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Short-Snouted New Caledonian Gecko

Short-Snouted New Caledonian Gecko

Rhacodactylus chahoua commonly known as the Mossy New Caledonian gecko or short-snouted New Caledonian gecko, is an arboreal gecko found natively on the southern portion of the island of New Caledonia and on the outlying islands of Ile de Pines and Grande Terre. R. chahoua is currently being evaluated by CITES as a possible candidate for protective status. R. chahoua was first described by Bavay in 1869. R. chahoua gets its common name from the moss or lichen-like pattern it displays. Colors range from rusty red and brown to green or gray. There has been some notation that color could possibly be a geographic indicator in this species as the geckos from the outter islands most often display the lighter gray patterns. It commonly reaches a snout to vent length (SVL) of 5.5 inches. R. chahoua, like all of the Rhacodactylus geckos are omnivores. Their diet in the wild consists of various insects and fruits. They may also consume small lizards as part of their diet. R. chahoua lays two well calcified eggs that become adhered to one another shortly after laying. This is known as "egg gluing". R. chahoua is the only Rhacodactylus gecko that lays adhering eggs. The eggs are generally laid ontop of the substrate (generally behind loose tree bark) and are guarded by the female. The eggs hatch 60-90 days after laying. This gecko is seen in the herpetology trade but rarely. A male-female pair may be kept in a terrarium with a minimum size of 24x18x18, but with all arboreal geckos, the taller the better. Category:Geckos

Arboreal

, the tallest tree species on earth]] A tree can be defined as a large, perennial, woody plant. Though there is no set definition regarding minimum size, the term generally applies to plants at least 6 m (20 ft) high at maturity and, more importantly, having secondary branches supported on a single main stem or trunk (see shrub for comparison). Compared with most other plant forms, trees are long-lived. A few species of trees grow to 100 m tall, and some can live for several thousand years. Trees are important components of the natural landscape and significant elements in landscaping, and in agriculture supplying orchard crops (such as apples). Trees also play an important role in many of the world's mythologies (see Tree (mythology)).

Classifications

Tree (mythology)]] A tree is a plant form and trees occur in many different orders and families of plants. Trees thus show a wide variety of growth form, leaf type and shape, bark characteristics, reproductive structures, etc. The earliest trees were tree ferns and horsetails, which grew in vast forests in the Carboniferous Period; tree ferns still survive, but the only surviving horsetails are not of tree form. Later, in the Triassic Period, conifers, ginkgos, cycads and other gymnosperms appeared, and subsequently flowering plants in the Cretaceous Period. Most species of trees today are flowering plants and conifers. The listing below gives examples of many well-known trees and how they are typically classified. A small group of trees growing together is called a grove or copse, and a landscape covered by a dense growth of trees is called a forest. Several biotopes are defined largely by the trees that inhabit them; examples are rainforest and taiga (see ecozones). A landscape of trees scattered or spaced across grassland (usually grazed or burned over periodically) is called a savanna.

Morphology

The basic parts of a tree are the roots, trunk(s), branches, twigs and leaves. Tree stems consist mainly of support and transport tissues (xylem and phloem). Wood consists of xylem cells, and bark is made of phloem and other tissues external to the vascular cambium. Trees may be broadly grouped into exogenous and endogenous trees according to the way in which their stem diameter increases. Exogenous trees, which comprise the great majority of modern trees (all conifers, and all broadleaf trees), grow by the addition of new wood outwards, immediately under the bark. Endogenous trees, mainly in the monocotyledons (e.g. palms), grow by addition of new material inwards. As an exogenous tree grows, it creates growth rings. In temperate climates, these are commonly visible due to changes in the rate of growth with temperature variation over an annual cycle. These rings can be counted to determine the age of the tree, and used to date cores or even wood taken from trees in the past; this practice is known as the science of dendrochronology. In some tropical regions with constant year-round climate, growth is continuous and distinct rings are not formed, so age determination is impossible. Age determination is also impossible in endogenous trees. dendrochronology, Chile]] The roots of a tree are generally embedded in earth, providing anchorage for the above-ground biomass and absorbing water and nutrients from the soil. Above ground, the trunk gives height to the leaf-bearing branches, aiding in competition with other plant species for sunlight. In many trees, the arrangement of the branches optimizes exposure of the leaves to sunlight. Not all trees have all the plant organs or parts mentioned above. For example, most palm trees are not branched, the saguaro cactus of North America has no functional leaves, tree ferns do not produce bark, etc. Based on their general shape and size, all of these are nonetheless generally regarded as trees. Indeed, sometimes size is the more important consideration. A plant form that is similar to a tree, but generally having smaller, multiple trunks and/or branches that arise near the ground, is called a shrub. However, no sharp differentiation between shrubs and trees is possible. Given their small size, bonsai plants would not technically be 'trees', but one should not confuse reference to the form of a species with the size or shape of individual specimens. A spruce seedling does not fit the definition of a tree, but all spruces are trees. Bamboos by contrast, do show most of the characteristics of trees, yet are rarely called trees.

