Adrián: -Where is Emma-Sofia?
TROPICAL FOREST ECOSYSTEM DYNAMICS
Group No 1.
Participants: Eva Ehrnsten, Emma-Sofia Hyytiäinen, Mamo Kebede, Siriwat Suebsai, Somsack
Sysomvang
Group work report for the course "Forest Landscape Restoration in the Mekong River Basin"
Laos and Thailand, 4-27 September 2009
Organised by the National University of Laos (NUOL), Vientiane, Laos
In cooperation with VITRI/University of Helsinki, and Kasetsart University, Bangkok
Under the framework of the FORMEB project of the Finnish Ministry for Foreign Affairs
Institutional Cooperation Instrument (ICI)
Table of contents
1. Introduction...............................................................................................................................3
2. Tropical forest ecology.............................................................................................................4
2.1. Definitions..............................................................................................................................4
2.2. Natural regeneration of forests.......................................................................................... 4
2.3. Types of forest based on the degree of disturbance...........................................................7
3. Forests in the Lao PDR ............................................................................................................ 7
3.1. General information .......................................................................................................... 7
3.2. Forest types in the Lao PDR ............................................................................................. 7
3.3. Shifting cultivation in the Lao PDR................................................................................ 11
4. Case study: Forest succession after shifting cultivation ........................................................ 12
4.1. Study area........................................................................................................................ 12
4.2. Survey methods ............................................................................................................... 14
4.3. Data analysis ................................................................................................................... 16
4.4. Results ............................................................................................................................. 16
5. Discussion .............................................................................................................................. 21
5.1. Succession........................................................................................................................23
5.2. Dominant species: Peltophorum dasyrachis....................................................................23
5.3. Bamboo............................................................................................................................24
5.4. Limitations of the study...................................................................................................25
6. Conclusions.............................................................................................................................24
7. References...............................................................................................................................25
Appendix 1. List of all the 71 species encountered....................................................................28
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1. Introduction
More than 250 million people in the tropics practise shifting cultivation. It is a cultivation system
in which cropping and fallow phases follow each other. Shifting cultivation can be seen as
sustainable practise when the fallow periods are long enough for restoration of organic layer and
nutrients, and it is thought to be adapted to tropical soils and climates. It is a cheap method and is
therefore suitable for small farmers (Metzger 2003).
In mountainous areas of Southeast Asia, there are the largest still remaining tropical forests in the
mainland of Southeast Asia. There is a great variety of ethnic minority groups in the
mountainous areas, and together these groups have extensive knowledge about land and forests
management. Shifting cultivation practises in the area vary very much, but practises can be
divided in two basic types. These types are pioneer and rotational shifting cultivation systems.
Pioneer shifting cultivation means that the villagers clear one piece of forest, cultivate it for some
years and move to another place to start from clearing again. Nowadays this practice is getting
rarer, and shifting cultivation systems are more often rotational, in most cases meaning that the
farmers are settled in one place and clear forest in the vicinity, cultivate it for one year and then
let secondary vegetation take over the field. Also many forms of agroforestry are used in
Southeast Asia (Rekasem et al. 2009).
Fallow periods of rotational shifting cultivation vary. Long fallow periods result in a mosaic of
cultivated fields, fallows of different ages and mature forests. When the fallow period is reduced
even only to a couple of years the outcome is a more homogenous landscape, mostly dominated
by agricultural land and young secondary vegetation. The changes in the landscape may leed to
local extinctions of species as the old secondary forests and mature forests disappear. Those
species may be important for the regenaration of the forest, many seeds are dispersed by birds or
bats that live in the older forest stages. Therefore extinctions of these species may leed to
reduced biodiversity and slower regeneration. When boundaries between secondary vegetation
and forests are shortened due to shortened fallow periods, seed flux to younger forest may be
reduced. (Metzger 2003).
Shifting cultivation is common in the Lao PDR. There is much discussion about the
sustainability of the method. It is estimated that 6% of the population in Lao PDR is practising
shifting cultivation. It is practised by people in the mountainous areas, especially in the north.
Because there is not suitable land for permanent agriculture, people have to rely on the
traditional way of farming in upland areas, shifting cultivation. In 1999, the area under shifting
cultivations was estimated to be 600.000 ha (Lao PDR 2001).
We studied the forest succession after shifting cultivation in the field to get an idea of how fast
the forest regenerates after fire and how fire affects the species community. The study was
performed by comparing the species composition in four forest plots of different ages after
burning.
To understand the consequences of shifting cultivation on tropical forests, it is essential to
understand the natural dynamics of forests. Therefore, this work starts with a description of
tropical forest ecology with emphasis on the regeneration and succession of forests. Since the
study was performed in Lao PDR, some background on the forests in this country is also
presented.
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2. Tropical forest ecology
2.1. Definitions
Ecosystem is defined as functional interacting system of living organisms, atmospheric and
mineral components active within any space and engineered by solar energy. The term
ecosystem was suggested by an English ecologist, Tansley. He defined it as including “not only
the organism-complex, but the whole complex of physical factors forming what we call the
environment” (Tansley 1935). More recently, Odum (1971) proposed a longer but more explicit
definition: “Any unit that includes all of the organisms (i.e., the community) in a given area
interacting with the physical environment so that a flow of energy leads to a clearly defined
trophic structure, biotic diversity, and material cycles is an ecological system or ecosystem”.
There are different definitions given to a forest. In 2000, FAO has defined forests as areas biger
than 0.5 ha having minimum 10% crown cover and not being primarily under agricultural or
urban use (FAO 2000). A forest is a complex biological and physical system in which there is an
enormous variety of interactions and interdependency among the different parts. The forest may
be considered as an assemblage of plants and animals living in a biotic association. The forest
association, or forest community, then, is an assemblage of plants and animals living together in
a common environment (Spurr & Barnes 1980).
By naming the predominant trees, we can classify the forest type (Spurr & Barnes 1980). Thus,
we think of Dipterocarps forest, Mangrove forest, or of other forest types.
2. 2. Natural regeneration of forests
Tree seedling ecology
Tree seedling ecology is very much related with gap phase dynamics. Gap is the area between
the edges of the crowns of peripheral trees projected vertically down to ground level (Brokaw
1982).
Pioneers are those that require full light for both germination and establishment and climax
species are those that can germinate and establish below a forest canopy. Seedlings of climax
species are released from forest floor seedling bank in small gaps to form the next growth cycle
but are replaced in big gaps by pioneer species, germinated from seed after gap creation. Within
the climax species there are many different degrees of seedling shade tolerance. Very shade
tolerant species form the next growth cycle where gaps are tiny, and as gap size increases
progressively less shade tolerant species (more light demanding) climax species for the next
growth cycle until in the biggest gaps pioneer species do so instead. The species that colonize the
gap depends on the success of competition among established seedlings and saplings and
recently germinated seeds (Whitmore 1993).
