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Laurel forest, also calledlaurisilva orlaurissilva, is a type ofsubtropicalforest found in areas with highhumidity and relatively stable, mild temperatures. The forest is characterized bybroadleaf tree species withevergreen, glossy andelongated leaves, known as "laurophyll" or "lauroid". Plants from the laurel family (Lauraceae) may or may not be present, depending on the location.
Laurel and laurophyll forests have a patchy distribution in warmtemperate regions, often occupying topographic refugia where themoisture from the ocean condenses so that it falls as rain or fog and soils have high moisture levels.[1] They have a mildclimate, seldom exposed tofires orfrosts and are found in relatively acidic soils.Primary productivity is high, but can be limited by mild summer drought. The canopies are evergreen, dominated by species with glossy- or leathery-leaves, and with moderate tree diversity.Insects are the most important herbivores, butbirds andbats are the predominant seed-dispersers andpollinators.Decomposers such as invertebrates, fungi, and microbes on the forest floor are critical tonutrient cycling.[2]
These conditions of temperature and moisture occur in four differentgeographical regions:
Some laurel forests are a type ofcloud forest. Cloud forests are found on mountain slopes where the dense moisture from the sea or ocean is precipitated as warm moist air masses blowing off the ocean are forced upwards by the terrain, which cools the air mass to thedew point. The moisture in the air condenses as rain or fog, creating a habitat characterized by cool, moist conditions in the air and soil. The resulting climate is wet and mild, with the annual oscillation of the temperature moderated by the proximity of the ocean.[citation needed]
Laurel forests are characterized by evergreen and hardwood trees, reaching up to 40 m (130 ft) in height. Laurel forest, laurisilva, and laurissilva all refer to plant communities that resemble thebay laurel.[citation needed]
Some species belong to the true laurel family,Lauraceae, but many have similar foliage to the Lauraceae due toconvergent evolution. As in any other rainforest, plants of the laurel forests must adapt to high rainfall and humidity. The trees have adapted in response to these ecological drivers by developinganalogous structures, leaves that repel water.Laurophyll orlauroid leaves are characterized by a generous layer ofwax, making them glossy in appearance, and a narrow, pointed oval shape with anapical mucro or "drip tip", which permits the leaves to shed water despite the humidity, allowing respiration. The scientific nameslaurina,laurifolia,laurophylla,lauriformis, andlauroides are often used to name species of other plant families that resemble the Lauraceae.[6] The termLucidophyll, referring to the shiny surface of the leaves, was proposed in 1969 by Tatuo Kira.[7] The scientific namesDaphnidium,Daphniphyllum,Daphnopsis,Daphnandra,Daphne[8] from Greek: Δάφνη, meaning "laurel",laurus,Laureliopsis,laureola,laurelin,laurifolia,laurifolius,lauriformis,laurina,Prunus laurocerasus (cherry laurel),Prunus lusitanica (Portugal laurel),Corynocarpus laevigatus (New Zealand Laurel), andCorynocarpus rupestris designate species of other plant families whose leaves resemble Lauraceae.[6] The term "lauroid" is also applied to climbing plants such asivies, whose waxy leaves somewhat resemble those of the Lauraceae.
Mature laurel forests typically have a densetree canopy and low light levels at the forest floor.[7] Some forests are characterized by an overstory ofemergent trees.
Laurel forests are typically multi-species, and diverse in both the number of species and the genera and families represented.[7] In the absence of strong environmental selective pressure, the number of species sharing the arboreal stratum is high, although not reaching the diversity of tropical forests; nearly 100 tree species have been described in the laurisilva rainforest ofMisiones (Argentina), about 20 in the Canary Islands. This species diversity contrasts with other temperate forest types, which typically have a canopy dominated by one or a few species. Species diversity generally increases towards the tropics.[9] In this sense, the laurel forest is a transitional type between temperate forests and tropical rainforests.[citation needed]
Laurel forests are composed ofvascular plants that evolved millions of years ago. Lauroid floras have included forests ofPodocarpaceae andsouthern beech.