Champion trees

The world's champion trees can be considered on several factors; height, trunk diameter or girth, total size, and age. It is significant that in each case, the top position is always held by a conifer, though a different species in each case; in most measures, the second to fourth places are also held by conifers. ;Tallest trees The heights of the tallest trees in the world have been the subject of considerable dispute and much (often wild) exaggeration. Modern verified measurement with laser rangefinders combined with tape drop measurements made by tree climbers, carried out by the [http://www.uark.edu/misc/ents/home.htm U.S. Eastern Native Tree Society] has shown that most older measuring methods and measurements are unreliable, often producing exaggerations of 5% to 15% above the real height. Historical claims of trees of 114 m, 117 m, 130 m, and even 150 m, are now largely disregarded as unreliable, fantasy or outright fraud. The following are now accepted as the top five tallest reliably measured species: # Coast Redwood Sequoia sempervirens: 112.83 m, Humboldt Redwoods State Park, California ([http://www.conifers.org/cu/se/index.htm Gymnosperm Database]) # Coast Douglas-fir Pseudotsuga menziesii: 100.3 m, Brummit Creek, Coos County, Oregon ([http://www.conifers.org/pi/ps/menziesii2.htm Gymnosperm Database]) # Sitka Spruce Picea sitchensis: 96.7 m, Prairie Creek Redwoods State Park, California ([http://www.conifers.org/pi/pic/sitchensis.htm Gymnosperm Database]) # Giant Sequoia Sequoiadendron giganteum: 93.6 m, Redwood Mountain Grove, California ([http://www.conifers.org/cu/se2/index.htm Gymnosperm Database]) # Australian Mountain-ash Eucalyptus regnans: 92.0 m, Styx Valley, Tasmania ([http://www.forestrytas.com.au/forestrytas/tasfor/tasforests_12/tasfor_12_09.pdf Forestry Tasmania] [pdf file]) ;Stoutest trees The girth (circumference) of a tree is – or at least should be – much easier to measure than the height, as it is a simple matter of stretching a tape round the trunk, and pulling it taut to find the circumference. Despite this, U.K. tree author Alan Mitchell made the following comment about measurements of yew trees in the British Isles: :"The aberrations of past measurements of yews are beyond belief. For example, the tree at Tisbury has a well-defined, clean, if irregular bole at least 1.5 m long. It has been found to have a girth which has dilated and shrunk in the following way: 11.28 m (1834 Loudon), 9.3 m (1892 Lowe), 10.67 m (1903 Elwes and Henry), 9.0 m (1924 E. Swanton), 9.45 m (1959 Mitchell) .... Earlier measurements have therefore been omitted". As a general standard, tree girth is taken at 'breast height'; this is defined differently in different situations, with most foresters measuring girth at 1.3 m above ground, while ornamental tree measurers usually measure at 1.5 m above ground; in most cases this makes little difference to the measured girth. On sloping ground, the "above ground" reference point is usually taken as the highest point on the ground touching the trunk, but some use the average between the highest and lowest points of ground. Some of the inflated old measurements may have been taken at ground level. Some past exaggerated measurements also result from measuring the complete next-to-bark measurement, pushing the tape in and out over every crevice and buttress. Modern trends are to cite the tree's diameter rather than the circumference; this is obtained by dividing the measured circumference by π; it assumes the trunk is circular in cross-section (an oval or irregular cross-section would result in a mean diameter slightly greater than the assumed circle). This is cited as dbh (diameter at breast height) in tree literature. A further problem with measuring baobabs Adansonia is that these trees store large amounts of water in the very soft wood in their trunks. This leads to marked variation in their girth over the year, swelling to a maximum at the end of the rainy season, minimum at the end of the dry season. Although baobabs have some of the highest girth measurements of any trees, no accurate measurements are currently available, but probably do not exceed 10-11 m diameter. The stoutest species in diameter, excluding baobabs, are: # Montezuma Cypress Taxodium mucronatum: 11.42 m, Árbol del Tule, Santa Maria del Tule, Oaxaca, Mexico (A. F. Mitchell, International Dendrology Society Year Book 1983: 93, 1984). # Giant Sequoia Sequoiadendron giganteum: 8.85 m, General Grant tree, Grant Grove, California ([http://www.conifers.org/cu/se2/index.htm Gymnosperm Database]) # Coast Redwood Sequoia sempervirens: 7.44 m, Prairie Creek Redwoods State Park, California ([http://www.conifers.org/cu/se/index.htm Gymnosperm Database]) ;Largest trees The largest trees in total volume are those which are both tall and of large diameter, and in particular, which hold a large diameter high up the trunk. Measurement is very complex, particularly if branch volume is to be included as well as the trunk volume, so measurements have only been made for a small number of trees, and generally only for the trunk. No attempt has ever been made to include root volume. The top four species measured so far are ([http://www.conifers.org/topics/biggest.htm Gymnosperm Database]): # Giant Sequoia Sequoiadendron giganteum: 1489 m³, General Sherman tree # Coast Redwood Sequoia sempervirens: 1045 m³, Del Norte Titan tree # Western Redcedar Thuja plicata: 500 m³, Quinault Lake Redcedar # Kauri Agathis australis: 400 m³, Tane Mahuta tree (total volume, including branches, 516.7 m³)
However, the Alerce Fitzroya cupressoides, as yet un-measured, may well slot in at third or fourth place, and Montezuma Cypress Taxodium mucronatum is also likely to be high in the list. The largest angiosperm tree is a Australian Mountain-ash, the 'El Grande' tree of about 380 m³ in Tasmania. ;Oldest trees The oldest trees are determined by growth ring counts in cores taken from the edge to the centre of the tree or from entire cross-sections. Accurate determination is only possible for trees which produce growth rings, generally those which occur in seasonal climates; trees in uniform non-seasonal tropical climates grow continuously and do not have distinct growth rings. It is also only possible for trees which are solid to the centre of the tree; many very old trees become hollow as the dead heartwood decays away. For some of these species, age estimates have been made on the basis of extrapolating current growth rates, but the results are usually little better than guesswork or wild speculation. The verified oldest measured ages are ([http://www.conifers.org/topics/oldest.htm Gymnosperm Database]): # Great Basin Bristlecone Pine Pinus longaeva: 4844 years # Alerce Fitzroya cupressoides: 3622 years # Giant Sequoia Sequoia sempervirens: 3266 years # Huon-pine Lagarostrobos franklinii: 2500 years # Rocky Mountains Bristlecone Pine Pinus aristata: 2435 years Other species suspected of reaching exceptional age include European Yew Taxus baccata (probably over 3000 years) and Western Redcedar Thuja plicata. The oldest verified age for an angiosperm tree is 2293 years for the Sri Maha Bodhi Sacred Fig (Ficus religiosa) planted in 288 BC at Anuradhapura, Sri Lanka; this is also the oldest human-planted tree with a known planting date.

Major tree genera

Flowering plants (Magnoliophyta; angiosperms)

Dicotyledons (Magnoliopsida; broadleaf or hardwood trees)

- Anacardiaceae (Cashew family)
- Cashew, Anacardium occidentale
- Mango, Mangifera indica
- Pistachio, Pistacia vera
- Sumac, Rhus species
- Lacquer tree, Toxicodendron verniciflua
- Annonaceae (Custard apple family)
- Cherimoya Annona cherimola
- Custard apple Annona reticulata
- Pawpaw Asimina triloba
- Soursop Annona muricata
- Apocynaceae (Dogbane family)
- Pachypodium Pachypodium species
- Aquifoliaceae (Holly family)
- Holly, Ilex species
- Araliaceae (Ivy family)
- Kalopanax, Kalopanax pictus Kalopanax tree (background) in fall]]
- Betulaceae (Birch family)
- Alder, Alnus species
- Birch, Betula species
- Hornbeam, Carpinus species
- Hazel, Corylus species
- Bignoniaceae (family)
- Catalpa, Catalpa species
- Cactaceae (Cactus family)
- Saguaro, Carnegiea gigantea
- Cannabaceae (Cannabis family)
- Hackberry, Celtis species
- Cornaceae (Dogwood family)
- Dogwood, Cornus species
- Dipterocarpaceae family
- Garjan Dipterocarpus species
- Sal Shorea species
- Ericaceae (Heath family)
- Arbutus, Arbutus species
- Eucommiaceae (Eucommia family)
- Eucommia Eucommia ulmoides
- Fabaceae (Pea family)
- Acacia, Acacia species
- Honey locust, Gleditsia triacanthos
- Black locust, Robinia pseudoacacia
- Laburnum, Laburnum species
- Pau Brasil, Brazilwood, Caesalpinia echinata
- Fagaceae (Beech family )
- Chestnut, Castanea species
- Beech, Fagus species
- Southern beech, Nothofagus species
- Tanoak, Lithocarpus densiflorus
- Oak, Quercus species
- Fouquieriaceae (Boojum family)
- Boojum, Fouquieria columnaris
- Hamamelidaceae (Witch-hazel family)
- Sweetgum, Liquidambar species
- Persian Ironwood, Parrotia persica
- Juglandaceae (Walnut family)
- Walnut, Juglans species
- Hickory, Carya species
- Wingnut, Pterocarya species
- Lauraceae (Laurel family)
- Cinnamon Cinnamomum zeylanicum
- Bay Laurel Laurus nobilis
- Avocado Persea americana
- Lecythidaceae (Paradise nut family)
- Brazil Nut Bertholletia excelsa
- Lythraceae Loosestrife family
- Crape-myrtle Lagerstroemia species
- Magnoliaceae (Magnolia family)
- Tulip tree, Liriodendron species
- Magnolia, Magnolia species
- Malvaceae (Mallow family; including Tiliaceae and Bombacaceae) Bombacaceae
- Baobab, Adansonia species
- Silk-cotton tree, Bombax species
- Bottletrees, Brachychiton species
- Kapok, Ceiba pentandra
- Durian, Durio zibethinus
- Balsa, Ochroma lagopus
- Cacao (cocoa), Theobroma cacao
- Linden (Basswood, Lime), Tilia species
- Meliaceae (Mahogany family)
- Neem, Azadirachta indica
- Bead tree, Melia azedarach
- Mahogany, Swietenia mahagoni
- Moraceae (Mulberry family)
- Fig, Ficus species
- Mulberry, Morus species
- Myristicaceae (Nutmeg family)
- Nutmeg, Mysristica fragrans
- Myrtaceae (Myrtle family)
- Eucalyptus, Eucalyptus species
- Myrtle, Myrtus species
- Guava, Psidium guajavaGuava in flower]]
- Nyssaceae (Tupelo family; sometimes included in Cornaceae)
- Tupelo, Nyssa species
- Dove tree, Davidia involucrata
- Oleaceae (Olive family)
- Olive, Olea europaea
- Ash, Fraxinus species
- Paulowniaceae (Paulownia family)
- Foxglove Tree, Paulownia species
- Platanaceae (Plane family)
- Plane, Platanus species
- Rhizophoraceae (Mangrove family)
- Red Mangrove, Rhizophora mangle
- Rosaceae (Rose family)
- Rowans, Whitebeams, Service Trees Sorbus species
- Hawthorn, Crataegus species
- Pear, Pyrus species
- Apple, Malus species
- Almond, Prunus dulcis
- Peach, Prunus persica
- Plum, Prunus domestica
- Cherry, Prunus species
- Rubiaceae (Bedstraw family)
- Coffee, Coffea species
- Rutaceae (Rue family)
- Citrus, Citrus species
- Cork-tree, Phellodendron species
- Euodia, Tetradium species
- Salicaceae (Willow family)
- Aspen, Populus species
- Poplar, Populus species
- Willow, Salix species Willow
- Sapindaceae (including Aceraceae, Hippocastanaceae) (Soapberry family)
- Maple, Acer species
- Buckeye, Horse-chestnut, Aesculus species
- Mexican Buckeye, Ungnadia speciosa
- Lychee, Litchi sinensis
- Golden rain tree, Koelreuteria paniculata
- Sapotaceae (Sapodilla family)
- Gutta-percha, Palaquium species
- Tambalacoque, or "dodo tree", Sideroxylon grandiflorum, previously Calvaria major
- Simaroubaceae family
- Tree of heaven, Ailanthus species
- Theaceae (Camellia family)
- Gordonia, Gordonia species
- Stuartia, Stuartia species
- Thymelaeaceae (Thymelaea family)
- Ramin, Gonystylus species
- Ulmaceae (Elm family)
- Elm, Ulmus species
- Zelkova, Zelkova species
- Verbenaceae family
- Teak, Tectona species

