MINISTRY OF EDUCATION
MINISTRY OF AGRICULTURE
AND RURAL DEVELOPMENT
VIETNAMESE ACADEMY OF FOREST SCIENCES
Tran Hong Son
INVESTIGATION AND EVALUATION SOME SILVICULTURAL CHARACTERISTICS
AND GROWTH AS A BASIS FOR DEVELOPING PARACHILELIA BRAIANENSIS DANDY
SPECIES IN THE DIRECTION OF BUSINESS LARGE TIMBER
IN KON HA NUNG, TAY NGUYEN
Major: Forest planning and investigate
Code: 9 62 02 08
SUMMARY OF THE RESEARCH RESULTS
HA NOI - 2019
The thesis is completed at:
Vietnamese Academy of Forest Sciences
Scientific guide: 1. Associate professor (Ph.D.), Nguyen Ngoc Lung;
2. Doctor, Phan Minh Sang.
The thesis was defended in front of the Institute-level Council at the Vietnamese Academy of Forest
Sciences at . ... .... date .. ... 2019
The thesis can be found at the National Library and Library of the Vietnamese Academy of Forest
1. The urgency of the subject
Facing the increasing demand of the society for timber and non-timber forest products, the
reality of forestry production requires constant research and selection of valuable species to
supplement the group of companies plant structure. However, the lack of information on the
biological characteristics of the species, propagation techniques, intensive farming techniques ... has
been a major barrier to the goal of the forestry sector in order to proactively source timber for the
public wood processing industry serving domestic and export. Therefore, the research and
development of promising plants is a right direction, necessary and suitable for the sustainable forest
management process in our country today, in which the research and development of native tree
species multi-effects are very important.
The Parachichelia Braianensis Dandy is a large evergreen tree, 30 - 40m high, 60 - 120cm
in diameter. This species is endemic to Vietnam, only found in the Central Highlands provinces from
Gia Lai, Dak Lak to Lam Dong (Di Linh, Braian). Trees are distributed at an altitude of 600 - 1000m
in natural evergreen broadleaf forests or mixed forests with coniferous trees. Despite being an
endemic and narrowly distributed species in the Central Highlands, the P. Braianensis has the
advantage of high growth, high productivity, yield, and commercial quality, and is used for many
other purposes. each other such as handicrafts, household furniture, construction ... are very popular in
the domestic and foreign markets. Over the past 30 years, there have been studies and experiments to
plant this species in Kon Ha Nung area, Tay Nguyen, however studies on structural and regeneration
characteristics of natural forests have been distributed. , models of the P. Braianensis forest plantation
have been ... have not been studied in a systematic and thorough way to serve as a basis for proposing
the development of the P. Braianensis species in the direction of big timber business in Kon Ha
Sesame, Central Highlands.
Stemming from the above facts and reasons, the implementation of the Project
"Investigation and evaluation some silvicultural characteristics and growth as a basis for
developing Parachichelia Braianensis Dandy species in the direction of business large timber in
Kon Ha Nung, Tay Nguyen "are very necessary and meaningful both in terms of science and practice.
2. The scientific and practical significance of the thesis
2.1. Scientific significance
The thesis has developed scientific arguments for the cultivation and development of the P.
Braianensis species in the direction of business large timber in the Central Highlands.
2.2. Practical implications
Proposing a number of technical solutions to develop the P. Braianensis species in the
direction of trading large timber in the Central Highlands.
3.1. Overall objectives:
Develop a scientific basis to propose technical solutions to develop the P. Braianensis species
in the direction of business large timber in the Central Highlands.
3.2. Specific goal:
Supplementing some forestry characteristics such as ecological characteristics, forest
structure, phenology and species regeneration in the study area;
Identify the growth and growth characteristics of the species of different species in the study
Evaluate the growth ability of models of the P. Braianensis forest in Kon Ha Nung, and
propose solutions to develop the P. Braianensis species in the direction of business large timber.
4. New point of the thesis
Provide database on silviculture characteristics (ecological characteristics, structure,
phenology, regeneration, growth, ...) species of the P. Braianensis; Supplementing scientific and
practical basis for the development of the P. Braianensis species in the study area;
Proposing technical solutions to develop the P. Braianensis species in the direction of
business large timber in the study area.
5. Subjects and research locations
5.1. Research subjects
The object of the study is the natural forest status in the study area with the distribution of
the P. Braianensis antler and the model of the P. Braianensis in the period of 1986 - 2001 in Kon Ha
Nung, Tay Nguyen.
5.2. Research location
- Natural forest area in KBang district, Gia Lai province;
- Kon Chu Rang Nature Reserve, KBang District, Gia Lai Province;
- Krong Pa Forestry Company, KBang district, Gia Lai province.
6. Research limit of the thesis
6.1. Limit on research content
- The thesis only focuses on researching some forestry characteristics of the P. Braianensis
species belonging to natural forest stands (such as ecological characteristics, morphological structure,
phenology, regeneration, and growth characteristics, increasing. chief) in Kon Ha Nung, Central
- Evaluate gibbon species growth of forest planting models in Kon Ha Nung, and propose
solutions to develop the P. Braianensis species in the direction of business large timber;
6.2. Limited scope of research
The thesis implements the research contents of Kon Ha Nung area, Tay Nguyen.
OVERVIEW OF STUDIES
1.1. Studies in the world
1.1.1. Study on classification and morphology of the Parachichelia Braianensis
Studies of genus botanical classification Magnolia and Michelia have been studied by many
scientists around the world, such as Figlar (2000) ,Xia et al (2008), Armiyanti, Kadir MA and et al
(2010), Do, N. D, and et al (2016), ... The P. Braianensis has the scientific name Magnolia brainensis
(Gagnep) named by Figlar.
The P. Braianensis (Gagnep.) Dandy was first mentioned in 1938, is a large tree, 20-30m
tall, upright, the diameter can reach 60cm. Leaves have red hairs, thick and dense. Oblong leaves or
oval, prison base, pointed head, size 8-14 x 46cm. The leaf stalk is 1-2cm long, the leaves are broad,
the red veins are below the leaf surface, there are 14 pairs of leaf veins, visible mesh veins. Flowers
grow in leaf axils, single flowers, 4-5cm long and expand, flower stalks are 1cm long. Flowers have a
radio, fat, covered with yellow hair. Petals 20, aligned, slightly wide; 8-10mm long stamens, 1.5mm
long sessile stalks, round shape and attached triangle with 1mm long tip. The flower has 20 carpels,
yellow-sheathed, bony, stalks 4-5mm long (International Plant Names Index, 2005).
1.1.2. Research on distribution and ecological characteristics
The P. Braianensis is an endemic species in Vietnam, distributed in tropical and subtropical
humid forests with high mountains and low mountains (Khe La, 2014). Therefore, there is no work in
the world to study the characteristics of distribution and ecology of velvet species; there are only
some research results on some other species belonging to Michelia only, especially the Michelia
mediocris Dandy species.
1.1.3. Research on forest structure and regeneration
Currently, there are no studies in the world on structure, layer, growth and regeneration of
the P. Braianensis species. However, a number of other species of the Magnoliaceae and the Michelia
have also been studied, especially the Michelia mediocris Dandy species. Scientists are interested in
research such as: Zang et al (2005); Naidu and Kumar (2016) ... Studies on regeneration
characteristics have shown that Michelia mediocris Dandy is a species capable of regenerating seeds
quite well and soil and light factors that make a big decision. natural regeneration ability of the
species. This is an important basis for other studies on the regeneration of the P. Braianensis species
in our country.
1.1.4. Research on afforestation
There are currently no studies on the technique of growing the P. Braianensis published.
