with man, who favoured the development of secondary formations, variegated and quite often enriched in several types of flora and fauna. These interactions - the history and above all the initial conditions of which are not always easy to reconstruct - have certainly not spared the Mediterranean maquis, which originally grew along most of the coastline of the Italian peninsula and its islands and, in the southernmost regions, extended to the hills inland. Attentive naturalists will be able to recognize, in the diversity of maquis formations, those few but precious and beautiful remnants which are still in a more or less well-preserved state of naturalness. This volume of the "Italian Habitats" series covers a detailed itinerary through all the various types of primary and secondary maquis, reconstructing its ancient dynamics and presenting its most significant aspects from the botanical and zoological viewpoints. When attempting to document the historical processes undergone by the animal and plant populations of the maquis environment - so characteristic in a country like Italy, so essentially part of the Mediterranean world and its life-style - the role played by Natural History museums is fundamental, since these institutions preserve and house irreplaceable information on all types of fauna and flora and their distribution on the territory. With this series of "Italian Habitats", therefore, the Friuli Museum of Natural History is proud to contribute to the further knowledge of these important and indeed unique parts of the environmental mosaic of Italy. Carlo Morandini Director, Friuli Museum of Natural History

4 Italian habitats Contents Introduction Giuseppe Carpaneto Gaudenzio Paola Simonetta Peccenini Vegetation Gaudenzio Paola Simonetta Peccenini 1 Caves and karstic phenomena 2 Springs and spring watercourses 3 Woodlands of the Po Plain 4 Sand dunes and beaches 5 Mountain streams Fauna Giuseppe Carpaneto Preservation and management Giuseppe Carpaneto Gaudenzio Paola Simonetta Peccenini Suggestions for teaching Margherita Solari 6 The Mediterranean maquis 7 Sea cliffs and rocky coastlines 8 Brackish coastal lakes 9 Mountain peat-bogs 10 Realms of snow and ice Select bibliography Glossary List of species Pools, ponds and marshland 12 Arid meadows 13 Rocky slopes and screes 14 High-altitude lakes 15 Beech forests of the Appennines

5 Introduction GIUSEPPE CARPANETO GAUDENZIO PAOLA SIMONETTA PECCENINI 9 He took to the hills. How many times have we seen these words in the adventure stories we read in our youth! Robbers, thieves and bandits, in all societies, always took to the hills to avoid the legal consequences of their illegal actions, and were often able to hide for long periods of time. In the Mediterranean context, taking to the hills means plunging into the maquis, that sea of green, which closes above our heads and hides us completely from the external world. Particularly during the foreign colonization of Southern Italy and in the confused years following the unification of Italy, brigands and bandits took refuge here and, during the Second World War, so did partisans and members of the resistance. But what exactly is the maquis? In the general acceptance of this French word, which cannot really be translated into English, the maquis is a vegetal formation with prevailing large shrubs or small to medium-sized trees, often spaced so far apart that light can penetrate well. This allows the development of a thick, intricate undergrowth formed of shrubs and creepers. These formations are found where the original broad-leaved forest has been felled, and they generally evolve in order to reconstitute that forest by means of a long process of self-restoration, called succession. The maquis, in its widest sense, may be composed of deciduous broad-leaved trees which tend towards the reconstruction of the original deciduous oak forest, or evergreen shrubs which tend to recompose the Mediterranean forest, dominated by evergreens like holm oak and cork oak. In a strict sense, the word maquis is mainly applied to its Mediterranean version - that formation resulting from the destruction of the evergreen forest (mainly holm oak, as regards Italy), which grows prevalently along the coastline. As regards its extent, evergreen maquis is currently the main vegetal formation in coastal and subcoastal areas of the Mediterranean, and it thus covers much of the Italian peninsula and its islands. In addition, from the coast, the maquis often penetrates inland, developing on the warmest, often southfacing flanks of the anti-appennine and pre-appennine hills. Even in the heart of the Appennines and in some Prealpine districts, so-called xerothermic areas may be found, where favourable local climatic conditions allow the Maquis with rockrose and oleander along littoral of Focene (Latium). Oleander (Nerium oleander) is a common riverbank species in southern Europe; elsewhere, it is planted by man

6 10 conservation of biocenoses associated with hot, arid climates. These biocenoses are relicts from interglacial periods, during which mountain vegetation was forced to retreat due to climatic warming, thus allowing the advance of biological communities generally found near the coast. This is why, as well as evergreen plants, xerothermic areas may host a fauna usually associated with coasts and with limited capacities for dispersion, like some gastropod molluscs and wingless insects. The development of the Mediterranean maquis is a very ancient process, which began in prehistorical times and which reflects the growing impact of human activities on the environment. At least in Italian territory, evergreen maquis is the result of man s direct or indirect intervention on the environment of coastal belts - burning scrub and woodland, felling trees, and grazing livestock. Initially, tens of thousands of years ago, during the hunter-gatherer phase of human development, fires were set in vegetation to frighten wild animals and drive them towards points at which they could be ambushed and trapped. Later, during agricultural and livestock farming phases, the purpose of setting fire to the surrounding vegetation was to create space for settlements and agricultural exploitation, or to stimulate the growth of forage for livestock. Thus, with the passing of centuries, the evergreen Mediterranean maquis became the prevailing landscape of the Italian coastline. 11 Mediterranean maquis with Euphorbia dendroides on island of Caprara (Tremiti, Apulia) Pines in Mediterranean maquis along Tuscany coast