This type of vegetation characterized parts of the ancientsupercontinent ofGondwana and once covered much of thetropics. Some lauroid species that are found outside laurel forests arerelicts of vegetation that covered much of the mainland ofAustralia, Europe, South America, Antarctica, Africa, and North America when their climate was warmer and more humid. Cloud forests are believed to have retreated and advanced during successive geological eras, and their species adapted to warm and wet conditions were replaced by more cold-tolerant or drought-tolerantsclerophyll plant communities. Many of the late Cretaceous – early Tertiary Gondwanan species of flora became extinct, but some survived as relict species in the milder, moister climate of coastal areas and on islands.[10] Thus Tasmania and New Caledonia share related species extinct on the Australian mainland, and the same case occurs on theMacaronesia islands of the Atlantic and on theTaiwan,Hainan,Jeju,Shikoku,Kyūshū, andRyūkyū Islands of the Pacific.[citation needed]
Although some remnants of archaic flora, including species and genera extinct in the rest of the world, have persisted as endemic to such coastal mountain and shelter sites, their biodiversity was reduced. Isolation in these fragmented habitats, particularly on islands, has led to the development ofvicariant species and genera. Thus, fossils dating from before thePleistoceneglaciations show that species ofLaurus were formerly distributed more widely around the Mediterranean andNorth Africa. Isolation gave rise toLaurus azorica in the Azores Islands,Laurus nobilis on the mainland, andLaurus novocanariensis in the Madeira and the Canary Islands.[citation needed]
Laurel forests occur in small areas where their particular climatic requirements prevail, in both the northern and southern hemispheres. Inner laurel forest ecoregions, a related and distinct community ofvascular plants, evolved millions of years ago on the supercontinent ofGondwana, and species of this community are now found in several separate areas of theSouthern Hemisphere, including southernSouth America, southernmostAfrica,New Zealand,Australia andNew Caledonia. Most Laurel forest species are evergreen, and occur in tropical, subtropical, and mild temperate regions andcloud forests of the northern and southern hemispheres, in particular theMacaronesian islands, southernJapan,Madagascar,New Caledonia,Tasmania, and centralChile, but they are pantropical, and for example in Africa they are endemic tothe Congo region,Cameroon,Sudan,Tanzania, andUganda, in lowland forest andAfromontane areas.Since laurel forests are archaic populations that diversified as a result of isolation on islands and tropical mountains, their presence is a key to dating climatic history.[citation needed]
Laurel forests are common in subtropical eastern Asia, and form the climax vegetation in far southern Japan,Taiwan, southern China, the mountains ofIndochina, and the easternHimalayas. In southern China, laurel forest once extended throughout the Yangtze Valley and Sichuan Basin from theEast China Sea to theTibetan Plateau. The northernmost laurel forests in East Asia occur at 39° N. on the Pacific coast of Japan. Altitudinally, the forests range from sea-level up to 1000 metres in warm-temperate Japan, and up to 3000 metres elevation in the subtropical mountains of Asia.[9] Some forests are dominated byLauraceae, while in others evergreen laurophyll trees of the beech family (Fagaceae) are predominant, including ring-cupped oaks (Quercus subgenusCyclobalanopsis), chinquapin (Castanopsis) and tanoak (Lithocarpus).[7] Other characteristic plants includeSchima andCamellia, which are members of the tea family (Theaceae), as well asmagnolias,bamboo, andrhododendrons.[11] These subtropical forests lie between the temperate deciduous and conifer forests to the north and the subtropical/tropical monsoon forests of Indochina and India to the south.
Associations of Lauraceous species are common in broadleaved forests; for example,Litsea spp.,Persea odoratissima,Persea duthiei, etc., along with such others asEngelhardia spicata, tree rhododendron (Rhododendron arboreum),Lyonia ovalifolia, wild Himalayan pear (Pyrus pashia), sumac (Rhus spp.), Himalayan maple (Acer oblongum), box myrtle (Myrica esculenta),Magnolia spp., and birch (Betula spp.). Some other common trees and large shrub species of subtropical forests areSemecarpus anacardium,Crateva unilocularis,Trewia nudiflora,Premna interrupta, Vietnam elm (Ulmus lancifolia),Ulmus chumlia,Glochidion velutinum, beautyberry (Callicarpa arborea), Indian mahogany (Toona ciliata), fig tree (Ficus spp.),Mahosama similicifolia,Trevesia palmata, brushholly (Xylosma longifolium), false nettle (Boehmeria rugulosa),Heptapleurum venulosum,Casearia graveilens,Actinodaphne reticulata,Sapium insigne, Nepalese alder (Alnus nepalensis), marlberry (Ardisia thyrsiflora), holly (Ilex spp),Macaranga pustulata,Trichilia cannoroides, hackberry (Celtis tetrandra),Wenlendia puberula,Saurauia nepalensis, ring-cupped oak (Quercus glauca),Ziziphus incurva,Camellia kissi,Hymenodictyon flaccidum,Maytenus thomsonii, winged prickly ash (Zanthoxylum armatum),Eurya acuminata, matipo (Myrsine semiserrata),Sloanea tomentosa,Hydrangea aspera,Symplocos spp., andCleyera spp.