However, there were many species belonging to the Michelia and the Magnoliaceae genera which
were studied on planting techniques. The authors are: Edward (1999); Rami Rez Bamonde and cs
(2005); Orwa et al (2009); ... However, in the world, there has not been any research on techniques of
the P. Braianensis forest planting because this is an endemic species of Vietnam. However, there have
been many researches on techniques of afforestation with some species of the Michelia and
Magnoliaceae such as Michelia figo, Magnolia dealbata, Michelia champaca, ...
1.1.5. Research on growth and growth
Studies on the growth of forest trees and stand were built into mathematical models and
published in the research works of Meyer, H.A and D.D Stevenson (1943), Schumacher, FX and Coil,
TX ( 1960), Alder (1980), Clutter J. L; Allion B.J (1973) ... Growth function is the simplest growth
model that describes the growth process of forest trees as well as forest stands. Based on the growth
function, the maximum value of the growth quantity at the final age and the maximum growth rate
can be anticipated.
1.1.6. Research on use value
Currently, there has not been a systematic study in the world published on the use value of
the P. Braianensis species. However, the species belonging to Michelia and Magnoliaceae are
considered to be multi-effects from the use of wood, landscape plants and chemical compounds. The
authors include: Sosef and et al, 1998; Edward, 1999; Chan and et al, 2014; Do and et al, 2016.
1.2. Studies in Vietnam
1.2.1. Research on classification and morphology
The classification of the P. Braianensis species in the country studied by scientists can include
authors such as Pham Hoang Ho (1999); Nguyen Tien Ban et al (2003). Currently, most botanists in
the country agree to use the name P. Braianensis (Gagnep.) Dandy is the official scientific name of
the P. Braianensis species. Studies on morphological characteristics of gibbon species of the authors
such as Vo Van Chi (1997), Tran Hop and Hoang Quang Ha (1997), Pham Hoang Ho (1999), Nguyen
Hoang Nghia (2010) affirmed that the P. Braianensis is a big tree, 30 - 40m high, diameter can reach
60 - 100cm, so it is possible to develop large timber plantations.
1.2.2. Research on distribution and ecological characteristics
The P. Braianensis is a large timber tree, distributed at an altitude of 600 - 1,000m in
broadleaf evergreen or mixed broadleaf evergreen forest. Studies on distribution characteristics and
ecology of the P. Braianensis species can be mentioned by authors such as: Nguyen Tien Ban and
colleagues (1984, 2003); Vo Van Chi (1997); Tran Hop and Hoang Quang Ha, 1997; Bui Doan et al
(2001); Ho Duc Soa (2004); Forest Inventory and Planning Institute (2009) ... The P. Braianensis is an
endemic tree of Vietnam, only met at the points of Kon Ha Nung (Gia Lai), Dao Nghia (Dak Nong)
and Braian (Lam Dong) and new here discovered in Pu Mat National Park (Nghe An).
1.2.3. Research on forest structure and regeneration
The authors study the forest structure, where the P. Braianensis species is distributed, such
as: Bui Doan et al (2001); Ho Duc Soa (2001); Vu Dinh Phuong and Dao Cong Khanh (2001);
Nguyen Hoang Nghia (2010); Phan Van Thang (2014). Studies on the forest structure of the species
where the P. Braianensis species are distributed evenly show that, depending on the natural forest
stands, the species is either an ecological predominant group or not belonging to the ecological
advantage group in the structure. the nest is broad-leaved natural evergreen or broad-leaved mixed
1.2.4. Research on afforestation
The authors are interested in the study of afforestation with the species Michelia (P.
Braianensis and Michelia mediocris Dandy) as: Ho Duc Soa (2001, 2004, 2009); Vo Dai Hai, 2007;
Tran Van Con (2009); Nguyen Xuan Quat and Le Van Thanh (2015) ... Research results on
afforestation by the P. Braianensis species in different sub-regions, on different site types and, the
application of measures different silvicultural techniques give overall average growth in tree diameter
and height. The selection of the P. Braianensis species is the main forest tree species providing large
timber in the Central Highlands Programs/Projects.
1.2.5. Research on growth
The research on growth and growth for species and stands of mixed natural forests in our
country faces many difficulties due to the complex research objects. Vu Tien Hinh (1987, 1998).
developed a method to determine the law of growth for natural forest tree species and simulate the
dynamics of diameter distribution based on regular regular growth. of mixed species of different age
Vu Tien Hinh (2010) studied and completed the method of determining the growth and
prediction of natural forest production in Vietnam, in which the author applied a combination of both
methods of investigation, that is, method of investigation on temporary plots by beveling method and
method of survey on fixed plots. The average diameter of the year has been determined for 33 species
of natural forest in the Northeast and 34 species in the Northwest. This is a good reference for forestry
research and production in the provinces of our Northeast and Northwestern regions.
1.2.6. Research on use value
The P. Braianensis is a large tree, wood has sense and core distinguish, yellowish green
core and light yellow, smooth, glossy. Wood has a density of 0.65, good wood, smooth, flexible
structure, less cracked, less termite, easy to process, often use household furniture, sawn boards, make
plywood and use in building houses (Nguyen Tien Ban et al., 2003; Vo Van Chi, 1997; Tran Hop and
Hoang Quang Ha, 1997; Vietnam Red Book, 2007; Nguyen Hoang Nghia , 2010 ).
1.3. General discussion
- In the world, researches on the P. Braianensis tree stop at the classification of plants,
morphological characteristics. However, studies on distribution, ecology, forest structure, regeneration
and planting techniques have not been conducted. Because, the P. Braianensis tree is endemic to
Vietnam, only met at the points Kon Ha Nung (Gia Lai), Dao Nghia (Đak Nong) and Braian (Lam
Dong); Recently, it was discovered in Pu Mat National Park (Nghe An) and, so far, no documents
have been found about the wildly distributed Macaque species in another country.
- The research results in the world do not have any research on the P. Braianensis, because
this is an endemic species in Vietnam. Yes, only studies related to genus Michelia and Magnoliaceae.
This is the basis for proposing the development of silvicultural measures with the P. Braianensis
forest in general.
- In Vietnam, the research works on the P. Braianensis trees are still relatively few, the
studies only focus on plant classification, description of morphological characteristics, distribution
areas. Researches on afforestation only stop at some single plantation techniques in some models of
mixed forest restoration. Therefore, the research has only solved every single aspect so there is not
enough scientific basis to develop this species, in particular, there is no in-depth and systematic
research on forest characteristics. biology (structure, regeneration, ecology and distribution) for the
species of the P. Braianensis. Studies on growth and growth of species are also rarely paid attention to
on the location tracking plots for a long time.
CONTENT AND METHOD
- Study morphological characteristics, phenology, physiology and distribution, ecology of the
+ Morphological characteristics of tree parts;
+ Physiological characteristics (leaf anatomy, chlorophyll content a and b in leaves);
+ Characteristics of post-species phase of the P. Braianensis species;
+ Distribution and ecological characteristics.
- Study the forest structure and natural regeneration characteristics of the forest distribution:
+ Characteristics of high tree layer structure (average criteria of timber tree layer, structure
of forest density, N/D structure, high tree structure, second layer structure and canopy cover);
+ Biodiversity of natural forest stands with the P. Braianensis species distributed;
+ Characteristics of natural forest regeneration (density structure of regenerated tree layers,
structure of regenerated tree layers, decentralization of regenerated tree height, quality and origin of
regenerated tree layers).
- Study and evaluate models of the P. Braianensis plantation in Kon Ha Nung, Tay Nguyen:
+ Situation of development of models of plantation forests have been established;
+ Evaluate the technical measures applied in the plantation forest model;
+ Growth and development of gibbon species in plantation models.