7 Vegetation GAUDENZIO PAOLA SIMONETTA PECCENINI 13 Introduction What is the Mediterranean maquis, exactly? Seen from a distance, the maquis is a sea of changing tones of green, covering hilly slopes near the sea, glowing in spring with the yellow flowers of broom, the white or pink of rockrose, and the blue of rosemary (Rosmarinus officinalis) and germander (Teucrium fruticans). Only if we approach closely can we see the dense intertwinings of the bushes which compose it: holm oak (Quercus ilex), strawberry tree (Arbutus unedo), buckthorn (Rhamnus alaternus), broad-leaved phillyrea (Phillyrea latifolia), laurustine (Viburnum tinus), a representative of the honeysuckle family with pretty corymbs of white flowers and fruit of a beautiful metallic blue, tree heath (Erica arborea) and other types of heath (e.g., Erica scoparia), prickly juniper (Juniperus oxycedrus) and cork oak (Quercus suber), with its characteristic thick bark which protects it from bad weather and from fire. The maquis sometimes contains a series of lower shrubs like butcher s broom (Ruscus aculeatus) with evergreen leaves broadened to form cladodes holding small star-shaped flowers and then its typical red berries; ivy (Hedera helix), or plaited lianas like asparagus (Asparagus acutifolius), madderwort (Rubia peregrina), ruby-coloured with evergreen leaves, verticillate, with small hooked hairs on the edges; Mediterranean honeysuckle (Lonicera implexa), with highly perfumed flowers and connate leaves, i.e., welded together at the base round the stem; sarsaparilla (Smilax aspera) and rose (Rosa sempervirens). The last two make the maquis almost impenetrable with their thorns - as clearly suggested by the common Italian name for Smilax: strappabraghe ( tears your trousers )! In cooler locations, we find laurel (Laurus nobilis), flowering ash (Fraxinus ornus) with pennate deciduous leaves and highly scented white blossom, terebinth (Pistacia terebinthus), and in warmer spots many-flowered heath (Erica multiflora), tree euphorbia (Euphorbia dendroides), Phoenician juniper (Juniperus phoenicea), with scale-shaped leaves, another form of juniper (Juniperus oxycedrus spp. macrocarpa) with needle-shaped leaves and large brown berries, colonizing sandy dunes, myrtle (Myrtus communis), wild olive (Olea Holm oak (Quercus ilex) in flower

8 europaea var. sylvestis), progenitor and sometimes used to graft cultivated olives, carob (Ceratonia siliqua), with horny, evergreen leaves, paripennate and with large brown, sugary pods, thorny oak (Quercus coccifera, Q. calliprinos), with evergreen leaves with very thorny edges, narrow-leaved phillyrea (Phillyrea angustifolia), lentisk (Pistacia lentiscus), Jupiter's beard (Anthyllis barbajovis), a legume with silvery foliage and white flowers, and dwarf palm (Chamaerops humilis), the only species of palm growing spontaneously in Italy. Locally, types of common broom may prevail, leguminous with yellow flowers, like spiny broom (Calicotome spinosa, C. villosa, C. infesta), cytisus (Cytisus villosus), hairy cytisus (Chamaecytisus hirsutus), European broom (Cytisus scoparius) and Spanish broom (Spartium junceum). In other places, where fires are frequent, we find abundant pink rockrose and Cretan rockrose (Cistus albidus, C. creticus), sage-leaved rockrose (Cistus salvifolius) and Montpellier rockrose (Cistus monspeliensis). The Mediterranean maquis in the world The Italian macchia and the French maquis are used throughout the world, mainly in the scientific literature, to indicate the shrubby, stiff-leaved, evergreen vegetation so typical of the Mediterranean climate. But there are also many other names: matorral in Spanish-speaking countries (Spain and Chile), chaparral in California, strandveld and renosterveld (according to dominant floristic composition) in South Africa, and mallee in Australia. When increasing summer aridity or heightened pressure of anthropic activities means that the vegetation becomes scanty and low, without the typical features of maquis, it is called gariga in Italy, garrigue in France, phrygana in Greece, batha in Israel, jaral in Cile, and coastal sage in California. Instead, the term fynbos, used in southern Africa, means the Mediterraneantype vegetation growing in those parts: dominated by heath, it is very similar to the moorland of temperate climates, which develops in soils particuarly poor in nutrients Just as the term Alpine derives from the geographic name for the Alps, Mediterranean refers to the basin of the Mediterranean Sea in a geographic sense. However, it is also used to indicate the complex of climatic conditions which occur in this part of the world. This complex may also be observed in some parts of other continents: in the Americas (California, central Chile), southern Africa, and south-western and southern Australia. None of these areas covers an area comparable with that of the Mediterranean basin, but their vegetation is very similar to the Mediterranean version from the structural viewpoint and from that of the morphology of the prevailing plant species. In areas so far removed from each other, floristic diversity is remarkable. The Mediterranean basin is also an area in which several civilizations followed each other in ancient times, and man s relationship with his environment contributed to a marked degree in structuring and consolidating the essential features of the landscape. In spite of its territorial continuity, the Mediterranean region is in fact highly diversified. Generally, we can distinguish its northern and southern parts, as aridity gradually increases from north to south. The western portion is also different from the eastern one, with rainfall which decreases from west to east. But, above all, there are great differences in the history of man s relationship with the territory, which began in the east about 4,000 years before it did in the west. Most of the Mediterranean plants of agricultural interest originated in the Eastern Mediterranean. Myrtle (Myrtus communis)

