Nghiên cứu một số đặc điểm cấu trúc và tái sinh tự nhiên các quần xã thực vật rừng hỗn giao cây lá rộng, lá kim vườn quốc gia bidoup núi bà, tỉnh lâm đồng tt

MINISTRY OF EDUCATION &

MINISTRY OF AGRICULTURE &

TRAINING

RURAL DEVELOPMENT

VIETNAM ACADEMY OF FOREST SCIENCES

TRAN THI THANH HUONG

RESEARCH ON STRUCTURAL AND NATURAL
REGENERATION CHARACTERISTICS OF MIXED
BROAD-NEEDLE LEAF FOREST COMMUNITIES
IN BIDOUP - NUI BA NATIONAL PARK, LAMDONG PROVINCE

Major: Silvilculture
Code: 9620205

SUMMARY OF FOREST DOCTOR THESIS

HA NOI- 2019


The thesis has been achieved in Vietnam Academy of Forest Sciences

Academic advisor: 1. Assoc. Prof. Dr Nguyen Đang Hoi
2. Assoc. Prof. Dr Trieu Van Hung
TS. Phí Hồng Hải

Chairman:
Review 1:
Review 2:
Review 3:

The thesis was discussed at the Institute evaluation Council
in Vietnam Academy of Forest Sciences

At ....... , Date ....... Month ....... Year ..............

The thesis is available at: National Library,
Library of Vietnam Academy of Forest Sciences,and
Library of Vietnam-Russian Tropical Center


LIST OF PUBLISHED ARTICLES
1. Tran Thi Thanh Huong, Nguyen Dang Hoi, Kuznetsov A.N, Dang Hung Cuong (2017),
Classification of forests in Bidoup - Nuiba national park, Lamdong province, VietNam Journal
of Forest Science, No.2, pp.20-28
2.

Tran

Thi

Thanh

Huong,

Nguyen

Dang

Hoi,

Trieu

Van

Hung

(2017),

Differentiationcharacteristics of mixed broad-needle leaf forest type in Bidoup - Nuiba national
park, Journal of Tropical Science and Technology, No.14, pp. 76-86.
3. Tran Thi Thanh Huong, Nguyen Dang Hoi, Trieu Van Hung(2018), Structural
characteristics of high trees of mixed broad, needle leaf forest communities in Bidoup - Nui Ba
national park, Lam Dong province, Science and Technology journal of Agriculture & Rural
development, No.10, pp.133-138.
4. Tran Thi Thanh Huong, Nguyen Dang Hoi, Trieu Van Hung (2018), Natural
regeneration characteristics under the canopy of closed evergreen mixed broad, needle leaf
forest types in Bidoup - Nui Ba national park, Lam Dong province, VietNam Journal of Forest
Science, No.2, pp.59-67.
5. Tran Thi Thanh Huong, Nguyen Dang Hoi, Trieu Van Hung, Le Xuan Dac, Dang Ngoc
Huyen (2019), Natural regeneration characteristics of Keteleria everyliana in Bidoup – Nui Ba
national park, Lam Dong province, Science and Technology journal of Agriculture & Rural
development, No.6/2019, pp. 96-102.


INTRODUCTION

1. BACKGROUND
Under the core zone of the Biosphere Reserve International Langbiang,
Bidoup - Nui Ba national park was rated as one of the centers of biodiversity in
Vietnam, where the preserved area of the large primary forest. Forest types of
closed evergreen mixed broad-needle leaf in Bidoup - Nui Ba, including forest
plant communities of mixed between broadleaf trees to rare conifers species
were always considered as natural heritage of the region, with outstanding
values of landscape ecology and conservation science. There, the conifers had a
role to form groups dominant plant ecology, was the main ingredient to make up
dominant layers, dominant unit layers of forest types. The forest types been
assessed to be of high biodiversity not only with woody plants that herbaceous
plants, plant exchange floors. However, the results of research on distribution,
structure and natural regeneration of the mixed forest communities have been
still limited; the rare species conservation and development have been difficult.
For these reasons, the topic "Research on structural and natural
regeneration characteristics of mixed broad-needle leaf forest communities in
Bidoup - Nui Ba national park, Lam Dong Province" was made.
2. RESEARCH OBJECTIVES
2.1. Theoretical
Establish a scientific basis for the conservation of mixed broad, needle leaf
forest communitiesin Bidoup - Nui Ba national park, Lam Dong Province.
2.2. Practices
Identify the distribution, structure and natural regeneration characteristics
of mixed broad-needle leaf forest communities for improving the effectiveness of
the forest communities conservation and development, and some rare conifer
species in Bidoup - Nui Ba national park, Lam Dong province.
3. LIMIT SCOPE OF RESEARCH
- Limit of contents: Focusing research on distribution, structure, and
natural regeneration characteristics of mixed broad-needle leaf forest
communities (with the participation of at least one species of coniferous:

Fokienia hodginsii, Keteleeria evelyniana, Pinus krempfii, Pinus dalatensis)
and they were denoted QXRK in thesis.
- Limitation of space: Bidoup - Nui Ba national park, Lam Dong
province.
4. SCIENTIFIC AND PRACTICE SIGNIFICANCE OF THE TOPIC
4.1. Scientific significance
Additional database of distribution, structure, and natural regeneration
characteristics of QXRK in Bidoup - Nui Ba national park in subtropical


highlands climatic conditions of Vietnam in particular and forest types of closed
evergreen mixed broad, needle leaf in general.
4.2. Practical significance
Provide scientific basis for the conservation and development of QXRK,
including some rare coniferous species; contribute to improving the efficiency of
management, conservation and sustainable using of natural resources
biodiversity, in Bidoup - Nui Ba national park, Lam Dong province, as well as
references for training and research in the domain related areas.
5. NEW CONTRIBUTIONS OF THE THESIS
- Identified and analyzed to quantify some distribution, morphology
structure characteristics of QXRK and structure and natural regeneration
characteristics of typical QXRK with natural regeneration characteristics of some
rare conifers in Bidoup - Nui Ba national park, Lam Dong province.
- Determined the distribution and spatial orientation for QXRK
conservation, development priorities, as well as suitable solution groups for
these priorities.
6. STRUCTURE OF THE THESIS
The thesis has 142 pages , includes: Introduction (4 pages); Chapter 1.
Overview (35 pages); Chapter 2. Contents and Methods (27 pages); Chapter 3.
The results and discussion (73 pages); Conclusions (3 pages) and the thesis

