Terrain shapes and bedrock
COUNTRYAAH, most of Laos is highland, especially in the north where a
series of steep ridges with sharp ridges in the northeast -
southwest direction meet the country. The peaks reach a
height of nearly 2,500 meters above sea level. The border
area with Vietnam to the east is also mountainous, with
heights of over 2,700 meters above sea level. It is a
continuation to the southeast of the Himalayan mountain
ranges, here called the Annamitic Mountains, which extend in
the northwest - southeast direction.
The main river in Laos is the Mekong. Especially on the
eastern side of the river large plains are spreading. Also
in the highlands north are important plains, such as the
strategically and politically important Krukslätten. The
lowlands, which descend from east to west in a number of
plateaus, have been built up of alluvial material that the
rivers brought down from the mountains. Another fertile area
is the Boloven Plateau in the south at an altitude of about
1,200 m above sea level.
The bedrock consists mostly of rocks formed during
Mesozoic and Tertiary, in the south especially volcanoes.
Laos has a tropical monsoon climate with rainy season
during May - October, when the southwest monsoon gives the
country 1,300-2,300 mm of rain. In some places the rainfall
is higher, so get e.g. The Boloven Plateau 4 100 mm/year.
During the dry season from November to April, the northeast
monsoon reigns, and the average temperature is then 16-21 ～
C, except in March and April, when it is about 32 ～ C. The
humid summer has a temperature of around 27 ～ C.
It has been estimated that Laos was previously covered by
about 70% of forests, but now these have been severely
decimated, among other things. by felling. The evergreen
mountain rainforest mainly dominated the northern parts of
the country, while lowland rainforest spread on the plain
along the Mekong River. Among the characteristic trees in
the rainforest should be mentioned a number of high-rise
dipterocarpus plants, some of which can reach 60 m in
height; These include species such as Dipterocaʹrpus
alaʹtus, Anisoʹptera cochinchineʹnse,
Parashoʹrea stellaʹta and several Hoʹpea
species. In addition, several tree-shaped pea plants, e.g.
Pterocaʹrpus macrocaʹrpus and Dalbeʹrgia
The more open and slightly more mature and deciduous
monsoon forests are found on some soils north and west of
the Mekong River. It is in the monsoon forest that there is
a stock of teak.
The original forest now accounts for about 30% of the
land area, while another 25% is depleted secondary forest.
The forestless parts of Laos are dominated by culturally
created grasslands, savannas, bush landscapes and bamboo
The fauna is similar to that of other Indochina but is
relatively poorer. In the rainforests there are semi-monkeys
and monkeys, among others. trigloria, minor trigloria (Nycticeʹbus
pygmaeus [-mɛʹ: -]), the rare black-legged costume
monkey (Pyʹgathrix niʹgripes) and black gibbon
(Hyloʹbates coʹncolor). Both Chinese and Malay
ant cones (Maʹnis pentadaʹctyla and M.
javaʹnica, respectively) occur. Among the predators are
leopard, tree leopard, marble cat (Pardofeʹlis
marmoraʹta), collar bear and Malay bear, and among the
ungulates mouth jackals, sambar deer and ox banteng, gaur
and kouprey (very rare in southern Laos). Indian elephant is
rare, and in the south there may be scab paper.
On the rivers are kingfishers, storks, herons and in
southern Laos Indian scissors (Ryʹnchops albicoʹllis).
In the forests there are bulbils, needle birds, tailors,
sunbirds, rhinoceros, beards and chickens, among others.
Among the herbivores are python norms, cobras, wares and
rare in southern Laos siam crocodile (Crocodyʹlus
From completely lacking nature-protected areas, Laos
deposited 17 so-called national biodiversity reserves in
1993-94, and in recent years another four reserves have been