9 16 Ecology of the Mediterranean maquis 17 The climatic context. Within the framework of the large-scale climatic zones of our planet, the climate of the Mediterranean basin represents the transition between the temperate belt of Europe and the arid tropical belt of North Africa. The Mediterranean climate has autonomous characteristics, which may be briefly described as follows: maximum annual precipitation concentrated in cold periods of the year (autumn, winter); arid conditions during the warmest months (summer); very variable precipitation from one year to the next; hot or very hot summers and cool or cold winters, but without great differences between day-night temperatures or between the various seasons of continental type, i.e., very marked; and, lastly, intense solar radiation, above all in summer. The size of the Mediterranean basin and the complex morphology of the lands which border and sometimes influence it cause local variations in the general climate, usually distinguished into four main types, mainly based on the length of the arid period. Thermometric trends during the course of the year, although kept in consideration, play a secondary role. The Mediterranean climate is thus subdivided into: xero-mediter- Areas of world with prevalent Mediterranean maquis vegetation (red) COLD CURRENTS WARM CURRENTS Distribution of olive in Mediterranean basin. Although a cultivated species, olive does approximately indicate the belt of Mediterranean vegetation

10 18 ranean (or arid), with no rain for 9-10 consecutive months; thermo- Mediterranean (semi-arid), with 7-8 months without rain; meso- Mediterranean (sub-humid), with aridity lasting for 5-6 months, and sub-mediterranean (damp), with only 3-4 consecutive months without rain. The xero-mediterranean type of climate represents the borderline situation with the desert-type climates of the Sahara; the sub- Mediterranean climate, extensive in Italy, connects the temperate climates of northern Italy and, thence, central Europe. Clearly, therefore, only part of Italy can be considered strictly Mediterranean. We can draw an ideal line across the Italian boot running from Liguria (on the Tyrrhenian side) to the Conero promontory in the Marches (Adriatic), and thus divide the country into two climatically different parts: continental Italy, which includes the Alpine arc and the whole of the Po Plain, with a temperate climate; and peninsular Italy, mainly of Mediterranean type. This approximate subdivision must be further refined by bearing in mind Italy s complex morphology. First of all, there is the Appennine chain which, although extending within the Mediterranean area, does not present its typical features. The Appennines generally have a climate tending towards San Fruttuoso Island of Ponza Island of San Pietro Cilento coast Approximate subdivision of Italy into climatic zones Salina Trieste Salento green: temperate-continental; blue: cool sub-mediterranean; light blue: medium sub-mediterranean; yellow: warm sub-mediterranean; red: meso-mediterranean 19

11 20 Holm oak Gaudenzio Paola Holm oak (Quercus ilex) Family: Fagaceae. A medium-sized evergreen tree (sometimes reaching 20 m) or shrub, dense, spherical foliage, short trunk, ascending branches; dark brown bark, divided into small square plaques. Simple alternate leaves, very variable in shape according to their position on the tree and where it grows, hard, oval-elliptical in shape (4-8 x 2-4 cm), shiny above and covered with short hairs below, margin entire or dentate. Small, inconspicuous flowers, acorns 2-3 cm long, partly covered by a cupule with flat, downy scales. The once extensive holm oak groves, coppiced, supplied high-quality firewood and charcoal.the wood is hard and heavy, suitable for making objects subjected to great mechanical stress, e.g., the moving parts of carts. The bark was once used to tan hides and the acorns as food for pigs or even, in times of famine, for humans. Distribution of holm oak in Italy, approximately coinciding with meso-mediterranean and warm/medium sub-mediterranean climatic zones temperate, at least as far down as Campania. Naturally, altitude plays an essential role, so that part of the Appennines affected by the sea only rises to a few hundred metres on the flanks of the central and northern mountains, but widens gradually and steadily to the south and the islands. The belt with the most marked and typical Mediterranean features, with summer aridity of 5-6 months (meso-mediterranean) involves most of Sardinia, the southern coastline of Sicily, Salento, the Lucanian and Apulian coastlines facing the Gulf of Taranto, and part of the Apulian coast south of the Gargano promontory. The belt where summer aridity is limited to a period of 3-4 months (sub- Mediterranean) is very wide, and includes the remaining parts of the two largest islands (excluding their highest reliefs), the Tyrrhenian coast from Calabria northwards to Liguria (excluding those parts of eastern Liguria and northwestern Tuscany where the morphology of the land (with very steep reliefs on the seaward side and/or conspicuous mountain systems only slightly inland) reduces the arid period, and the remaining Calabrian and Adriatic coast northwards, more or less as far as the Conero promontory. The internal parts of peninsular Italy have increasingly less marked Mediterranean features as we move inland and upwards from the sea. The arid period steadily becomes shorter until it may fade away completely; at the same time, winter temperatures fall, so that most of the Appennine chain, defined as medium and cold sub-mediterranean, shows more or less marked features common to continental climates. There is a small, cold, sub-mediterranean zone along the Gulf of Trieste, again associated with the peculiar morphological and pedological characteristics of the local territory. 21 The soil. Soil may be defined as that superficial part of the Earth s crust which is the result of interactions between physico-chemical alteration of rocks (weathering) and decomposition of the organic matter which is deposited on them. Plants send their roots down into the soil, and find the water and minerals necessary to their metabolism in it. Geologically, Italy is made up of a large variety of rocks, often leading to considerable diversification of soil substrates, even within the same valley or mountain chain. Two of the main soil parameters which are important for plant life are the quantity of lime present, and the degree of acidity. Calcifuge species show signs of distress if they are obliged to live in limestone soils. Examples are bracken, or brake (Pteridium aquilinum), European broom, green heath, cork oak, and maritime pine (Pinus pinaster). Instead, calcicole species prefer soils rich in lime.