consists of 36 tables, 20 pictures, diagrams. The thesis had 145 primary
references (103 Vietnamese and 40 foreign languages and 2 Website).
Chapter 1. OVERVIEW
1.1. On the world
1.1.1. Vegetation classification
The first vegetable classification system, representing the view of climate
is a key element of Schimper (1898), the author has divided the vegetation into 3
formations: climate formation, soil formation and mountain formation. In 1903,
Tanfilev based on the classification system to study the vegetation and
vegetation mapping in Russia. Champion (1936) based on the temperature to
divide the forest in India - Burma into 4 types: rainforest, subtropical, temperate
and alpine. Beard (1938) studied on tropical forests and showed that: tropical
forests jungle consists of 5 series: green on the season forest series formation,
dry evergreen forest series formation, mountainous series formation, flooded on
the season series formation and evr-flooded on the season series formation.
Vegetation classification of UNESCO (1973) was based on the principle of
external appearance and structure, the system has divided the world vegetation
into 5 formation classes: closed forest formation class, woodlands formation


class, shrubs formation class, dwarf shrubs formation class and herbaceous trees
formation class.
Besides, many authors around the world have based elevations to classify
vegetation, such as: Hajra, Rao (1990), Michael A. and Avi Shmida (1993),
Hegazy et al (1998), Fabio RS (2002), Jon CL (2006), Rainer WB (2006),
Zhang JT, Zhang F. (2007) ... the studies showed that, according to elevations,
vegetations changed on structure, such as: species composition, dominant
species groups, communities density etc.
1.1.2. Forest structure
Qualitative research: Typical as Richards (1952), Catinot (1965), the

authors descripted formal structure of forests, the structural criteria were
analyzed under the concept of life forms, canopy etc. According to Chevalier
(1917), Mildbraed (1922), Booberg (1932) said that: stratification in the tropical
rain forests was not clear, methods based on height of plant to stratification is
the lack of scientific basis. In contrast, many studies suggest that tropical rain
forests have a clear stratification. Richards (1952) confirmed the primeval mixed
forests near Moraballico river had 3 layers structure distinctly: trees layer,
shrubs layer and ground layer. Catinot (1965) also said that the communities in
tropical rainforest humid were different from height. Stevenson (1940) divided
the forests in Honduras into 4 layers. In addition, when researched at Kinshara
forest - Congo, Malaysia, Taylor (1960), Gerad (1906), Myatt Sonith (1963)
also divied the forests into 3-5 layers.
Forest structure was also described by life-form, typically described by
Raunkiaer system (1934). The author has relied on various adaptive signs of
vegetation over time disadvantage in that particular location of the shoots on the
ground to describe.
Quantitative research: The target structure was quantified first to mention
as: Curtis et al (1951) used IV% index to determine species composition,
indicators of biodiversity species of Shannon - Wiener (1988) Simpson (1949),
the degree of common of Margalef (1958), biomass, basal area etc. Many authors
also used mathematical functions for structural modeling, distribution of trees
density according to diameter size (N/Dbh), according to the size of tree height
(N/H) etc. Spicially the works of Bertram (1972), Prodan (1968), Snedecor (1956)
etc.
1.1.3. Reforestation
Van Steenis (1956) suggested that, for tropical forest regeneration had
two common characteristics were reborn dispersed, continuous streaks and
regeneration (rebirth holes). The views on regeneration holes were also
researched by many authors: Yamamoto (2000), Brokaw (1985), Denslow
(1995), Sapkota (2009) etc. In addition, research on the similarities or

differences between the tree layer and seedling layer were interested by many
scientists, such as: Richards (1952), Baur (1964) etc. Obrevin (1938) said that
the mother plant species composition and regeneration downstairs composition
were vary greatly.
The study of ecological factors was very important in the study of forest
regeneration. According Aubreville (1949), group climate factors - hydrology
were a key element group, decide the form and structure of vegetation types.
Andel (1981) demonstrated that optimal coverage of high trees’canopy for the
normal development of the timber is 0.6 to 0.7. Ghent (1969) said that litter,
hydrothermal regime, topsoil and regeneration always existed close relationship.
Denslow (1995) when studyed reforestation in Costa Rica, said that
geographical factors that affect the density and species composition, shrubs,
small trees regenerate.
1.2. In Vietnam
1.2.1. Vegetation classification
Ngu Tran Phuong (1970) was based on topographic conditions, ecological
and species composition to classify forest in Northern Vietnam into 3 main
belts, including: tropical monsoon forest belts; subtropical rain forest belts;
subtropical alpine rain forest belts. Thai Van Trung (1972) also gave a
vegetation types classification system in Vietnam with 14 vegetation types
belonging to four groups, including: closed-lowland forests, closed-highland
forests, woodlands, drought-cold highland formations. Phan Ke Loc (1985)
based on the worldvegetation classification system of UNESCO (1973) to apply
the classification of vegetation in Vietnam. According, Vietnam vegetation was
divided into 5 formation classes, including close forest, woodland, shrubland,
dwarf-shrub, and herbaceous vegetation.
Tran Dinh Ly et al (2017) inherited classification of UNESCO (1973) and
the taxonomic rank below formations of Thai Van Trung (1999), the scale

elevations of Vu Tu Lap (2003) to construct vegetation classification system in
Vietnam, including 5 formation classes: closed forest, woodland, shrubland,
dwarf-shrub and related communities, and herbaceous vegetation.
1.2.2. Forest structure
- Stage structure: Thai Van Trung (1978) was divided into 5 layers, including
emergent (A1), ecological dominant (A2), understorey (A3), shrub (B) and herbage
(C).
- Composition structure: Thai Van Trung (1999) assembled a group of less
than 10 species (each species was valuable IV% greater than 5% and the total
valuable IV% of the group was greater than or equal to 40%) will form plant
dominions. Nguyen Thanh Men (2005) based on the IV% index to divide