Plant population biology seen through different phases (Harper 1977):
A) Recruitment phase (Establishment phase)
The first phase includes the two population processes, natality and dispersal which also includes
seed rain. Seed rain varies as a function of distance from the plant, wind, and other factors that
influence seed dispersal. Seed dispersal is a key process in the regeneration and recruitment of
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plants. It is generally taken as an adaptation to increase the probability of survival of the
offspring. Propagules may be dispersed by one or several dispersal mechanisms but in tropical
regions dispersal by animals is the predominant form of dissemination. Wind is also common in
dry habitats. The seed rain contributes to the seed bank: the population of living but
ungerminated seeds contained in the soils.
In addition to the seed bank, there is often bud bank, a population of buds in the lower stem, root
or other underground organs. The meristem of this buds remain dormant under the influence of
hormones. When the biomass is killed these meristems become active and produce another
biomass. This is an important characteristic of plants in fire prone areas. The seedling bank
seedling of shade tolerant species can remain in the under storey as suppressed seedlings or
saplings for century. Where there is well-established seedling bank, it may dominate the seed
rain, seed bank and bud bank in the post disturbance community.
The establishment phase gives the biggest demographic squeeze to the seedling population.
Establishment can fail if seedlings occur on the wrong micro sites or due to predation. The
recruitment from the seed rain or seed bank depends upon the existence of the so-called “safe
sites”. Availability and characteristics of the “safe sites” in an area acts as an environmental filter
that results in the species composition of germinants to be different from that of the seed rain
and/or seed bank.
B) Survival phase
Seeds that germinate to become seedlings, buds that develop shoots (ramets) and/or seedlings
released from the seedling bank form over storey plants. These plants will exhibit a characteristic
survivorship curve, the shape of which varies among different plant species and different
environments. As in many animal populations, there is heavy juvenile mortality in most plant
populations. Tree populations have survivorship curves and age-class distributions, which vary
greatly between species and the stage of development of the plant community. Light-demanding
pioneer species tend to have a small number of age classes (e.g. are even-aged) that pass up
and out of the age-class distribution as the species is eliminated in the course of succession.
Shade-tolerant climax species in old growth forests have a more stable age distribution.
C) Juvenile stage
For most tree species, this stage will be much longer than the preceding stages and this stage will
include many large individuals, including saplings and trees. Capture or attraction of symbionts
often occurs in the seedling stage. Tropical seedlings may have ectomycorrhizal infections
within twenty days after germination (Alexander et al. 1992). Seedlings of many tree species
show enhanced growth or survival within 1 year of inoculation with arbuscular mycorrhizae
(Janos 1980). Large seeds allow development of extensible root systems which are needed to
encounter mycorrhizal inocula. We should establish at what stage roots or tropical tree seedlings
are susceptible to or require mycorrhizal infection and rhizobial nodulation and whether there are
particular root architectures or root system sizes that enhance encounter rates.
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Stand development as a result of self-thinning and competition
Generally, there are four main stages in the development of an-initially even-aged stand (Oliver
and Larson 1990):
Stand initiation: Early development of a population prior to canopy closure, the mortality factor
here is mainly density independent and interspecific competition.
Stem exclusion: Following the closure of the canopy additional recruitment ceases and density
dependent mortality factors operate mainly by competition for light and moisture. The stand
undergoes self-thinning.
Understorey reinitiation: As self-thinning proceeds, canopy gaps will be created and reinitiated.
The increased light availability at the ground level permits the development of under storey
vegetation and recruitment of seedling bank.
Old growth: As the stand ages the shade tolerant seedlings and saplings in the understorey will
be recruited in to the canopy leading to the mixed age multicanopy forest, with standing dead old
trees (snags). The forest develops in to old growth stage.
2.3. Types of forest based on the degree of disturbance
Primary forests
By definition, primary forests are those that have not been touched by man or have only slightly
been influenced from outside, so that the natural structure, functions and dynamics of forests
have not been affected in the way, which would danger the elastic capacity of forests (ITTO
2002).
Secondary forests
There is considerable ambiguity and confusion in the current use of the term „secondary forest‟
both in the literature and in people‟s perceptions. The term has been applied to numerous types
of forests with different characteristics and arising from many different processes. ITTO (2002)
defines it as: woody vegetation regrowing on land that was largely cleared of its original forest
cover (e.g. carried less than 10% of the original forest cover).
On the basis of this definition it can be seen that secondary forests:
• result from significant disturbance to the original primary forest, with major changes in its
structure and composition. Hence, for example, a primary forest that has been selectively logged
does not qualify as secondary forest;
• are distinct from shrubland, grassland or other non-forest vegetation. A forest is defined by
FAO as land with more than 10% canopy cover (FAO 2000); and
• occupy a successional position between non-forest vegetation and primary forest. Over
a long period of time, secondary forests can develop similar structures and functions to those of
the original forest. Secondary forests often develop on land abandoned after shifting cultivation,
settled agriculture, pasture or failed tree plantations (ITTO 2002).
Secondary forests are often of special importance to the rural people. They can provide a range
of goods to meet immediate livelihood needs, such as timber, food, and herbal medicines.
Secondary forests are also recognized for their value in fallow agriculture, in the industrial
timber sector as sources of locally or commercially valuable non-timber forest products, and for
the provision of environmental services such as biodiversity conservation, carbon storage, water
regulation and erosion control (ITTO 2002).
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Degraded forest lands
Degraded forestland is defined by ITTO (2002) as: former forestland severely damaged by the
excessive harvesting of wood and/or non-wood forest products, poor management, repeated fire,
grazing or other disturbances or land-uses that damage soil and vegetation to a degree that
inhibits or severely delays the re-establishment of forest after abandonment.
3. Forests in the Lao PDR
3.1. General information
Lao PDR is situated between 13°54' and 22°3'N and between 100°05' and 107°38'E on the
Southeast Asian peninsula. It covers an area of 236,800 km². Most of the land surface, total 80%,
is mountainous and hilly, and cultivated food plains are situated along Mekong River and the
larger tributaries. Fertile soils that can be irrigated are situated in the Central and Southern
regions of Lao PDR, and the North is mountainous without big irrigable plains. The country can
be divided in to three agricultural climatic zones. Mountainous north with its rugged terrain and
quite poor soils is not suitable for intensive agriculture. In the Centre and the South there are
mountainous areas that resemble those in the North, but in the Boloven Plateau the conditions for
agriculture are better. Third zone consists of plains along the Mekong and its tributaries and
these plains support more than the half of the population. 80 % of the land area is in the Mekong
Basin and the drain is westwards, whereas other parts drain eastwards (Lao PDR 2001).
Forest cover in the Lao PDR was 41.5 % in 2002. In 1943 forest cover was still 70 % and in
1982 49.1 %. Forest loss is estimated to be 0.6 % per year. Forests have declined much, even
tough in the neighbouring countries forest loss has been even more rapid (Lao PDR 2001,
Nathavong 2009).
