Mediterranean forests, woodlands, and scrub

(Redirected from Mediterranean ecosystem)

Mediterranean forests, woodlands and scrub is a biome defined by the World Wide Fund for Nature.[1] The biome is generally characterized by dry summers and rainy winters, although in some areas rainfall may be uniform. Summers are typically hot in low-lying inland locations but can be cool near colder seas. Winters are typically mild to cool in low-lying locations but can be cold in inland and higher locations. All these ecoregions are highly distinctive, collectively harboring 10% of the Earth's plant species.[2]

Extent of Mediterranean forests, woodlands, and scrub
Jabal Moussa Biosphere Reserve in Lebanon

Distribution

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A Mediterranean forest, in the Region of Murcia (Spain).

The Mediterranean forests, woodlands, and scrub biome mostly occurs in, but not limited to, the Mediterranean climate zones, in the mid-latitudes:[1]

The biome is not limited to the Mediterranean climate zone. It can also be present in other climate zones (which typically border the Mediterranean climate zone), such as the drier regions of the oceanic and humid subtropical climates, and as well as the lusher areas of the semi-arid climate zone. Non-Mediterranean climate regions that would feature Mediterranean vegetation include the Nile River Valley in Egypt (extending upstream along the riverbanks), parts of the Eastern Cape in South Africa, southeastern Australia, southeastern Azerbaijan, southeastern Turkey, far northern Iraq, the Mazandaran Province in Iran, Central Italy, parts of the Balkans (including Northern Greece), as well as Northern and Western Jordan.[citation needed]

Vegetation

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Close up of Ephesos ancient Greek amphitheatre with a maquis shrubland

Vegetation types range from forests to woodlands, savannas, shrublands, and grasslands; "mosaic habitat" landscapes are common, where differing vegetation types are interleaved with one another in complex patterns created by variations in soil, topography, exposure to wind and sun, and fire history. Much of the woody vegetation in Mediterranean-climate regions is sclerophyll, which means 'hard-leaved' in Greek. Sclerophyllous vegetation generally has small, dark leaves covered with a waxy outer layer to retain moisture in the dry summer months.[citation needed]

Phytogeographers consider the fynbos (South Africa) as a separate floral kingdom because 68% of the 8,600 vascular plant species crowded into its 90,000 square kilometers (35,000 sq mi) are endemic and highly distinctive at several taxonomic levels.[1][3] This is equivalent to about 40% of the plant species of the United States and Canada combined, found within an area the size of the state of Maine. The fynbos and Southwest Australia shrublands have flora that are significantly more diverse than the other ecoregions, although any Mediterranean shrubland is still rich in species and endemics relative to other non-forest ecoregions.[1][3]

Biome plant groups

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Springtime in Chilean Matorral a few kilometers north of Santiago along the Pan-American Highway

Major plant communities in this biome include:

Fire as a medium of change

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Scrubland of the Sierra Pelona Mountains, Southern California

Fire, both natural and human-caused, has played a large role in shaping the ecology of Mediterranean ecoregions.[4] The hot, dry summers make much of the region prone to fires, and lightning-caused fires occur with some frequency. Many of the plants are pyrophytes, or fire-loving, adapted or even depending on fire for reproduction, recycling of nutrients, and the removal of dead or senescent vegetation. In both the Australian and Californian Mediterranean-climate eco-regions, native peoples used fire extensively to clear brush and trees, making way for the grasses and herbaceous vegetation that supported game animals and useful plants.[citation needed]

The plant communities in these areas adapted to the frequent human-caused fires, and pyrophyte species grew more common and more fire-loving, while plants that were poorly adapted to fire retreated. After European colonization of these regions, fires were suppressed, which has caused some unintended consequences in these ecoregions; fuel builds up, so that when fires do come they are much more devastating, and some species dependent on fire for their reproduction are now threatened. The European shrublands have also been shaped by anthropogenic fire,[5] historically associated with transhumance herding of sheep and goats.

