Diapositive 1

14:19:46. 1. Introduction Biodiversity & Mediterranean Biodiversity Biogeography & Mediterranean Biogeography The Mediterranean Biodiversity Hotspot Origins of today’s Mediterranean flora Introduction to floral Realms The Paleotropical origins Holarctic origins.

Levels of biodiversity. Genetic diversity: Genetic diversity is the variety of genes within a species..

[Virtual Presenter] Where does this high biodiversity come from? What explains the high level of Mediterranean floral endemism?.

4. Geological & climatic History The formation process which took over 230 Ma, during which numerous isolated floral niches were formed followed by the reconstruction of the modern mediterranean puzzle..

5. Habitat Diversity Regional climatic patterns, orography and topography, ancient floral refuges, islands, etc… The Mediterranean has >5000 islands, 4000 of them are uninhabited (Together, they have an area <10 000 Km2).

6. The Mediterranean Biogeographical position The Mediterranean is a crossroads of different realms and floral regions; its role as a huge vegetation tension zone. Vegetation tension zone is a transitional area in which many species from different phytochorions (i.e. a geographic area with a relatively uniform composition of plant species) overlap..

Cosmopolitan Distribution A taxon range extends across all/most of the world appropriate habitats. Example: Plantago, humans, rock pigeon.

Disjunct distribution Disjunct distribution pattern refers to the discontinuous distribution of con-generic plants and sometimes con-specific taxa. Examples include the Mediterranean-Californian link and the Lusitanian distribution..

Endemic Distribution A taxon is restricted to one geographical regions Example: orange-breasted sunbird (fynbos), the komodo dragon (Sumatra and Komodo islands), etc..

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5,000 4,000 3,000 zooo 1,000 1 2 3 4 5 6 7 8 9 1011 12 13 14 151617 18 19 2021222324252627 Range size (number Of regions where a species is present) :igure 2.1 The prevalence of narrow endemism in the Mediterranean region (drawn from data in Greuter 1991)..

300 Rate of endemism 20% Rate of endemism between 10 and Fig. 3.3 Hotspot areas for plant species diversity in the Mediterranean Basin, Macaronesia. (Reproduced with permission from Quézel and Médail 1995.).

Grey-leaved cistus (Cistus albidus). Résultat de recherche d'images pour "Astragalus tragacantha".

What is a biodiversity hotspot? A Biodiversity hotspot is a region that meets two strict criteria (1) it must contain at least 0.5% or 1,500 species of vascular plants as endemics, and (2) it has lost at least 70% of its primary vegetation.

ATLANTIC PORTUGAL Madeira Canaries FRANCE SPAIN ALGERIA ITALY GREECE rz-zA (Black Sea URKE RIA anecin Sea EGYp LIBYA Cape Verde MOROCCO TUNISIA 1500 kilometers O Cl 2005 Mediterranean Basin Hotspot.

[Virtual Presenter] Six realms are identified subdivided into subkingdoms, regions and provinces, Boundaries between the floral realms are called vegetation tension zones which are transitional areas; many species from different regions overlap,.

Origins of today’s Mediterranean flora Floral Realms & Vegetation Tension Zones.

Madrean Teth an. Flora of Paleotropical Origins. Madrean-Tethyan community (Alt. Mediterranean–Californian disjunction).

19. Madrean-Tethyan Link (Alt. Mediterranean–Californian disjunction) Includes the most ancient Mediterranean floral groups, Representatives mostly found in North Africa and Near/Middle East Examples: Sclerophyllous vegetation, e.g. Evergreen hard-leaved oak, jasmine, fig, strawberry tree, rose….

20. Rand-flora Community The “Rand Flora” is a pattern of disjunct distributions across many plant groups, between northwest Africa-Macaronesia, Horn of Africa-southern Arabia, and southeast Africa. Represented by many endemic species in north African mountain ranges..

Colchicum autumnale naked lady. The dragon tree. s.st'.a—w.'.

Vicariance hypothesis: Scattered distribution caused by Habitat Fragmentation due to Geological Processes or Global Climatic change.

