Malesia
Encyclopedia
Malesia is a biogeographical
region straddling the boundaries of the Indomalaya
ecozone
and Australasia ecozone
, and also a phytogeographical
floristic region in the Paleotropical Kingdom
.
, the Malay archipelago
, New Guinea
, and the Bismarck Archipelago
, based on a shared tropical flora derived mostly from Asia
but also with numerous elements of the Antarctic flora
, including many species in the southern conifer families Podocarpaceae
and Araucariaceae
. The floristic region overlaps four distinct mammal
ian faunal regions.
, Java, Bali
, and Borneo
, shares the large mammal fauna of Asia and is known as Sundaland
. These islands are on Asia's relatively shallow continental shelf
, and were linked to Asia during the ice age
s, when sea levels were lower. The eastern edge of Sundaland is the Wallace line
, named after Alfred Russel Wallace
, the nineteenth-century British naturalist who noted the difference in fauna between islands on either side of the line. Dipterocarps are predominant trees in the lowland forests of Sundaland.
, were never linked to the neighboring continents, and have a flora and fauna that include Indomalayan and Australasian elements.
of eastern Indonesia, is linked to Australia by a shallow continental shelf, and shares many marsupial
mammal and bird taxa
with Australia. New Guinea also has many additional elements of the Antarctic flora, including southern beech (Nothofagus
) and Eucalypt
s. New Guinea has the highest mountains in Malesia, and vegetation ranges from tropical lowland forest to tundra.
Biogeography
Biogeography is the study of the distribution of species , organisms, and ecosystems in space and through geological time. Organisms and biological communities vary in a highly regular fashion along geographic gradients of latitude, elevation, isolation and habitat area...
region straddling the boundaries of the Indomalaya
Indomalaya
The Indomalaya ecozone is one of the eight ecozones that cover the planet's land surface. It extends across most of South and Southeast Asia and into the southern parts of East Asia....
ecozone
Ecozone
An ecozone is the broadest biogeographic division of the Earth's land surface, based on distributional patterns of terrestrial organisms.Ecozones delineate large areas of the Earth's surface within which organisms have been evolving in relative isolation over long periods of time, separated from...
and Australasia ecozone
Australasia ecozone
The Australasian zone is an ecological region that is coincident, but not synonymous , with the geographic region of Australasia...
, and also a phytogeographical
Phytogeography
Phytogeography , also called geobotany, is the branch of biogeography that is concerned with the geographic distribution of plant species...
floristic region in the Paleotropical Kingdom
Paleotropical Kingdom
The Paleotropical Kingdom is a floristic kingdom comprising tropical areas of Africa, Asia and Oceania , as proposed by Ronald Good and Armen Takhtajan. Its flora is characterized by about 40 endemic plant families, e.g. Nepenthaceae, Musaceae, Pandanaceae, Flagellariaceae...
.
Floristic province
Malesia was first identified as a floristic region that included the Malay PeninsulaMalay Peninsula
The Malay Peninsula or Thai-Malay Peninsula is a peninsula in Southeast Asia. The land mass runs approximately north-south and, at its terminus, is the southern-most point of the Asian mainland...
, the Malay archipelago
Malay Archipelago
The Malay Archipelago refers to the archipelago between mainland Southeastern Asia and Australia. The name was derived from the anachronistic concept of a Malay race....
, New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...
, and the Bismarck Archipelago
Bismarck Archipelago
The Bismarck Archipelago is a group of islands off the northeastern coast of New Guinea in the western Pacific Ocean and is part of the Islands Region of Papua New Guinea.-History:...
, based on a shared tropical flora derived mostly from Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
but also with numerous elements of the Antarctic flora
Antarctic flora
The Antarctic flora is a distinct community of vascular plants which evolved millions of years ago on the supercontinent of Gondwana, and is now found on several separate areas of the Southern Hemisphere, including southern South America, southernmost Africa, New Zealand, Australia and New Caledonia...
, including many species in the southern conifer families Podocarpaceae
Podocarpaceae
Podocarpaceae is a large family of mainly Southern Hemisphere conifers, comprising about 156 species of evergreen trees and shrubs. It contains 19 genera if Phyllocladus is included and if Manoao and Sundacarpus are recognized....
and Araucariaceae
Araucariaceae
Araucariaceae, commonly referred to as araucarians, is a very ancient family of coniferous trees. It achieved its maximum diversity in the Jurassic and Cretaceous periods, when it was distributed almost worldwide...
. The floristic region overlaps four distinct mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
ian faunal regions.
Sundaland
The western part of Malesia, which includes the Malay Peninsula and the islands of SumatraSumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, Java, Bali
Bali
Bali is an Indonesian island located in the westernmost end of the Lesser Sunda Islands, lying between Java to the west and Lombok to the east...
, and Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
, shares the large mammal fauna of Asia and is known as Sundaland
Sundaland
Sundaland is a biogeographical region of Southeastern Asia which encompasses the areas of the Asian continental shelf that was exposed during the last ice age. It included the Malay Peninsula on the Asian mainland, as well as the large islands of Borneo, Java, and Sumatra and their surrounding...
. These islands are on Asia's relatively shallow continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...
, and were linked to Asia during the ice age
Ice age
An ice age or, more precisely, glacial age, is a generic geological period of long-term reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental ice sheets, polar ice sheets and alpine glaciers...
s, when sea levels were lower. The eastern edge of Sundaland is the Wallace line
Wallace Line
The Wallace Line separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present...
, named after Alfred Russel Wallace
Alfred Russel Wallace
Alfred Russel Wallace, OM, FRS was a British naturalist, explorer, geographer, anthropologist and biologist...
, the nineteenth-century British naturalist who noted the difference in fauna between islands on either side of the line. Dipterocarps are predominant trees in the lowland forests of Sundaland.
Wallacea
The islands between Sundaland and New Guinea, called WallaceaWallacea
Wallacea is a biogeographical designation for a group of Indonesian islands separated by deep water straits from the Asian and Australian continental shelves. Wallacea includes Sulawesi, the largest island in the group, as well as Lombok, Sumbawa, Flores, Sumba, Timor, Halmahera, Buru, Seram, and...
, were never linked to the neighboring continents, and have a flora and fauna that include Indomalayan and Australasian elements.
Philippines
The Philippines were also never connected to Asia, and have a largely Asian-derived flora with some Australasian elements, and a distinct mammalian fauna.New Guinea and the Bismarck Archipelago
The eastern end of Malesia, which includes New Guinea and the Aru IslandsAru Islands
The Aru Islands are a group of about ninety-five low-lying islands in the Maluku province of eastern Indonesia. They also form a regency of Indonesia.-Geography:...
of eastern Indonesia, is linked to Australia by a shallow continental shelf, and shares many marsupial
Marsupial
Marsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
mammal and bird taxa
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
with Australia. New Guinea also has many additional elements of the Antarctic flora, including southern beech (Nothofagus
Nothofagus
Nothofagus, also known as the southern beeches, is a genus of 35 species of trees and shrubs native to the temperate oceanic to tropical Southern Hemisphere in southern South America and Australasia...
) and Eucalypt
Eucalypt
Eucalypts are woody plants belonging to three closely related genera:Eucalyptus, Corymbia and Angophora.In 1995 new evidence, largely genetic, indicated that some prominent Eucalyptus species were actually more closely related to Angophora than to the other eucalypts; they were split off into the...
s. New Guinea has the highest mountains in Malesia, and vegetation ranges from tropical lowland forest to tundra.
See also
- Flora of the Malesian region
- Phytochorion - floristic regions and provinces