Forestry Law 1996 forests were classified into 5 categories: protection forest, conservation forest,
production forest, rehabilited forest and degraded forest (Lao PDR 2001). New Forestry Law
came in 2007, and now forests are classified into three categories: protection, conservation and
production forests (Lao PDR 2001, Nathavong 2009).
Forest products are especially important for the rural people. From non-timber forest products
people get supplementary food for cultivated crops, construction materials, fuel wood and
traditional medicines. There are 757 plant and 150 animal species identified as NTFPs in the Lao
PDR, but the real number of species used is probably much higher, even five times (NAFRI,
NUoL & SNV 2007). NTFPs give also income to the local people, since the products such as
bamboo, rattan, cardamom and pine resin are commercially important. Small amounts of these
products are also exported, mainly to Viet Nam and Thailand. Forest resources are important for
the Lao economy. Forest products provide more than 40% of annual official exports. Forests
contain variety of species and ecosystems, important both nationally and internationally. They
also provide environmental services by controlling soil erosion and protecting watersheds and
thus support agriculture and hydro-energy production (Lao PDR 2001).
3.2. Forest types in the Lao PDR
In the Lao PDR there are many forest types. Dry evergreen forest can be found in the North,
where there are also areas of tropical montane deciduous forest and tropical montane forest. In
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the highland areas of Boloven Plateau and Annamite mountains, there are tropical montane
evergreen forest and pine forests. Lowland semievergreen dipterocarp forests can be found in the
Mekong River Plain and in the South there are dry dipterocarp forests and mixed deciduous
forests( Lao PDR 2001). The following information is from Environmental Ecology, by
Raungphanit 1998.
Evergreen forest
Coniferous forest
Dominant species: Pinus merkusii, P. kesuya, co dominant species: Facaceae (Quercus,
Castanopsis, Lithocarpus) Zyzygium, Shorea Dipterocarpus, shrubs: Phoenix, Cycas,
Rhododendron.
Dry evergreen forest
Dry evergreen forests have three-storeyed canopy. Less than 1/3 of species of canopy, shed their
leaves. In shrub layer there are woody climber species and especially in moist areas palms. Dry
evergreen forests are found in elevations of 100 to 300 m from sea level. Dominant species:
Anisoptera costata, Dipterocarpus alatus, Dipterocarpus costatus, Dipterocarpus turbinatus and
Hopea odorata.
Source: http://cyberlab.lh1.ku.ac.th/elearn/faculty/forest/fo24/silvics/picture/Na-Haeo-dry-evergr-for_small.jpg
Figure 1. Dry evergreen forest.
Deciduous Forests
Precipitation is low (< 1000 mm) and climate is more seasonal. Soil is either sandy or gravelly
loam and sometimes lateritic. Tree species shed their leaves during the dry season and the forest
is more or less subjected to ground fires during the dry season. The height of the predominant
threes (20-25 m) is lower than that in evergreen forest.
I. Mixed deciduous forest
1. Moist upper mixed deciduous forest
Moist upper mixed deciduous forests are located on 300-600 masl. and they have 3-storied
profile. Dominant species: Tectona grandis, Terminalia alata, Anogeissus acuminate, Xylia
xylocarpa, Peterocarpus macrocarpus and Lagerstroemia calyculata.
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Photo by Siriwat Suebsai.
Figure 2. Mixed deciduous forest: Moist upper mixed deciduous forest.
2. Dry upper mixed deciduous forest
Dry upper mixed deciduous forests are located on 300-500 masl. and have 3-storied profile.
The vegetation becomes more open due to the evaporation, exposure, surface erosion and the
leaching of organic components from the soil. The soil is either sandy loam or lateritic.
The ground flora is frequently destroyed by fire. Dominant species: Terminalia alata, Anogeissus
acuminate, Xylia xylocarpa, Peterocarpus macrocarpus and Lagerstroemia calyculata. No
Tectona grandis.
Photo by Siriwat Suebsai.
Figure 3. Mixed deciduous forest: Dry upper mixed deciduous forest.
3. Lower mixed deciduous forest
These forests are located 50-300 masl. and have 3-storied profile. They grow in the dry zone
where the soil is either sandy loam or lateritic. The absence of teak (Tectona grandis) from the
upper storey is a distinct characteristic. Dominant species: Lagerstroemia calyculata,
Lagerstroemia tormentosa, Bombax insigne, Afzelia xylocarpa and Terminalia bellerica.
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Photo by Siriwat Suebsai.
Figure 4. Mixed deciduous forest: Lower mixed deciduous forest.
II. Deciduous dipterocarp forest
On the undulating peneplain and ridges, where the soil is either sand or lateritic, and subjected to
extreme leaching, erosion and annual burning, the vegetation is markedly changed into a
subclimax type. The predominant species belong to the Dipterocarpaceae. The forest is rather
open and can be consider as two-storeyed. Dominant species:
The upper storey (20-25 m): Dipterocarpus obtusifolius, Dipterocarpus tuberculatus, Shorea
obtusa, Shorea siamensis and Quercus kerrii.
The second storey: Strychnos nux-vomica, Aporosa villosa, Phyllanthus emblica and Canarium
subulatum.
Photo by Siriwat Suebsai.
Figure 5. Deciduous dipterocarp forest.
III. Pine deciduous dipterocarp forest
This is a vegetation type with a notable inclusion of native pine species (Pinus merkusii & Pinus
kesiya). It is generally located at elevations of approximately 550 masl. and is more abundant
from 800-1200 masl. This type is promoted by fires in the cool dry season (December-February)
Dominant species:
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Upper storey: Pinus kesiya- Pinus merkusii- Dipterocarpus tuberculatus- Quercus rambottomiiQuercus kerrii
Lower storey: Anneslea fragrand- Aporosa villosa- Shcima wallichii
Photo by Siriwat Suebsai.
Figure 6. Pine deciduous dipterocarp forest.
3.3. Shifting cultivation in the Lao PDR
In the Lao PDR the most important factors leading to forest loss are extensive timber harvesting,
shifting cultivation, forest fires and upland encroachment. It is estimated that 6% of the
population in the Lao PDR is practising shifting cultivation. People in the mountainous areas,
especially in the North, practice shifting cultivation. Because there is not suitable land for
permanent agriculture, people have to rely on this traditional way of upland cultivation. In the
North region, it is estimated that 280,000 households get their living from shifting cultivation,
which is the majority of households. In 1998, 70% of the land area in rain-fed upland areas in the
North was under shifting cultivation, whereas about 15% of the land in the Centre and the South
was under shifting cultivation. In the Centre and the South there is encroachment of land by
lowland farmers, who are, even tough they have irrigation system, dependent on rainfall. Yields
are low because farmers use traditional rice varieties and they do not have the knowledge and
training in the use of organic fertilizers. Therefore, lowland farmers also use shifting cultivation.