Monocotyledons (Liliopsida)

Monocotyledon
- Agavaceae (Agave family)
- Cabbage tree, Cordyline australis
- Dragon tree, Dracaena draco
- Joshua tree, Yucca brevifolia
- Arecaceae (Palmae) (Palm family)
- Areca Nut, Areca catechu
- Coconut Cocos nucifera
- Date Palm, Phoenix dactylifera
- Chusan Palm, Trachycarpus fortunei
- Poaceae (grass family)
- Bamboos Poaceae subfamily Bambusoideae
- Note that banana 'trees' are not actually trees; they are not woody nor is the stalk perennial.

Conifers (Pinophyta; softwood trees)

- Araucariaceae (Araucaria family)
- Araucaria, Araucaria species
- Kauri, Agathis species
- Cupressaceae (Cypress family)
- Cypress, Cupressus species
- Cypress, Chamaecyparis species
- Juniper, Juniperus species
- Alerce or Patagonian cypress, Fitzroya cupressoides
- Sugi, Cryptomeria japonica
- Coast Redwood, Sequoia sempervirens
- Giant Sequoia, Sequoiadendron giganteum
- Dawn Redwood, Metasequoia glyptostroboides
- Bald Cypress, Taxodium distichum
- Pinaceae (Pine family)
- White pine, Pinus species
- Pinyon pine, Pinus species
- Pine, Pinus species
- Spruce, Picea species
- Larch, Larix species
- Douglas-fir, Pseudotsuga species
- Fir, Abies species
- Cedar, Cedrus species
- Podocarpaceae (Yellowwood family)
- African Yellowwood, Afrocarpus falcatus
- Totara, Podocarpus totara
- Sciadopityaceae
- Kusamaki, Sciadopitys species
- Taxaceae (Yew family)
- Yew, Taxus species

Ginkgos (Ginkgophyta)

- Ginkgoaceae (Ginkgo family)
- Ginkgo, Ginkgo biloba

Cycads (Cycadophyta)

- Cycadaceae family
- Ngathu cycad, Cycas angulata
- Zamiaceae family
- Wunu cycad, Lepidozamia hopei

Ferns (Pterophyta)

- Cyatheaceae and Dicksoniaceae families
- Tree ferns, Cyathea, Alsophila, Dicksonia (not a monophyletic group)

Life stages

The life cycles of trees, especially conifers, are divided into the following stages in forestry for survey and documentation purposes: # Seed # Seedling: the above ground part of the embryo that sprout from the seed # Sapling: After the seedling reaches 1m tall, and until it reaches 7cm in stem diameter # Pole: young trees from 7-30cm diameter # Mature tree: over 30cm diameter, reproductive years begin # Old tree: dominate old growth forest; height growth slows greatly, with majority of productivity in seed production # Overmature: dieback and decay become common # Snag: standing dead wood # Log/debris: fallen dead wood Tree diameters are measured at height of between 1.3-1.5m above the highest point on the ground at its base. The 7cm diameter definition is economically based, from the smallest saleable stem size (for paper production, etc), and the 30cm diameter is the smallest base diameter for sawlogs. Each stage may be uniquely perceptive to different pathogens and suitable for especially adapted arboreal animals.

External links

- [http://www.globaltrees.org/default.asp GLOBAL TREES .org] Campaigning to save the world's most threatened trees
- [http://www.fssca.net/romero/ Romero Memorial Tree Project] Plant a tree in El Salvador

Bibliography

- Pakenham, T. (2002). Remarkable Trees of the World. ISBN 0297843001
- Pakenham, T. (1996). Meetings with Remarkable Trees. ISBN 0297832557 Category:Plants
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- Category:Botany Category: plant morphology ms:Pokok ja:木 simple:Tree th:ต้นไม้

New Caledonia

:For the former North American colony called New Caledonia, see New Caledonia (Canada). New Caledonia (Canada) New Caledonia (French: Nouvelle-Calédonie; popular names: Kanaky, Le caillou) is a "sui generis collectivity" (in practice an overseas territory of France) made up of a main island (Grande-Terre de la Nouvelle-Calédonie) and several smaller islands. It is located in the region of Melanesia in the southwest Pacific. It has a land area of 18,575.5 km² (7,172 sq. miles). The population at the 2004 census was 230,789 inhabitants. It has an Internet country code top-level domain (ccTLD) of .nc. The capital and largest city of the territory is Nouméa. The currency is the Comptoirs Francais du Pacifique franc (international code XPF). Since 1986 the United Nations Committee on Decolonization has included New Caledonia on the United Nations list of Non-Self-Governing Territories, a highly political list that is disputed by France, Morocco, the United States, and the United Kingdom, which all have territories on the list. The list is partial and controversial because it does not cover all peoples and territorial entities in the world which are neither sovereign countries nor part of any sovereign country. New Caledonia will decide whether to remain within the French Republic or become an independent state in a referendum sometime after 2014. Its capital Nouméa is the seat of the regional organization the Secretariat of the Pacific Community (formerly the South Pacific Commission). Secretariat of the Pacific Community Secretariat of the Pacific Community]

Name

The name Caledonia derives from the Latin name of an area corresponding to modern Scotland. The name Kanaky is also in common usage in French, English and the indigenous languages. This name is favored by Melanesian nationalists. The word comes from kanaka, a Polynesian word meaning human used by Polynesians to call themselves. The word was later used by the French to call all the native inhabitants of the South Pacific Ocean, including the Melanesian (non-Polynesian) native inhabitants of New Caledonia. The word, turned into Canaque in French, became derogative. In the 1960s and 1970s, when the Melanesian native inhabitants started to organize themselves into political parties and ask for independence, this derogative word was turned into a symbol of political emancipation and pride. In 1983, during the period of political turmoil, the terms KANAK and KANAKY became a political brand names and almost instantly disappeared from the lips of the Caldoches who realised how the name had changed into a political statement.

Geography

Caldoche Main article: Geography of New Caledonia New Caledonia is located around in the southwest Pacific Ocean, approximately 1,200 km east of Australia and 1,500 km northwest of New Zealand. The island nation of Vanuatu lies to the northeast. New Caledonia is made up of a main island, the Grande Terre, and several smaller islands, the Belep archipelago to the north of the Grande Terre, the Loyalty Islands to the east of the Grande Terre, the Île des Pins to the south of the Grande Terre, and the Chesterfield Islands and Bellona Reefs further to the west. The Grande Terre is by far the largest of the islands, and the only mountainous island. It has an area of 16,372 km² (6,321 sq. miles), and is enlongated northwest-southeast, 350 km in length and 50 to 70 km wide. A mountain range runs the length of the island, with five peaks over 1500 meters. The highest point is Mont Panié at 1,628 meters elevation (5,341 ft). New Caledonia contains about one-quarter of the world's nickel resources.

Climate

New Caledonia lies astride the Tropic of Capricorn, between 19° and 23° south latitude. The climate of the islands is tropical, and rainfall is highly seasonal, brought by trade winds that usually come from the east. Rainfall averages about 1,500 mm yearly on the Loyalty Islands, 2,000 mm at low elevations on eastern the Grande Terre, and 2,000-4,000 mm at high elevations on the Grande Terre. The western side of the Grande Terre lies in the rain shadow of the central mountains, and rainfall averages 1200 mm per year.