evergreen broadleaf forest in Phu Yen into 3 different plant dominions, complex
for the state IV and IIIB.
- Research to quantify forest structure using mathematical functions: Bao
Huy (1988, 1993) tested 5 theory distribution types were Poisson, Distance,
Geometry, Meyer and Weibull to simulate the structure of the Lagerstroemia
forest in Highland. Tran Van Con (2001), Le Minh Trung (1991) studied the
structure of natural forest in Dak Lak, Highlands and showed that Weibull
function was the best distribution for natural forests in the region.
1.2.3. Reforestation
Research on forest regeneration are particularly interested from the last
decades of the twentieth century, typical: Program investigate the situation
natural regeneration for the economic regions in Northern Vietnam of Institute
of Forest Inventory and Planning or Vu Dinh Hue's research (1975), Pham Dinh
Tam (1987), Vu Tien Hinh (1991), Tran Dinh Ly et al (1995) etc focused
assessment density, composition, distribution characteristics etc of natural
regeneration under the canopy layer.
Thai Van Trung (1999) emphasized that the light was ecological factor

which controlled regeneration process in both primary forests and secondary
forests. In other cases, Pham Ngoc Thuong (2003) concluded: distance from
where regeneration to supply seed resources was as far as, regeneration density
and species numbers were as low as.
Simulate distributed tree numbers according to height, distribution on
forest land surface, typical: Ngo Kim Khoi (1999), Pham Ngoc Thuong (2003),
Ma Thi Ngoc Mai et al (2009) used standards of Clark and Evans U to study
morphological regeneration distribution on forest floor, Mayer was chosen to
model distribution of the number of regeneration trees and the number of
regeneration spicies with height levels.
1.3. In Bidoup - Nui Ba
In describing fotrest types (2004), Bidoup - Nui Ba national park had 6
forest types and forest subtypes: (i) Forest type of closed - evergreen moist-rain
subtropical medium mountain distributed from 1,700 meters or more; (ii) Forest
sub-type of closed mixed broad-needle leaf trees subtropical appeared at an
altitude of 1,700 m or more; (iii) Forest sub-type moss, dwarf mountain; (iv)
Forest type of woodland coniferous subtropical low mountain; (v) Forest type of
mixed wood - bamboo, bamboo monoculture and (vi) Plantation forests.
Nguyen Dang Hoi and Kuznetsov AN (2011) suggested that in Bidoup Nui Ba national park, forest types had 3 layers, the 1st layer was the component
tree dominant ecological height superiority, the 2nd layer was the component
tree under the canopy and the 3rd layer was component shrubs.


Luu Hong Truong et al (2014) observed that forest type of closed mixed
broad-needle leaf subtropical low moutain had high bio-diversity. Nguyen
Trong Binh (2014) also confirmed the forest had high biodiversity, with the
index Shannon - Wiener reached to 3.62. According to Do Van Ngoc (2015),
forest plant communities of mixed broad-needle leaf where P.krempfii
distribution had rather high bio-diversity, He ' index was 3.6837 and Cd index
was 0.0357.

1.4. General comment
The work on classification, structure and natural regeneration of forest
types were quite diverse and achieved great achievements in forestry science.
However, until now, studies as well as a database on distribution, structure,
natural regeneration of mixed broad-needle leaf forest types aren’t much. In
Bidoup - Nui Ba national park, the study of the structure, natural regeneration or
characteristics of mixed broad-needle leaf forest types achieved certain results,
but also some existences:
- The forest types of Bidoup - Nui Ba national park (2008) has been
applied in many documents, reports don’t fully reflect the characteristics of the
flora of the park. The actual distribution of mixed broad-needle leaf forest type
hasn’t been shown on map of Bidoup - Nui Ba national park forest status;
- The studies haven’t reflected the distribution, structure and natural
regeneration characteristics of the forest in general, especially the plant
communities of mixed broad-needle leaf specific in Bidoup - Nui Ba region
particular.
- The ex-situ conservation of rare precious conifers species have not
achieved many positive results. In addition, the in-situ conservation solutions of
habitats and rare precious conifers species have been mainly management and
protection, without paying attention to the natural recovery measures.
1.5. Some viewpoits and concepts were used in the thesis
- The idea of mixed broad-needle leaf fores type
Concept of mixed broad-needle leaf fores type was used in the thesis, apart
from the area under the provisions of Circular 34/2009/C-MARD also is the
distribution area of rare precious conifers species, including: P. krempfii, P.
dalatensis, Fokienia hodginsii, Keteleeria evelyniana, in which, the number of
coniferous individuals aren’t reached 25% of total individuals of the communities.
- The viewpoint of terrain elevations: to base on the viewpoit of terrain
elevations of Vu Tu Lap (2003): Lowland <500 m, low-mountain: 500-1500 m,
medium mountain: 1500-2500 m, high mountain > 2500m. Also in the process

of analyzing and synthesizing data, medium mountain belt was divided into sub
belt 1500-1700 m and > 1700 m.
- Concept QXRK, typical QXRK


+ QXRK was denoted and used in the thesis, that was the forest plant
communities of mixed broad-needle leaf trees, with the participation of at least
one of four rare-precious conifers, including: P. krempfii, P. dalatensis,
Fokienia hodginsii, Keteleeria evelyniana.
+ Typical QXRK were the communities that had domination on IV% of each
species or species group (P. krempfii, P. dalatensis, Fokienia hodginsii,
Keteleeria evelyniana) over a period of a certain area (2,500 m2). The research
results from secondary documents, interviews and field surveys showed, there
were 6 typical QXRK types in Bidoup - Nui Ba national park, including: typical
QXRK with the participation of Fokienia hodginsii (Pm); typical QXRK with the
participation of Fokienia hodginsii and P. krempfii (Pm + Tld); typical QXRK
with the participation of P. krempfii, P. dalatensis (Tld + Tnl); typical QXRK
with the participation of P. krempfii (Tld); typical QXRK with the participation
of P. dalatensis (Tnl); typical QXRK with the participation of Keteleeria
evelyniana (Ds).
Chapter 2. CONTENTS AND METHODS
2.1. Research contents
- Characteristics of the forest types in Bidoup - Nui Ba national park
- Distribution characteristics of QXRK
- Some structural characteristics of typical QXRK
- Some natural regeneration characteristics of typical QXRK
- Orientation of conservation sollutions for the species and QXRK
2.2. Research Methods
2.2.1. Inheritance
Inheriting selective data on meteorological, soil, topography, classification