12 22 This preference is not due to lime in itself, but to the particular conditions of heating and aridity of the substrate which these warmth- and heat-loving species find in such soils. The degree of soil acidity is also a factor determining the geographic distribution of many species of plants. Maquis species which prefer acid substrates include cork oak, strawberry tree, tree heath, and wild lavender (Lavandula stoechas); those preferring alkaline soils are Spanish broom, many-flowered heath, Aleppo pine, rosemary, and many types of juniper. So many calcifuge species are also acid-loving, whereas those preferring alkaline soils often live well on limestone. To summarize, since all plant species establish their own personal relationships with the soil, the maquis in various parts of Italy has similar structural aspects but diverse floristic composition, due to the local soils. Adaptations to drought by hard-leaved plants Comparison between an ordinary leaf and one from a hardleaved plant (oleander) upper epidermis with cuticle; in oleander, epidermis has several layers and cuticle is very thick palisade-type chlorophyll tissue lacunose chlorophyll tissue lower epidermis 23 Biology and phenology of plants. The Mediterranean maquis is thus closely associated with precise local conditions, mainly as regards climate. Maquis is limited to those portions of the globe where annual precipitation is irregular over the course of the year, most rainfall being concentrated in late autumn and winter, and more or less prolonged aridity in summer. In areas with temperature trends like those of the Mediterranean climate, Wild lavender (Lavandula stoechas) but where precipitation increases in quantity and duration over the year, conditions conducive to tree growth prevail. Here, the vegetation is mainly composed of true evergreen woods and forest. Instead, in areas where dry summers are longer, the vegetation becomes impoverished and the arid shrub typical of sub-desert and desert zones dominates. Maquis is formed of species adapted mainly to summer drought, thanks to their leaf structure and morphology. Leaves are those parts of plants which are most sensitive to variations in the availability of water. Stiff-leaved plants, or sclerophylles (from the Greek scleros, meaning stiff, rigid), have long-lasting, hard leaves, thick cuticles, and deep stomata protected by hairs, which limit transpiration. An excellent example is the leaf of the holm oak. Other species, like tree euphorbia and spiny broom, adopt a different strategy to cope with st cr cs in oleander, stomas are located in deep pockets and protected from excessive transpiration by a mesh of hairs ample development of cuticular layer on upper side of epidermal cells leaf margins turned downwards leaf blade folds on itself during periods of drought stoma embedded with respect to leaf surface cr stomatic crypt st stomatic cells cs substomatic chamber ramified multi-celled hair in lavender shielded hair of olive, seen from above and in cross-section

13 summer drought, losing their leaves as summer approaches (a phenomenon called estivation, very frequent in hot, arid, tropical and equatorial zones). As well as summer drought, plants living in the Mediterranean environment may have to face a second critical period during winter, due to low temperatures. Maquis species do not generally resist cold well, and can only tolerate short periods of frost. Snow damages Mediterranean vegetation, both due to the thermic shock it causes, and mechanically, by breaking branches, especially if high winds accompany low temperatures. Perennial species begin their vegetative activity with the first autumn rains and pass through an intense period of assimilation, extending to December; then a pause intervenes, due to the cold. Vegetative activity starts up again more intensely in spring and continues until the beginning of the dry period; summer is a phase of almost complete repose. In southern Italy and the islands, winter temperatures are sometimes sufficiently high to allow vegetative activity to continue without interruption; in these cases, summer drought often arrives early, sometimes already at the end of May. The seeds of annual plants germinate in autumn or spring. In most cases, the dormant period is relatively short and seeds already germinate with the first autumn rains. In particularly short-lived species, dormancy is extended and germination is delayed until February or March of the year after that in which the seeds were produced: in this case, the vegetative period is reduced to only 2-3 months. In the coolest season, growth and flowering are at their peak, and fructification and dissemination take place with the arrival of the dry season. These species cope with summer aridity in the form of seed. Despite seasonal changes, the maquis Juniper misshapen by prevailing direction of wind almost always looks the same, because the plants which flower every month generally have small, relatively inconspicuous flowers. But, especially where the maquis is less dense and less dominated by holm oak, it presents fruits of all colours: the various tones of red of sarsaparilla, rose and strawberry tree, the metallic reflections of laurustine, the bluish-black of myrtle, and the fluffy white festoons of clematis (Clematis flammula). The maquis takes on a much more varied aspect when clearings open, and the blooming of the so-called early Mediterranean microflora may be briefly admired in spring. The influence of wind must not be underestimated. The shapes into which trees are modelled by the wind reveals its strength and frequency. Sometimes, isolated shrubs or entire areas of maquis are prostrate, or grow curved in the direction of the prevailing wind. Strawberry tree (Arbutus unedo) with fruit Dynamism, primary maquis and secondary maquis. The various shrubby associations collectively called Mediterranean maquis are part of that evolution of vegetation dominated by holm oak or undergrowth with wild olive and carob, or a degraded series due to various kinds of disturbance, mainly anthropic. In practice, the following evolutionary sequence may be established: naked soil - steppe with grasses - garrigue - low maquis - high maquis - forest. Not all the Mediterranean maquis has the same origin and the same history; its origin may be viewed as primary or secondary, and it is not always easy to distinguish between the two. Interpreting Mediterranean shrubby formations is quite difficult everywhere, because they are mostly the result of a lengthy history which includes several kinds of activity on the part of man: deforestation, grazing, agriculture, and more or less frequent fires. Primary maquis is the original type, not the result of the involution of preceding