Ecology

Unlike many of the Pacific islands which are of relatively recent volcanic origin, New Caledonia is an ancient fragment of the Gondwana supercontinent. New Caledonia and New Zealand separated from Australia 85 million years ago, and from one another 55 million years ago, and New Caledonia still carries many unique and endemic plants and animals of Gondwanan origin. (see Biodiversity of New Caledonia and Endemic Birds of New Caledonia). The best known is a hen-sized bird, the Cagou or Kagu, which cannot fly, has a large crest, and a funny cooing, and whose song and image serves as an emblem. The Niaouli tree, which also grows in Australia and New Guinea, is of medical interest, as its sap gives gomenol, which smells like camphor and is used to treat head colds. Before the Europeans arrived, there was no mammal other than the roussette (aka flying fox), a big vegetarian bat, a local delicacy. The islands make up two terrestrial ecoregions, the New Caledonia rain forests on the Loyalty Islands, Ile des Pins, and the eastern side of Grand Terre, and the New Caledonia dry forests in the rain shadow on the western side of Grand Terre. As the Europeans settled on the dry west coast and left the east to Kanaks, the political division maps the natural one. New Caledonia's freshwater ecology also evolved in long isolation, and the New Caledonia rivers and streams are home to many endemic species. The New Caledonia Barrier Reef, which surrounds the Grande Terre and the Île des Pins, is the second-largest coral reef in the world after Australia's Great Barrier Reef, reaching a length of 1500 km. The reef has great species diversity, is home to endangered dugongs (Dugong dugon), and is an important nesting site for Green Sea Turtle (Chelonia mydas).

Administration

Along with other Pacific Ocean's territories of French Polynesia and Wallis and Futuna, New Caledonia is part of the French Republic. Its official status is that of a sui generis collectivity (collectivité sui generis), a status unique in the French Republic. New Caledonia was a colony until 1946, then an overseas territory (territoire d'outre-mer, or TOM) from 1946 to 1999. The capital is Nouméa.

History

The western Pacific was first populated about 50,000 years ago. The Austronesians moved into the area later. The diverse group of people that settled over the Melanesian archipelagos are known as the Lapita. They arrived in the archipelago now commonly known as New Caledonia and the Loyalty Islands around 1500 BCE. The Lapita were highly skilled navigators and agriculturists with influence over a large area of the Pacific. From about the 11th century CE Polynesians also arrived and mixed with the populations of the archipelago. Europeans first sighted New Caledonia and the Loyalty Islands in the late 18th century. The British explorer James Cook sighted Grande Terre in 1774 and named it New Caledonia after the Scottish Highlands, which it resembled. Caledonia was a popular poetic and patriotic term for Scotland, and James Cook's father was Scottish. British and North American whalers and sandalwood traders became interested in New Caledonia and tensions developed as their approach became increasingly dishonest (an arrogant attitude and cheating became commonplace). Europeans used alcohol and tobacco amongst other things to barter for commodities. Contact with Europeans brought new diseases such as smallpox, measles, dysentery, influenza, syphilis and leprosy. Many people died as a result of these diseases. Tensions developed into hostilities and in 1849 the crew of the Cutter were killed and eaten by the Pouma clan. As trade in sandalwood declined it was replaced by a new form of trade. Blackbirding involved enslaving people from New Caledonia, the Loyalty Islands, Vanuatu, Papua New Guinea and the Solomon Islands to work in sugar cane plantations in Fiji and Queensland. The trade ceased at the start of the 20th century. Catholic and Protestant missionaries first arrived in the 19th century. They had a profound effect on indigenous culture. They insisted people should wear clothes to cover themselves. They eradicated many local practices and traditions. The island was made a French possession in 1853 in an attempt by Napoleon III to rival the British colonies in Australia and New Zealand. Following the example set by the British in nearby Australia, between 1854 and 1922 France sent a total of 22,000 convicted felons to penal colonies along the south-west coast of the island; this number includes regular criminals as well as political prisoners such as Parisian socialists and Kabyle nationalists. Towards the end of the penal colony era, free European settlers (including former convicts) and Asian contract workers by far out-numbered the population of forced workers. The indigenous Kanak populations declined drastically in that same period due to introduced diseases and an apartheid-like system called Code de l'Indigénat which imposed severe restrictions on their livelihood, freedom of movement and land ownership. New Caledonia has been on a United Nations list of non-self-governing territories since 1986. This list includes such places as the American Samoa, the British Falkland Islands, or the New Zealand territory of Tokelau, but noticeably it does not include places like Tibet or West Papua, which has led to its reputation as a politically biased list. Agitation by the Front de Libération Nationale Kanak Socialiste (FLNKS) for independence began in 1985. The FLNKS (led by the late Jean Marie Tjibaou, assassinated in 1989) advocated the creation of an independent state of 'Kanaky'. The troubles culminated in 1988 with a bloody hostage taking in Ouvéa. The unrest led to agreement on increased autonomy in the Matignon Accords of 1988 and the Nouméa Accord of 1998. This Accord describes the devolution process as "irreversible" and also provides for a local Caledonian citizenship, separate official symbols of Caledonian identity (such as a "national" flag), as well as mandating a referendum on the contentious issue of independence from the French Republic sometime after 2014.

Politics

Main article: Politics of New Caledonia The unique status of New Caledonia is in between that of an independent country and a regular overseas département of France. On the one hand, a territorial Congress (Congrès du territoire) and a government of the territory have been established, and a devolution of powers is organized by the 1998 Nouméa Accord. Key areas such as taxation, labor law, health and hygiene and foreign trade are already in the hands of the territorial Congress. Further competence will supposedly be given to the territorial Congress in the near future. Eventually, the French Republic should only remain competent for foreign affairs, justice, defence, public order, and treasury. A New Caledonian "citizenship" has also been introduced: only New Caledonian "citizens" have the right to vote in the local elections. This measure has been criticized, because it creates a second-class status for French citizens living in New Caledonia who do not possess New Caledonian "citizenship" (because they settled in the territory recently). New Caledonia is also allowed to engage in international cooperation with independent countries of the Pacific Ocean. Finally, the territorial Congress is allowed to pass statutes that are derogatory to French law in a certain number of areas. On the other hand, New Caledonia remains an integral part of the French Republic. Inhabitants of New Caledonia are French citizens and carry French passports. They take part in the legislative and presidential French elections. New Caledonia sends two representatives to the French National Assembly and one senator to the French Senate. The representative of the French central state in New Caledonia is the High Commissioner of the Republic (Haut-Commissaire de la République, locally known as "haussaire"), who is the head of civil services, and who seats in the government of the territory. It was decided in the Nouméa Accord that the territorial Congress will have the right to call for a referendum on independence after 2014, at a time of its choosing. The current president of the government elected by the territorial Congress is Marie-Noëlle Thémereau, from the loyalist (i.e. anti-independence) Avenir ensemble party ("Future together"), which toppled the long-time ruling RPCR (Rally for Caledonia inside the Republic) in May 2004. "Future Together" is a party of mostly Caucasian and Polynesian New Caledonians opposed to independence but tired of the hegemonic and allegedly corrupt anti-independence RPCR. Their toppling of the RPCR (that was until then seen as the only voice of New Caledonian whites) was a surprise to many, and a sign that the society of New Caledonia is undergoing changes. "Future together", as the name implies, is opposed to a racial vision of New Caledonian society, opposing Melanesians native inhabitants and European settlers, and is in favor of a multicultural New Caledonia, better reflecting the existence of large populations of Polynesians, Indonesians, Chinese, and other immigrants. Some members of "Future Together" are even in favor of independence, though not necessarily on the same basis as the Melanesian independence parties.