23. Sudanian Community Link Sudanian vegetation belongs to a floral province found in sub-Saharan tropical Africa Found in isolated tongues around the Dead Sea and in North Africa, Thought to have arrived recently to the Mediterranean region: Low level of endemism, Economic value, Examples: Acacia tree, Zizyphus and Date Palm tree..

o Mediterranean SAHARO- ARABIAN Sea B/ock Sea Ontic) IRANO- TURANIAN SUDANIAN Red Sea Fig. 2.1 Phytogeographical subdivisions of the eastern Mediterranean and, in the box, of.

25. Palm Orchids (top left), Capparis aegyptia (shrub) near an Acacia raddiana tree in the Dead Sea Valley (top right), thorny keel (down left) common in the Dead Sea Region and Zizyphus Tree (down right).

26. The Holarctic Component Flora form Euro-Siberian origins Introduced into the northern Mediterranean during the Pleistocene (ca. 2.6-0.012 Mya) Survived the glaciations events in refugia in southern European islands, the Balkans and north-east basin, Re-colonized the Mediterranean after the end of the last glacial maxima (ca. 15kya) Found in the north-western and common in the north-eastern Mediterranean Examples include: chestnut, walnut, beech, fir, pine, etc….

27. Corylus 10000 Ouercus 12000 7000 1.8 Isopoll maps illustrating the northward expansion of oaks (Quercus spp.) and hatelnut (Corylus sp.) over the last 12000 years and 10000 years respectively. Three of pollen density are shown: stipple 2—5%, horizontal stripe 5—10%, black fill > 10%. (Reproduced with permission, after Huntley 1988.).

Mediterranean forests, the most biodiverse in Europe.

29. The Irano-Turanian Component. 15 26 32 28 10 31.

Judas Tree (Cercis siliquastrum). 30. The Irano-Turanian Component Vegetation of dry forest-steppes of central-west Asia, Mostly deciduous trees, Found mostly in the Eastern Mediterranean region, Ex. Judas tree, Apple tree (more than 60 species, 14 genera).

31. Goosefoot. World biogeographical regionalisation, with 1, Mexican; 2, Saharo-Arabian; 3, Chinese; 4, Indo-Malayan; 5, South American transitions.

Mediterranean Irano-Turanian Sudanian SahÜ0-ArabiN1 Egypt (Sinai) Syria Jordan Iraq Saudi Arabia.

The geological sciences were not spared imaginative ef- forts to explain the unknown. including the mechanisms for continental drift. Eötvös was a "pole fleeing" force whereby objects on the surface of a rotating sphere were envisioned as somehow moving laterally in opposite direc- tions and sliding down the curved surface of the sphere. The balloon hypothesis was born out of the observation that if paper representations of the continents were glued onto a balloon. they would soparate and reunite as it eX- panded and contracted. A mechanism for the required pe- riodic doubling of the Eartlfi diameter proved elusive. All of these early attempts to explain patterns evident in the modern distribution of organisms and land fragments failed because Of the lack Of accurate phylogonies and an integrated model of plate movement. land bridges. past cli- mates. and tho fossil record. Current distribution patterns and biotic affinities are residues of history. and their origin now can be more accurately traced through bottcr docu- mented. albeit less spectacular, events (Morrone and Crisci. 1995). FLORISTIC AFFINITIES BETWEEN SOUTHWESTERN UNITED STATES-NORTHERN MEXICO AND MEDITERRANEAN REGION The dry sclerophyllous vegetation of the southwestern United States continues southward into northern Mexico and is characterized by numerous shared and re- lated species of Pinus and Quercus. This assemblage is known as Madrean sclerophyllous vegetation aner the Sierra Madre of Mexico. A community similar in structure and composition occurs in the Mediterranean region and is called Tethyan sclerophyllous vegetation after the ancient Tethys Sea whose remnant is represented by the modern Mediterranean Sea. Examples of the affinity include spe- Cies of Cupressus, Juniperus (Fig. 9.1). Pinus. Aesculus. Ar- butus. Buxus. Cercis. Datisca. lavatera. Liquidambar. Pla- tonus, Prunus, Quercus, Rhamnus. Rhus. Staphylea. and Styrax. The Madman —Tbthyan hypothesis was proposed to explain the relationship and sugests that there was a band of dry sclerophyllous vegetation extending across the mid- latitudes of North America and Europo in tho Early Tyrtiary when the continents were closer together (Axelrod. 1975. fig. 1). Other possible explanations include long-distance dispersal (Meusol. 1969; Raven, 1971) and convergence from widespread mesic-habitat boreotropical ancestors as progressive drying and greater seasonality in rainfall de- veloped in the southwestern United States—northern Mex• ico and in the Mediterranean region in Eocene and later times (Raven. 1973; Wolfe. 1975). The Madrean—Tethyan hypothesis can be tested by ex- amining some of the expected consequences if the extant species were derived from ancestors that wero part of a continuous Or nearly continuous belt Of Early Tertiary veg• etation. One consequence is that each group constituting an example of the Madrean—Tethyan link should be mono- phyletic (as opposed to polyphyletic. derived indepen- dently from different ancestral stocks). Another is that b+ cause the marine barrier across the north-central Atlantic.