of forest types, the results of the study on the forest types (diversity, structure,
regeneration), the coniferous ( information geographical indications, ecology etc);
the results of research topics E1.2 code of Tropical Center Vietnam - Russia and
the survey data stories tall trees from 2 plots (2,500 m2) in typical QXRK with the
participation of Fokienia hodginsii and P. krempfii (Le Canh Nam, 2010). Data
and mapping, remote sensing, such as: topographic maps; soil maps; forest status
map (2015); map inventory and monitoring of changes in forest ( 2016); SPOT 5
satellite imagery etc.
2.2.2. Interviewing
Respondents mostly local people, local officials, officers in charge of the
unit management, forest protection. Interview content is to use open questions
about the distribution area of the species: P. krempfii, P. dalatensis, Fokienia
hodginsii, Keteleeria evelyniana.
2.2.3. Group fieldwork methods


- Method of determining the survey line and choose the sampling location
- Methods for characterizing breadth of QXRK by elevation
- Methods for investigation the ecological factors in the distributed
QXRK:
+ Research topographical features: DEM (digital elevation models) was
built from the class contours, spot heights, hydrology on topographic maps
based on GIS software algorithms ArcGIS 10.1.
+ Investigate soil characteristics: Each major group where QXRK was
investigated a soil profile (each 1.2m x 0.8m x 1m in size). Observe, describe soil
sampling and analysis of indicators: pH, humus, total NPK, NPK bearable.
+ Research characteristics of climate: Meteorological data (temperature,
humidity) are monitored by temperature and humidity measuring devices iButtons
in time (16/10/2017-16/12/2017) in the distribution reagion of the QXRK.
- Research methodology structural features and the natural regeneration of

typical QXRK:
+ A total of 12 plots at 6 typical QXRK types were established or
inherited to investigate, collect data on the structure and natural regeneration.
Each plot was 2,500 m2 area (50 mx 50 m in size). Processing survey based on
biodiversity research methods of Nguyen Nghia Thin (1997) and Tran Van Con
(2015). Each grade A plot was described the indicators there on the coordinates,
altitude, direction of exposure, slope, etc and measured growth indicators (Dbh,
H, Dt – canopy diameter) for all trees with Dbh ≥ 10 cm. Four grade B plots
were established, that had total an area 250 m2 (each 25m x 2,5m in size) in the
center of the grade A plot to measure the number of regenerations, that had H >
2m and Dbh ≤ 10cm with the following criteria: name species, Dbh, H, quality
and originy. And five grade C plots had total an area 20 m2 (each 2m x 2m in
size), which were evenly distributed on grade A plot to measure of all
regeneration trees (0.3m ≤ H ≤ 2 m), with the following criteria: name of the
species, H, quality and originy; to investigate shrubs, vegetation under the
following criteria: name of the species the average height, ground cover (%);
and to investigate litterfall based on the criteria: form, ground cover (%),
thickness (cm).
+ Research on natural regeneration characteristics of P. krempfii species:
at the locations of the distribution of at least 3 small regeneration trees (not
including seedlings), 31 plots with an area of 5m x 5m each plot were
established to measure all of regeneration trees of P. krempfii: H, quality,
number of seedlings; and to investigate shrubs, vegetation under the following
criteria: name of the species the average height, ground cover (%); and to
investigated litterfall with the criteria: form, thickness (cm), ground cover (%),
the thickness of humus (cm), the distance to the nearest mother plant.


+ Research on natural regeneration characteristics of Keteleeria evelyniana
species: in the typical distribution of the species (sub-zones 125, 128), ten mother

plants (appeared at least 10 seedlings have H ≥ 0.3m under the canopy and in the
surrounding ranges ≥ 2.5 times height of mother plant, there weren’t any mother
trees) were selected to plots design. With each mother plant was chosen, maximum
of 8 plots were established with each 2m x 2m in size, including: from 1 to 4 plots
under the shadow of the mother tree’s canopy and 1-4 plots outside the shadow of
the mother tree’s canopy (within 1 H of mother plants from the edge canopy) at the
locations where natural regeneration trees distributed (priority points had many
prospect regeneration trees). In each plot, the following criteria of the regeneration
trees and ecological factors were mesured: H, quality, coverage vegetation, shrubs
(%), the thickness of dry the litterfal (cm), the thickness of the litter (cm ), humus
thickness (cm), the distance to the mother plant (m).
2.2.4. Data analysis and processing methods
- The data were aggregated, statistical analysis on the 13.0 software Excel,
SPSS 20.0, 18.0 Stagraphic Centurion, Corel Draw X6, Gap Light Analyzer
GLA_v2.0 according to research content.
- Species and QXRK conservation orientation proposing method: From
the research findings, the method of analysis, integrated assessment were
applied to propose conservation-oriented solutions and QXRK species.
2.2.5. Map methods
- Data processing: Building a model of high-DEM; mapping slope,
elevation; Image SPOT 5 satellite was processed in natural color, normalized
with coordinates VN-2000, conducted interpreted by classification method
photo automatically, using proven templates scene photos, status updates from
forest resources available maps.
- Construction forest types map, scale 1/50,000: Conducted adjustment
boundary update batches forest status based SPOT 5 satellite images in 2017 (if
volatile); Conducted layer overlay maps with elevation and slope maps;
Checked and adjusted the boundaries of the units classified vegetation from the
survey results online if there was a discrepancy with the field - the map. Bidoup
- Nui Ba forest types map (2018) corrected boundary presented last (if any

difference) after stacking layers QXRK distribution maps.
- Construction of the QXRK distribution map, scale 1/50,000: On the
basis of the map forest types Bidoup - Nui Ba 2018 (provisional), ungroup
objects mixed forest of broad-needle leaf and based on distribution
characteristics, ecological adaptation of QXRK from the results of field surveys,
combied technology FlyCam image and the template key construction of the
QXRK images for conducting construction of QXRK distribution map class.