Though adapted to infrequent fires, chaparral plant communities can be eliminated by frequent fires. A high frequency of fire (less than ten years) will result in the loss of obligate seeding shrub species such as Manzanita spp. This high frequency disallows seeder plants to reach their reproductive size before the next fire and the community shifts to a sprouter-dominance. If high frequency fires continue over time, obligate resprouting shrub species can also be eliminated by exhausting their energy reserves below-ground. Today, frequent accidental ignitions can convert chaparral from a native shrubland to non-native annual grassland and drastically reduce species diversity, especially under drought brought about by climate change.[6][7]

On 25 July 2023, devastating wildfires were burning in at least nine countries across the Mediterranean, including Croatia, Italy, and Portugal, with thousands of firefighters in Europe and North Africa working to contain flames stoked by high temperatures, dry conditions, and strong winds. The wildfires led to casualties, evacuations of thousands of people, and widespread destruction of homes and forests.[8]

Degradation

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Mediterranean cork oak trees, in Monchique, Algarve, Portugal
 
Sclerophyll woodland, Sydney
 
Festival of degradation VRUJA established by activists and artists in 2021 in Dalmatia, Croatia

Mediterranean ecoregions are some of the most endangered and vulnerable on the planet. Many have suffered tremendous degradation and habitat loss through logging, overgrazing, conversion to agriculture, urbanization, fire suppression, and introduction of exotic and invasive species. The ecoregions around the Mediterranean basin and in California have been particularly affected by degradation due to human activity, suffering extensive loss of forests and soil erosion, and many native plants and animals have become extinct or endangered.

See also

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References

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  1. ^ a b c d   This article incorporates text available under the CC BY-SA 3.0 license. World Wide Fund for Nature. "Mediterranean Forests, Woodlands, and Scrub Ecoregions". Archived from the original on 1 April 2011. Retrieved 27 May 2010.
  2. ^ Cody, M.L. (1986). "Diversity, rarity, and conservation in Mediterranean-climate regions". In Soulé, M.E. (ed.). Conservation biology. Massachusetts, US. pp. 122–152.{{cite book}}: CS1 maint: location missing publisher (link)
  3. ^ a b Cowling, R.M.; MacDonald, I.A.W.; Simmons, M.T. (1996). "The Cape Peninsula, South Africa: Physiographical, biological and historical background to an extraordinary hot-spot of biodiversity". Biodiversity and Conservation. 5 (5): 527–550. Bibcode:1996BiCon...5..527C. doi:10.1007/bf00137608. S2CID 23314811.
  4. ^ Gil-Tena, Assu; Aquilue, Nuria; Duane, Andrea; de Caceres, Miquel; Brotons, Lluis (2016). "Mediterranean fire regime effects on pine-oak forest landscape mosaics under global change in NE Spain". European Journal of Forest Research. 135 (2): 403–416. doi:10.1007/s10342-016-0943-1. S2CID 15011913.
  5. ^ Casals, Pere; Valor, Teresa; Besalú, Arnau; Molina-Terren, Domingo (2016). "Understory fuel load and structure eight to nine years after prescribed burning in Mediterranean pine forests" (PDF). Forest Ecology and Management. 362: 156–168. Bibcode:2016ForEM.362..156C. doi:10.1016/j.foreco.2015.11.050. Archived (PDF) from the original on 24 February 2021. Retrieved 25 July 2016.
  6. ^ Syphard, Alexandra D.; Radeloff, Volker C.; Keeley, Jon E.; Hawbaker, Todd J.; Clayton, Murray K.; Stewart, Susan I.; Hammer, Roger B. (1 July 2007). "Human Influence on California Fire Regimes". Ecological Applications. 17 (5): 1388–1402. Bibcode:2007EcoAp..17.1388S. doi:10.1890/06-1128.1. ISSN 1939-5582. PMID 17708216.
  7. ^ Pratt, R. Brandon; Jacobsen, Anna L.; Ramirez, Aaron R.; Helms, Anjel M.; Traugh, Courtney A.; Tobin, Michael F.; Heffner, Marcus S.; Davis, Stephen D. (1 March 2014). "Mortality of resprouting chaparral shrubs after a fire and during a record drought: physiological mechanisms and demographic consequences". Global Change Biology. 20 (3): 893–907. Bibcode:2014GCBio..20..893P. doi:10.1111/gcb.12477. ISSN 1365-2486. PMID 24375846. S2CID 19688559.
  8. ^ Sullivan, Helen; Tondo, Lorenzo (26 July 2023). "'Like a blowtorch': Mediterranean on fire as blazes spread across nine countries". The Guardian. Archived from the original on 31 July 2023. Retrieved 31 July 2023.
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