In the temperate zone, the cloud forest between 2,000 and 3,000 m altitude supports broadleaved evergreen forest dominated by plants such asQuercus lamellosa andQ. semecarpifolia in pure or mixed stands.Lindera andLitsea species, Himalayan hemlock (Tsuga dumosa), andRhododendron spp. are also present in the upper levels of this zone. Other important species areMagnolia campbellii,Michelia doltsopa, andromeda (Pieris ovalifolia),Daphniphyllum himalense,Acer campbellii,Acer pectinatum, andSorbus cuspidata, but these species do not extend toward the west beyond central Nepal. Nepalese alder (Alnus nepalensis), a pioneer tree species, grows gregariously and forms pure patches of forests on newly exposed slopes, in gullies, beside rivers, and in other moist places.
The common forest types of this zone includeRhododendron arboreum,Rhododendron barbatum,Lyonia spp.,Pieris formosa;Tsuga dumosa forest with such deciduous taxa as maple (Acer) andMagnolia; deciduous mixed broadleaved forest ofAcer campbellii, Acer pectinatum, Sorbus cuspidata, andMagnolia campbellii; mixed broadleaved forest ofRhododendron arboreum, Acer campbellii,Symplocos ramosissima and Lauraceae.
This zone is habitat for many other important tree and large shrub species such as pindrow fir (Abies pindrow), East Himalayan fir (Abies spectabilis),Acer campbellii, Acer pectinatum, Himalayan birch (Betula utilis),Betula alnoides, boxwood (Buxus rugulosa), Himalayan flowering dogwood (Cornus capitata), hazel (Corylus ferox),Deutzia staminea, spindle (Euonymus tingens), Siberian ginseng (Acanthopanax cissifolius),Coriaria terminalis ash (Fraxinus macrantha),Dodecadenia grandiflora,Eurya cerasifolia,Hydrangea heteromala,Ilex dipyrena, privet (Ligustrum spp.),Litsea elongata, common walnut (Juglans regia),Lichelia doltsopa,Myrsine capitallata,Neolitsea umbrosa, mock-orange (Philadelphus tomentosus), sweet olive (Osmanthus fragrans), Himalayan bird cherry (Prunus cornuta), andViburnum continifolium.
In ancient times, laurel forests (shoyojurin) were the predominant vegetation type in theTaiheiyo evergreen forests ecoregion of Japan, which encompasses the mild temperate climate region of southeastern Japan's Pacific coast. There were three main types of evergreen broadleaf forests, in whichCastanopsis,Machilus, orQuercus predominated. Most of these forests were logged or cleared for cultivation and replanted with faster-growingconifers, likepine orhinoki, and only a few pockets remain.[12]
Laurel forests occupy the humid tropical highlands of theMalay Peninsula,Greater Sunda Islands, and Philippines above 1,000 m (3,300 ft) elevation. The flora of these forests is similar to that of the warm-temperate and subtropical laurel forests of East Asia, including oaks(Quercus), tanoak(Lithocarpus), chinquapin(Castanopsis), Lauraceae,Theaceae, andClethraceae.