Demographics

Main article: Demographics of New Caledonia Though still the relative majority the indigenous Melanesian Kanak community now represents 42.5% of the population (as of 2005). This is due to a population decline during the early stages of the colonisation process. Later it was the immigration under French rule that influenced the balance in favour of other minority groups. The current population is made up of numerous ethnic groups who arrived in New Caledonia over the past 200 years: Whites (37.1%), Polynesians (Wallisians, Tahitians) (12.2%), Javanese (3.6%), Vietnamese (1.6%), and various other groups such as ni-Vanuatu, Malabaris, Maghrebins, Japanese, Chinese, Fijians (3.0%). Some of this immigration was a direct consequence of various conflicts around the world but in particular of the crumbling of the French Empire. The Kanak are known officially as Melanesians. Similarly, those whose roots are in French Polynesia are known either as Tahitians (which excludes persons originating in the other archipelagoes of French Polynesia) or simply as Polynesians (which would include both Tahitians and Wallisians, as well as many other minor groups). Whites that have lived in New Caledonia for several generations are locally known as "Caldoches", whereas newcomers who have immigrated from metropolitan France are called "Métros" or "Métropolitains". Within the official statistical category "Europeans" no distinction is made between Caledonian-born whites and French-born whites, however it is estimated that approximately two thirds identify themselves with the Caldoche community while the rest see themselves primarily as French immigrants. There is a significant contingent of people that arrive from France to work for a year or two and others that have come to retire. The Caldoche usually refer to themselves simply as "calédoniens" and may be either white (mostly French or German) or white with an admixture of Asian, Melanesian or Polynesian ancestry. Caldoche culture has many similarities with Australian and Afrikaner culture. Until very recently the Kanak population held an economically disadvantaged position in New Caledonian society, while wealthy French expatriats formed the top of the socio-economic hierarchy. The Asian and Polynesian inhabitants dominate certain segments of the local economy. There have been frequent accusations by the pro-independence movement that the French government is attempting to skew the demographic balance between the ethnic communities by clandestinely settling thousands of people from mainland France among the white Caledonians. They argue that current French policies in New Caledonia mimic those of Turkey, which has for many years been secretly chanelling in Anatolian Turks settlers to assimilate into the Turkish Cypriot population of Northern Cyprus for many years. Censuses are extremely critical to the balance of power in New Caledonia, and the organization of a new census was regularly postponed after 1996. Eventually the census was carried out in August and September 2004, amidst raging controversies over ethnic questions. Due to an intervention by French president Jacques Chirac, questions asking for the ethnicity of people were deleted from the 2004 census, officially because they were deemed to contravene the French Constitution, which states that no distinction based on ethnicity or religion should be made among French citizens. The indigenous Melanesian Kanak leaders, who are extremely sensitive to ethnic balance issues, called for New Caledonians of Kanak ethnicity not to return census forms if questions regarding ethnicity were not asked, threatening to derail the census process. Eventually, the stalemate was resolved when the local New Caledonian statistical office (a branch of the national French statistical office INSEE) agreed to ask questions regarding ethnicity. However, it is not known whether questions regarding ethnicity were asked to all residents of New Caledonia, and at any rate no data have been released, leaving the ethnic tables from the 1996 census as the only information on ethnicity currently available. According to the 2004 census, there were 230,789 inhabitants in New Caledonia as of September 2004. This means a population increase of 1.9% per year since 1996, which is less than had been anticipated. In particular, Kanak leaders were fearful of a large influx of white people from metropolitan France which would alter the ethnic balance in the territory. Census results show that immigration to New Caledonia was not as high as anticipated, with nonetheless a positive migration flow of about 1,000 people yearly to New Caledonia between 1996 and 2004 (i.e. there are 1,000 more people who migrate to New Caledonia every year than people who leave New Caledonia).

Miscellaneous

- Communications in New Caledonia
- Disputes - international: Matthew and Hunter Islands claimed by France and Vanuatu.
- Economy of New Caledonia
- Military of New Caledonia
- Music of New Caledonia
- Sister city: Gold Coast, Australia
- Transportation in New Caledonia

Publications

- J. W. Anderson, Fiji and New Caledonia, (London, 1880)
- Alfred Schreiner, La Nouvelle-Calédonie depuis sa découverte jusqu'à nos jours, (Paris, 1882)
- León Vallée Essai d'une bibliographie de la Nouvelle-Cadédonie et dépendances, (Paris, 1885)
- G. Griffith, In an Unknown Prison Land: An Account of Convicts and Colonists in New Caledonia, (London, 1901)
- J. B. Alberti, La colonisation à la Nouvelle-Calédonie, (Paris, 1909)

External links and references

- [http://www.endemia.nc Endemic flora of New-Caledonia] (French language)
- [http://www.southpacific.org/text/new_caledonia.html Finding New Caledonia]
- [http://members.ozemail.com.au/~rodeime/newcal/ "France's Best Kept Secret"] by Roderick Eime
- [http://www.janeresture.com/newcal/index.htm Jane's New Caledonia Home Page]
- [http://www.mapsouthpacific.com/new_caledonia/index.html Map of New Caledonia]
- [http://www.virtualoceania.net/newcaledonia/photos/ New Caledonia photos]
- [http://www.pacific-pictures.com/new_caledonia/index.html New Caledonia travel photos]
- [http://www.photos-nouvelle-caledonie.com/ New-Caledonia pictures] 500 high-quality pictures of New-Caledonia (French language)
- [http://www.kanaky-nouvelle-caledonie.com/ Tourism Information of New-Caledonia] (French language)
- [http://www.anytravels.com/australia/caledonia/ New Caledonia Travel Overview]
- This article incorporates edited material from the CIA World Factbook 2000
- [http://www.willgoto.com/categories.aspx?Destination=340&Langue=1 Willgoto New Caledonia] Travel guide and directory
- [http://www.vie-publique.fr/decouverte_instit/instit/instit_3_7_0_q0.htm past and current developments of France's overseas administrative divisions like New Caledonia (French language)]
- [http://www.croixdusud.info/eng/acc_eng/nc_acc_eng.php Croix du Sud] Good source of information in English and French
- [http://www.brousse-en-folie.com/broussefolie/dico/dic_acc.php Dictionnaire Franco-Calédonien de brousse-en-folie.com] A comprehensive list of French words, idioms and phrases unique to New Caledonia Category:Melanesia Category:New Caledonia Category:Special territories of the EU zh-min-nan:Sin Calédonie ja:ニューカレドニア

Grande-Terre

Guadeloupe consists of two islands separated by a salt river and whose combined shape resembles a butterfly. The western island is Basse-Terre and the eastern island is Grande-Terre. Grande-Terre's indented coastline is surrounded by coral reefs and the island itself is a limestone plateau. Its surface is a series of rolling hills, white sand beaches and cliffs. Of the two islands, Grande-Terre is home to the majority of Guadeloupe's farmlands and tourist resorts. Category:Guadeloupe Category:Caribbean islands ---- Grande Terre is also the name of the main island of New Caledonia.

CITES

The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) is an international agreement between Governments, drafted as a result of a resolution adopted in 1963 at a meeting of members of the World Conservation Union (IUCN). Its aim is to ensure that international trade in specimens of wild animals and plants does not threaten their survival and accords varying degrees of protection to more than 30,000 species of animals and plants. Not one species protected by CITES has become extinct as a result of trade since the Convention entered into force in 1975.

The convention

CITES is one of the largest conservation agreements in existence. Participation is voluntary, and countries that have agreed to be bound by the Convention are known as Parties. Although CITES is legally binding on the Parties, it does not take the place of national laws. Rather it provides a framework to be respected by each Party, which has to adopt its own domestic legislation to make sure that CITES is implemented at the national level. The text of the Convention was opened for signature at a meeting of representatives of eighty countries in Washington, D.C., United States, on 3 March 1973, and entered into force on 1 July 1975. As of February 2005, 167 Parties had entered the convention.