- Study on growth and growth characteristics of the P. Braianensis species in Kon Ha Nung,
+ Some criteria for growth of forest stand and species of gibbon;
+ Growth model diameter of velvet species.
- Proposing orientations for some solutions to develop the P. Braianensis in the direction of big
timber business in Kon Ha Nung, Central Highlands:
+ Technical solutions to nurture natural forests where the Parachichelia Braianensis
species are distributed in the direction of business large timber;
+ Technical solutions for afforestation the P. Braianensis in the direction of business large
- Access to the system
- Access to the ecosystem
- Participatory approach
2.2.2. Methods of collecting and processing data
18.104.22.168. Method of inheriting secondary documents
- Inheriting 10 OTC positioning from the topic "Study of forestry characteristics
(succession, structure, composition, regeneration, growth, hydrological climate, soil ...) of some
forest ecosystems themselves mainly in Vietnam ”of Assoc. Dr. Tran Van Con has established in
K'Bang district, Gia Lai province, in which, the thesis inherits the growth monitoring data from 2004 2012, and has additional surveys at the time of 2017.
22.214.171.124. Research method of biological characteristics of the P. Braianensis
* Setting up OTC research
- Natural forest area in KBang district, Gia Lai province: Inherited 10 OTC positioning
(symbol from OV1 to OV10), area of 1 ha (100m x 100m) from the project of Assoc. Dr. Tran Van
Con established in K'Bang district, Gia Lai province.
- Kon Chu Rang Nature Reserve, KBang District, Gia Lai Province and Krong Pa Forestry
Company, KBang District, Gia Lai Province: Prepare 6 OTC, size 2.500m2 (50m x 50m) for research.
In addition, 3 more OTC projects with the size of 2.500m2 are set up in the stands of natural forests
where the velvet species are distributed in the district of KBang to study. Total 9 OTC.
* Morphological and morphological characteristics of the P. Braianensis species
In each study area, choose 6 mother trees the P. Braianensis as standard plant to study
morphological and phenotypic characteristics. Special observation and monitoring indicators include:
Period of leaf change; the time of budding, flower buds, flowers, and results; fruit ripening period;
describe and photograph morphology, leaf size, flowers, fruits, seeds; wrong cycle. Monitoring and
recording of the animal phase of the species in three consecutive years (2014, 2015, and 2016).
* Study some physiological characteristics
Anatomy of the velvet leaf anatomy: The structure of leaf anatomy at different stages of
development is shown through stages of forest formation (stage of regeneration tree - position under
canopy, canopy, and canopy), determined by taking 9 leaf samples from 3 standard trees/each position
in the forest canopy structure.
Determination of the content of photosynthetic pigment (chlorophyll): Determination of
chlorophyll content and chlorophyll b in the leaves of the P. Braianensis in different positions in the
forest canopy structure according to the method of Grodzinxki A. M and Grodzinxki D. M (1981).
* Characteristics of distribution and ecology of the P. Braianensis species
- Ecological characteristics: Using GPS locator to collect information on topography, slope,
elevation belt ... At the same time, collect information on forest status, shrub layer characteristics,
fresh carpets ... in the place where the velvet antler is distributed; combine collecting hydrological
climate data at monitoring stations in the study area.
* Study forest structure and regeneration characteristics of natural forest stands with distribution of
the P. Braianensis species
- Locate plants and identify plants
+ Numbering trees and mapping tree positions: all trees measured in the secondary plot are
numbered and marked for each tree, and mapping their location in the OTC location.
+ Identify the name of the tree: all the surveyed trees in all 3 levels: tree species,
regenerated tree species are identified species names.
- Measuring the forestry indicators in the researched OTC: DBH, tree height, canopy
diameter, growth quality, regenerating tree ...
- Painting of forest furniture: Standing and horizontal surgery in accordance with methods
of Richards and Davis (1934). On each OTC, a typical forest strip of 250m 2 (50m x 5m) is defined.
Then determine the position, height, diameter of the trunk, width, and foliage thickness of all trees on
the forest strip and are shown on paper cups with a scale of 1/100.
126.96.36.199. Method of assessing models of the P. Braianensis forest planting
The thesis applied semi-structured interview tool in PRA toolkit to collect information
related to the research contents of the thesis. For each model of plantation enriched with natural
forest, typical and temporary 03 OTC layout, the area of each OTC is 2.500m2. For concentrated
plantation models, typical and temporary OTC 03 layout. The area of each OTC is 500m2. Total OTC
is 15 plots (6 forest enrichment OTC and 9 OTC plantations). In the OTC, collecting and measuring
all information on forest plant species, including growth criteria, tree quality, survival rate,
productivity of planted forests ...
188.8.131.52. Methods of studying the growth and growth characteristics of the P. Braianensis species
From the collected data, the thesis selects 12 the P. Braianensis trees, which represent
different age levels for analysis, each level is 5 years old (age of A I = 1 - 5 years old, AII = 6-10 years
old, AIII = 11-15 years old, and each age group takes 4 trees to cut down and determine the diameter at
different trunk positions corresponding to each age. Standard trees after cutting down, conducting
sawing into segments (D0, D1, D1.3, D2, D4, D6, D8, D10, D12, D14, D16, D18, D20). Through the
number of years at each cutting board on the different positions of the stem, determine the diameter in
different positions corresponding to each age.
184.108.40.206. Data processing methods
The survey data is synthesized and analyzed according to the research objectives of the
thesis topic based on the algorithms of R software (Nguyen Van Tuan, 2014).
2.3. Characteristics of the study area
- Geographical position: K'Bang was established on May 19, 1985 on the basis of
separation from An Khe district. K'Bang is located in the northeast of Gia Lai province, including the
northeastern mountains and Kon Ha Nung plateau.
- Climate: The average annual rainfall is more than 2,400 mm, the most rainy months are
September, October and November. The wet season is humid, the dry season is enough moisture in the
type of high mountain climate. The average annual humidity is over 90%, the southern district is
- Topography and soil: K'Bang district owns the most rugged mountainous terrain of Gia
Lai province. Surrounding the west of the district is Mang Yang mountain range with a height of over
1000m with the highest peak of Kon Ka Kinh in Gia Lai province and gradually decreasing from
North to South and from West to East. K'Bang has all kinds of soils distributed in Gia Lai province.
Communes in the north of the district mainly have soil types developed on basalt, most of which are
covered by natural forest and nutrient-rich soil, which is favorable for trading forest trees, specialty
trees and industrial trees like Cinnamomum cassia, Litsea, Coffee, ...
- Forest resources: The total forest area of K'bang district (in 2015) is 125,385 ha,
accounting for nearly 70% of the total natural area of the district, of which: Natural forests have
123,650 ha, accounting for 98.6%, and Plantation only 1,735 hectares, accounting for 1.4%.
Reviews and general reviews
* Advantage :
- The study area has favorable climate and soil conditions for the development of many
agricultural and forestry plants.
- Infrastructure conditions, especially transportation, are gradually improved, convenient
for trading and trading with other districts in the area.
- Large area of forest and forestry land, rich land, very convenient for the development of
forest trees, especially the restoration of natural forests and afforestation for large timber supply.
- People are ethnic minorities who live closely with generations of forests and have
experience in forestry production.
- The area receives special attention to support economic development, infrastructure,
agricultural and forestry extension activities of local authorities.
- Large area of mountains and forests but many areas are difficult and difficult to travel, so
it is difficult to manage, protect and exploit forest resources effectively.