There are numerous different shifting cultivation systems, but not so much is known about them
(Lao PDR 2001).
There are relatively recent statistics on the extent of shifting cultivation in the Lao PDR. In 1992,
the area under shifting cultivations was 1.6 million ha, whereas in 1999 the area was estimated to
be 600.000 ha. According to the Government 200 000 ha of forest is deforested by shifting
cultivation each year. It is also estimated, that 90 percent of forest fires are caused by shifting
cultivation, and therefore the Government takes credit for reducing the area of shifting
cultivation. The shifting cultivation practices, including encroachment, together with forest fires
contribute to 300 000 ha forest clearing per year (Lao PDR 2001, London 2001).
Land degradation in the Lao PDR is mostly associated with shifting cultivation. In areas where
the population pressure is high, rotation periods have been shortened and lowland farmers
encroach on neighbouring uplands. Fallow periods less than 10 years are seen to cause
degradation of soil fertility, weed infestation and rapid loss of soil moisture. Land and forest
management in the Lao PDR are closely related since the encroachment and shifting cultivation
play their part not only in forest degradation but also in land degradation (Lao PDR 2001).
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In the Lao PDR areas for shifting cultivation are cleared between January and Mars and burned
in April. Rice is planted in May and weeding is practised for three months, from June to August.
Rice is harvested in October (Takeda 2003).
4. Case study: Forest succession after shifting cultivation
4.1. Study area
The study was performed around the Na po village in the northwestern part of Sangthong
province in the Vientiane capital region (Figure 7). The village lies in an upland area and the
forest in the area (Figure 8) is mostly upland and lowland mixed deciduous forest (categories 13
and 14, respectively, on the map). Natural bamboo forests and unstocked forests (i.e. logged-over
forests that have little value for timber extraction) also occur in the area.
The old Na po village land-use plan gives a closer picture of the forest types in the village area
(Figure 9). The following information is based on personal communication with the local
paratxonomist and Somsack Sysomvang. As all forestland in Lao PDR, the government owns the
forest, but the village has use-rights to a certain area. In 1999, the Faculty of Forestry of the
National University of Laos (NUOL) started a cooperation project with the Na po village. The
village land-use plan from 1998 shown in the map is a result of this cooperation and is based on
the forest law of 1996. According to this law, the forest was classified into five categories:
conservation, production, unstocked, rehabilitation and protection forest. Based on this, the
village classified its forests into five categories: use forest, mixed deciduous forest, bamboo
forest, conservation forest and protection forest. Use forest means that the villagers can extract
timber and non-timber forest products (NTFPs) for household use. The mixed deciduous forest
can be used for shifting or shifting cultivation. From the bamboo forest, villagers are allowed to
extract bamboo. From both the conservation and protection, forest villagers can take NTFPs but
they are not allowed to practice shifting cultivation in these forest types. Since the forest law
changed in 2007 the village land-use plan of the Na po village was renewed with the help of the
Faculty of Forestry of NUOL to agree with the new law, but unfortunately, we did not get access
to the new land-use plan.
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Na po
village
Vientiane
Figure 7. The districts in the Vientiane capital region and the location of the study area. Map
made by Somsack Sysomvang in ArcGIS.
Na po
village
Figure 8. Forest cover map of the Vientiane capital region and the location of the study area.
Map made by Somsack Sysomvang in ArcGIS based on data from the Forest inventory and
planning centre (FIPC).
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Use forest
Mixed deciduous forest
Bamboo forest
Conservation forest
Protection forest
Picture taken by Eva Ehrnsten and interpreted by Somsack Sysomvang.
Figure 9. Land-use plan of the Na po village from 1998.
4.2. Survey methods
We measured the species richness, volume and height of trees and other, mostly woody species
in forest plots of different ages to study the succession of secondary mixed deciduous forest after
shifting cultivation.
With the help of a parataxonomist from the Na po village, we located four plots in the vicinity of
the Na po village. The plots represented forests of different ages after shifting cultivation: 2 years,
3-5 years, 10 years and 13 years. All plots were located in upland mixed deciduous forests. The
slope of the plots varied from 5-30 % with different aspects (Table 1). The quality of the soil also
varied slightly, but all the plots had clay as the main soil component.
Table 1. Summary of the surveyed forest plots.
Age
Plot no.
Coordinates
(years)
N
Forest type
Soil description
Slope
Aspect
Sandy clay
30%
SE
Clay
20%
SE
Loamy clay
Loamy clay with
conglomerates
5%
W
10%
E
E
2
3
18°16‟40‟‟ 102°10‟44‟‟
3-5
1
18°15‟32‟‟ 102°10‟29‟‟
10
2
18°15‟36‟‟ 102°10‟40‟‟
13
4
Mixed
deciduous
Mixed
deciduous
Mixed
deciduous
Mixed
deciduous
The plots were divided into three sub-plots for measuring different tree categories (Figure 10). A
circular plot with a radius of 20 m and area of 1256 m² was established for measuring mature
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trees, and inside this two smaller plots were established for measuring seedlings and saplings.
The edge of the 20 m radius plot was set at least 20 m from the nearest road to avoid edge effects.
The centre of the plot was marked with a fibre band around a tree. Another circular plot with the
same centre point was estblished for measuring and identifying saplings.Radius of this plot was
10 m and area 314 m². For measuring seedlings a plot with a radius of 0.8 m (a=2 m²) was
established at a randomly selected place within the big plot. The centre of the seedling plot was
marked with a fibre band, and the perimeter was measured with a 0.8 m long wooden stick.
r = 0.8m
Figure 10. The plot design. Blue=seedling plot, yellow=sapling plot, yellow+green= mature tree
plot.
For all tree categories, the species were identified by the local parataxonomist. For three plots,
the Lao names were written down as heard in phonetic script. For one plot, the names were
written down in Thai. The Lao names were later corrected and the scientific names added
(Appendix 1). The species were also assigned to categories according to their growth habit. The
categories are: tree, shrub, climber, bamboo, palm and herb. Exotics in all categories were also
separated.
For seedlings, the height was measured as the length from the ground to the beginning of the top
shoot. For saplings, the height was estimated by sight. For mature trees the diameter at breast
height (dbh) was measured. Because of a mix-up during the field work, the height of mature trees
was not measured. The criteria for the different tree categories were as follows:
Seedling:
Sapling:
Mature tree:
h<130 cm
h >130 cm, dbh < 5 cm
dbh > 5 cm
Bamboos were measured in the mature tree plot. For bamboos, the number of clumps and the
number of big and small culms (stems) within each clump were recorded. There was no limit set
between the big and small culms, but they were easily distinguished by sight in the field.
