Ecoregions

Mediterranean conifer and mixed forests

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Middle Atlas cedar forest near Azrou, Morocco. @ C.Michael Hogan

Scattered through North Africa (and southernmost mountains of Cádiz and Málaga in Spain), Mediterranean conifer and mixed forests occur on high elevations of major mountain massifs. Relict stands of these fir and pine forests are endemic, and survive in isolated locations in areas of limited areal extent. The flowering plants on these ranges have high rates of endemism, with over 450 strictly endemic plant species, as a result of the long isolation of Holarctic taxa at these high elevations. The faunal diversity is the greatest in the Palearctic realm, with a mixture of Palearctic, Afrotropical and more restricted North African taxa. Mammals found in this region include the only African endemic species of deer, Cervus elaphus barbarus, the Barbary leopard (Panthera pardus panthera), the Barbary macaque (Macaca sylvanus), and before its extinction in the 1930s, the Atlas lion (Panthera leo leo). One strict endemic bird species, the Algerian nuthatch (Sitta ledanti), is also found. These forests have been utilized since ancient Roman times, but deforestation has increased dramatically in the past century. Human impact is significant, compounded by the socio-economic instability of the Maghreb countries.

Location and General Description


 

The Mediterranean Conifer and Mixed Forest ecoregion is scattered geographically. These forests occur in the humid and very humid, medium to high elevations of major mountain massifs in North Africa. They are found in northern Morocco, northern Algeria, and northwestern Tunisia. In Morocco, this forest ecoregion can be found on the Rif, with its highest elevation at 2448 meters (m) on Mt. Tidirhin, and in the Middle Atlas, with its highest elevation at 3340 m on Mt. Bou Naceur. In northern Algeria, examples of this ecoregion occur in the Tellien Atlas and the Saharan Atlas Mountain Ranges at about 2000 m. In northwestern Tunisia, this Mediterranean conifer and mixed forest can be found in the Kroumerie and Mogod Mountain Ranges at their highest elevations of around 1000 m. Even though they lack high elevations, the Tunisian examples are included because their mixed deciduous and evergreen oak forests were once representative of this ecoregion.

The ecoregion receives an average annual rainfall of 1000 millimeters (mm), but in certain high elevations average annual rainfall can range between 1600 to 2200 mm. Snow falls frequently during winter, and average minimum temperatures are generally below 0° Celcius (C); the average minimum temperature is -5° C in Djebel Babor, northeastern Algeria.

caption Near Azrou, Middle Atlas Mountains, Morocco. @ Tedd Buelow

The North African Mountains are of alpine orogenic origin and contain a complex lithological composition, including sedimentary rocks such as sandstone, dolomite, limestone and marl, crystalline metamorphic rocks such as quartzite and schist, as well as igneous granites and volcanic formations. The topography is characterized by steep, high elevations, mainly related to the calcareous massifs, and by the alternation of mountain summits and high plateaus from about 500 to 1200 m high. This particular landform pattern, together with the distance of the Middle Altas and Saharian Atlas from sea influence, creates an intense continental gradient. As a result, sharp changes in microclimates and vegetation are seen between the northern humid slopes and the cold, dry southern slopes.

Forest Types

The wide elevational range of this ecoregion produces two major forest zones. The conifer zone includes the higher elevations from 1200 to 2500 m and a mixed broadleaf zone, which includes the lowland and medium elevation from the sea to about 1500 m. The dominant canopy tree species of the montane conifer forests is the endemic Atlas cedar (Cedrus atlantica), which normally constitutes mixed stands with the evergreen holm oak (Quercus ilex subsp. ballota) and less frequently with deciduous oak species (Quercus faginea, Q. canariensis). The Atlas cedar forests extend over 150 kilometers2 (km) in the Rif Mountains and 1000 km2 in the Middle Atlas. In the Tellien Atlas, they form very scattered populations stretching 300 km2. Moreover, endangered relic and endemic fir forests (Abies numidica in the Algerian mountains Djebel Babor and Tababort; Abies marocana in the Moroccan Rif range), and pine forests (Pinus nigra subsp. mauretanica in the Moroccan Rif and the Algerian Djurdjura, and Pinus pinaster subsp. hamiltonii var. Maghrebiana in the Rif and Middle Atlas), are today represented by only few hundred to a few thousand hectares (A fir species, Abies pinsapo, closely related to the Moroccan fir, characterizes three relict forest areas in South Spain (the Sierras of Grazalema, Sierra de las Nieves, and Bermeja), that are very similar to the North African fir forests from an ecological and bioclimatic point of view.