Chapter 3. RESULTS AND DISCUSSION
3.1. Forest vegetation in Bidoup - Nui Ba national park
3.1.1. The forest types in Bidoup - Nui Ba national park
Forest vegetation in Bidoup - Nui Ba national park include the following
types:
(1) Forest type of closed evergreen broadleaf rain moisture tropical,
subtropical low mountain (500-1500 m) distributed in the Northeast (Da Chais
commune) andin the Northwest (Dung Kno commune), with a total area of
11,497.5 hectares, accounting for 16.5% of the park area;
(2) Forest type of closed evergreen broadleaf rain moisture subtropical
medium mountain distributed in elevation from 1,500 m, which had an area of
17,219.88 hectares, accounting for 24.7% of the park area.
(3) Forest type of closed evergreen mixed broad-needle leaf moisture
tropical, subtropical low mountain distributed mainly in the Northeast and
Northwest of the park (Dung K'No commune, Da Chais commune and Da
Nhim commune), with an area of 6,881.14 hectares, accounting for 9.9% of the
park area;
(4) Forest type of closed evergreen mixed broad-needle leaf moisture
subtropical medium mountain distributed primarily in the Southwest and East of
the park, (Lat and Da Chais communes), with an area of 5,442.73 hectares;
(5) Evergreen rather dry coniferous tropical, subtropical low mountain

woodland type distributed in elevation from 600 m, concentratly in the subzones 22, 25, 44, 49, 52, 55, 57, etc with an area of 14,973.58 hectares,
accounting for 21.2% of the park area,;
(6) Evergreen rather dry coniferous subtropical medium mountain
woodland type distributed concentratly in the sub-zones 80, 82, 127B, 129, 130
etc, a total area 6,725.8 hectares, accounting for 9.7% of the total area of the park;
(7) Bamboo - broadleaf trees mixed or pure bamboo forest type had an
area of 1,778.7 ha, distributed mainly in the tropical belt (below 1,000 meters),
along the tributaries and Krong Kno & Dak Dom rivers;
(8) Plantation forests had an area of 2,228.48 hectares, accounting for
nearly 3.2% of the total area of the Park. Plantations largely deployed in
subtropical belt, Northwest and Southwest of the park (Da Nhim commune, Lat
commune).
3.1.2. Characteristic of mixed broad-needle leaf forest types
- Distribution dotted with small area interspersed forest types of evergreen
woodlands coniferous and evergreen broadleaf.
- The mixed broad-needle leaf forest types have a total area of 12,323.87
hectares including: Forest type of mixed evergreen broad-needle leaf moisture


tropical, subtropical low mountain and Forest type of mixed evergreen broadneedle leaf moisture subtropical medium mountain.
- Stratified structure: The forest plant communities of mixed broadleaf
trees with P. kesiya species often consist of 2-3 layers, the first layer was 20-25
m high, with the participation of P. kesiya and some broadleaf species belonging
to Euphorbiaceae, Fagaceae, etc. The second layer often was fragmented, with
much lower height (5-10 m). The forest plant communities of mixed broadleaf
trees with other coniferous species such as: P. krempfii, P. dalatensis, Fokienia
hodginsii, Keteleeria evelyniana, Podocarpus neriifolius etc had structural
diversity, consisting of 3-4 layers or 2-3 layers, especially sometimes no
stratification at the tops and the slopes of mountains.
3.2. Distribution characteristics of QXRK

3.2.1. Distribution characteristics
QXRK have distributed clusters, sometimes appear scattered in the vertex
ridges or slopes, guide rib positive location, mainly exposure directions
including: West – North, East - South, West - South and East - West, belong to
the part of the region Eastern - South and Western - South.
The research results indicated that the distribution QXRK in two
elevations, including: the tropical, subtropical low moutain (1200-1500 m) and
subtropical medium moutain (1500-2200 m), but the communities have
distributed more in the belt from 1500-1700 m (subtropical medium mountain),
concentrated in the southeast of the Park (Da Chais commune). The total area of
QXRK was 2277.95 ha, accounting for 18.48% of the total area of the forest
types of mixed broad-needle leaf in Bidoup - Nui Ba national park.
3.2.2. Characteristics of dominant ecological factors in the regional
distribution
- Topographical factors: QXRK have distributed mainly in subtropical
medium mountain, with an area of 1803.02 hectares, accounting for 79.1% of
total area of QXRK and specially, concentrated distribution in elevations from
1500-1700 m, with 1363.15 ha area, accounting for 59.8%. So that, the
elevations from 1500-1700 m was the typical distribution and most
comprehensive gathering QXRK types and typical QXRK types with the
participation of P. krempfii, P. dalatensis, Keteleeria evelyniana. QXRK with the
participation of Fokienia hodginsii distributed mainly at elevations from 1,700
m. The study results also showed that 67.1% of the area of QXRK distributed in
location rib, particularly in the direction of positive slopes, with small slopes.
- Climatic factors: Climate in Bidoup - Nui Ba national park had 2 seasons
(rainy season and dry season). The rainy season usually lasts from April to
October, accounting for 92.4% of the total annual rainfall. The wettest month is


August, with an average rainfall to 340.3 mm/month. The dry season was often

from November to March in year, big changes’re from 3,8- 73.8 mm month-1 in
rainfall. In particular, January, Ferbruary and December were the dry months of
the year, because they had very low rainfall. The QXRK distributed mainly in
humid climatic conditions of subtropical low, medium mountain and few
communities distributed in areas with humid climate typical of subtropical high
mountain.
- Soil factors: The QXRK scattered across the 3 land groups: humus
yellow-red soil; red-yellow soil and light yellow humus soil. In particular, the
QXRK distributed mainly in red-yellow soil on shale development and
metamorphism (Fs), with 1,126.04 hectares area, red-yellow soil on magma acid
development (Fa) with an area of 500, 80 hectares and of yellow-red loamy soil
on magma acid (Ha) with an area of 483.11 hectares. Light yellow humus soil
had very small area, was the distribution of QXRK with the participation of
Fokienia hodginsii.
The results of soil profile description showed that, soil stratificated clearly
and had quite thin thickness. The conifers had the most clearly affected the litter
layer thickness. The analysis result of chemical indicators showed that soil
acidity response, nutritional ingredients at poor to average.
3.2.3. Differentiation characteristic of QXRK by elevation
Types QXRK different at higher elevations had less morphological
differentiation external appearance structure. If in the subtropical low mountain
belt, QXRK with the participation of P. krempfii, P. dalatensis, consisting of 3-4
layers, but the 1st layer dominant as unknown, 4th layer (layer lawns, shrubs)
passable developing, in the subtropical medium mountain belt, QXRK with
participation of P. krempfii, P. dalatensis, Fokienia hodginsii, Keteleeria
evelyniana, also include 3-4 layers, and they had 1st layer dominant, often
fragmented belonging to the conifers, 4th layer (grass, shrubs)
underdevelopment.
3.3. Structural characteristics of typical QXRK
3.3.1. Structure of high trees