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4.3. Data analysis
For most analyses only the tree and shrub species were included, since these were the major
focus of the study. For climbers only their contribution to the total woody species pool was
calculated, i.e. the number of climber individuals divided by the total number of individuals. The
frequency of bamboo clumps and culms were analysed separately. In all other analyses the
climbers, bamboos, palms, herbs and exotic species were excluded.
The succession of species was analysed by comparing species numbers, frequencies of
individuals and the Shannon diversity index (H) between the plots. The number of species was
analysed as the total number of species in each plot and tree category (i.e. seedling, sapling and
mature tree). For the frequencies, the number of individuals per hectare was calculated for each
plot and tree category.
The Shannon diversity index was calculated by the following formula:
Where:
H = Shannon diversity index
pi = The proportion of species i relative to the total number of species
The Shannon diversity index gives an estimation of the species diversity taking into account both
the total species number and the relative abundances of the different species. This is a very crude
estimate of the actual biodiversity of the plot, but the values of the index make it possible to
quantitatively assess if the diversity increases or decreases as the succession proceeds.
The succession of species was also assessed by making lists of the more common species in each
plot and tree category. The criterion for the lists of mature trees and seedlings was species of
which more than one individual was encountered on the plot. For the saplings, the limit was set
at more than two individuals, because the list would otherwise have been very long.
4.4. Results
General results
The total number of species recorded was 71. Of these, 56 were trees and shrubs, 1 bamboo, 2
palms, 8 woody climbers and 4 herbs. Three exotic species were found: Acacia catechu (a tree),
Chrysalidocarpus lutescens (a palm) and Chromolaena odoratum (a herb).
The succession in form of the number of species and the frequencies is shown in figures 11-16.
From these figures it can be seen that the number of seedling species was fairly constant at
different ages, while the frequency increased with age. In the 2 year plot, only seedlings occurred.
From 3-5 years onwards, both the number of species and the frequencies of individuals grew for
both the seedlings and the mature trees. Number of sapling individuals also grew with the plot
age, whereas increase in the number of species was not so clear.
16
No of seedling spp.
Number of seedling
species
14
12
10
8
No of seedling spp.
6
4
2
Number of seedlings /ha
350 000
300 000
250 000
200 000
150 000
100 000
50 000
0
0
2
3-5
10
2
13
3-5
Age after disturbance
Figure 11. Number of seedling species as a
function of age after disturbance
Saplings/ha
7 000
30
6 000
25
20
No of sapling spp.
15
10
5
sapling density
35
5 000
4 000
Saplings/ha
3 000
2 000
1 000
0
0
2
3-5
10
13
2
Age after disturbance
3-5
10
13
Age after disturbance
Figure 13. Number of sapling species as a
function of age after disturbance
Figure 14. Frequency of sapling individuals as
a function of age after disturbance
No of mature tree spp.
Mature trees/ha
16
14
12
10
8
6
4
2
0
700
No of mature tree spp.
mature tree density
Sapling species
13
Figure 12. Frequency of seedling individuals as
a function of age after disturbance
No of sapling spp.
Number of tree species in
themature class
10
age after disturbance
600
500
400
Mature trees/ha
300
200
100
0
2
3-5
10
13
Age after disturbance
Figure 15. Number of mature tree species
as a function of age after disturbance
2
3-5
10
13
Age after disturbance
Figure 16. Frequency of mature tree
individuals as a function of age after
disturbance
17
Diversity
The Shannon diversity indices for the different tree categories and plot ages are shown in
Figure17 and Table 2. For seedlings the diversity shows a declining trend with age after
disturbance. For saplings the diversity is fairly constant from 3-5 years onwards, while for
mature trees the diversity increases with plot age.
3,5
Shannon diversity index
3,0
2,5
Seedligs
2,0
Saplings
1,5
Mature trees
1,0
0,5
0,0
2
3-5
10
12
Age after disturbance, yr
Figure 17. The Shannon diversity index for the different tree categories as a function of age after
disturbance.
Table 2. The Shannon diversity index for the different tree categories and plot ages.
Age ->
2
3-5
10
12
1,841
2,324
0,902
1,307
Seedligs
2,860
2,595
3,227
Saplings
0,245
0,495
1,369
Mature trees
Species-specific results
Only one species of bamboo (Dendrocalamus longispathus) was found in the study, but this
species was found in all plots. For the two-year-old plot, no bamboos happened to be within the
seedling plot, although the forest contained lots of bamboo. For the plots 3-5 years and 12 years
after fire, the number of clumps was equal (Table 3).
Table 3. The frequency of bamboo (Dendrocalamus longispathus) clumps in the plots and the
frequency of big and small culms.
Age
No of clumps/ha Big culms/ha Small culms/ha
3-5
64
57
132
10
13
16
64
72
31
147
174
18
Eight species of climbers were recorded in the study. In all plots except the 10-year plot, the
climbers made up a significant part of the seedling population (Table 4).
Table 4. The frequency of climber individuals compared to the total frequency of woody species
individuals and the number of climber species per plot.
Age
Seedlings Saplings Mature trees No of climber species
16,13 %
2
2
29,03 %
1,75 %
5
3-5
5,13 %
2
10
59,02 %
17,53 %
4
12
The species varied a lot between the plots. Only a few species occurred repeatedly in the plots of
different ages, as shown in tables 5-7. Notice that the most infrequent species are not shown in
the tables, i.e. those with only one individual recorded for seedlings and mature trees and with
one or two individuals recorded for the saplings.
Table 5. Seedling species of which more than one individual was recorded in the seedling plot.
Species repeatedly occurring in plots of different age are bolded.
2 years
3-5 years
10 years
13 years
Species
Ind/ha
Species
Ind/ha
Species
Ind/ha
Species
Ind/ha
Dendrolobium
Ormosia
30 000
Rinoria
Rinoria
75 000
baccatum
20 000
cambodiana
boisseui
85000
boisseui
Lepisanthes
Memecylon
15 000
Diospyros
35 000
rubiginosa 15 000
scutellatum
malabarica
Memecylon
Streblus
15 000
scutellatum 10 000
ilicifolius
Diospyros
Chrysalidocarpus 10 000
mollis
10 000
lutescens
Magnolia
10 000
elegans
Homalium
10 000
dasyanthum
Table 6. Sapling species of which more than two individuals were recorded in the sapling plot.
Species repeatedly occurring in plots of different age are bolded.