The Atlas cedar forests are characterized by the presence of a significant number of unique ecotypes of sub-Mediterranean and Euro-Siberian tree and shrub species, which reach their southernmost range limits here. These include Taxus baccata, Sorbus aria, S. torminalis, Acer opalus subsp. granatensis, A. campestre, A. monspessulanum, Prunus mahaleb, P. insititia, Ilex aquifolium, Betula pendula subsp. fontqueri, Populus tremula, Lonicera etrusca, and L. arborea. Juniper (Juniperus thurifera) woodlands, more frequently distributed in the Mediterranean High Atlas Conifer and Evergreen Broadleaf Woodlands ecoregion, also appear in certain high elevations of the Moroccan Middle Atlas and the Algerian Aurès Ranges. Above the timberline, which reaches 2,700 m in Morocco and 2100 m in Algeria, the vegetation is very rich in endemic species, dominated by cushion and thorny shrublands (Astragalus boissieri, A. numidicus, Vella mairei, and Arenaria pungens) and meadows (Festuca algeriensis and Festuca desertii).

Broadleaf mixed oak forests are dominant at medium and low elevations on humid slopes and valleys in the coastal and less continental Rif, Tellien Atlas, and Kroumerie-Mogod mountain ranges. The North African oak forests are dominated by Quercus canariensis , which mainly grows on siliceous substrates in humid climates. This area receives an average of 900 mm of annual rainfall and frequent mists from the sea to about 1500 to 1900 m. This oak species forms large forest stands in the Tellien Altas and Kroumerie Mountains that define the northern border between Algeria and Tunisia. Quercus canariensis spreads into the more continental Middle Atlas and High Atlas mountain massifs where it constitutes small thickets in wet valleys. Other deciduous oak species rarely form large forest stands, and grow in few areas of this terrestrial ecoregion. For example, Quercus faginea and Q. pyrenaica forests are extensively distributed in the Iberian Deciduous Mixed Forests ecoregion, but occupy only about 250 km2 in a few areas of the Rif Mountains. The Quercus afares forests, an endemic species growing in the Kabylie Mountains in Algeria and the Krumerie Mountains in Tunisia cover only about 100 km2 in total (Another rare and endemic oak species, Quercus lusitanica, which defines shrub communities, is found only in the very windy summits of medium elevations that typify both sides of the Strait of Gibraltar, and all along the Atlantic coastal mountains of the Iberian Peninsula. Pinus pinaster subsp. hamiltonii var. Maghrebiana characterizes certain highly diverse mixed oak and pine forest stands, which spread in the low elevations of the Algerian coastal Kabilye in a humid and warm climate.

A very rich evergreen and subtropical mixing of small trees and high shrubs characterize the broadleaf mixed oak forests. These include Laurus nobilis, Arbutus unedo, Erica arborea, Ilex aquifolium, Phillyrea latifolia, P. angustifolia, Viburnum tinus, Cytisus villosus, and Myrtus communis. There is a representative liana layer that includes Lonicera periclymenum subsp. hispanica, Smilax aspera subsp. mauretanica, Rubia peregrina var. longifolia, Hedera helix, H. algeriensis, and a number of Tertiary relicts, such as Prunus lusitanica. The herbaceous layer normally includes many species that also characterize the moist conifer mountain forests, and some other endemic and more thermophilous taxa, such as Cyclamen africanum, Acanthus mollis, Gallium elipticum, Vicia atlantica, Saxifraga atlantica, and Myosotis collina.

caption Near Tamalout, High Atlas Mountains, Morocco (Photograph by Tedd Buelow)

Biodiversity and Endemism

The rate of endemism in the total flowering plants is higher than 20 percent on the main mountain ranges (the Rif, the Middle Atlas, and the Tellien Atlas) where these forests grow. The Middle Atlas Range has 237 endemic plant species, the Rif Massif has at least 190 endemics, and the Tellien Atlas contains 91 endemic plants. The high rate of endemism is partly the result of the long isolation of Holartic taxa in the high elevations of these North African mountain ranges. Here, they have been able to speciate into new forms, partly due to the presence of Tertiary relict plant groups in this area.