Epiphytes, including orchids, ferns, moss, lichen, and liverworts, are more abundant than in either temperate laurel forests or the adjacent lowland tropical rain forests.Myrtaceae are common at lower elevations, and conifers and rhododendrons at higher elevations. These forests are distinct in species composition from the lowland tropical forests, which are dominated byDipterocarps and other tropical species.[13]
Laurel forests are found in the islands ofMacaronesia in the eastern Atlantic, in particular theAzores,Madeira Islands, andCanary Islands from 400 to 1200 metres elevation. Trees of the generaApollonias (Lauraceae),Ocotea (Lauraceae),Persea (Lauraceae),Clethra (Clethraceae),Dracaena (Asparagaceae),Picconia (Oleaceae) andHeberdenia (Primulaceae) are characteristic.[14] TheGarajonay National Park, on the island ofLa Gomera and the Laurisilva in theMadeira Island were designatedWorld Heritage sites byUNESCO in 1986 and 1999, respectively. They are considered the best remaining examples of the Atlantic laurel forest, due to their intact nature.[15] The paleobotanical record of the island of Madeira reveals that laurisilva forests have existed on this island for at least 1.8 million years.[16]
Around 50 million years ago, during thePaleocene, Europe took the form of a set of large islands spread through what was theTethys Sea. The climate was wet andtropical with monsoon summer rains.[17] Trees of the laurel andFagaceae family (oaks with lauroid-shape leaves andCastanopsis) were common along several species of ferns.[18][19] Around theEocene, the planet began cooling, ultimately leading to thePleistocene glaciations. This progressively deteriorated the Paleotropical flora of Europe, which went extinct in the latePliocene. Some of these species went globally extinct (e.g. laurophyllQuercus), others survived in the Atlantic islands (e.g.Ocotea), or in other continents (e.g.Magnolia,Liquidambar) and some adapted to the cooler and drier climate of Europe and persisted as relicts in places with high mean annual precipitation or in particular river basins, such as sweet bay(Laurus nobilis) and European holly(Ilex aquifolium), which are fairly widespread around the Mediterranean basin.[20]
Descendants of these species can be found today in Europe, throughout the Mediterranean, especially in theIberian Peninsula and the southernBlack Sea Basin. The most important isivy, a climber or vine that is well represented in most of Europe, where it spread again after the glaciations. The portuguese laurel cherry (Prunus lusitanica) is the only tree that survives as a relict in someIberian riversides, especially in the western part of the peninsula. In other cases, the presence of Mediterranean laurel (Laurus nobilis) provides an indication of the previous existence of laurel forest. This species survives natively inMorocco,Algeria,Tunisia,Spain,Portugal,Italy,Greece, the Balkans, and the Mediterranean islands. Themyrtle spread through North Africa.Tree heath(Erica arborea) grows in southern Europe, but without reaching the dimensions observed in the temperate evergreen forest of Macaronesia or North Africa. The broad-leavedRhododendron ponticum baeticum and/orRhamnus frangula baetica still persist in humid microclimates, such as stream valleys, in the provinces ofCádiz andMálaga inSpain,[21] in the PortugueseSerra de Monchique, and theRif Mountains ofMorocco.[22][verification needed] TheParque Natural de Los Alcornocales has the biggest and best preserved relicts of Laurisilva inWestern Europe.[23]
Although the Atlantic laurisilva is more abundant in the Macaronesian archipelagos, where the weather has fluctuated little since theTertiary, there are small representations and some species contribution to the oceanic and Mediterranean ecoregions of Europe,Asia minor and west and north of Africa, where microclimates in the coastal mountain ranges form inland "islands" favorable to the persistence of laurel forests. In some cases these were genuine islands in the Tertiary, and in some cases simply areas that remained ice-free. When theStrait of Gibraltar reclosed, the species repopulated toward the Iberian Peninsula to the north and were distributed along with other African species, but the seasonally drier and colder climate, prevented them reaching their previous extent. In Atlantic Europe, subtropical vegetation is interspersed with taxa from Europe and North Africa in bioclimatic enclaves such as the Serra de Monchique,Sintra, and the coastal mountains fromCadiz toAlgeciras. In the Mediterranean region, remnant laurel forest is present on some islands of theAegean Sea, on theBlack Sea coast ofGeorgia andTurkey, and theCaspian Sea coast ofAzerbaijan andIran, including theCastanopsis and truelaurus forests, associated withPrunus laurocerasus, and conifers such asTaxus baccata,Cedrus atlantica, andAbies pinsapo.
