Vegetation of Southeast Asia Studies of Forest Types 1963-1965

The country may be divided into three topographic regions: (a)
Upper Laoc, mainly ru.^ed mountain chains arid /~or^e-like valleys,
with some pe.-iks attaining a height exceeding u,OOC feet (2,500 rn.);
(b) sloping taolelands that border the Annamite Chain in Lower Laos;
and (c) lowland valleys of the Mekong river and its tributaries.
The Mekong river, which has lon^ played an important role in the
life of the Lao people, flows for several hundred miles, in a broad
valley along the western border and throu ^h northern I/aotian territory.
It constitutes the country's main artery of communication.
During low water the river is shallow, but at the nei ; ;ht of the rains
it rices more tnan 20 feet (6 m.). (3ee I'!;. 0.}
Soil fertile enough to support intensive agriculture is limited
to the river valleys and on the Boloven Plateau near the Cambodian
border. The people's life is closely tiea to agriculture and rice
is largely cultivated for domestic needs.
Population: No accurate data are available regarding the population
figure of Laos. Lucent official estimar.es ran^e from 1.5 to
3 millions. The sparse copulation is unevenly spread, with the
greatest concentration in the basin of the Mekong, and is comprised
of many tribal groups with d.ivercent backgrounds, r'or administrative
purposes they are classified into two principal groups: (a) Lao,
probably descended from tribes whose origin way Thai, account for
approximately 42 percent of the total population. The related Thai, .
representing about 15 percent of the population, have a somewhat
similar ethnic heritage. These people inhabit the plains, living in
densely populated villages, and their livelihood depends entirely
on rice growing. Their predominant, religion is Buddhisn. (b) Lao-
Theung, who live mostly in the hiJls and mountainous area, constitute
about 29 percent of the population. With inheritance stemming from
several different ethnic cultures, these upland tribes include the
Kha, IvJec, Yao, Phouthai and Lu. They inhabit the forests of the hip,h
plateaus and mountains, and practice ohe shifting system of agriculture,
by burning cff hillsides to secure tillable land and seek new
fields, when soil exhaustion makes old oites undesirable (Fig.118).
l.'n these snail patches they yrow annual crops, upland rice and other
food prouuce, as well as opium poppy.
Ir: audition, tribes of proto-Malayan stock or Indonesian descent,
live under primitive conditions scattered in the mountains and forests,
Foreigners who reside in the towns a:id conduct most of the banking
and -commerce ircl'.-de Vietnamese, Chinese, Cambodians, Indians and
Pakistanis.
It is impossible to determine the -exact numoer of inhabitants by
region, out the following figures indicate the approximate density
of the population. In mountain regions there are roughly 5 inhabitants
per square mile; while in the plain regions the average is
about 39 inhabitants per square mile.