The species

CITES works by subjecting international trade in specimens of selected species to certain controls. These require that all import, export, re-export and introduction of species covered by the Convention has to be authorized through a licensing system. Roughly 5,000 species of animals and 28,000 species of plants are protected by CITES against over-exploitation through international trade. The species are grouped in the Appendices according to how threatened they are by international trade.
- Appendix I includes species threatened with extinction. Trade in specimens of these species is permitted only in exceptional circumstances.
- Appendix II includes species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival.
- Appendix III contains species that are protected in at least one country, which has asked other CITES Parties for assistance in controlling the trade. Each Party to the Convention must designate one or more Management Authorities in charge of administering the licensing system and one or more Scientific Authorities to advise them on the effects of trade on the status of the species. Source: [http://www.cites.org/ CITES Secretariat] (external link to official site)

Member countries

See [http://www.cites.org/eng/disc/parties/index.shtml official List of Parties]

External links

- [http://www.cites.org/ CITES homepage]
- Elephants and Ivory: Lessons from the Trade Ban by Ike Sugg and Urs Kreuter (IEA, 1994) [http://www.iea.org.uk/record.jsp?type=publication&ID=75]

Moss

:This is an article about the plant. For other uses, see Moss (disambiguation)
- Sphagnidae
- Andreaeidae
- Tetraphidae
- Polytrichidae
- Archidiidae
- Buxbaumiidae
- Bryidae Bryidae Mosses are small plants that are rarely taller than 2 inches (50mm). They typically grow close together in clumps or mats in damp or shady locations. They do not have flowers and their simple leaves cover the thin wiry stems. At certain times mosses produces spore capsules which may appear as beak-like capsules borne aloft on thin stalks.

Overview

Botanically, mosses are bryophytes, or non-vascular plants. They can be distinguished from the apparently similar liverworts (Marchantiophyta or Hepaticae) by their multi-cellular rhizoids. Other differences are not universal for all mosses and all liverworts but the presence of clearly differentiated stem and leaves, the lack of deeply lobes or segmented leaves,and the absence of leaves arranged in three ranks all point to the plant being a moss. The division Bryophyta formerly included not only mosses, but also liverworts and hornworts. These other two groups of bryophytes now are often placed in their own divisions. Aside from lacking a vascular system, they have a gametophyte-dominant life cycle, i.e. the plant's cells are haploid for most of its life cycle. Sporophytes (i.e. the diploid body) are short-lived and dependent on the gametophyte. This is in contrast to the pattern exhibited by most "higher" plants and by most animals. In vascular plants, for example, the haploid generation is represented by the pollen and the ovule, whilst the diploid generation is the familiar flowering plant.

Life cycle

Most kinds of plants have a double portion of chromosomes in their cells (diploid, i.e. each chromosome exists with a partner that contains the same genetic information) whilst mosses (and other bryophytes) have only a single set of chromosomes (haploid, i.e. each chromosome exists in a unique copy within the cell). There are periods in the moss lifecycle when they do have a full, paired set of chromosomes but this is only during the sporophyte stage. sporophyte The life of a moss starts from a haploid spore, which germinates to produce a protonema, which is either a mass of filaments or thalloid (flat and thallus-like). This is a transitory stage in the life of a moss. From the protonema grows the gametophore ("gamete-bearer") that is differentiated into stems and leaves ('microphylls'). From the tips of stems or branches develop the sex organs of the mosses. The female organs are known as archegonia (singular archegonium) and are protected by a group of modified leaves known as the perichaetum (plural perichaeta). The archegonia have necks called venters which the male sperm swim down. The male organs are known as antheridia (singular antheridium) and are enclosed by modified leaves called the perigonium (plural perigonia). Mosses can be either dioicous (compare with dioecious in seed plants) or monoicous (compare monoecious). In dioicous mosses, both male and female sex organs are borne on different gametophyte plants. In monoicous (also called autoicous) mosses, they are borne on the same plant. In the presence of water, sperm from the antheridia swim to the archegonia and fertilisation occurs, leading to the production of a diploid sporophyte. The sperm of mosses is biflagellate, i.e. they have two flagella that aid in propulsion. Without water, fertilisation cannot occur. After fertilization, the immature sporophyte pushes its way out of the archegonial venter. It takes about a quarter to half a year for the sporophyte to mature. The sporophyte body comprises a long stalk, called a seta, and a capsule capped by a cap called the operculum. The capsule and operculum are in turn sheathed by a haploid calyptra which is the remains of the archegonial venter. The calyptra usually falls off when the capsule is mature. Within the capsule, spore-producing cells undergo meiosis to form haploid spores, upon which the cycle can start again. The mouth of the capsule is usually ringed by a set of teeth called peristome. This may be absent in some mosses. In some mosses, green vegetative structures called gemmae are produced on leaves or branches, which can break off and form new plants without the need to go through the cycle of fertilization. This is a means of asexual reproduction.

Classification of mosses

asexual reproduction asexual reproduction Mosses were traditionally grouped with the liverworts and hornworts in the Division Bryophyta (bryophytes), within which the mosses made up the class Musci. This group, however, is paraphyletic and now tends to be split up. In such system, the Division Bryophyta refers specifically to mosses. They appear to be the closest living relatives of the vascular plants. The mosses are grouped as a single class, now named Bryopsida, and divided into seven subclasses:
- Andreaeidae
- Sphagnidae
- Tetraphidae
- Polytrichidae
- Buxbaumiidae
- Bryidae
- Archidiidae Andreaeidae are distinguished by the biseriate (two rows of cells) rhizoids, multiseriate (many rows of cells) protonema, and sporangium that splits along longitudinal lines. Most mosses have capsules that open at the top. The Sphagnidae, the peat-mosses, comprise the single genus Sphagnum. These form extensive acidic bogs in peat swamps. The leaves of Sphagnum have large dead cells alternating with living photosynthetic cells. The dead cells help to store water. Aside from this character, the unique branching, thallose (flat and expanded) protonema, and explosively rupturing sporangium place it apart from other mosses. The Tetraphidae are unique as their name implies, in having only four large peristome teeth surrounding the opening of the capsule. Polytrichidae have leaves with lamellae, which are flaps on the leaves that look like the fins on a heat sink. These help it retain moisture. They differ from other mosses in other details of their development and anatomy too. The Buxbaumiidae are called 'bug mosses' because they usually have a very small and reduced gametophore and the whole plant is mostly the sporophyte capsule. The shape reminds one of a bug, which is the reason for its common name. Most (>95%) mosses belong to the Bryidae. The Archidiidae are distinguished by their extremely large spores and the way the sporangium develops.

Habitat

Sphagnum Sphagnum Sphagnum Mosses are found chiefly in areas of low light and dampness; any area of the world. Mosses are common in wooded areas and at the edges of streams. A few species are wholly aquatic and otherwes such as mist Sphagnum spp inhabit bogs, marshes and very slow moving water-ways. Mosses are also found in cracks between paving stones in damp city streets. Some types have adapted to urban conditions and are found only in cities. Wherever they occur, mosses require moisture to survive because of the small size and thinness of tissues, lack of cuticle (waxy covering to prevent water loss), and the need for liquid water to complete fertilisation. Some mosses can survive desiccation, returning to life within a few hours of rehydration. In northern latitudes, the north side of trees generally will have more moss on average than other sides. This is assumed to be because of the lack of sufficient water for reproduction on the sun-facing side of trees. South of the equator the reverse is true. In deep forests where sun-light does not penetrate mosses grow equally well on all sides of the tree trunk

Cultivation

Moss is considered a weed in grass lawns, but is deliberately encouraged to grow under aesthetic principles exemplified by Japanese gardening. In old temple gardens, moss can carpet a forest scene. Moss is thought to add a sense of calm, age and stillness to a garden scene. Rules of cultivation are not widely established. Moss collections are quite often begun using samples transplanted from the wild in a water-retaining bag. However, specific species of moss can be extremely difficult to maintain away from their natural site (with its unique combination of light, humidity, shelter from wind, etc). Growing moss from spore is even less controlled. Moss spores fall in a constant rain on exposed surfaces - those surfaces which are hospitable to a certain species of moss will typically be colonized by that moss within a few years of exposure to wind and rain. Materials which are porous and moisture retentive, such as brick, wood, and certain coarse concrete mixtures are hospitable to moss. Surfaces can also be prepared with acidic substances, including buttermilk, yogurt, urine, and gently pureed mixtures of moss samples, water and ericaceous compost.

Mossery

A passing fad for moss collecting in the late 19th Century led to the establishment of mosseries in many British and American gardens. The mossery is typically constructed out of slatted wood, with a flat roof, open to the north side (maintaining shade). Samples of moss were installed in the cracks between wood slats. The whole mossery would then be regularly moistened to maintain growth.

Commercial use of Mosses

There is a substantial market in mosses gathered from the wild. The uses for intact moss are principally in the florist trade and for home decoration. Decaying moss in the genus Sphagnum is also the major component of peat, which is "mined" both as a soil additive and for use in smoking malt in the production of Scotch whiskey. There are growing concerns in parts of the world where this trade is growing that significant environmental damage may be caused by the activities of commercial moss harvesters.