- Forest area of Kon Ha Nung area is distributed in difficult terrain conditions, so it greatly
affects management and protection activities of localities. The phenomenon of illegal encroachment
and illegal logging by people still occurs.
- Percentage of ethnic minorities accounts for a large proportion, most of these people have
obsolete farming practices, low educational level, so it is very difficult in the propaganda of protection
and development. forest, transfer of scientific and technical achievements to the people.
RESULTS AND DISCUSSION
3.1. Morphological characteristics, phenology and ecological distribution of the P. Braianensis
species in Kon Ha Nung, Tay Nguyen
3.1.1. Morphological and physical characteristics
a) Morphological characteristics
The P. Braianensis is a large timber tree, trunk diameter (D1.3) in the surveyed stands
varies from 27,6 to 65,1cm, (with D1.3 to 160cm, 40m high), round body straight, the average height
(Hvn) ranges from 17,6 to 29,4m. The root has high buttresses, natural branches, young branches and
leaves with dark colored feathers, canopy diameter ranges from 3,7 - 9,0m.
Leaves are single, sprouting, with leaves, original cover, young brown leaves, gradually
turning dark brown, oblong or oval leaves, 8 - 15cm long, 3,0 - 6,5cm wide, stalks leaves 2.5 - 3cm
long. The front of the leaf is dark green, the back is brown or reddish brown, hairy.
The fruit grows in clusters, each cluster has 10-15 fruits, the fruit is 1,5 - 2,0cm long, 1,0 1,5cm wide. The fruit base is attached to the fruit bearing branch. Green fruits are green, lumpy, and
ripen into 3 - 4 pieces, revealing inner seeds. The P. Braianensis seeds have a red membrane covering,
each fruit has 10 - 15 seeds.
- Structure of anatomical leaf anatomy:
+ The P. Braianensis leaves in different canopy sites in the forest structure have a thickness
ranging from 231,09 ± 0,03 μm (natural regenerated tree in the position under the forest canopy) to
237,38 ± 0,04 μm (tree over canopy), and there is a statistically significant difference between the
canopy positions in the forest structure.
+ The upper cutin layer of the P. Braianensis leaf has a thickness ranging from 2.97 to 3.76
μm and there is no clear difference between the leaf sampling positions. However, the upper cuitin
layer of the P. Braianensis leaves in the canopy position is 0,24 - 1,32 μm higher than the position
below the canopy.
+ The upper epidermis of the P. Braianensis leaves has a thickness ranging from 18,60 ± 1,00
μm (position in the canopy) to 52,76 ± 1,04 μm (position of canopy), and there is a statistically
significant differences between leaf sampling locations in the forest structure.
- Thickness of roost layer ranged from 54,26 ± 1,04 μm to 81,77 ± 0,97 μm and there was a
clear difference between sampling positions in the forest structure. The thickness of the layer of
rooster tissue is 0,48 - 0,72 times lower than that of the tissue layer. Meanwhile, the thickness of the
defective tissue ranges from 112,34 ± 0,54 μm to 113,76 ± 0,25 μm and there is no significant
difference between the sampling locations.
Chlorophyll content in the leaves of the P. Braianensis
The total amount of chlorophyll (chlorophyll a + chlorophyll b) in the leaves of the P.
Braianensis varies greatly and there is a statistically significant difference at the 95% confidence level
between the different sampling locations in forest canopy. Total chlorophyll content ranged from 6,69
± 0,33 mg/g fresh leaf (canopy position) to 12,47 ± 0,11 mg/g fresh leaf (position in canopy). Thus,
the P. Braianensis tree in the canopy position and at the bottom of the canopy shows the light
neutrality at these stages and absolutely loves light when the tree grows overcapacity.
The post-phase phases of the P. Braianensis species are not large fluctuations between the
study areas. There is a period of young leaves from December of last year to January of the next year,
and the period of shoots is from February to March. The period of young shoots and leaves is 2
months. The period of buds starts from March to April (Kon Ha Nung and Krong Pa) to April - May
(Kon Chu Rang), flowers from April to May, but the main flower season focuses mainly in May. The
period fruits from May to June and ripe fruits from September to October. The fruits ripen if not
harvested in time, the fruit will crack into 3-4 pieces, and the seeds will be dispersed out.
The average number of fruit per standard branch in 3 years has a statistically significant
difference between the study sites. In Kon Chu Rang, on average, there are 257 ± 5 ,5 fruits/branches
in 3 years, higher than the meaning of 20 - 39 fruits/branches compared to Kon Ha Nung area (on
average, 218 ± 5,5 fruits/branch) and significantly higher than the 7 - 12 fruits/branch compared to the
Krong Pa area (206 ± 10 fruits/branch). However, there is no statistically significant difference in the
number of fruits/branches in the three years of observation between Kon Ha Nung and Krong Pa
areas. Thus, it can be affirmed that the false fruit cycle of the P. Braianensis antler has not been
significantly affected by the height or sub-climate conditions (annual average temperature, average
annual rainfall ...) in the study area, meaning with the wrong period of the fruit of the P. Braianensis is
3.1.2. Distribution and ecology characteristics
Characteristics of natural distribution area of the P. Braianensis species is an endemic species
of Vietnam, found in Kon Tum, Gia Lai and Lam Dong, in evergreen broadleaf evergreen or broadleaf
evergreen mixed forest with pine forest, at an altitude of 600 - 1.000m. The P. Braianensis species
often grows into mixed populations with Michelia mediocris, Podocarpus annamensis, Cephalotaxus
fortunei and some other species of the Fagaceae. Through the results of the actual survey of the
project, the P. Braianensis distributed at elevations from 757m (in Kon Ha Nung) to 815m (Kon Chu
Rang NR) in evergreen broadleaf forest.
Ecological characteristics of the P. Braianensis species
The soil grows well on many types of soil with different parent rocks such as Bazan, Granis ...
In general, it is good soil, good drainage, nutrient-rich, soil depth is over 80 cm, the organic matter
content of A layer is > 3%, the protein content ranges from 0,43 to 0,88%, and the dry season lasts no
more than 4 months.
3.2. Characteristics of forest structure and natural regeneration have the P. Braianensis species
distributed in Kon Ha Nung, Tay Nguyen
3.2.1. Characteristics of high tree structure at the natural forest stands where the P. Braianensis
species are distributed
The average criteria for timber trees
- Fluctuations in the forestry indicators (D1.3, Hvn, Dtan) of the stands of natural forests
where the P. Braianensis species are distributed are relatively large, ranging from 32,6 to 87,0%, of
which, the forest stands in Kon Ha Nung had the highest fluctuations in all the forestry indicators
surveyed. Changes in targets D1.3 in Kon Ha Nung range from 64,3 to 87,0%, while in Kon Chu
Rang and Krong Pa, the coefficient varies only from 51,4 to 70,8%. Similarly, for the expenditure of
Hvn and Dtan, in Kon Ha Nung, the coefficient of variation is much higher than the remaining forest
- The average density and cross-section of forest stands were not significantly different with
95% confidence among stands in Kon Ha Nung, Kon Chu Rang, and Krong Pa (p> 0.05). The average
density of stands varies from 548 trees/ha (KHN 12) to 1.127 trees/ha (KHN 04), of which 75% of
forest stands have an average density of 927 trees/ha.
- Average reserve of forest stands has not been significantly different between stands in Kon
Ha No and Krong Pa; between Krong Pa forest areas and Kon Chu Rang forest, and between forest
stands in Kon Ha Nung and Kon Chu Rang. The average volume of stands in Kon Ha Nung reached
the highest value, M = 307 ± 69,6 m3/ha, ranging from 212,7 to 434,0m3/ ha; Next is the stands at Kon
Chu Rang (M = 227,8 ± 29,9 m3/ha), and the lowest is the forest stands in Krong Pa (M = 221,5 ±
22,1 m3/ha) ).