2 years
3-5 years
10 years
13 years
Species
Ind/ha
Species
Ind/ha
Species
Ind/ha
Species
Ind/ha
Clerodendrum
viscosum
Pterospermum
diversifolium
Nephelium
hypoleucum
Artocarpus
kemando
287
223
159
127
Peltophorum
dasyrachis
Diospyros
malabarica
Streblus
ilicifolius
Pterospermum
diversifolium
1 051
446
318
255
159
Gluta usitata
Schleichera
oleosa
Ormosia
cambodiana
Pterospermum
diversifolium
955
350
223
19
Sterculia
villosa
127
96
Gluta usitata
Peltophorum
dasyrachis
Peltophorum
dasyrachis
Schleichera
oleosa
96
159
159
159
Gluta usitata
Homalium
tomentosum
127
96
Vitex pierrei
Elaeocarpus
grandiflorus
96
Streblus
ilicifolius
Wrightia
arborea
Diospyros
malabarica
Cratoxylum
formosum
Irvingia
malayana
Nephelium
hypoleucum
Cinnamomum
porrectum
Tarenna
collinsae
Baccaurea
ramiflora
Barringtonia
macrocarpa
Cratoxylum
cochinchinense
Syzygium
cumini
223
223
223
223
191
159
127
127
96
96
96
96
Table 7. Mature tree species of which more than one individual was recorded in the mature tree
plot. Species repeatedly occurring in plots of different age are bolded.
2 years
3-5 years
10 years
13 years
Species
Ind/ha
Species
Ind/ha
Species
Ind/ha
Species
Ind/ha
Macaranga
denticulata
111
Peltophorum
dasyrachis
Schleichera
oleosa
366
40
Peltophorum
dasyrachis
Nauclea
orientalis
Ormosia
cambodiana
Nauclea
orientalis
Artocarpus
kemando
Nephelium
hypoleucum
Barringtonia
macrocarpa
406
32
32
15
15
15
15
20
The only species that occurred in more than one tree category is Peltophorum dasyrachis (Miq.)
Kurz (Sa farng). The species was not found as seedling in any of the plots (Table 5). In the 3-5
year and 10 year plot, saplings occurred. In the 10 year plot also mature trees were found, and in
the 13 year plot only mature trees were found. In the 10 year plot, the combined frequency of
saplings and mature trees of P. dasyrachis was as high as 812 individuals per hectare. In the 13
year plot, the total frequency of mature trees of all species was 589 trees/ha and the frequency of
P. dasyrachis was 406 trees/ha, so P. dasyrachis made up over 93% of the mature trees.
Figure 18. The frequencies of Peltophorum dasyrachis (Sa farng) as a function of plot age and
tree category. No seedlings were encountered.
5. Discussion
5.1. Succession
In the study we had four plots in ages between 2 and 13 years after fire and we could see some
characteristics of the succession. Seedlings was the most abundant tree class, whereas mature
trees was the smallest. This is logical; not all the seedlings become saplings and not all the
saplings become mature trees due to death by competition or other factors. Seedling density was
highest in the oldest plot, which might be due to the presence of Peltophorum dasyrachis (Sa
farng). The species is known to provide many ecological services. Due to a high content of
polyphenolic substances, leaf litter decomposition is slow, which reduces erosion and improves
the soil quality by allowing a humus layer to build up in the soil. The slow rate of decomposition
of the leaves also contributes to the suppression of weeds (World Agroforestry Centre 2009).
Both the soil improvement and weed suppression might result in bigger numbers of seedlings.
Addition of new species had also increased with age and P. dasyrhachis might have helped in
this too.
Since the plots of different tree categories are of different sizes, we can not say anything about
the differences in species number between different tree age classes. It is also difficult to give
good estimates on seedlings per hectare for we had only one 2 m² plot for seedlings in each study
site. So any estimation on seedling density can go wrong. Because the data is very limited,
differences observed among the plots may also be due to other factors than age of the plots. Even
21
tough all the plots were in mixed deciduous forest, it is possible that sites differ in surrounding
vegetation or some other characteristics affecting things we studied and this is causing the
differences encountered between the plots. Species turn over for example seems to be high when
we look at our results, but this might be only because the study sites are different and not
because species in a forest change so quickly. More study plots would have needed to be able to
say which explanation is right.
It is interesting to notice that seedlings in our plots were of different species than mature trees in
the same plots. Metzger (2003) points out how several studies show that amount and
composition of seed rain depends on the surrounding vegetation of the area in question. Seed rain
to old forest can come from younger patches and otherwise. Regeneration can be more strong
when there is apatch of dense forest near (Thomlinson et al. 1996). Our study also suggests that
the seed rain comes from the surrounding vegetation. It would have been interesting to know,
wether the ages of surrounding vegetation of our plots were differing, and therefore possibly
contributing to the differences seen between seedling frequencies and species.
5.2. Dominant species: Peltophorum dasyrachis
The only species that can be called dominant in the study
forests is Peltophorum dasyrachis. The Agroforestree
database of the World Agroforestry Center provides
information on P. dasyrhachis. and the following facts about
the species is based on this information when no other
refernce is mentioned. P. dasyrhachis is a deciduous tree
belonging to the legumes (Fabaceae). It is a fast growing
species that can be up to 30 m tall, with a straight trunk and
rather diffuse crown. The trunk can be up to 70 cm in
diameter. P. dasyrhachis is found in secondary, deciduous or
evergreen forest in Thailand, Indo-China, Peninsular
Malaysia, Sumatra and Borneo. It is also cultivated in many
other tropical regions, e.g. in Java. It occurs on altitudes
between 0 and 1000 m asl., where the mean annual
temperature is 20-25 °C and rainfall 700-2500 mm. It grows
mainly on ultisols.
Source: Wikimedia commons
Figure 19. Flowers, fruits and leaves of
Due to its relatively deep rooting system with a well
Peltophorum dasyrachis.
developed tap root and few superficial roots, P.
dasyrhachis is drought tolerant. Its hairiness and fairly thick bark have been associated with its
tolerance of fire. The seeds germinate in abundance after a bush fire. This explains why the
species was so abundant on our plots, which have been burned. Takeda (2003) also reports that
the species is common in naturally regenerated fallow lands in mountainous regions of Lao PDR.
Our results indicate that saplings of P. dasyrhachis occur about 3-10 years after disturbance, and
mature trees start to develop at the latest 10 years after disturbance in upland mixed deciduous
forests. Since we have no data between the 3-5 year plot and the 10 year plot, it is not possible to
estimate if mature trees develop between 3 and 9 years after disturbance. These figures are
generally only tentative, since they are based on a very limited data set.
It is surprising that no seedlings of P. dasyrhachis were found. One possible reason for this is
that the time since fire is long enough so that all seedlings have already developed into saplings
22
or mature trees. It is also possible, that not all the seedling species could be identified, so even if
there was P. dasyrhachis in the 2 year plot, it was not recorded. One option is that the slope in
the 2 year plot was too steep for P. dasyrhachis, it was steeper than in the other plots, but for
this as a real explanation we have no evidence. One plausible explanation is that the absence of
P. dasyrhachis was due to the limited sampling: we had only four times one 2 m² plot for
seedlings. Therefore it is possible that in the area there were seedlings of the species, but we did
not encounter them.