14 26 forest vegetation, and is rarer. It has two aspects: 1, it is found in areas where holm oak forest is not the present-day climax, e.g., at the geographical and altitude limits of the area covered by holm oak; 2, the maquis grows in situations which limit its expansion, e.g., steep slopes, high contents of salt in the soil, or the continual drying capacity of wind, which means that woody plants cannot grow tall. These cases may be interpreted as permanent stages of vegetation, or subclimax. Thus, in most cases, the heterogeneous aspects of Mediterranean maquis present intermediate stages in the course of evolution or degradation of vegetation, and are thus to be considered as aspects of secondary maquis. The most common causes leading to secondary maquis are anthropic in origin: felling, or coppicing, of trees, fires, and grazing, which often follow the first two and contribute further to making the original vegetation retreat. Many holm oak forests have been destroyed in historical times, both to create pasture for livestock, and to grow crops, mainly vines and olives. Following the abandonment of cultivation, both vegetation and soil progressively undergo degradation, which may even lead to naked rock being exposed. But sometimes plants do manage to regrow, in the form of evergreen shrubs, very REGRESSION HOLM OAK PINEWOOD, ALEPPO PINE AND MAQUIS UNDERGROWTH MAQUIS reafforestation PROGRESSION 27 GARRIGUE MEDITERRANEAN STEPPE MEADOW CULTIVATION: VINEYARDS AND OLIVE GROVES Goats grazing on garrigue in Sardinia Simplified sketch of Mediterranean vegetation. Man s intervention to create space for agriculture and grazing causes either a reduction in the structural complexity of hard-leaved Mediterranean formations or their disappearance. Abandon of cultivated or grazing land results in the development of vegetation which, if no fires occur, leads to increasingly complex formations in the course of time, until the reconstitution of maquis or holm oak woodland

15 similar to those which made up the undergrowth of the primitive forest, but with new, more sun-loving components, extraneous to the original vegetation. Sometimes maquis deriving from evergreen forests which have since disappeared is almost entirely composed of the undergrowth of those forests, without tree cover. This occurs when the climate has become more continental and no longer allows evergreen shrubs to reconstitute themselves, so that many forms of maquis may be considered as the remains of once flourishing holm oak groves, or when such groves, periodically and continually exploited by man by means of coppicing, are transformed into tall, dense thickets according to coppicing method used and the length of time in which trees were left to grow freely. In the case of holm oak coppicing, the maquis which appears afterwards is a transitory stage, necessary to create the conditions suitable for future growth of holm oak seedlings and shoots. The most evolved forms of maquis contain heath, strawberry tree, and holm oak thickets. The least evolved contain rockrose, associated with garrigue. As these associations are not fully evolved, each of them is affected by soil characteristics (ph, amount of lime, etc.) and climate (above all aridity) more than forest formations. The relationship between fire and maquis Mosaic of maquis/garrigue along Cilento coast (Campania) When discussing the effects of fire, a distinction must be made between occasional and repeated outbreaks. Occasional fires allow the vegetation to continue its normal evolutionary course towards forested land, and thus the maquis which establishes itself represents a transitory phase. However, in most cases, fires are recurring phenomena and may give rise to cycles called pyrogenic, i.e., caused by fire itself, so that the vegetation which is burnt is the result of sometimes many preceding fires. The interval between one fire and another, and its violence, determine both the type of starting maquis, and how long it takes to regrow. For example, the region of Liguria - that part of Italy ranging from Tuscany along the coast northwards, and then bending west towards France - contains extensive woods of Aleppo pine (Pinus halepensis) or umbrella pine, with a thick shrub layer. The high degree of combustibility of the pines and the presence of inflammable shrubs mean that flames can reach even the tops of the trees. Much of the vegetation is destroyed but, although most of the pines die, the shrubby layer, formed of species with good capacity for producing shoots which grow from stumps, re-establishes itself quite quickly. The grassy layer, which was almost absent even before the fire, increases in the first post-fire stages, thanks to the new space created, but then immediately decreases, as shrubs take over. If the shrubby layer is composed of species with poor capacity for producing shoots, regrowth will be slower. In these cases, renewed growth on the part of pines takes on an important role. Fire enhances the scatter and germination of pine-nuts and many seedlings develop, because there is no competition from other species. The result is a thick population of pines alone - easy prey for later fires which, if they occur before the young trees have had time to reach reproductive maturity, destroy them completely. There are also vast extents of maquis composed mainly of strawberry tree, tree heath and spiny broom. This is often the result of a succession like that described above for pine woods. In this type of vegetation, fire spreads rapidly and is totally destructive. If species which can produce shoots easily (like strawberry tree and heath) predominate, then the shrubby layer regrows quickly and does not allow the entry of sun-loving or grassy species. Sometimes, in the most mesophilous situations, bracken may prevail in the early post-fire stages, but is later destined to be supplanted by maquis shrubs. After 8-10 years, if no more fires occur, the shrubby layer returns to its previous state, as regards ground cover and height.