The density structure of the stands of natural forests where the P. Braianensis species are
The density of high tree layer of natural forest is high and low, varying greatly, ranging from
548 trees/ha (KHN12) to 1.127 trees/ha (KHN04), in which Kon Ha Nung area, The average tree
density is high Nbq = 850 trees/ha higher and coefficient of variation (CV%: 23,8%) is greater than 2
areas of Kon Chu Rang (Nbq = 759 trees/ha, 11,0%) and Krong Pa (Nbq = 593 trees/ha, 6,9%).
The density of the P. Braianensis belongs to the high tree layer in the surveyed plots is quite
low, ranging from 4 to 63 trees / ha, accounting for 0,6 - 8,3% of the density of forest stands, in which
Kon Ha No billion area rate In the forest stand is higher than the other two areas. However, there was
no significant difference between the regions, between Kon Ha Nung and Kon Chu Rang (p = 0,614>
0,05); Krong Pa with Kon Khong Rang (p = 0,545), and between Krong Pa and Kon Ha Nung (p =
The structure of N/D of the surveyed stands in Kon Ha Nung, Kon Chu Rang and Krong Pa
has reduced distribution, the largest number of trees in the smallest diameter (diameter of 10-14cm),
the number of concentrated trees from 115 trees/ha (KRP) to 181 trees/ha (KCR) and decrease
gradually when the diameter increases, the lowest number of trees ranges from 1 tree/ha in diameter
98 - 102cm (KHN) and diameter 62 - 66cm to 66 - 70cm (KCR) to 3 plants/ha in diameter 70-74cm,
and 74-78cm (KRP).
High tree structure
The forest composition of OTC natural forests with the P. Braianensis species distributed in
Kon Ha Nung, Kon Chu Rang, and Krong Pa is quite rich, showing very high species diversity,
ranging from 26 to 100 species/ha. However, the number of key species involved in forest formation
ranges from 4 to 7 species/ha only. The predominant species are usually valuable, fast growing and
light-demanding trees, such as: Fagaceae, Syzygium wightianum Wall. Ex Wight et Arn, Gironniera
subaequalis Planch., Ormosia balansae Drake, Machilus parviflora Meisn, …, with the coefficient of
composition (IV%) from 5.1 to 28.8%.
The number of species participating in forest formation tends to increase when the total
number of species increases (the total number of species increases from 25 to 40 species) in the stands
at Kon Chu Rang, Krong Pa, and Kon Ha Nung (KHN 11, KHN 12, and KHN 13). However, this
trend started to decrease when the total number of species in the forest stands increased (the total
number of species increased from 40 to 100 species) in the remaining stands in Kon Ha No (from
KHN 01 - KHN 10).
The structure of the layer and the crown cover the trees
In addition to the shrubs and fresh carpets, the natural forest tree layer where the velvet
species is distributed is divided into 3 main canopy layers:
- Canopy floor (H1> 20m): This is a floor with a height greater than the average height of
the stand, average height H1> 20m. Consisting of light-demanding, fast-growing, large-sized plants,
growth surpasses the main canopy of the forest. The dominant tree species such as: Dialium
cochinchinensis, Syzygium wightianum, Machilus parviflora..., accounting for 18,4 - 36,2% of the
total trees in the high tree layer of the stand.
- Main canopy layer (10m
the average height of the stand, ranging from 10 - 20m and forming a continuous band. The dominant
species such as Fagaceae, Syzygium cumini ... account for 33.1 - 64.6% of the total trees in the stand.
Most of the species of the Parachichelia Braianensis are found to have a height distribution in this
canopy but not yet a dominant species.
- Lower canopy floor (H3≤10m): This floor consists of trees with a height lower than the
average height of the stand, ranging from 5 - 10m, including light-demanding trees or shade-tolerant
plants (shade trees), missed later will participate in the main canopy and canopy floor) dominate such
as: Symplocos racemosa, Artocarpus rigidus..., accounting for 14.6 - 42.4% of the total stand of trees.
3.2.2. Biodiversity of natural forest stands has a distribution of the P. Braianensis species
The general trend in the diversity index of species richness (R), Shannon index (H), and
Margalef species richness index (d) tends to increase when the total number of species (m) in forest
stands naturally, there is an increase in the distribution of the P. Braianensis. This indicates stability in
the P. Braianensis of change in the community responding to disturbances in the surveyed stands.
However, the uniformity index (J’) tends to decrease when the total number of species in the forest
Renyi diverse index
The general trend of Renyi index of natural forest stands in the area of the P. Braianensis
species distributed in Kon Ha Nung is at a high level and there is no big difference between the
studied OTC. Comparison between 3 survey areas showed that 6 curves denoting Renyi index have
Hα index intersecting, ie in forest stands, there is a richer forest stand but less uniform distribution.
(ie, lower homogeneity) compared to the remaining stand.
3.2.3. Characteristics of natural forest regeneration with the P. Braianensis species distributed
Structure density of regenerated tree layer
The average density of regenerated tree layers in the natural forest stands with of the P.
Braianensis species is relatively rich, but there is no difference between the study areas. The average
density of regenerated trees in stands in Kon Ha Nung is NtsLP = 38.576 ± 5.409 trees/ha, ranging
from 7.680 trees /ha (KHN 13) to 71.250 trees/ha (KHN 07), in which, Kon Chu Rang and Krong Pa
stands, density of regenerated trees ranges from 8.800 trees/ha (KCR 03) to 17.280 trees/ha (KRP 01),
averaging from NtsLP = 10,880 ± 1,303 trees/ha (Kon Chu Rang) to NtsLP = 14.986 ± 1.155 trees/ha.
The structure of the regenerating tree layer
The number of regenerated trees appearing in the surveyed stands is quite diverse, ranging
from 16 to 46 species, of which only one species (KRP02) to 8 species (KCR 03) appears in the
formation. The dominant tree species in regenerated tree layers such as Nephelium lappaceum,
Callicarpa candicans, Dialium cochinchinensis, Ormosia pinnata ... are mainly inferior timber
species, light-demanding and fast-growing species; with composition coefficient ranges from 1,59 to
6,90. The forest composition of regenerated trees also appears some valuable timber species such as
Prunus arborea, Cinnamomum parthenoxylon,... with the coefficient of formation ranging from 0,82
to 2,11. Therefore, the impact of silvicultural measures must aim at reducing non-purpose
regenerating species, enabling the tree to regenerate and develop.
Decentralized height of regenerated tree
The number of regenerated trees decreases as height increases. The number of regenerated
trees at a height of <1m accounts for the largest proportion, ranging from 41,8 to 65,9% of the total
number of regenerated trees; then, gradually decreasing at the height of 1-3m (18,8 - 48,8%) and
height > 3m (4,9 - 21,8%). The reason for this phenomenon is due to the development process,
regenerating trees are influenced by many factors, such as the canopy cover, mother trees sown, fresh
carpet shrubs ... In the first stage, most of the trees are re-grown. born bear the ball so after
germination, seedlings exist with high density. Through natural selection process, the number of
regenerated trees decreases with time (height).
Quality and origin of regenerated plants
In the natural forest stands surveyed, the proportion of regenerated trees from seeds
accounted for 64,4 - 87,3% of the total regenerated trees, 51,7% higher than the rate of regenerated
trees originating from shoots (12,7 - 35,6%). In Kon Ha Nung, the rate of regenerated seeds is much
higher (80.4% on average), followed by Krong Pa (77,1%) and the lowest, Kon Chu Rang (71,9%).