Adaptation to Draught Draught tolerant Draught evaders Draught avoiders Adaptation to Fire Insulation Resprouting Serotiny Other adaptations Aromatic plants Halophytes Others.

14:19:46. 35. Drought Tolerant (enduring): The Sclerophyllous shrubs and Trees Common to all Mediterranean ecosystems and in other areas with stressful conditions,.

Adaptations in Mediterranean Flora I. Adaptations to draught.

14:19:46. 37. Oleander (Nerium oleander) whole plant (left) and xeromorphic leaf (right).

The stomatal crypt in Nerium oleander magnified. 14:19:46.

Drought Evaders (escapers) Producing leaves at the beginning of the wet season and loosing them during the dry season (summer or drought deciduousness ) Leaves adapted to environments where there is adequate soil moisture called mesomorphic leaves.

The ground looks like fall, but this is July. The ground looks like fall, but this is July.

In spring, while new leaves sprout on the branches of most plants, Euphorbia arborea (Euphorbia dendroides) takes on autumn colors and loses its leaves by exposing bare branches to the summer sun. Photo Anna Lacci (https://www.earthgardeners.it/en/2022/06/03/mediterranean-vegetation/).

Adaptations in Mediterranean Flora I. Adaptations to draught.

14:19:46. 43. Cross-section in the mesomorphic leaf of Syringa vulgaris (common Lilac).

14:19:46. 44. • T umuernssadsuozu xaov. Leaf dimorphism in Maple trees (Acer).

Drought Avoiders Winter Annuals They represent up to 75% of all flora in the Mediterranean region, They complete their life cycle and produce seeds before the dry season, They avoid draught by becoming dormant, Winter annuals include most weeds, cereals, peas, etc….

Cyclamen graceum (Greek cyclamen). Résultat de recherche d'images pour "lily tree".

47. FIGURE 4.6 Average forest fire density and burned forest fraction in Europe. 1998—2007 Of Of 0-0.01 C] 0.01-0.02 Ü 0.08-0.12 0.13-0.20 021-030 0.31-0.60 0.61-59.71 NO data available Area forest (S of total forest area) 001-0.02 C] 003-0.04 C] oos-ot,6 0.07-0.15 0.16--030 031-0.90 0.91-1222 NO data availabe.

48. Hectares (ha) 1 ooo ooo 800 000 600 ooo 400 000 200 000 Portugal Spain France Greece Total.

Resprouting Resprouters are plant species that are able to survive fire by the activation of dormant vegetative buds to produce regrowth. Plants may resprout by means of lignotubers at the base or epicormic buds on the trunk or major branches..

14:19:46. 50. Biu.. Insulation. landscape tree nature forest rock wilderness branch growth plant wood grain texture leaf trunk old summer bark travel formation dry remote environment rural orange pattern scenic autumn brown soil ancient close botanical cracked outdoors geology canada deciduous giant aging timber large area tree bark grooves stalactite big tree giant trees woody plant.