- Species composition
The number of high trees species ranged from 31 to 57 species plot-1,
including 3-9 dominant species participated in species composition formula,
formed 9 plant dominions, including: (1) P. krempfii + Syzygium zeylanicum +
Fokienia hodginsii + Quercus augustinii + Lithocarpus campylotropis +
Exbucklandia populnea; (2) Castanopsis wilsonii + P. krempfii + Syzygium
zeylanicum + Calophyllum rugosum + Illicium cambodianum + Fokienia
hodginsii; (3) Fokienia hodginsii+ Litsea glutinosa + Lithocarpus stenopus +


Schima superba + Cinnamomum aff. tsoi; (4) P. dalatensis + Engelhardia
roxburghiana + Dacrydium elatum + P. krempfii + Schima superba; (5)
Craibiodendron henryi + Quercus augustinii + Eriobotrya acuminatissima +
Elaeocarpus harmandii + Syzygium zeylanicum + Dacrydium elatum + P.
dalatensis + Rhodoleia championii + P. krempfii; (6) P. krempfii + Castanopsis
echidnocarpa + Syzygium zeylanicum + Vaccinium sprengelii + Pentaphylax
euryoides + Craibiodendron henryi + Engelhardia roxburghiana; (7) P.
dalatensis + Craibiodendron henryi + Dacrydium elatum; (8) P. dalatensis +
Quercus augustinii + Syzygium zeylanicum + Syzygium wightianum + Rhodoleia
championii + Engelhardia roxburghiana; (9) Keteleeria evelyniana + Castanopsis
echidnocarpa + Craibiodendron henryi + Cinnamomum aff. tsoi. The conifers (P.
krempfii, P. dalatensis, Fokienia hodginsii, Keteleeria evelyniana) were species
or groups of species with the highest compossion coefficient in the plots, that the
IV% value reached up to 25.4%, occupied an important contribution forming
plant dominions.
- Diversity of species: Typical QXRK had diversity high trees and
relatively evenly between these communities. Mixed coefficient ranged from
1/5-1/9, meaning that 5-9 individuals of high trees shall be 1 species appear.
He’ index wasquite high, ranged from 3.42 to 3.92, Cd index from 0.03 to
0.05, the level of species diversity between the communities didn’t have a large

difference. Pm, Tld+Tnl, Ds communities group had Hα (- meaing that species
diversity and uniformity of individuals of the species) higher than Tld, Tnl,
Tld+Pm communitiesgroup.
- Species distribution by elevations
Component plants high trees were surveyed, tend to change from tropical
species, such as: Cinnamomum ovatum, Cinnamomum kunstleri etc to the
species of subtropical low mountain, medium mountain, such as: Rhododendron
irroratum, Camellia kissi, etc. There was transition between two adjacent
elevations, with many species appearing at the same time: 23 species, equivalent
to 15.9% of the total number of recorded species appeared simultaneously in
both 1500-1700m and > 1700m. At altitudes 15,00-1,700 m and <1,500 m with
26 species appeared simultaneously, accounting for 17.9% of the total number
of species recorded. However, only 3 species appeared simultaneously at
altitudes <1,500m and> 1,700m. The study results also recorded that, a total of
42 species (accounting for 29.7% of the surveyed species) had broad ecological
amplitude, appeared at 3 elevations, the mainly species of the families:
Lauraceae, Fagaceae.


- Structure of density and growth indicators
High trees density averaged from 676-1,002 individuals ha-1, the growth
indicators (Dbh, H) were quite large, with average diameter from 22.6 to 28.1
cm, average height from 12.5 to 18.1 m. The forests were rich to rich state, with
average basal area from 46.2 to 68.3 m2 ha-1.
- Structure N/Dbh
Simulation results of N/Dbh distribution of high trees in the study area by
distance function were shown in the following table:
Typical
QXRK
Tld + Pm

Pm
Tld + Tnl
Tld
Tnl
Ds

Distance distribution
Plot





2n

205

Conclude

1

0.009
0.299
0.297
0.004
0.204
0.351
0.224
0.341

0.267
0.013
0.281
0150

0.689
0.682
0.702
0.706
0.695
0.618
0.651
0.710
0.76
0.624
0.783
0803

12.31
3.17
8.91
15.94
10.28
9.50
10.44
16.29
7.80
13.55
13.33
6.29

15.51
14.07
15.51
16.92
15.51
11.07
15, .51
14.07
14.07
12.59
14.07
15.51

Ho+
Ho+
Ho+
Ho+
Ho+
Ho+
Ho+
Ho Ho+
Ho Ho+
Ho+

2
3
4
5
6

7
8
9
10
11
12

With 95% reliability, there were 10/12 plots to accept the assumption Ho+
2
(𝜒𝑡2 <𝜒05
), meaning that distance functions simulated well distribution N/Dbh in
the typical QXRK. Density of high trees focused primarily in the 10- 30 cm
diameter and reduced significantly in larger diameter, especially in the 50 cm
diameter, and 1-5 trees/diameter size. Besides, with the distance 4cm between the
diameter sizes, each plot had from 15-20 diameter sizes. Coniferous rate of the top
50 cm diameter accounted for 41.3% of conifers in the community, and the rest of
the tree from 10 to 30 cm diameter only 30% of the total coniferous communities .
3.3.2. Variety of plant life-form
The existence of a variety of plant life-forms of the typical QXRK were
written by following formula:
SB = 91.6 Ph + 4.2 Th + 1.9 Ch + 1.9 Cr + 0.4 Hm
The result reflected the typically characteristics of the mixed broad-needle
leaf forest plant communities in Bidoup - Nui Ba national park. Phanerophytes
(Ph) were the most dominant life-forms with about 91.6%, Therophytes (Th)
accounted for 4.2%, Chamaephytes (Ch) and Cryptophytes (Cr) were about
1.9% in each group, Hemicryptophytes (Hm) were the smallest participation
life-forms with about 0.4%.