External links

- [http://www.hcs.ohio-state.edu/hcs300/liver2.htm Information, diagrams, and photos]
- [http://149.152.32.5/Plant_Biology/moss.html Moss description] Category: Bryophyta Category: Bryophytes Category: cryptogams ja:蘚類 simple:Mosses

Lichen

:For other things named "lichen", see: Lichen (disambiguation). Lichen (disambiguation) Lichens are symbiotic organisms made up by the association of microscopic green algae or cyanobacteria and filamentous fungi. Lichens take the external shape of the fungal partner and hence are named based on the fungus. The fungus most commonly forms the majority of the lichen's bulk, though in filamentous and gelatinous lichens this may not always be the case. The lichen fungus is typically a member of the Ascomycota—rarely a member of the Basidiomycota. Some lichen taxonomists place lichens in their own division, the Mycophycophyta, but this practice ignores the fact that the components belong to separate lineages. The algal cells contain chlorophyll, permitting them to live in a purely mineral environment by producing their own organic compounds (see photosynthesis). The fungus protects the alga against drying out and, in some cases, provides it with minerals obtained from the substratum. If a cyanobacterium, such as in Terricolous Lichens, is present this can fix atmospheric nitrogen, complementing the activities of the green alga.

Morphology and structure

Lichens live on various surfaces: soil, trees, rocks, and walls. They are often the first to settle in places lacking soil, constituting the sole vegetation in some extreme environments such as found at high mountain elevations and at high latitudes. Some survive in the tough conditions of deserts, and others on frozen soil of the arctic regions. Recent NASA research shows that lichen can even endure extended exposure to space. Some lichens have the aspect of leaves (foliose lichens); others cover the substratum like a crust (crustose lichens); others adopt shrubby forms (fruticose lichens); and there are gelatinous lichens (see lichen forms below). Although the form of a lichen is determined by the genetic material of the fungal partner, association with a photobiont is required for the development of that form. When grown in the laboratory in the absence of its photobiont a lichen fungus develops as an undifferentiated mass of hyphae. If combined with its photobiont under appropriate conditions the morphogenesis of the lichen occurs and its characteristic form emerges. (Brodo, Sharnoff & Sharnoff, 2001) There is evidence to suggest that the lichen symbiosis is parasitic rather than mutualistic. The photosynthetic partner can exist in nature independently of the fungal partner but not vice versa. Furthermore, photobiont cells are routinely destroyed in the course of nutrient exchange. The association is able to continue because photobiont cells reproduce faster than they are destroyed. (Ibid.) When seen under magnification, a section through a typical foliose lichen thallus reveals four layers of interlaced filaments (fungus). The upper layer is formed by densely agglutinated fungal hyphae building a protective outer layer called the cortex. Cyanobacteria may be held in small eruptions of or under the surface called cephalopodia. Beneath the upper cortex is an algal layer composed of algal cells embedded in rather densely interwoven fungal hyphae. Each cell or group of cells of the photobiont is usually individually wrapped by hyphae and in some cases penetrated by an haustorium. Beneath the algal layer is a layer of loosely interwoven fungal hyphae without algal cells. This layer is called the medulla. Beneath the medulla the bottom surface resembles the upper surface and is called the lower cortex, consisting of densely packed fungal hyphae. The lower cortex often bears structures, such as rhizines or a tomentum, serving to attach the thallus to the substratum on which it grows. Lichens also sometimes contain structures made from fungal metabolites, for example crustose lichens sometimes have a polysaccharide layer in the cortex. Although each lichen thallus generally appears homogenous, it may consist of several different species of fungus and photobiont living together.

Reproduction

Lichens most frequently reproduce asexually, either by vegetative reproduction or through the dispersal of diaspores containing algal and fungal cells. Soredia (sing. soredium) are small groups of algal cells surrounded by fungal filaments that form in cavities called soralia, which open when the lichen dries or surrounding tissues die and release the soredia to be dispersed by wind. Another form of diaspore are isidia, elongated outgrowths from the thallus that break off for dispersal. Fruticose lichens in particular can easily fragment. Due to the relative lack of differentiation in the thallus, the line between diaspore formation and vegetative reproduction is often blurred. Many lichens break up into fragments when they dry, dispersing themselves to resume growth when moisture returns. soredium Lichens also reproduce sexually in a manner typical of fungi, forming fungal and algal "propagules" that following germination must meet with a compatible partner before a functional lichen can form. This is generally not a common means of reproduction for most lichens, though it is more common in basidiomycetous lichens since they appear to lack structures specifically designed for asexual reproduction. Spores are produced in spore producing bodies, the three most common spore body types are the apothecia, perithecia and the pycnidia.

Ecology

Because lichens are morphologically small relative to most terrestrial plants, yet require access to sunlight in order to grow, most forms are attached to either large boulders, other inert surfaces, or woody plants in somewhat to completely open or exposed situations. However, where adequate moisture exists, lichens develop on surfaces (particularly those of slow-growing trees) in forests as part of an epiphyte community. Stability (that is, longevity) of a surface is a commonality of most lichen habitats. Lichens are relatively slow-growing, and do not always compete well against even similarly low-growing mosses or liverworts where conditions of adequate moisture will favor the latter. Lichens are a part of the food available for many animals, such as reindeer, living in arctic regions. The larvae of a surprising number of Lepidoptera species feed exclusively on lichens. These include Common Footman and Marbled Beauty. Although lichens typically grow in harsh environments in nature, many lichens are sensitive to man-made pollutants. Hence, they have potential as pollution indicator organisms. When growing on mineral surfaces, some lichens slowly degrade their substrate by secreting acids that dissolve the minerals, contributing to the process of weathering by which rocks are gradually turned into soil. While this contribution to weathering is usually benign, it can cause problems for man-made stone structures. For example, there is an ongoing lichen growth problem on Mount Rushmore National Memorial that requires the employ of mountain climbing conservators to clean the monument. The European Space Agency has discovered that Lichens can survive unprotected in space. In an experiment led by Leopoldo Sancho from the Complutense University of Madrid, two species of lichen – Rhizocarpon geographicum and Xanthoria elegans – were sealed in a capsule and launched on a Russian Soyuz rocket on 31 May 2005. The Lichens were exposed to temperatures ranging from -20°C to 20°C, the vacuum of space and radiation for 15 days. Afterward, they were found to be in the same state as the start of the experiment.

Classification

Lichens are informally classified by growth form into:
- crustose (paint-like, flat), e.g., Caloplaca flavescens
- filamentose (hair-like), e.g., Ephebe lanata
- foliose (leafy), e.g., Hypogymnia physodes
- fruticose (branched), e.g., Cladina evensii, C. subtenuis, and Usnea australis
- leprose (powdery), e.g., Lepraria incana
- squamulose (consisting of small scale-like structures, lacking a lower cortex), e.g., Normandina pulchella
- gelatinous lichens, in which the cyanobacteria produce a polysaccharide that absorbs and retains water. image:Lichen_squamulose.jpg|A foliose lichen on basalt image:Lichen_fruiticose.jpg|Usnea australis, a fruticose form, growing on a tree branch Image:Lichen02.jpg|Map lichen (Rhizocarpon geographicum) on rock image:Hyella caespitosa hypae.jpg|The cyanobacterium Hyella caespitosa with fungal hyphae in the lichen Pyrenocollema halodytes

References

Brodo, I.M., S.D. Sharnoff, and S. Sharnoff, 2001. Lichens of North America. Yale University Press, New Haven. http://www.newscientistspace.com/article/dn8297 Hardy lichen shown to survive in space

External links

- [http://bugs.bio.usyd.edu.au/Mycology/Plant_Interactions/Lichen/lichenBiology.shtml University of Sydney lichen biology]
- [http://thavibu.com/caliciales/ Crustose species of lichen order Caliciales in Norway]
- [http://www.esa.int/esaHS/SEMUJM638FE_index_0.html ESA article on lichen survivability in low earth orbit] Category:Symbiosis Category:Mycology Category: cryptogams ja:地衣類

Species

In biology, a species is the basic unit of biodiversity. In scientific classification, a species is assigned a two-part name in Latin. The genus is listed first (and capitalized), followed by a specific epithet. For example, humans belong to the genus Homo, and are in the species Homo sapiens. The name of the species is the whole binomial not just the second term (the specific epithet). The binomial, and most other purely formal aspects of the biological codes of nomenclature, were formalized by Carolus Linnaeus in the 1700's and as a result are called the "Linnaean system". At that time, species were thought to represent independent acts of creation by God, and were therefore considered objectively real and immutable. Since the advent of the theory of evolution, the conception of species has undergone vast changes in biology, however no consensus on the definition of the word has yet been reached. The most commonly cited definition of "species" was first coined by Ernst Mayr. By this definition, called the biological species concept or isolation species concept, species are "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups". However, many other species concepts are also used (see other definitions of species below). The scientific name of a species is properly typeset in italics. When an unknown species is being referred to this may be done by using the abbreviation "sp." in the singular or "spp." in the plural in the place of the second part of the scientific name. Note that the word "specie" is not the singular of "species". It refers to coined money.