16 When the maquis is composed of species with poor capacity for producing shoots, shrubs grow more slowly and a stage dominated by grassy or suffruticous sun-loving species prevails. Fires are quite frequent in Mediterranean and sub-mediterranean vegetation, and so it is rare to find areas which have never been burnt before. The vegetation is thus already the result of perhaps several preceding fires. As fire has played an important role ever since prehistory in the evolutionary processes of man in general and of his environment, it would be true to state that the development of Mediterranean vegetation has taken place in close relationship with fire and has been considerably influenced by it. The resulting natural selection of hard-leaved evergreen species over time has led to great uniformity in response to fires, and most of the perennial maquis species have good shoot-producing capacity. Regrowth is very rapid after fires, so that these species quickly colonize the terrain, and they stop, or at least greatly reduce, the possibility that species extraneous to the pre-fire populations can establish themselves in the area. One of the consequences is that, after fires, Mediterranean maquis tends to re-establish itself quickly. This happens even though the soil may contain vital seeds belonging to other extraneous species. In conclusion, therefore, single fire events do not excessively change the existing vegetation structure and floristic composition - or, rather, the more or less accentuated variations which may be caused by the passage of fire are cancelled in a short, sometimes very short, time. The maquis, particularly if composed of species which produce shoots easily, like tree heath and strawberry tree, immediately varies its structure considerably, but can grow again in the course of only a few years. However, there are cases when such changes are very severe, i.e., when the tree cover is composed of trees containing resin and the undergrowth is dense and composed of several layers. But even here, at least shrubs tend to reestablish themselves quite rapidly. The present-day Mediterranean vegetation is influenced not only by man s various activities, but also by the frequency of fires. In places where they are very frequent, the prevailing vegetation is garrigue or poor, sometimes discontinuous meadowland, occasionally thinly covered with pines. When fires occur every few years, the maquis is mainly composed of spiny broom, heath and strawberry tree, with or without pine cover. The tendency of Mediterranean vegetation, in the absence of fires, to regrow quite quickly is confirmed in areas where agriculture has been greatly reduced during the last few decades and where, probably thanks to difficult or impossible access by traffic, fires have not occurred for at least twenty years A B C D E before fire before fire after fire before fire first post-fire phase second post-fire phase before fire first post-fire phase second post-fire phase before fire first post-fire phase second post-fire phase after fire Effect of passage of fire on various types of Mediterranean vegetation. A: pinewood with abundant undergrowth; B: pinewood with scarce undergrowth; C: maquis; D: hard-leaved evergreen woodland; E: mixed hard-leaved evergreen woodland and pines

17 32 The main aspects of maquis 33 Cork oak (Quercus suber) One first, physiognomic, distinction to be made in maquis is its growth upwards. There is tall maquis, sometimes 4-5 m high, with prevailing holm oak, strawberry tree, sometimes cork oak and, on cooler slopes or at higher altitudes, deciduous oak such as pubescent oak (Quercus pubescens) and cerris or turkey oak (Quercus cerris). Instead, in low maquis, plants rarely exceed metres in height, with lentisk, buckthorn, juniper, phillyrea, rockrose, etc. But what really differentiates the maquis is its composition as regards flowers. They exhibit Wild olive (Olea europea var. sylvestris) considerable variability from place to place, according to many ecological factors and, inevitably, man s intervention. Often the plants are not stable, but represent stages of degradation or regeneration, according to changes occurring in the environment. Although within the polymorphism of the maquis, only dynamic types can be defined, there are more highly evolved types which grow in cooler spots, like holm oak maquis (phytosociologically framed in the order of Quercetalia ilicis and in the Quercion ilicis alliance). Rosemary (Rosmarinus officinalis) Nearer the sea in hot, arid spots, we find formations of Pistacio-Rhamnetalia alaterni, subdivided into maquis with strawberry tree and tree heath (Erica arboreae), and maquis with carob, wild olive (Oleo-Ceratonion) and common juniper (Juniperion turbinatae). Where the maquis tends towards garrigue, low, discontinuous shrubby cover occurs, with abundant wild lavender and rockrose (Cisto-Lavanduletea) on acid soils, and maquis with many-flowered heath and rosemary (Rosmarino- Ericion, Rosmarinetalia) on limestone and marly soils.