In Europe the laurel forest has been badly damaged by timber harvesting, by fire (both accidental and deliberate to open fields for crops), by the introduction of exotic animal and plant species that have displaced the original cover, and by replacement with arable fields, exotic timber plantations, cattle pastures, andgolf courses and tourist facilities. Most of thebiota is in serious danger of extinction. The laurel forest flora is usually strong and vigorous and the forest regenerates easily; its decline is due to external forces.[citation needed]
In the Himalayas, in Nepal, subtropical forest consists of species such asSchima wallichii,Castanopsis indica, andCastanopsis tribuloides in relatively humid areas. Some common forest types in this region includeCastanopsis tribuloides mixed withSchima wallichi,Rhododendron spp.,Lyonia ovalifolia,Eurya acuminata, andQuercus glauca;Castanopsis-Laurales forest withSymplocas spp.;Alnus nepalensis forests;Schima wallichii-Castanopsis indica hygrophile forest;Schima-Pinus forest;Pinus roxburghii forests withPhyllanthus emblica.Semicarpus anacardium,Rhododendron arboreum andLyoma ovalifolia;Schima-Lagerstroemia parviflora forest,Quercus lamellosa forest withQuercus lanata andQuercus glauca;Castanopsis forests withCastanopsis hystrix and Lauraceae.[citation needed]
Laurel forests are also prevalent in the montane rain forests of theWestern Ghats in southernIndia.
Laurel forest occurs in the montane rain forest ofSri Lanka.[9]
TheAfromontane laurel forests describe the plant and animal species common to the mountains ofAfrica and the southernArabian Peninsula. The afromontane regions of Africa are discontinuous, separated from each other by lowlands, resembling a series of islands in distribution. Patches of forest with Afromontane floristic affinities occur all along the mountain chains. Afromontane communities occur above 1,500–2,000 m (4,900–6,600 ft) elevation near the equator, and as low as 300 m (980 ft) elevation in theKnysna-Amatole montane forests ofSouth Africa. Afromontane forests are cool and humid. Rainfall is generally greater than 700 mm/a (28 in/year), and can exceed 2,000 mm (79 in) in some regions, occurring throughout the year or during winter or summer, depending on the region. Temperatures can be extreme at some of the higher altitudes, where snowfalls may occasionally occur.
InSubsaharan Africa, laurel forests are found in theCameroon Highlands forests along the border ofNigeria andCameroon, along the East African Highlands, a long chain of mountains extending from theEthiopian Highlands around theAfrican Great Lakes toSouth Africa, in the Highlands ofMadagascar, and in the montane zone of theSão Tomé, Príncipe, and Annobón forests. These scattered highland laurophyll forests of Africa are similar to one another in species composition (known as theAfromontane flora), and distinct from the flora of the surrounding lowlands.
The main species of the Afromontane forests include the broadleaf canopy trees of genusBeilschmiedia, withApodytes dimidiata,Ilex mitis,Nuxia congesta,N. floribunda,Kiggelaria africana,Prunus africana,Rapanea melanophloeos,Halleria lucida,Ocotea bullata, andXymalos monospora, along with the emergent conifersPodocarpus latifolius andAfrocarpus falcatus. Species composition of the Subsaharan laurel forests differs from that of Eurasia. Trees of theLaurel family are less prominent, limited toOcotea orBeilschmiedia due to exceptionalbiological andpaleoecological interest and the enormousbiodiversity mostly but with many endemic species, and the members of the beech family (Fagaceae) are absent.[9]
Trees can be up to 30 or 40 m (98 or 131 ft) tall and distinct strata of emergent trees, canopy trees, and shrub and herb layers are present. Tree species include: Real Yellowwood (Podocarpus latifolius), Outeniqua Yellowwood (Podocarpus falcatus), White Witchhazel (Trichocladus ellipticus),Rhus chirendensis,Curtisia dentata,Calodendrum capense,Apodytes dimidiata,Halleria lucida,Ilex mitis,Kiggelaria africana,Nuxia floribunda,Xymalos monospora, andOcotea bullata. Shrubs and climbers are common and include: Common Spikethorn (Maytenus heterophylla), Cat-thorn (Scutia myrtina), Numnum (Carissa bispinosa),Secamone alpinii,Canthium ciliatum,Rhoicissus tridentata,Zanthoxylum capense, andBurchellia bubalina. In the undergrowth grasses, herbs and ferns may be locally common: Basketgrass (Oplismenus hirtellus), Bushman Grass (Stipa dregeana var.elongata), Pigs-ears (Centella asiatica),Cyperus albostriatus,Polypodium polypodioides,Polystichum tuctuosum,Streptocarpus rexii, andPlectranthus spp. Ferns, shrubs and small trees such asCape Beech (Rapanea melanophloeos) are often abundant along the forest edges.[citation needed]
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According to the recent study by Box and Fujiwara (Evergreen Broadleaved Forests of the Southeastern United States: Preliminary Description), laurel forests occur in patches in the southeastern United States from southeastVirginia southward toFlorida, and west toTexas, mostly along the coast and coastal plain of the Gulf and south Atlantic coast. In the southeastern United States, evergreenHammock (ecology) (i.e. topographically induced forest islands) contain many laurel forests. These laurel forests occur mostly in moist depression and floodplains, and are found in moist environments. In many portions of the coastal plain, a low-lying mosaic topography of white sand, silt, andlimestone (mostly inFlorida), separate these laurel forests. Frequent fire is also thought to be responsible for the disjointed geography of laurel forests across the coastal plain of the southeastern United States.