The quality of good regenerated trees (A) accounts for the majority of regenerated trees in the stand,
ranging from 48,7 to 74,5%, followed by; average quality (11,9 - 31,2%) and lowest, bad quality of
regenerated trees (8,13 - 29,4%)
3.3. Situation of development of existing the P. Braianensis forest planting models in Kon Ha No,
3.3.1. Situation of development of existing the P. Braianensis forest planting models
The cultivation and testing of the P. Braianensis species by the method of enriching the forest
as well as the research on the techniques of forest plantation the supply of businees large timber has
been paid attention to be implemented quite early, clearly showing the important and potential role
testing of the P. Braianensis species in the restoration of natural forests and trading in businees large
timber forests in Kon Ha Nung, Tay Nguyen areas. However, this interest has not been invested in
research and development in a systematic way to bring this potential tree species into production on a
3.3.2. Evaluation of technical measures applied in the P. Braianensis plantation models in Kon Ha
Nung, Tay Nguyen
The models of the P. Braianensis plantation in Kon Ha Nung area are located in the natural
distribution area of the species, on the sites of red brown Feralit soil, basalt red soil, quite flat terrain,
with a slope of 5 - 150. Seed sources used for afforestation and forest enrichment are collected from
natural forests, not selected. The standard of seedlings for planting is generally small, the average
stem diameter is from 0,45 to 0,50 cm, the average tree height reaches 50cm.
3.3.3. Growth and development of the P. Braianensis species plantation models
Survival rate, growth and growth of the P. Braianensis species
The plantation models of the P. Braianensis according to the method of forest enrichment and
afforestation to supply large timber all have a relatively high survival rate, ranging from 66,0 to 91%
when the forest reaches the age of 13 - 29 years, in which, forest enrichment planting models with
survival rates ranged from 73,0 to 75,0% (P. Braianensis), from 76,0 to 78,0% (Michelia mediocris),
and models of afforestation for timber supply large survival rate of Giua velvet ranged from 66.0 to
91.0%. In general, in the P. Braianensis afforestation models at the age of 14-21 years, the proportion
of forest stands reached 66,0% compared to the original design and still ensured the density needed
for the purpose of afforestation businees large timber.
The average growth targets of diameter and height of P. Braianensis have not been
statistically significant at the 95% confidence level between the enrichment planting models with the
models of large timber plantations. However, the average growth rate of the canopy diameter in the
business large timber plantation models is 0,03m/year higher than the average of the forest enrichment
Canopy cover, forest canopy and regeneration under forest canopy in planted forest models
The models of P. Braianensis plantations all have quite high canopy cover, ranging from
0,7 to 0,9, with such high canopy, which will greatly affect (strongly and strongly suppress) plant
species. Forest enrichment in general and the P. Braianensis tree in particular. The models of forest
enrichment planting are basically, the forest canopy layer in the ice should not overwhelm the planting
tape. In addition to participating in the lower canopy floor, some trees have also started to participate
in the main canopy along with the trees in the bandage, on average only 3-5m lower than the main
The number of regenerated trees under forest canopy in the surveyed stands is also quite
large, ranging from 3.060 to 8.438 trees/ha. The species of regenerated trees under the canopy of P.
Braianensis are also quite diverse, mainly species: Syzygium wightianum, S. Zeylanicum, Cratoxylum
maingayi, Pterospermum heterophyllum, Endospermum chinense, Dialium cochinchinensis,
Choerospondias axillaris... The average height of regenerated tree ranges from 0.9 to 1.8 m.
The successes and shortcomings of the Macadamia plantation models have been built
- The successes of the built models:
+ The site of P. Braianensis plantation is relatively suitable, the plantation models are
located in the natural distribution of the species;
+ Methods of afforestation and afforestation concentrate with different technical measures,
quite suitable to the ecological characteristics of the P. Braianensis species;
+ Forest planting models are all aimed at enriching forests, planting forests to business
large timber, with appropriate planting density;
+ Experimental models for planting business large timber are applied fairly technical
measures from the stage of fertilizer application, care, monitoring and evaluation, so the plants grow
- Some shortcomings of models built:
+ Through surveying and surveying forest planting models, many localities have a need to
grow the P. Braianensis but the afforestation has not been successful due to the selection of the right
subjects, cultivation techniques and too forest nurturing care is still limited; no specific conditions for
site planting were identified;
+ The source of seed used has not been selected (not selected, because the plantation units
collect from many sources, mainly from natural forests, so there are also poor quality mother trees) so
the quality of trees seeds are not guaranteed and standards of unsecured seedlings (young trees, the
height is only 20 - 30cm, so seedlings are not competitive with the encroachment of weeds, vines and
shrubs), so they do not like suitable for forest enrichment and afforestation for business large timber
+ Models of plantation forest, especially models of forest enrichment planting, caring and
rearing after the expiry of basic construction period (3 years) are not allowed to continue, not open
canopy for forest plantation. Head grows well. So the tree in the ice is planted in the ice tree to
squeeze and overwhelm, leading to forest plants grow and develop poorly.
3.4. Growth and growth of the P. Braianensis species in natural forest stands in Kon Ha Nung,
3.4.1. Some indicators of stand growth and species of the P. Braianensis in forest stands
Some indicators for growth of forest stand and species of the P. Braianensis
The P. Braianensis species in the surveyed forest stands at a very low rate, from 1,7 to 6,2%
of the total number of individuals in stands and reserves accounting for 2,4 - 37,4% of the total forest
reserve. This shows that the number of individual species of the P. Braianensis is low but most of
them are large timber trees, with average trunk diameter ranging from 27,6 to 65,1cm, and height
average from 17,6 to 29,4m, higher than the mean of 114,3 - 243,2% of the average forest stand
diameter and 99,8 - 156,4% of the average forest stand height.
Some indicators of growth of new individuals from adjacent classes participate in trees in the
In the period from 2004 to 2017 in the surveyed forest stands, the number of newly emerging
individuals from the adjacent regeneration class participating in the high tree layer between the time
of the survey has not been significantly different. at all surveyed stands. At the time of the survey in
2008, the number of newly emerging individuals participating in high tree layers ranged from 2 - 30
new individuals/ha and the number of new individuals appeared the most, ranging from 59 - 99
individuals/ha at the time of the survey in 2012. However, at the time of the survey in 2004 and 2017,
no new individuals were seen from the nearby regeneration tree. The average cross-section increased
by new individuals participating in the tree layer reached 0,02 - 0,30m2/ha and the average volume
added to the stand was from 0,26 to 4,64m3/ha.
3.4.2. Growth model of the species of the P. Braianensis in the surveyed stands in Kon Ha Nung,
Growth model of the P. Braianensis species diameter
The annual growth rate of ZD tends to increase strongly in the period from 1 to 5 years, ZD =
0,23 - 0,83 cm/year, then tends to increase/decrease at different ages, ZD = 0,57 - 0,83 cm/year (6-10
years), ZD = 0,20 - 0,78 cm/year (11-20 years), and the annual growth is relatively stable in the period
after 20 years (ZD = 0,61 - 0,72 cm/year). Periodic growth (5 years) ranges from ZnD = 2,05 - 3,53
cm/year. The average periodic growth rate ∆nD = 0,56 cm in the first 5 years, then increases to ∆nD =
0,75 cm (6-10 years) and tends to decrease in the following years.