18 34 Types of true maquis Buckthorn and lentisk Gaudenzio Paola 35 Maquis with holm oak. High maquis with prevailing holm oak (Quercetum ilicis) represents one of the recently degraded, primary or secondary aspects of holm oak woods, i.e., very similar to them in composition and physiognomy. Holm oak maquis has more widespread distribution and thus greater importance with respect to the corresponding residual, fragmentary forest. Holm oak prevails more or less absolutely, followed in order of importance by strawberry tree, lentisk, phillyrea, buckthorn, and other hard-leaved evergreen shrubs. It is not a true association, but rather a stage determined and maintained by man s activities. It is poorest in species at the northern limits of its distribution. Near Duino (Venezia Giulia) it is composed only of holm oak, terebinth, Osyris alba and sarsaparilla. Further south, it is enriched with wild olive, prickly juniper and phillyrea, becoming impoverished in evergreen species and progressively mixed with deciduous trees and shrubs as altitude increases. There is a variation with particularly abundant heath, which approaches maquis with strawberry tree and tree heath, as we shall see later on. In Italy, the distribution of holm oak maquis with altitude varies considerably due to the great adaptational flexibility of holm oak itself. It ranges from sea level near Trieste to more than 1000 metres on the slopes of Mt. Procinto (Apuan Alps), Calabria, Sicily and Sardinia. Buckthorn, stinkwood (Rhamnus alaternus) Family: Ramnaceae. An evergreen shrub, 1-5 m tall; trunk ramified low down; hairy branchlets; reddish-grey, finely striated bark; dark yellow wood; spherical, compact foliage. Simple leaves, alternate or subopposed, hard, glabrous, oval, pointed, margin saw-edged or entire, 3-6 cm long. Yellowish-green flowers, with an unpleasant odour, gathered in spherical axillary racemes, no petals or only one. Flowers from January to April. The fruit is a spherical drupe, 0.5 cm across, dark red when ripe, with three kernels. The wood, excellent for fine cabinet-making, is very heavy and fine-grained, but it emits such a foetid smell while it is being worked that it is also known as legno puzzo (stinking wood). In dyeing, the leaves and fresh twigs may be used to dye fabrics a fine orange-yellow shade, and the fruit give a vegetal green. The drupe was once used medicinally as a drastic purge. Lentisk (Pistacia lentiscus) Family: Anacardiaceae An evergreen shrub (sometimes a small tree, up to 5 m tall), dense, highly ramified, rounded in shape, scaly brown bark; small, glabrous, reddish-brown branchlets. Composite alternate leaves, with an alate stalk, paripinnate, leaflets with entire margins, obtuse or briefly mucronate at the apex, pale green and shiny above, paler and opaque underneath, glabrous, with a strong resinous odour. The flowers are dioecious, in small, dense axillary racemes, dark red in colour. Flowers appears from March to June. The fruit is a spherical-compressed drupe, reddish or almost black when ripe. The species is sun- and heat-loving, and prefers siliceous, highly fertile soils. A Sardinian proverb says: Terra da chessa, terra trigale (Lentisk land, good wheat land). The wood, with yellow sapwood (alburnum) and reddish heartwood (duramen), is hard, veined, with poorly marked rings, but is not often used owing to the small size of the shrub. It makes excellent fuel. The drupes provide oil as fuel and also for cooking purposes. The resin which weeps from gashes in the bark supplies a mastic, which is used as an ingredient in industrial paints and varnishes. Holm oak maquis between Camogli and Punta Chiappa (Liguria)

19 36 Heath and strawberry tree Heath (Erica arborea) Family: Ericaceae. An evergreen shrub, with many branches, 2-4 m tall, with an erect but often contorted trunk, and rough reddish-brown bark. Simple leaves, in whorls of 3-4, linear, slightly stiff, 4-8 mm long, and very narrow. Small, perfumed, pendent flowers, gathered in thick racemes, white or pink bell-shaped corolla, mm long, shorter than its stalk. The fruit is in the form of a small capsule, divided into 4 locules. Spring flowering. Heath plays an important role in maquis formations, but may also be found high up, among broad-leaved trees. Where it covers large areas, heath gives the landscape a characteristic aspect. It was used in the past to produce charcoal and to make coarse brooms. Small bundles of its branches were used to cover the roofs and walls of poor people s homes. The bunches of dried branches on which silk-worms were placed when they were ready to spin their cocoons were often composed of heath. When coppiced, the plant produces a swelling at the height of the collar, used to make the bowls of pipes. Heath flowers are an important source of nectar for bees. Gaudenzio Paola Strawberry tree (Arbutus unedo) Family: Ericaceae. An evergreen shrub, occasionally a small tree growing to about 10 m, with reddish-brown bark which flakes off in thin scales. Simple leaves, alternate, 4-10 cm long, elliptical, crenate or saw-edged, dark green and shiny above, paler underneath, with short stalks. Small flowers of 5-7 mm, in terminal clusters, pendent, very thick, jarshaped corolla, 5-dentate, creamy white in colour. Fruit in the form of spherical berries, 1-2 cm in diameter, granulous-tubercular on the surface, first yellowish in colour, then orange, and bright red when ripe, sweet and edible, containing many seeds. The fruit requires one year to mature, with the result that, in autumn, the plant may show both flowers and ripe fruit from the previous year, at the same time. Like all plants with winter fructification, strawberry tree is very important for birds at a time when little other food is available for them. Maquis with buckthorn and lentisk. On limestone or limestone-marly slopes, the degradation of holm oak woods or the evolution of garrigue with heath and rosemary creates very dense maquis, quite homogeneous because it is mainly composed of buckthorn and lentisk, with the typical lianas of holm oak, like sarsaparilla, madderwort, Mediterranean honeysuckle and asparagus. This maquis is frequent along the western Ligurian riviera. The Pistacio lentisci-rhamnetum alaterni association represents a stage in the climacic series of holm oak, but aridity due to type of soil and lower rainfall greatly slows its evolution with respect to maquis with strawberry tree and tree heath. Madderwort (Rubia peregrina) Maquis with strawberry tree and tree heath. This type of maquis, mainly silicicolous, located in the sub-mediterranean belt, anticipates holm oak or represents permanent communities in xerophytic biotopes, and is phytosociologically called Ericion arboreae. It is widespread along all Tyrrhenian coastal areas. Strawberry tree prevails on siliceous, acid soils rich in humus, with cool exposures, and is sometimes found quite high. Tree heath appears in more degraded stages due to further aridity and impoverishment of the soil. The stages of transition between maquis with strawberry tree, strawberry tree plus heath, and prevailing heath, can all be identified. As these two main species are the ones which vegetate first, sometimes only a few weeks after a fire, their prevalence may be due to the practice of deliberately setting fire to vegetation. The association is well characterized by Pulicaria odora, and is constantly accompanied by spiny broom, myrtle, lentisk, buckthorn, holm oak, sarsaparilla, madderwort, asparagus, sage-leaved rockrose, and pubescent oak. From the dynamic viewpoint, Erico-Arbutetum is a quite evolved stage, mainly belonging to the climacic series of holm oak or, further inland and at higher altitudes, that of pubescent oak. The evolution of these formations towards holm oak, in the absence of any 37