All pine, cedar and fir species that characterize the North African conifer forests are endemic to the ecoregion. The Mediterranean moist conifer forests are also rich in endemic plant species that characterize the forest understory. These include Paeonia maroccana, P. corallina, Doronicum atlanticum, Calamintha baborensis, Cynosurus balansa, Geranium malviflorum, Rubia laevis, Scilla hispanica susbsp. algeriensis, Senecio perralderanius, Satureja baborensis, Viola nymbiana, Crataegus laciniata, Cotoneaster atlanticus, Cytisus megalanthus, Lonicera kabylica, and Argyrocytisus battandieri.

Many plant taxa found in these forest ecosystems have a restricted distribution range, and are included as threatened species in the 1997 IUCN Red List of Threatened Plants. The total number of threatened plant species in Morocco is 186 species; Algeria 141 species; and Tunisia, 24 species. Abies maroccana, with a total range of 40 km2 in the Rif, and Abies numidica, with only three km2 in the Kabylie, are two endangered tree species from this ecoregion, that should also be highlighted on the IUCN Red List.

caption Barbary macaque, cedar forest near Azrou. @ C.Michael Hogan

The fauna diversity of the North African moist conifer and broadleaf mixed forests can be considered among the most significant of the Palearctic. They represented the last refuge of the Atlas lion (Panthera leo subsp. leo), which survived in the wild until 1930. A number of rare and endemic mammals are still present in these conifer forests, including the threatened Barbary macaque (Macaca sylvanus), and the last individuals of the Barbary leopard (Panthera pardus subsp. panthera). Other species comprise a mixture of Palaearctic, African, and more restricted North African taxa, such as the Maghrebian wild cat (Felis libyca), the red fox (Vulpes vulpes), the common jackal (Canis aureus), the Algerian hedgehog (Erinaceus algirus), the wild boar (Sus scrofa) and the polecat ferret (Mustela putorius) Nowell et al.

The extensive mixed Quercus canariensis and Quercus suber forests of the Tellien Atlas and Kroumerie Mountains on the border between Algeria and Tunisia host the last existing populations of the only African endemic deer species, Cervus elaphus susbsp. barbarus. This endangered species was once broadly distributed in the conifer and broadleaf forests from Morocco to Libya. These oak forests are also the last refuge for the serval (Felis serval), which has been almost extirpated in the Mediterranean region.

The moist conifer and broadleaf mixed forest ecosystems contain one endemic bird, the endangered Algerian nuthatch (Sitta ledanti) which is found in Djebel Babor and a few other Algerian forest areas. According to some bird taxonomists the North African woodpecker (Picus vaillantii) is also recognized as an endemic species, although others regard it as a subspecies of green woodpecker (Picus viridis levaillanti). The forests also provide habitat for raptors including golden eagle (Aquila chrysaetos), Bonelli’s eagle (Hieraaetus fasciatus), booted eagle (Hieraaetus pennatus), red kite (Milvus milvus), and long-legged buzard (Buteo rufinus). Some species of Palearctic birds also have their southernmost distribution range in these forests, including the lesser spotted woodpecker (Dendrocopos minor) and the great spotted woodpecker (Dendrocopos major) The Rif and Algeciras Mountains on both sides of the Gibraltar Strait and the Middle Atlas Mountain lakes are crucial for large-scale bird migrations to and from northern Europe to Africa.

Among the invertebrate fauna of the moist conifer forests, there is high species richness among butterflies, including several endemics such as the Moroccan grayling (Pseudochazara atlantis), which is mostly found in Jbel Lakraa, the Donzel’s Silver-line (Cigaritis zohra), and Martin’s blue (Plebejus martini).