Table 3.1. Predictive growth equation for average trunk diameter
of the P. Braianensis tree according to age
D1.3 (I) = - 0,064 + 0,269 * A (1-5)
D1.3 (II) = - 0,109 + 0,302 * A (6-10)
D1.3 (III) = - 0,908+ 0,376* A (11-15)
D1.3 (IV) = 2,252 + 0,121 * A (16-20)
D1.3 (V) = - 0,341 + 0,403 * A (21-25)
D1.3 (VI) = - 2,419 + 0,327 * A (26-30)
Predictive growth equation trunk diameter
D1.3 = 14,804 * exp (-2,964 * exp (-0,094 * A (1-30)
D1.3 = 28,465 * exp (- 30,182/(A (1-30) + 6,910))
D1.3 = 12,972/(1 + 9,849 * exp (-0,165 * A (1-30)))
The rule of growth of diameter of the gibbon tree at the surveyed stands for the whole period
(from 1-30 years old) was simulated through the Johnson-Schumacher jaw form (D1.3 = 28,465 * exp
(- 30,182/( A (1-30) + 6,910) is most appropriate, based on the model parameters that exist in the whole,
the correlation coefficients (R2), and AIC values are the smallest of 3 values. The results show that the
rule of changing the average diameter growth of the P. Braianensis tree by age is as follows:
- Growth process trunk diameter increases with age;
- In the research scope of the thesis (from 1 to 30 years), growth of trunk diameter has not
reached the maximum point. Therefore, during this period, adjusting the density as well as the impact
of silvicultural techniques is necessary to promote the growth of diameter of the P. Braianensis tree in
the growing period of the fastest and strongest increase in diameter.
3.5. Proposing some solutions to develop the P. Braianensis species in the direction of business
timber business in Kon Ha Nung, Tay Nguyen
3.5.1. A number of technical solutions to nurture natural forest with the P. Braianensis distribution
in the direction of business large timber
- Based on some growth indicators of diameter, height and timber quality as well as demand
and value, the P. Braianensis wood meets the criteria under current regulations. Therefore,
afforestation with large timber supply is perfectly suitable and feasible.
- Appropriate conditions for planting: The P. Braianensis supplying business large timber in
Kon Ha Nung needs to ensure the ecological ecological requirements of: (i) Climate conditions, (ii)
Terrain conditions, (iii) Conditions soil, and (vi) Vegetation condition, in which the site of planting
should be ensured to ensure Feralit soil on the stone with the magic of crabs; Good soil, drainage, soil
depth above 80cm, soil rich in nutrients, and dry season lasts no more than 4 months. The P.
Braianensis is a large tree, growing fast, good wood; The wide ecological range can be grown in
many regions/sub-regions with similar ecological characteristics, but most suitable in places with
elevations between 600 and 1.000m. Places with average annual temperature of about 19 - 250C,
average rainfall of 1.500 - 2.500mm/year ...
- About seed sources: In the year of flowering, annual results, cycle of fruits often every 2
years, the main fruit season from September to October every year, high yield can ensure the supply
of seed sources for planting forests on a large scale. The P. Braianensis is regenerated by seeds, less
likely to regenerate shoots, so it is only traded from seeds. However, if the main season is not
harvested in time, the fruit will crack into 3-4 pieces, and the seed will be dispersed out.
- Determining the structure of high tree layer and regenerated tree layer to have a direction to
adjust the target tree species, especially the species of the P. Braianensis, gradually eliminating nonpurpose tree species, meeting economic objectives. Large wooden joint of the forest. Determining the
density of high tree layer and regenerated tree layer to assess the ability of species to use nutrient
space in the stand, thereby adjusting the density of high tree layers and regenerating trees in the
approach with even distribution, especially, favorable conditions yhe P. Braianensis species in the
high tree layer provide quality seed sources, as well as the development of the P. Braianensis
seedlings under the forest canopy.
- Based on the features of anatomical structure, the total amount of chlorophyll, the ratio of
chlorophyll a/b in the samples of the P. Braianensis in different canopy sites in the forest structure can
be seen: The P. Braianensis can be slightly shaded at the stage of regeneration (under the canopy), the
stage in the canopy when expressing medium light preference, and can rise to the perfect light on the
5-7 year old stage. Therefore, in afforestation, there should be appropriate silvicultural solutions for
plants to grow and participate in high tree structure as well as dominant tree species in stand,
especially planting forest towards business large timber.
+ The P. Braianensis antler grows slowly in the first 3 years, so it is necessary to take care
continuously for the first 5 years. The first three years of care 2 times/year by giving birth to
vegetation and weeding, 2 years later just need to clear the vegetation once a year. Technical measures
to take care such as clearing creepers and shrubs; Hoe, cultivate soil around the stump with a diameter
of 1.0m. For models of forest enrichment planting, in addition to the above care, it is necessary to
handle open canopy in the bandages, avoid pinching and overwhelming the main crop. Planting
enriches poorly exhausted secondary forests with tight bandages from 1/3 - 1/2 height of forest
canopy and planted on shrubs above 3m high with 3m wide band, creating favorable ecological
microclimate conditions for birth the head of the the P. Braianensis tree.
+ Nourish the forest the P. Braianensis plant enriches poorly degraded secondary forest by
opening the canopy to increase the illumination for the plants, ensuring that the trees are not shaded
on the top of the growth to create conditions for the trees to join. into the main canopy. The time of
opening the forest stand is in the 7th - 8th and 10th years - 11 years. With the technique of tightening
the trees, pests and plants cover the main crops, cut the liana, comprehensive shrub, and re-promote
- Silvicultural measures affecting the forest are eliminating non-purpose tree species, trees
with bad quality, poor economic value. In order to adjust the density appropriately, create conditions
for valuable plants and regenerating trees to have good growth and development conditions,
especially the P. Braianensis species in the stands.
- The impact method is to regulate the composition and morphology distributed in the
direction of even distribution through the nurturing and promotion of natural regeneration of valuable
regenerated tree species, in which the the P. Braianensis is preferred. At the same time, combining the
growth of vines, bushes, and vegetation creates favorable conditions for regenerating species to grow
and develop well.
3.5.2. Some technical solutions for forest plantation the P. Braianensis in the direction of business
- Kon Ha Nung area (Central Highlands) is a natural distribution area of the P. Braianensis,
so it is suitable for planting and developing this species. It is recommended to select areas with forest
soil, good soil, low rate of mixed stone, deep soil layer.
- Need to research and create breeds the P. Braianensis has high productivity, quality,
exceeds 15 - 20% compared to the current mass for forest planting. In the immediate future, there are
no varieties selected and tested for provenances, so it is necessary to use the varieties collected from
the transformed seed forests in Kon Ha Nung area.
- Planting method: Planting enriches poorly exhausted secondary forests with tight
bandages from 1/3 - 1/2 height of forest canopy and growing on shrubs above 3m high with 3m wide
bandages, creating postnatal gas conditions. ergonomically suitable for the growth of the P.
Braianensis tree. In addition, it is also possible to grow in a banded mix, a ratio of 1: 1 ( P.
Braianensis : Michelia mediocris).
- Techniques for planting and taking care of planted forests:
+ Creating seedlings: The P. Braianensis tree when nursery is light shade, suitable for shade
of 50% in the period of 1 - 4 months of age, 30% in the period of 5-8 months of age, removing the
cover 1 month before planting. Create seedlings with PE plastic pots, size 12cm x 20cm, potting mix:
93% soil A + 2% phosphate + 5% micro organic fertilizer. Top dressing with diluted NPK mixture
directly applied to the bed.
+ Treating vegetation: Treating vegetation cover completely or by band or by crowd. The
direction of ice is open in the East-West direction to increase the lighting time of the day. Combine the
removal of pests and diseases on the ice, leaving the target tree, and large wood regeneration trees.
+ Soil preparation: digging holes with the size of 40cm x 40cm x 40cm.