P. dasyrhachis has many uses. In Lao PDR the bark is used for treating diarrhoea (Asia Pacific
Medicinal Plant Database 2005) and an infusion can be used against cough. The species is also
used as firewood. The timber is locally used for planks in house building, but is of little market
value. The yellowish-red heartwood is heavy, but brittle and is easily attacked by termites and
boring insects. We assume that since it also provides ecological services such as erosion control,
reclamation, shade and shelter, soil improvement and suppression of weeds, it could possibly be
used as a species to facilitate regeneration of secondary forest. Perhaps species could be even
planted, since it has so many positive characteristics.
5.3. Bamboo
The reason why the 10-year plot had less bamboo is probably that bamboo was extracted from
the forest. There were clear signs of cut bamboo within this forest. Taking this into account, it
seems that in this study the number of bamboo clumps is constant between the different ages of
the plots. The ratio between big and small culms is changing, though. The number of small
culms increases with the age after fire while the number of big culms decreases with the age of
the forest. This pattern is natural, since young bamboo produces big culms while older bamboo
produces small culms. Bamboo might be so frequent in the plots because in the area there have
been bamboo forests as shown in the Figure 9.
5.4. Limitations of the study
We also had an intention to interview farmers who had practised swidden cultivation on our
plots, but due to missunderstandings and time limitations we were not able to do that. We would
have been interested in the way shifting cultivation was practised and in the species present on
the plot before logging and burning. Due to this limitation, we can not say if the method used in
shifting cultivation or the precious vegetation had some effect on our findings. We did not mark
down what was the surrounding vegetation of the plots, and therefore can not surely say what
kind of effects it had.
The main limitation was time. This came up by two different ways. First of all we had not
enough time to talk as a group within the course limits. Since not all the group members had the
same experience of using english language due to different bakgrounds, we would have needed
more time for discussion. And because for us communication in the group was important, and we
still tried to talk as much as possible about our group work, we did not have much time for
analysing the data, writing the report or making the presentation. It would have been really nice
to learn more from each other and discuss the study plan and results in more detail. That would
have been good for all the group members.
Secondly, the time used for the field work was extremely short, only two days. It is questionable,
what is the meaning of an ecological study on forest succession made in two days, and within
four 20 m radius plots. It is true that we found some interesting things that can be explained by
23
previous studies, but due to the very limited data, we can not really say anything new or give any
recommendations based on our field study. Therefore it would seem much more interesting to
spend more time with the group and in the field during the course, if it is meant that we make a
field study. Even tough the lectures in the course were interesting and lecturers excellent, it could
be a good idea to spend more time with the group work in similar courses to come. On the other
hand it is still nice to do at least a little bit of field fork and from the literature we can learn more
about our topic.
6. Conclusions
Shifting cultivation is practised in the tropics worldwide by more than 250 million people and
therefore it is important to take care that the practise is sustainable. Now the fallow periods are
getting shorter due to the population growth and growing demand for cultivated land. This has an
effect on the whole landscape, reducing the amount of mature and old secondary forest, and
forest regeneration and diversity of forests can be in danger. Shifting cultivation in Lao PDR is
important especially to the people in upland areas of the northern part of Lao PDR. In the North
there is not enough suitable land for permanent agriculture so people traditionally practise
shifting cultivation. Shifting cultivation can be sustainable, when rotation cycles are long enough,
so that soil fertility and organic layer are restored after cropping phase.
When the fallow period is reduced the outcome is more homogenous landscape, mostly
dominated by agricultural land and young secondary vegetation. This may lead to local
extinctions of older forest species and also reduce diversity and slow down regeneration of
secondary forests. Therefore long fallow periods are recommended. When this seems not to be
possible due to population growth or other reasons, other options should be considered.
Agroforestry can be one option to use land available in a more effective way. We also suggest
that indigenous knowledge should be used when trying to restore or maintain forest diversity and
functioning. Local people may well have knowledge about good practises, and their knowledge
combined to scientific findings could be the answer to the problems faced.
Peltophorum dasyrachis is a dominant species in our study plots of 10 and 13 years after fire.
We suggest that it could be used as a tool in managing shifting cultivation lands in mixed
deciduous forests similar to our study forests, since it makes soil better for growth and reduces
amount of weeds. Since the species has many other good qualities it could be favoured over less
advantageous species.
24
7. References
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Available at:
http://219.93.41.233/wapi/mctweb.dll/getObject?MID=MEDICINALPLANT&ObjID=2634
[Accessed 19 November 2009]
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Spurr, S.H. and Barnes, B.V. 1980. Forest Ecology. 3rd ed. John Wiley & Sons, New York. 687p.
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Appendix 1. List of all the 71 species encountered.
Lao name as
heard
Mai phang
Correct lao
name*
Pharng
Ham ngua/Ham
mua/Ma ha mua
Ham ngua
Khua ma woo
Mar vor
Mak taa
kuang/Taa kuang
Song hang
Tar kwarng
Hang nuu
Harng noo
Kuea laung
Kumpogng
laung
Kai dam
Khai lang
Hang kuang
Nja falang
Sorng harng
Harng
kwang
Nyar fa-lang
Scientific name**
Growing
habit
B
Family
C
APOCYNACEAE
C
ASCLEPIADACEAE
C
CELASTRACEAE
Bauhinia lakhonensis
Gagnep.
Tinospora crispa (L.)
Miers ex Hook.f. &
Thomson
Clematis buchananiana
DC.
Psychotria serpens L.
C
C
LEGUMINOSAE–
CAESALPINIOIDEAE
MENISPERMACEAE
C
RANUNCULACEAE
C
RUBIACEAE
Ancistrocladus tectorius
(Lour.) Merr.
Chromolaena odoratum
(L.) R.M.King & H.Rob.
C
ANCISTROCLADACEAE
ExH
COMPOSITAE
Dendrocalamus
longispathus (Kurz) Kurz
Melodinus
cochinchinensis (Lour.)
Merr.
Dregea volubilis (L.f.)
Hook.f.
Salacia verrucosa Wight
GRAMINEAE
26
Tong
lueang/Tong
hueang/Hai
lueang
Si siat
Leuang
Chrysalidocarpus
lutescens H.Wendl.
ExP
PALMAE
Si siat
ExT
Mak kuay paa
Kuay par
Acacia catechu (L.f.)
Willd.
Musa acuminata Colla
H
LEGUMINOSAE–
MIMOSOIDEAE
MUSACEAE
Tom
Tum
H
ARACEAE
Mak naeng
Mak neang
H
ZINGIBERACEAE
Tau
Tao
P
PALMAE
Om too
Orm toh
Alocasia macrorrhizos
(L.) G.Don
Amomum villosum Lour.
var. xanthioides (Wall. ex
Baker) T.L.Wu & S.Chen
Wallichia disticha
T.Anderson
Casearia flexuosa Craib
S
FLACOURTIACEAE
Phung
phing/Pung ping
Mjang nok kho
LABIATAE
S
Song faa
Sorng far
S
LEGUMINOSAEPAPILIONOIDEAE
LEGUMINOSAEPAPILIONOIDEAE
RUTACEAE
Lieung kheo
/Lueang kheo
Liin kauy
Leuang
kaew
Leen kway
Clerodendrum viscosum
Vent.