Endemic reptiles are also found in some mountain areas containing conifer and broadleaf oak forest, including Lataste's lizard (Lacerta pater), Chalcides montanus, Koelliker's glass lizard (Ophisaurus koellikeri), and mountain viper (Vipera monticola). Among amphibians, the most representative species of this ecoregion also characterize similar forest ecosystems - mountain conifer and broadleaf mixed forests - from the southern European Mediterranean countries. These include European fire salamander (Salamandra salamandra), olive midwife toad (Alytes obstetricans), and Mediterranean treefrog (Hyla meridionalis).

Current Status

It is difficult to establish a reliable chronology for the intense forest clearance of the North African moist conifer and broadleaf mixed forests. Forest stands of considerable size occurred in this region in Roman times (as it is reported by Strabo, Herodotus and Pliny) and in medieval times (as it is reported from the descriptions written by Leo Africanus). These medieval forests remained plentiful enough that Fez could serve as a major lumber center until the twelfth century, deriving its timber from both the Rif and the Middle Atlas Mountains. Pollen evidence indicates considerable clearing and widespread deforestation from about 1600 to 1900, presumably through the advent of livestock raising and settlement in the mountains. Some statistics indicate very rapid deforestation in the twentieth century in the three countries of this ecoregion. A quarter of Morocco’s forests --10,000 km2--vanished between 1940 and 1982. Algeria, far more than Morocco or Tunisia, felt the environmental consequences of colonization, which involved huge deforestation. Even in the Tunisian mountains, forest cover shrank by one-third between 1919 and 1970.

In comparison with the estimated original forest cover, the Maghreb countries have lost 75 percent of their cedar forests, 3300 km2 in Morocco and about 1000 km2 in Algeria. The Rif lost 1000 km2 of high forests between 1956 and 1971. This amounts to about 73 percent of this region’s total forest cover during the Spanish Protectorate. As a result, today the Rif looses soil faster than any other area in the Mediterranean region.

Few of the existing protected areas in this ecoregion have management plans, and fewer still have implemented them. Key protected areas include El Feija National Park in Tunisia, Chrea National Park, Djurdjura National Park and biosphere reserve in Algeria, and Ifrane Forest Reserve and Tazekka National Park in Morocco. All three countries intend to increase the protected areas network; especially Morocco where 154 natural sites have been identified and designated as candidate new protected areas. Generally, there are lack of resources (human, financial, and equipment) as well as knowledge (species, habitat distribution, and ecology) to help implement adequate conservation and sustainable use programs. Furthermore, habitats and species populations are not adequately represented to secure their long-term survival and the maintenance of the ecological processes related to them. A number of programs are in place to try to identify and protect the most important places for biodiversity conservation in the ecoregion.

Through collaboration with regional experts from research and governmental institutions and NGOs, the WWF Mediterranean Program Office has identified a number of Important Forest Areas. These constitute well-preserved forest stands with high biodiversity values in urgent need of protection. The same WWF office, in close collaboration with the Tunisian Forestry Department, has also been active in El Feija National Park, developing a number of environmental education, conservation (mainly related to the endangered and endemic Barbary deer (Cervus elaphus barbarus), and sustainable development activities.

Recently, the WWF Mediterranean office has launched a conservation initiative called "Green Belts against Desertification," a 5-year program to apply ecoregion conservation at a landscape level. There are two areas where WWF will be active: the "Kroumerie-Mogod Green Belt" in Tunisia (which includes El Feija National Park and all the Tunisian Important Forest Areas related to this ecoregion) and the "Middle Atlas Green Belt" in Morocco which includes Tazekka National Park and a number of other important sites.

In Morocco, the Water and Forest Directorate of the Forests and Water Ministry has recently identified 154 Sites of Biological and Ecological Interest, which basically correspond with the Moroccan Important Forest Areas. The Moroccan Government has also recently launched a World Bank/Global Environment Facility project on biodiversity conservation. The goal is to enlarge the national protected areas network, create new national parks, declare a number of these priority sites as nature reserves, and improve the management systems of 13 areas, by establishing management plans, improving local capacity, and involving local populations in nature resource management.

The Algerian government also has plans to enlarge the Protected Areas Network and to classify a number of key areas, such as Djebel Babor, as a nature reserve. In addition, a biodiversity strategy and action plan has been prepared, in which attention has been given to the design and management of protected areas in the country for the coming years.