+ Standard of seedlings for enrichment planting and planting of business large timber supply
forests, it is necessary to ensure a minimum of stem diameter from 1,0 to 1,3cm, tree height from 1,0
to 1,5m to ensure success.
+ Planting season: August - September.
+ Planting miles after planting 1 month and taking care for the first time after planting for 3
+ Cultivated forests should be taken care of continuously for 5 years. In the first 3 years of
care 2 times/year by clearing the vegetation and weeding the root, 2 years later just need to clear the
vegetation once a year. The first time in the beginning of the rainy season (May - June), the second
time in the middle of the rainy season (September - October).
CONCLUSION, EXISTENCE, AND RECOMMENDATIONS
* Morphological and ecological characteristics
The P. Braianensis Dandy is a large tree, D1.3 = 27,6 - 65,1cm, round body is straight, Hvn =
17,6 - 29,4m. The root have buttress, high natural branches, young branches and leaves with dark
colored hairs. The period of young leaves is from December last year to January of the next year, and
the period of shoots is from February to March. The period of young shoots and leaves is 2 months.
The period of flower buds ranges from March to April (Kon Ha Nung and Krong Pa) to April - May
(Kon Chu Rang), flowering period from April to May, but the main flower season focuses mainly in
May. The period fruits from May to June and fruits ripens from September to October. The P.
Braianensis Dandy has the wrong cycle every year.
* Characteristics of distribution and ecological
The P. Braianensis Dandy is species endemic of Vietnam, found only in the Central Highlands
provinces from Gia Lai, Dak Lak to Lam Dong (Di Linh, Braian) and recently discovered in Pu Mat
National Park (Nghe An) ), and so far no documents have been found about the natural distribution of
other. The P. Braianensis grows well on many soil types have a origin with different of parent rocks;
prefer good soil, drainage, nutrient-rich, soil depth above 80 cm.
* Characteristics of structure and natural regeneration
- High density of trees ranges from 548 to 1.127 trees/ha, in which the density of The P.
Braianensis is quite low (4 - 63 trees /ha), accounting for 0.6 - 8.3% of the density of forest stand.
- The structure of N/D in the surveyed stands has the form of distance distribution, the largest
number of trees in the smallest diameter (10-15cm) and decreases gradually when the diameter
- Forest composition in the surveyed forest stands is quite diverse, ranging from 26 to 100
species/ha, of which the main species involved in the forest composition are only 4 - 7 species/ha. The
predominant species are usually valuable, fast growing and light-demanding trees, such as: Fagaceae,
Syzygium wightianum Wall. Ex Wight et Arn, Gironniera subaequalis Planch., Ormosia balansae
Drake, Machilus parviflora Meisn, …, with the coefficient of composition (IV%) from 5,1 to 28,8%.
- The P. Braianensis Dandy only appears in the forest composition (according to IV%) in
11/19 OTC sites of Kon Ha Nung and Kon Chu Rang with IV% coefficient of 5,20 - 11,82%,
particularly in Krong Pa does not have the presence of the P. Braianensis in the forest composition.
- The abundance of the P. Braianensis species has large variation between the foests stands
survey, the R index ranges from 2,17 to 3,20. Species diversity index is quite high, ranging from 3,27
- The density of regenerated trees ranges from 7.680 - 71.250 trees/ha. The density of the P.
Braianensis species is relatively low in forest stands, ranging from 0 to 833 trees/ha, accounting for
less than 3,51% of the rate of regenerated trees in surveyed forest stands.
- The number of regenerated tree species participating in the regeneration of tree species in
the number of trees (Ni) ranges from 1 to 8 species, of which in Kon Ha Nung forest stands, number
of species ranges from 2 to 7 species, Kon Chu Rang (6-8 species) and Krong Pa (1-7 species). The
rate of regenerated trees from seeds accounted for 64,4 - 87,3% of the total number of regenerated
plants, 51,7% higher than the rate of regenerated trees originating from shoots (12,7 - 35,6%).
* Characteristics of growth
- The number of individuals participating in timber trees ranges from 459 - 689 trees/ha, of
which the P. Braianensis has 8 - 36 trees /ha, accounting for 1,7 - 6,2% of individuals in surveyed
- The average cross-sectional area of the forest stand reaches from 34,32 to 51,93 m 2, in
which, the basal area of the P. Braianensis species reaches from 1,19 to 14,72 m2, accounting for 2,628,8%. The average volume of forest stands reaches from 451,9 to 812,2 m 3/ha.
- ZD of the P. braianensis species tends to increase strongly in the period of 1-5 years, Z D =
0,23 - 0,83 cm/year, then tends to increase/decrease at different ages, and Z D is relatively stable in the
period after 20 years.
- Based on the age factor (A) of P. braianensis, it is possible to predict the growth factor in
diameter (D1.3) through the growth function Johnson - Schumacher, with the equation: D1.3 = 28,465
* exp ( - 30,182 /(A (1-30) + 6,910)).
* Situation of development of existing the P. braianensis forest planting models
- The models of plantation in Kon Ha Nung have been interested in research and
experiment since 1986 until now, mainly through 3 stages: (i) 1986 - 1988 period of forest enrichment
planting in the direction awakening of species (Michelia mediocris and P. braianensis, 1: 1 ratio),
with an area of 105ha; (ii) Period 1992 - 1994, planting enrichment forest, with an area of 100ha; and
(iii) In the period 2000 - 2001, forest planting the P. braianensis provided large timber, with an area
of 9 ha of concentrated forest.
- The average growth and growth of planted forests the P. braianensis there is a large
fluctuation between the surveyed stands, average diameter growth is from 0,53 - 1,12cm/year; average
height growth is from 0,61 - 1,00m/year, and average canopy growth is from 0,11- 0,25m/year.
* Proposing some solutions to develop the P. braianensis species in the direction of business
large timber in Kon Ha No, Tay Nguyen
(i) Planting in areas with forest land, good soil, thick soil layer; (ii) Researching and
selecting varieties the P. Braianensis has high yield, quality, exceeds 15 - 20% compared to the
current mass; (iii) Seedlings keeping in the field should be ensured (Dgoc = 1,0 - 1,3cm, Hvn = 1,2 1,5m); and (iv) Measures of fertilizer application (basal fertilizing, top dressing) and care should be
taken in the first 5 years need to be applied. Measures of care applied: clearing creepers and shrubs;
hoe, cultivate soil around the base of 1m, open forest canopy to ensure nutrient space for the P.
braianensis tree to grow, develop well and participate in the main canopy of the forest stand.
- The thesis is based only on 12 the P. braianensis trees and calculus to build the equation
for estimating the growth of trunk diameter at position by age, but has not studied deeply with large
sample volume and above wide scope. In addition, the thesis only studies the growth and growth of
diameter but has not studied the growth and growth in height of the the P. braianensis trees.
- Because the area of the P. braianensis plantation models is not much in the remaining
area, the evaluation of the models has not been comprehensive and complete. The monitoring and
evaluation of the models is not continuous, especially after the end of the project, so it is impossible to
assess the process of dispersing, pinching canopy from the bandages to suggest intervention solutions.
reasonable for each stage of development of the stand.
- Continuing to study the model of predicting the growth of age at breast height of age for a
long time and on a large scale. Moreover, it is necessary to study the growth and growth of the height
of the P. Braianensis trees.
- It is recommended to treat the pinched trees in the bandage to create the necessary
nutritional space for the P. Braianensis to grow and participate in the main canopy.
- Need to remodel the converted seed forests to serve the P. Braianensis forest.
- Continuing to study continuous technical measures to develop the P. Braianensis forest into
a major forest plant, supplying business large timber in Kon Ha Nung, Tay Nguyen areas.