Dendrolobium baccatum
(Schindl.) Schindl.
Flemingia macrophylla
(Willd.) Prain
Clausena wallichii Oliv.
var. guillauminii (Tanaka)
J.P.Molino
Rinoria boisseui
Gagnepain
Galearia fulva (Tul.) Miq.
S
Samhang
Phoong
phing
Mieng nok
khor
Sarm harng
S
VIOLACEAE
S/ST
EUPHORBIACEAE
Poo huu
Por hoo
S/ST
MALVACEAE
Fong nam
Fong nam
S/ST
MELASTOMATACEAE
Khi haet/Kho kii
haeet/Khe laot
Tha kai
Khee heat
S/ST
MORACEAE
S/ST
MYRSINACEAE
Kok muuk/Mai
muuk
Thong tjen/Tong
tjen
Duea pong
Mook
Hibiscus macrophyllus
Roxb. ex Hornem.
Memecylon scutellatum
Naudin
Streblus ilicifolius (Vidal)
Corner
Ardisia oxyphylla Wall. ex
A.DC
Wrightia arborea
(Dennst.) Mabb.
Macaranga denticulata
(Blume) Mull.Arg.
Ficus hispida L.f.
ST
APOCYNACEAE
ST
EUPHORBIACEAE
ST
MORACEAE
Mak duea
Deua
ST
MORACEAE
Mak nod
Nort din
ST
MORACEAE
Mak huat
Mak huat
ST
SAPINDACEAE
Nam khiang/Nam
kiang
Oi Sang
Nam kieng
T
ANACARDIACEAE
T
ANACARDIACEAE
Ham kinoi
Khae
T
BIGNONIACEAE
Dook deng/Mak
duk/Mak duuk
Nam njeu
Mak dook
T
CELASTRACEAE
T
COMBRETACEAE
Dok saan
Xarn,dork
Ficus tuphapensis Drake
var. annamensis Corner
Ficus semicordata Buch.–
Ham. ex Sm.
Lepisanthes rubiginosa
(Roxb.) Leenh.
Gluta usitata (Wall.) Ding
Hou
Lannea coromandelica
(Houtt.) Merr.
Markhamia stipulata
Seem. var. stipulata
Siphonodon celastrineus
Griff.
Terminalia bellirica
(Gaertn.) Roxb.
Dillenia obovata (Blume)
Hoogland
T
DILLENIACEAE
Tar kai
Tong khohp
Deua porng
Oy xarng
Ngaen
S
27
Mak saan
Xarn
Dillenia parviflora Griff.
T
DILLENIACEAE
Ka luem
Kar leum
T
EBENACEAE
Lang dam/Nang
dam/Nang heo
Nang dam
T
EBENACEAE
Mak guea
Mak guea
Diospyros pilosanthera
Blanco
Diospyros malabarica
(Desr.) Kostel. var.
siamensis (Hochr.)
Phengklai
Diospyros mollis Griff.
T
EBENACEAE
Sang dong
Morn khai
Diospyros rubra Lecomte
T
EBENACEAE
Som
phueng/Som
phung
Mak fai
Som pheung
Elaeocarpus grandiflorus
Sm.
T
ELAEOCARPACEAE
Mak fai
Baccaurea ramiflora Lour.
T
EUPHORBIACEAE
Homalium tomentosum
(Vent.) Benth.
Homalium dasyanthum
(Turcz.) Warb.
Cratoxylum
cochinchinense (Lour.)
Blume
Garcinia dulcis (Roxb.)
Kurz
Cratoxylum formosum
(Jack) Dyer
Irvingia malayana Oliv. ex
A.W.Benn.
Vitex pierrei
T
FLACOURTIACEAE
T
FLACOURTIACEAE
T
GUTTIFERAE
T
GUTTIFERAE
T
GUTTIFERAE
T
IRVINGIACEAE
T
LABIATAE
Cinnamomum porrectum
(Roxb.) Kosterm.
Barringtonia macrocarpa
Hassk.
Peltophorum dasyrachis
(Miq.) Kurz
Ormosia cambodiana
Gagnepain
Dalbergia cultrata
Graham ex Benth.
Pterocarpus macrocarpus
Kurz
Lagerstroemia
duperreana Pierre ex
Gagnep.
Magnolia elegans
(Blume) H.Keng
Michelia alba DC.
T
LAURACEAE
T
LECYTHIDACEAE
T
T
LEGUMINOSAE–
CAESALPINIOIDEAE
LEGUMINOSAEPAPILIONOIDEAE
LEGUMINOSAEPAPILIONOIDEAE
LEGUMINOSAEPAPILIONOIDEAE
LYTHRACEAE
T
MAGNOLIACEAE
T
MAGNOLIACEAE
Walsura trichostemon
Miq.
Artocarpus kemando Miq.
T
MELIACEAE
T
MORACEAE
T
MYRTACEAE
T
RUBIACEAE
Kha naang
Khok naam khao
kuang
Mai tiiw
Ngarm khao
kwang
Tiu
Sai suu
See
Thiu nam/Tiiw
nam
Ka bok/Mak bok
Tiu nam
Sa kham
Sa kharng
Mai juang
Juang
Nom njaan/Nom
njan
Sa fang
Nom nyarn
Khi mou/Khi
muu/Ki muu
Khum phi laung
Khee moo
Mai duu
Doo
Puei
Peuay
Jam paa paa
Cham par
Jam pi
Cham pee
Khi jaat
Khee chark
Mak mi pa/Mak
mi paa
Mak waa/Waa
Mak mee
par
Var
Dok Khem/Khem
khao
San maung
Khem khao
Syzygium cumini (L.)
Skeels
Tarenna collinsae Craib
Garn leaung
Nauclea orientalis (L.) L.
T
RUBIACEAE
Mak khom
Mak khor
Schleichera oleosa
(Lour.) Oken
T
SAPINDACEAE
Ka bok
Sa farng
Kam pee
T
T
T
28
Mak njeo/Mak
njeu
Ham au/Ma uo
Mak ngaew
Poo salee/Por
khum
Teen ped
Por sar
*Check list of
Lao plant names,
2003
T=tree
C=climber
**Thailand
plant name
(Tem S.)
B=bamboo
S=shrub
Ham ao
Teen pet
Nephelium hypoleucum
Kurz
Pterospermum
diversifolium Blume
Sterculia villosa Roxb.
T
SAPINDACEAE
T
STERCULIACEAE
T
STERCULIACEAE
Alstonia scholaris (L.)
R.Br.
T
APOCYNACEAE
P=palm
Ex=exotic
H=herb
29