The Tunisian Government, the World Bank, and UNDP, also have plans to develop a number of conservation and development activities in key forest sites in the northwestern part of Tunisia (El Feija National Park).

Types and Severity of Threats

Deforestation has been extensive through the ecoregion. Today, human impact is still high, mainly due to the socio-economic instability of the Maghreb countries. The collapse of the semi-nomadic Berber pastoral system has transformed summer camps in the high mountain grasslands into permanent human settlements. A large amount of firewood is collected, in many cases illegally. Intensive collection of cedar branches frequently kills the trees. Furthermore, the need for livestock fodder during winter gives rise to extensive overgrazing and soil degradation in the forest understory. Overgrazing and land conversion into agriculture is also an important human impact in the broadleaf forest area.

Kif (Cannabis sativa) cultivation in the Rif Mountains is an important source of revenue for local people. During the 1960s, 85 percent of all income in some villages of the region was derived from this crop. Today, people make quick money by cutting and selling cedar and fir are for timber, as well as selling kif. Thus, illegal logging is common and is destroying a significant number of old-growth forest stands throughout the ecoregion.

Threats in the forested Djebel Babor Nature Reserve (Atlas Tellien, Algeria) and Talassemtane Reserve (Rif, Morocco) consist mostly of fires, overgrazing and illegal logging. In Djebel Babor, the number of Abies numidica trees has decreased by half since the 1950s, and in the Tazaot area in the Rif Mountains a 1977 forest fire destroyed almost all the Abies maroccana var. tazzaota forest stand. The threat from fire is still significant. Plant regeneration is still seriously affected by continuing high pressure from domestic livestock grazing.

Uncontrolled medicinal and aromatic plant harvesting constitutes an important threat to the survival of many endemic aromatic species and for the conservation of soil and vegetation cover in many mountain areas. European cosmetic enterprises take advantage of the legislation gaps in the Maghreb countries, promoting the devastation of many natural areas.

Mediterranean conifer forests are also extremely threatened by climate change. Intensification of summer droughts and increase in the average annual temperature could strongly modify the bioclimate conditions necessary for survival of these forests. Furthermore, human impacts have considerably reduced the forest’s resilience to survive natural disturbances. During periods of intense drought, cedar forest stands can become very dry and prone to fires.

The rural population in this ecoregion is high and still growing in and around protected areas. People’s needs are normally in conflict with protected areas under the existing legislation. Tunisian National Parks are fenced areas where human presence is forbidden, and people’s rights of use are not clearly established, resulting in numerous illegal activities such as logging and overgrazing.

Justification of Ecoregion Delineation

This ecoregion follows the vegetation unit that White defines as Mediterranean montane forest and Altimontane shrubland, although the altimontane area (above 3200 m) was extracted as a separate ecoregion. Lower elevation areas from Tunisia are included because their mixed deciduous and evergreen oak forests were once representative of this ecoregion. The high levels of endemics and relict taxa, particularly among plants, makes this ecoregion distinct.