3.3.3. Variety of plant families and genuses

The statistical results showed that a total of 10 plant families were the
most diverse species accounted for 14.1% of families total and 46.3% of species
toal, which have been recorded at the typical QXRK. Lauraceae was the most
dominant species with 21 species, accounting for 9.7%; Fagaceae was 18
species, accounting for 8.3%; Theaceae’s 10 species, accounting for 4.6%;
Rubiaceae’s 9 species, accounting for 4.2%; Ericaceae’s 8 species, accounting
for 3.7%; Magnoliaceae’s 8 species, accounting for 3.7%; Orchidaceae’s 7
species, accounting for 3.2%; Euphorbiaceae’s 7 species, accounting for 3.2%;
Araliaceae’s 6 species, accounting for 2.8%; Arecaceae’s 6 species, accounting
for 2.8%. In particular, Cinamomum and Lithocarpus were the most species
with 9 species in each genus.
3.3.4. Variety of conservation value
There were 19 species belonging to 13 families were listed in the
Vietnam Data Red Book (2007) and the IUCN Red List (2018), representing
8.8% of 216 species total and 18.3% of 71 families total, which were
recorded in the typical QXRK.
3.3.5. Vertical structure
Typical QXRK can be classified into 3 main tree layers: 1st layer (upstairs)
had a height greater than 2/3 height of the forest canopy, with H ≥ 24m; 2nd layer
(middle layer) had a height from 1/3 to 2/3 height of the forest canopy, with 12m
≤ H < 24m, and 3rd layer (downstairs) had a height smaller than 1/3 height of the
forest canopy, with H <12m). The layer can be divided into the sub-layers: 3.1
layer consists trees with a height of 6-12 m, 3.2 layer consists trees with a height
of 2-6 m and 3.3 layer consists trees with a height of 0.3-2 m. Density of trees,
had H ≥ 0.3 m was about 31.380 individuals ha-1 at the typical QXRK. Therein, a
total of 30.615 trees ha-1 were at downstairs (corresponding to 97.56%), a total of
699 individuals ha-1 were at middle layer (corresponding to 2.23%) and a total of
66 individuals ha-1 were at upstairs (corresponding to 0.21%). The majority trees
of concentrated downstairs, a total of trees of upstairs and middle layer only
accounted for 2.44% of the total number of individuals surveyed, but again

predominate to 84.76% of the total basal area of communities. Whether
coniferous group accounted for only 4.36% density (corresponding to 1,376 trees
ha-1) but accounted for 32.36% of the total basal area of communities.
3.3.6. Shrub, dry litter, decay litter structure
Shrub was relatively underdeveloped in the typical QXRK. Shrubs &
vegetation layer was about 12.1% of average cover and had diversity of species,
with 55 species of 216 plants species were investigated. Typical QXRK had
quite large quantities of litter, dry litter, with average cover of 85%, from 1.3 to


3.2 cm in dry litter thickness, litter thickness ranged from 3.6 to 13.5 cm.
Particularly in the area within the canopy of large coniferous, there were very
thick liiter, averaged from 15 to 30 cm, specially reached to 80 cm in some
cases.
3.4. Natural regeneration characteristics of typical QXRK
3.4.1. Species composition
The regeneration species composition was quite diverse and rich, with
ingredients mostly species, rapid growth such as: the species of the genuses
(Symplocos, Lasianthus, Syzygium, Cinamomum, Castanopsis, Lithocarpus etc).
The number of advanced regeneration species between plots had large
fluctuations, from 20 to 47 species, with 3-6 dominant regenerated species in the
species composition formula. The small regeneration group (H ≤ 2m) had from
16-36 species in each plot, with 3-9 dominant species in the species composition
formula. The result of comparison between the communities showed that Tnl, Ds,
Tld, Tld + Tnl communities were more diverse regeneration species than Pm, Tld
+ Pm communities. The dominant conifers in high trees layer were not the
dominant species in the regeneration layers, except Keteleeria evelyniana species.
Species composition of high trees and species composition of
regeneration layers were similarities and were shown in the following table:

42

C
29

A&B
18

23

Similarity index
(SI)
SIA&B
SIA&C
0.38
0.55

80

44

32

34

28

0.55

0.50

Tld + Tnl

56

50

34

32

30

0.60

0.67

Tld

68

58

31

39

22

0.62

0.44

Tnl

73

65

44

43

39

0.62

0.67

Ds

76

65

47

44

31

0.62

0.50

Typical
QXRK

Species

Tld + Pm

A
54

Pm

B

Species homologous
A&C

SI index between tree layers in the study area was moderate (from 0.38 to
0.67). Thus, conclusion may be shown that at the time of the study, the process
of regeneration under the canopy at the typical QXRK occur randomly, the
relationship between species composition of high trees to species composition of
regeneration layers were moderate.
3.4.2. Diversity of regeneration species under the canopy
Shannon - Wiener index (He') of advanced regeneration trees ranged from
3.20 to 3.91, He’ value of small regeneration trees ranged from 2.80 to 3.59.