Despite being located in a humid climate zone, much of the broadleaf Laurel forests in the Southeast USA are semi-sclerophyll in character. The semi-sclerophyll character is due (in part) to the sandy soils and often periodic semi-arid nature of the climate. As one moves south into central Florida, as well as far southern Texas and the Gulf Coastal margin of the southern United States, the sclerophyll character slowly declines and more tree species from the tropics (specifically, theCaribbean andMesoamerica) increase as the temperate species decline. As such, the southeastern laurel forests gives way to a mixed landscape oftropical savanna andtropical rainforest.
There are several different broadleaved evergreen canopy trees in the laurel forests of the southeastern United States. In some areas, the evergreen forests are dominated by species of Live oak (Quercus virginiana), Laurel oak (Quercus hemisphaerica), southern magnolia (Magnolia grandiflora), red bay (Persea borbonia), cabbage palm (Sabal palmetto), and sweetbay magnolia (Magnolia virginiana). In several areas on the barrier islands, a stuntedQuercus geminata or mixedQ. geminata andQuercus virginiana forest dominates, with a dense evergreen understory of scrub palmSerenoa repens and a variety of vines, includingBignonia capreolata, as well asSmilax andVitis species'.Gordonia lasianthus,Ilex opaca andOsmanthus americanus also may occur as canopy co-dominant in coastal dune forests, withCliftonia monophylla andVaccinium arboreum as a dense evergreen understory (Box and Fujiwara 1988).
The lowershrub layer of the evergreen forests is often mixed with other evergreen species from the palm family (Rhapidophyllum hystrix), bush palmetto (Sabal minor), and saw palmetto (Serenoa repens), and several species in the Ilex family, includingIlex glabra,Dahoon holly, andYaupon holly. In many areas,Cyrilla racemiflora,Lyonia fruticosa, wax myrtleMyrica is present as an evergreen understory. Several species ofYucca andOpuntia are native as well to the drier sandy coastal scrub environment of the region, includingYucca aloifolia,Yucca filamentosa,Yucca gloriosa, andOpuntia stricta.
During theMiocene, oak-laurel forests were found in Central and SouthernCalifornia. Typical tree species included oaks ancestral to present-day California oaks, as well as an assemblage of trees from the Laurel family, includingNectandra,Ocotea,Persea, andUmbellularia.[24][25] Only one native species from the Laurel family (Lauraceae),Umbellularia californica, remains in California today.
There are however, several areas in Mediterranean California, as well as isolated areas of southernOregon that have evergreen forests. Several species of evergreenQuercus forests occur, as well as a mix of evergreen scrub typical ofMediterranean climates. Species ofNotholithocarpus,Arbutus menziesii, andUmbellularia californica can be canopy species in several areas.[citation needed]
The laurel forest is the most commonCentral American temperate evergreen cloud forest type. They are found in mountainous areas of southernMexico and almost all Central American countries, normally more than 1,000 m (3,300 ft) above sea level. Tree species include evergreen oaks, members of the Laurel family, and species ofWeinmannia,Drimys, andMagnolia.[26] The cloud forest ofSierra de las Minas,Guatemala, is the largest in Central America. In some areas of southeasternHonduras there are cloud forests, the largest located near the border withNicaragua. InNicaragua thecloud forests are found in the border zone with Honduras, and most were cleared to growcoffee. There are still some temperate evergreen hills in the north. The only cloud forest in the Pacific coastal zone of Central America is on theMombacho volcano in Nicaragua. InCosta Rica there are laurisilvas in the "Cordillera deTilarán" andVolcán Arenal, calledMonteverde, also in theCordillera de Talamanca.[citation needed]
TheYungas are typically evergreen forests or jungles, and multi-species, which often contain many species of the laurel forest. They occur discontinuously fromVenezuela to northwesternArgentina including inBrazil,Bolivia,Chile,Colombia,Ecuador, andPeru, usually in the Sub-Andean Sierras. The forest relief is varied and in places where the Andes meet the Amazon, it includes steeply sloped areas. Characteristic of this region are deep ravines formed by the rivers, such as that of theTarma River descending to the San Ramon Valley, or theUrubamba River as it passes throughMachu Picchu. Many of the Yungas are degraded or are forests in recovery that have not yet reached theirclimax vegetation.[citation needed]