Further Reading

  • For a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion.
  • Benabid, A. and M. Fennane. 1994. Connaissances sur la végétation du Maroc: phytogégraphie, phytosociologie et sèries de végétation. Lazaroa, 14: 21-97.
  • Blondel, J. and J. Aronson. 1999. Biology and wildlife of the Mediterranean region. Oxford University Press, Oxford. ISBN: 0198500351
  • Brandt, C.J. and J.B. Thornes, editors. 1996. Mediterranean Desertification and land use. Wiley, Chichester. ISBN: 0471942502
  • Barbéro, M. and P. Quézel. 1975. Les forets de sapin du pourtour méditerranéen. Anales del Instituto Botanico A.J. Cavanilles, 32 (2), 38 pp.
  • Charco J. 1999. El Bosque Mediterraneo en El Norte de Africa. Biodoversita y lucha contra la desertificacion. Agencia espagnola de cooperatioon internacional, Madrid.
  • Dallman, P.R. 1998. Plant Life in the world’s Mediterranean climates. Oxford University Press, Oxford. ISBN: 0520208099
  • Djellouli, Y. 1990. Flores et climats en Algérie Septentrionale. Déterminismes climatiques de la répartition des plantes. Thèse Doc. ès Sc. USTHB, Alger
  • Franco, J.A., 1986. Género Abies. Pages 164-167 in S. Castroviejo, editor. Flora ibérica: plantas vasculares de la Península Ibérica e Islas. Real Jardín Botánico, Madrid. Vol. I
  • Gómez-Campo, C, editor. 1985. Plant conservation in the Mediterranean area. W. Junk Publishers, Dordrecht. ASIN B000MUZD28.
  • Médail, F. and P. Quézel. 1997. Hot-spots analysis for conservation of plant biodiversity in the Mediterranean Basin. Annals of the Missouri Botanical Gardens 84: 112-127.
  • Mediouni, K. and R. Boutemine. 1988. Etude structurale et dynamique du peuplement de pin noir Pinus nigra ssp mauretanica du Djurdjura. Comm. Sem. Dehesas, Espagne. 12pp.
  • Mediouni, K. and N. Yahi. 1989. Etude structurale de la série du cèdre (Cedrus atlantica Manetti) d’Ait Ouabane (Djurdjura). Forêt Méditerranéenne, 11(2): 103-112. Marseille.
  • Mediouni K. 2000. Bilan, Stratégie et plan d’action d’utilisation durable de la diversité biologique algérienne, Direction Générale de l’Environnement/PNUD-GEF.
  • Ministère de l’Agriculture et de la mise en valeur agricole, 1992. Plan Directeur des Aires Protégées. VOL I, II. Royaume du Maroc.
  • Nowell, K., P. Jackson and IUCN/SSC Cat Specialist Group, editors. 1996. Wild cats: Status survey and conservation action plan. IUCN, Gland, Switzerland. ISBN: 2831700450
  • Ozenda, P. 1975. Sur les étages de végétation dans les montagnes du bassin méditerranéen. Doc. Cartogr. Ecolog. 16: 1-32.
  • Quézel, 1981. Les hautes montagnes du Maghreb et du Proche Orient : Essai de mise en parallèle des caractères phytogégraphiques. Actas III CONGR:OPTIMA. ANALES JARD. BOT. Madrid 37(2): 353-372
  • Quézel, P. 1983. Flore et végétation actuelles de l’Afrique du Nord, leur signification en fonction de l’origine, de l’évolution et des migrations des flores et structures de végétation passées. Bothalia, 14:3-4
  • Schoenenberger, A. 1995. Groupements végétaux des séries de végétation. La végétation forestière. Essai de synthèse sur la végètation et la phyto-écologie tunisiennes, II&III. Programme folore et végétation tunisiennes. Vols. 5 & 6
  • Stattersfield, A. J., M. J. Crosby, A. J. Long, and D. C. Wedge. 1998. Endemic Bird Areas of the World. Priorities for biodiversity conservation. BirdLife Conservation Series No. 7. BirdLife International, Cambridge, UK. ISBN: 1560985747
  • Thirgood, J.V. 1981. Man and the Mediterranean Forest. Academic Press. New York. ISBN: 0126872503
  • White, F. 1983. The vegetation of Africa, a descriptive memoir to accompany the UNESCO/AETFAT/UNSO Vegetation Map of Africa (3 Plates, Northwestern Africa, Northeastern Africa, and Southern Africa, 1:5,000,000). UNESCO, Paris.
  • WWF and IUCN. 1994. Centres of plant diversity. A guide and strategy for their conservation. Volume 1. Europe, Africa, South West Asia and the Middle East. IUCN Publications Unit, Cambridge, U.K. ISBN: 283170197X
  • WWF Mediterranean Programme Office. 2001. The Mediterranean Forests. A new conservation strategy.
  • WWF Mediterranean Programme Office. 2001. The major forest types in the Mediterranean. Map.
  • WWF. 1998. A conservation assessment of terrestrial ecoregions of Africa: Draft proceedings of a workshop, Cape Town, South Africa, August 1998. World Wildlife Fund, Washington, DC, USA.

Disclaimer: This article contains information that was originally published by the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth have edited its content and added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 

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Citation

Fund, W. (2014). Mediterranean conifer and mixed forests. Retrieved from http://www.eoearth.org/view/article/154551

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