Definitions of species

The definition of a species given above as taken from Mayr, is somewhat idealistic. Since it assumes sexual reproduction, it leaves the term undefined for a large class of organisms that reproduce asexually. Biologists frequently do not know whether two morphologically similar groups of organisms are "potentially" capable of interbreeding. Further, there is considerable variation in the degree to which hybridization may succeed under natural and experimental conditions, or even in the degree to which some organisms use sexual reproduction between individuals to breed. Consequently, several lines of thought in the definition of species exist: ; Typological species : A group of organisms in which individuals are members of the species if they sufficiently conform to certain fixed properties. The clusters of variations or phenotypes within specimens (ie: longer and shorter tails) would differentiate the species. This method was used as a "classical" method of determining species, such as with Linnaeus early in evolutionary theory. However, we now know that different phenotypes do not always constitute different species (e.g.: a 4-winged Drosophila born to a 2-winged mother is not a different species). Species named in this manner are called morphospecies. ; Morphological species : A population or group of populations that differs morphologically from other populations. For example, we can distinguish between a chicken and a duck because they have different shaped bills and the duck has webbed feet. Species have been defined in this way since well before the beginning of recorded history. This species concept is much criticised because more recent genetic data reveals that genetically distinct populations may look very similar and, contrarily, large morphological differences sometimes exist between very closely-related populations. Nonetheless, most species known have been described solely from morphology. ; Biological / Isolation species : A set of actually or potentially interbreeding populations. This is generally the most useful formulation for scientists working with living examples of the higher taxa like mammals, fish, and birds, but meaningless for organisms that do not reproduce sexually. It does not distinguish between the theoretical possibility of interbreeding and the actual likelihood of gene flow between populations and is thus impractical in instances of allopatric (geographically isolated) populations. The results of breeding experiments done in artificial conditions may or may not reflect what would happen if the same organisms encountered each other in the wild, making it difficult to gauge whether or not the results of such experiments are meaningful in reference to natural populations. ; Mate-recognition species : A group of organisms that are known to recognise one another as potential mates. Like the isolation species concept above, it applies only to organisms that reproduce sexually. Unlike the isolation species concept, it focuses specifically on pre-mating reproductive isolation. ; Phylogenetic / Evolutionary / Darwinian species : A group of organisms that shares an ancestor; a lineage that maintains its integrity with respect to other lineages through both time and space. At some point in the progress of such a group, members may diverge from one another: when such a divergence becomes sufficiently clear, the two populations are regarded as separate species. ; Microspecies : Species that reproduce without meiosis or mitosis so that each generation is genetically identical to the previous generation. See also apomixis. In practice, these definitions often coincide, and the differences between them are more a matter of emphasis than of outright contradiction. Nevertheless, no species concept yet proposed is entirely objective, or can be applied in all cases without resorting to judgement. Given the complexity of life, some have argued that such an objective definition is in all likelihood impossible, and biologists should settle for the most practical definition. For most vertebrates, this is the biological species concept, and to a lesser extent (or for different purposes) the phylogenetic species concept. Many BSC subspecies are considered species under the PSC; the difference between the BSC and the PSC can be summed up insofar as that the BSC defines a species as a consequence of manifest evolutionary history, while the PSC defines a species as a consequence of manifest evolutionary potential. Thus, a PSC species is "made" as soon as an evolutionary lineage has started to separate, while a BSC species starts to exist only when the lineage separation is complete.

Importance in biological classification

The idea of species has a long history. It is one of the most important levels of classification, for several reasons:
- It often corresponds to what lay people treat as the different basic kinds of organism - dogs are one species, cats another.
- It is the standard binomial nomenclature (or trinomial nomenclature) by which scientists typically refer to organisms.
- It is the only taxonomic level which has empirical content, in the sense that asserting that two animals are of different species is saying something more than classificatory about them. After thousands of years of use, the concept remains central to biology and a host of related fields, and yet also remains at times ill-defined and controversial.

Implications of assignment of species status

The naming of a particular species should be regarded as a hypothesis about the evolutionary relationships and distinguishability of that group of organisms. As further information comes to hand, the hypothesis may be confirmed or refuted. Sometimes, especially in the past when communication was more difficult, taxonomists working in isolation have given two distinct names to individual organisms later identified as the same species. When two named species are discovered to be of the same species, the older species name is usually retained, and the newer species name dropped, a process called synonymization, or convivially, as lumping. Dividing a taxon into multiple, often new, taxons is called splitting. Taxonomists are often referred to as "lumpers" or "splitters" by their colleagues, depending on their personal approach to recognizing differences or commonalities between organisms (see lumpers and splitters). Traditionally, researchers relied on observations of anatomical differences, and on observations of whether different populations were able to interbreed successfully, to distinguish species; both anatomy and breeding behavior are still important to assigning species status. As a result of the revolutionary (and still ongoing) advance in microbiological research techniques, including DNA analysis, in the last few decades, a great deal of additional knowledge about the differences and similarities between species has become available. Many populations which were formerly regarded as separate species are now considered to be a single taxon, and many formerly grouped populations have been split. Any taxonomic level (species, genus, family, etc.) can be synonymized or split, and at higher taxonomic levels, these revisions have been still more profound. From a taxonomical point of view, groups within a species can be defined as being of a taxon hierarchically lower than a species. In zoology only the subspecies is used, while in botany the variety, subvariety, and form are used as well.

The isolation species concept in more detail

In general, for large, complex, organisms that reproduce sexually (such as mammals and birds), one of several variations on the isolation or biological species concept is employed. Often, the distinction between different species, even quite closely related ones, is simple. Horses (Equus caballus) and donkeys (Equus asinus) are easily told apart even without study or training, and yet are so closely related that they can interbreed after a fashion. Because the result, a mule or hinny, is not usually fertile, they are clearly separate species. But many cases are more difficult to decide. This is where the isolation species concept diverges from the evolutionary species concept. Both agree that a species is a lineage that maintains its integrity over time, that is diagnosably different to other lineages (else we could not recognise it), is reproductively isolated (else the lineage would merge into others, given the chance to do so), and has a working intra-species recognition system (without which it could not continue). In practice, both also agree that a species must have its own independent evolutionary history—otherwise the characteristics just mentioned would not apply. The species concepts differ in that the evolutionary species concept does not make predictions about the future of the population: it simply records that which is already known. In contrast, the isolation species concept refuses to assign the rank of species to populations that, in the best judgement of the researcher, would recombine with other populations if given the chance to do so.

The isolation question

There are, essentially, two questions to resolve. First, is the proposed species consistently and reliably distinguishable from other species? Secondly, is it likely to remain so in the future? To take the second question first, there are several broad geographic possibilities.
- The proposed species are sympatric—they occupy the same habitat. Observation of many species over the years has failed to establish even a single instance of two diagnostically different populations that exist in sympatry and have then merged to form one united population. Without reproductive isolation, population differences cannot develop, and given reproductive isolation, gene flow between the populations cannot merge the differences. This is not to say that cross breeding does not take place at all, simply that it has become negligible. Generally, the hybrid individuals are less capable of successful breeding than pure-bred individuals of either species.
- The proposed species are allopatric—they occupy different geographical areas. Obviously, it is not possible to observe reproductive isolation in allopatric groups directly. Often it is not possible to achieve certainty by experimental means either: even