The laurel forests of the region are known as theLaurisilva Misionera, after Argentina'sMisiones Province. TheAraucaria moist forests occupy a portion of the highlands of southern Brazil, extending into northeastern Argentina. The forest canopy includes species of Lauraceae (Ocotea pretiosa,O. catharinense andO. porosa), Myrtaceae (Campomanesia xanthocarpa), and Leguminosae (Parapiptadenia rigida), with an emergent layer of the conifer Brazilian Araucaria (Araucaria angustifolia) reaching up to 45 m (148 ft) in height.[27] The subtropicalSerra do Mar coastal forests along the southern coast of Brazil have a tree canopy of Lauraceae and Myrtaceae, with emergent trees of Leguminaceae, and a rich diversity ofbromeliads and trees and shrubs of familyMelastomaceae.[28] The inlandAlto Paraná Atlantic forests, which occupy portions of the Brazilian Highlands in southern Brazil and adjacent parts of Argentina and Paraguay, are semi-deciduous.[citation needed]
The Valdivian temperate rain forests, orLaurisilva Valdiviana, occupy southernChile andArgentina from the Pacific Ocean to theAndes between 38° and 45° latitude. Rainfall is abundant, from 1,500 to 5,000 mm (59–197 in) according to locality, distributed throughout the year, but with some subhumid Mediterranean climate influence for 3–4 months in summer. The temperatures are sufficiently invariant and mild, with no month falling below 5 °C (41 °F), and the warmest month below 22 °C (72 °F).
Laurel forest appears on mountains of the coastal strip of New South Wales inAustralia,New Guinea,New Caledonia,Tasmania, andNew Zealand. The laurel forests of Australia, Tasmania, and New Zealand are home to species related to those in the Valdivian laurel forests,
Beilschmiedia tawa is often the dominant canopy species of the laural genusBeilschmiedia in lowland laurel forests in theNorth Island and the northeast of theSouth Island, but will also often form the subcanopy in primary forests throughout the country in these areas, withpodocarps. GenusBeilschmiedia are trees andshrubs widespread in tropicalAsia,Africa,Australia,New Zealand,Central America, theCaribbean, andSouth America as far south asChile. In theCorynocarpus family,Corynocarpus laevigatus is sometimes called laurel of New Zealand, whileLaurelia novae-zelandiae belongs to the same genus asLaurelia sempervirens. The treeniaouli grows in Australia, New Caledonia, and Papua.
TheNew Guinea and Northern Australian ecoregions are also closely related.[citation needed]
The eastern end ofMalesia, includingNew Guinea and theAru Islands of eastern Indonesia, is linked to Australia by a shallow continental shelf, and shares manymarsupial mammal and birdtaxa with Australia. New Guinea also has many additional elements of the Antarctic flora, including southern beech (Nothofagus) andEucalypts. New Guinea has the highest mountains inMalesia, and vegetation ranges from tropical lowland forest totundra.
The highlands of New Guinea andNew Britain are home to montane laurel forests, from about 1,000 to 2,500 m (3,300–8,200 ft) elevation. These forests include species typical of both Northern Hemisphere laurel forests, includingLithocarpus,Ilex, and Lauraceae, and Southern Hemisphere laurel forests, including Southern BeechNothofagus,Araucaria,Podocarps, and trees of the Myrtle family (Myrtaceae).[9][29] New Guinea and Northern Australia are closely related. Around 40 million years ago, theIndo-Australian tectonic plate began to split apart from the ancient supercontinent Gondwana. As it collided with thePacific Plate on its northward journey, the high mountain ranges of centralNew Guinea emerged around 5 million years ago.[30] In the lee of this collision zone, the ancient rock formations of what is nowCape York Peninsula remained largely undisturbed.[citation needed]
TheWWF identifies several distinct montane laurel forest ecoregions on New Guinea, New Britain, and New Ireland.[31]
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