20 38 Tree euphorbia and prickly juniper Tree euphorbia (Euphorbia dendroides) Family: Euforbiaceae. A large deciduous shrub, glabrous, spherical, up to 3 m tall, with thick foliage at the tips of branches, bluegreen in colour. Thick, oblong-lanceolate leaves, obtuse, with a mucro. Umbrella-shaped inflorescence, enclosed by bracts, with 5-8 rays, rather thick and stubby. The fruit is in the form of triangular capsules 5-6 mm across. Flowers from November to May. Unlike most Italian plants, it presents the phenomenon of estivation - that is, it enters a state of repose during the hot, dry summer period, instead of during winter. From June to September, it loses its leaves and looks as if it were dead, but then it starts vegetating again and flowers, from the first late summer rains onwards. Lke many other species belonging to the same genus, the trunk of tree euphorbia contains a poisonous white milky sap, once used to capture fish, mainly freshwater ones: large quantities of the branches of the tree were thrown into ponds or specially prepared traps, and the water thus poisoned. Gaudenzio Paola Prickly juniper (Juniperus oxycedrus) Family: Cupressaceae. An evergreen shrub 1-5 m tall, rarely a tree, reaching m. Needle-shaped, very prickly leaves, arranged in threes around branchlets, with two lines above. This is a dioecious species, i.e., specimens produce only male flowers or only female flowers; the flowers are devoid of involucre and are inconspicuous. The fruit is a berry, reddish-brown in colour and pruinous, 8-15 mm in diameter, maturing in the second year. This plant was known in ancient times, and was the subject of many legends and beliefs, one of the strangest being that its wood, if burnt, would keep snakes away. The wood of prickly juniper is very hard, excellent for producing charcoal, and was also used for making carved objects. The berries are considered delicious by birds. Cade oil or juniper-tar oil, prepared by dry-distilling the wood, has been used for thousands of years to treat skin diseases a reputation which is highly justified, since the oil has considerable disinfecting, resolvent and curative properties. kind of disturbance, is quite rapid, but the periodic passage of fire causes continual rejuvenation. In acid soils in Liguria, aspects with abundant green heath, honeysuckle (Lonicera etrusca) and narrow-leaved phillyrea may be identified. Elsewhere, the destruction of holm oak and cork oak groves has favoured groupings composed of spiny broom, daphne (Daphne gnidium) and sageleaved rockrose (Calicotomo infestae- Ericetum arboreae), or spiny broom, lentisk and rosemary (Pistacio lentisci- Calicotometum villosae) or, in damper locations, broom, myrtle and lentisk (Erico arboreae-myrtetum). Dwarf palm (Chamaerops humilis) Maquis with carob and wild olive. This type of maquis (Oleo-Ceratonion) is the most heat-loving shrubby formation found in Italy. It extends all along the central-southern Tyrrhenian coast and on the islands, composed of shrubs of wild olive, carob, tree euphorbia, lentisk and Cneorum tricoccum. It is the permanent vegetation in cliff or beach locations with little soil, or where heatloving holm oak retreats. In Italy, the distribution of this type of maquis is limited to low altitudes, except for unusual locations in Calabria, Sicily and Sardinia, where it may reach 600 metres. According to which species are present and how they are associated, there are different types with reciprocal dynamic affinities and relations. Maquis with wild olive and tree euphorbia. On rocky limestone coasts, we find the association with Oleo-Euphorbietum dendroidis: tree euphorbia, wild olive, prasium (Prasium majus), Jupiter s beard, buckthorn and lentisk. Tree euphorbia prevails, mainly along the warmest places of the mainland, definitely making its mark on the landscape. Maquis with lentisk and dwarf palm. Low maquis with lentisk, dwarf palm, broom and rockrose develop along coastal limestone cliffs in Sicily and Sardinia, deriving both from holm oak groves and broom covers and representing the Pistacio-Chamaeropetum humilis association, characterized by often abundant and sometimes dominant dwarf palm. 39