The result of comparing the characteristic of high trees showed that, species


diversity index decreased from high trees to advanced regeneration trees and to
small regeneration trees.
3.4.3. Density and growth of regeneration trees
Regeneration density of the typical QXRK in Bidoup - Nui Ba national
parkwas very high, ranged from an average of 22,500-38,530 individuals ha-1.
However, the rate of advanced regeneration (H > 2m) only accounted from 6.2
to 20.1%, corresponding to the 2,000-6,560 individuals ha-1, the Tnl
communities was the highest regeneration density (about 6,560 individuals ha1
). Density of small regeneration trees was quite high, but there were great
variations between plots at other communities, from 19,000-33,750 individuals
ha-1. The Pm communities were the lowest density of small regeneration trees
(average 19,000 individuals ha-1). Oppositely, the Tld + Tnl communities were
the highest density of small regeneration trees, with 33,750 individuals ha-1.
Height of advanced regeneration trees was from 4.3 to 5.2 m, and from 0.9 to
1.2 m with small regeneration trees.
3.4.4. Quality of regeneration trees
Regenerated trees of good quality with high average rates, ranged from
44% (in advanced regeneration trees) to 51% (in small regeneration trees), bad
regeneration trees ranged from 13-19%. However, the rate of good, medium
regeneration trees decreased gradually from small regeneration trees to
advanced regeneration trees, except for Pmcommunities, that had the lowest
density of small regenerated trees but the density of advanced regenerated trees
was quite high. Typically, Tld + Tnl communities had rate of good quality about
48.9% in small regenerated trees but in advanced regenerated trees, the rate was
only 29.3%.
3.4.5. Density distribution by regeneration height size
Distribution characteristics of regeneration density by height size in

typical QXRK were summarized in the following table:
Height size (H, m)
N
Typical
QXRK

Small regeneration trees
0.3-1 m

1-2 m

N

18,750

11,500

30.250 720

540

740

2,000

%

58.1

35.7

93.8

1.7

2.3

6.2

N

9,250

9750

19,000 1,060

1,360

1,080

3,500

(individuals

total

Advanced regeneration trees
2-3 m

3-6 m

>6m

total

ha-1)

Density
total Nts

Ratio (%)
Tld + Pm
Pm
Tld +
Tnl

%
N
%

41.1
18,250
47.4

43.3
15,500
40.2

84.4

2.2
4.7

33,750 2,060
87.6

5.3

6.1
2,060
5.4

4.8
660

15.6
4780

1.7

12.4

32,250
22,500
38 530


Tld
Tnl

N
%
N
%

N
Ds
%

13,500
47.4
16,500
50.3

9,250
32.5
9750
29.7

22 750 2,140
79.9

7.5

26 250 2.420
80.0

7.4

2,280
8.0
2.840
8.6

1,320
4.6
1,300
4.0

5,740
20.1
6560
20.0

28 490
32 810

25,0
3,34
1,060 1,440 840
00
0
28 340
27.3 88.2
3.7
5.1
3.0 11.8

17,250 7750

60.9

Advanced regeneration rates in the typical QXRK were from 6.2 to
20.1%. The Tnl communities had the highest advanced regeneration density,
with 6.000 individuals ha-1. The Tld + Pm communites had the lowest advanced
regeneration rate with to 6.2%, for a density of 2,000 individuals ha-1.
Besides, the regeneration capacity of coniferous species was poor, the
average rate of regeneration only 1.15% total regeneration density of
communities. There were many communities, such as: Pm, Tnl didn’t have any
regeneration tree of coniferous species with H ≥ 0.3 meters, the number of
seedlings were also very low. Regeneration capacity of Keteleeria evelyniana
was better than other coniferous species (P. krempfii, P. dalatensis, Forkienia
hodginsii), with average density about 1,480 individuals ha-1 (H ≥ 0.3m),
accounting for 5.22% of the regeneration density of communities but the density
also reduced significantly ccording to the increase at the height size.
3.4.6. Regeneration distribution on face-land
In small regeneration trees, there were only 5/12 plots had cluster
distribution. However, most of the plots were distributed clusters in
advanced regeneration trees. This can be concluded that, regenerated trees in
most plots of the mixed broad-needle leaf forest plant communities had
unevenly distribution, advanced regeneration trees often concentrated in
locations with more favorable conditions. Therefore, it’s very important to
take measures to promote natural regeneration and take care few advanced
reganeration trees of coniferours species.
3.4.7. Natural regeneration characteristics of some conifers
- P. krempfii species
Natural regeneration density of P. krempfii in the convergent regeneration
locations was 2,452 individuals ha-1. Density of advanced regeneration was
about 749 individuals ha-1. At the height size (H ≥ 3m) the density was average
271 individuals ha-1 and more convergent outsite the shadow of mother tree’s

canopy, with density of 427 individuals ha-1. In addition, the result also showed
that natural regeneration density of P. krempfii at the height size (H < 3m)
inside the shadow of mother tree’s canopy (from 494-800 individuals ha-1) was
more than outsite the shadow of mother tree’s canopy. Besides, the results of the


analysis showed that, with significance level (Sig = 0.04 <0.05) and R 2 = 0.13,
regeneration density at the height size (H > 3m) related to the distance to mother
trees. Or the ability regeneration of the species outside the shadow of mother
tree’s canopy was better than inside the shadow of mother tree’s canopy.
The study results showed that, P. krempfii regenerated generally in the
locations, where the slopes was low (5-10o) and had a positive towards the
slopes, coverage of high tree’s canopy was average 0.7, shrubs and vegetation
underdeveloped (average cover about 14%), decay litter layer was thick (about
14.1 cm).
- Keteleeria evelyniana
Natural regeneration density of 10 typical Keteleeria evelyniana mother
trees was summarized in the following table:

Location

Inside
canopy
Outside
canopy

Plots

Density
(individuals ha-1)

28

6,696 ± 5,094

Ratio
(%)
37
Ratio
(%)

100
12,635 ± 8,248
100

Small rageneration trees
(Hvn≤ 2m)

Advanced
regeneration
trees (Hvn> 2m)

<0.3

0.3-1

1-2

2-3

3-6

≥6

982

4,732

804

89

0

89

97.3
946

7,770
90.4

2.7
2,703

608

270
9.6

Natural regeneration density of Keteleria everyliana outside the shadow
of 10 typical mother tree’s canopy reached to 12,635 individuals ha-1, that was
1.8 times higher (6,696 individuals ha-1) than under the shadow of the mother
tree’s canopy. The rate of promising regenerated trees outside the canopy (9.6 %
- corresponding to 1,216 individuals ha-1) was more 6.8 times higher than in the
canopy (2.7% - corresponding to 178 individuals ha-1).
Rate of medium and bad regenerated trees is high (from 82.6 to 100%),
advanced regenerated trees ratio had only under 10%.
The results of ecological factors investigation also showed that Keteleria
everyliana regenrated the locations, where dry litterfall layer was thick (from 3.6
to 3.9 cm), decay litter layer ranged from 6.1 to 7.4 cm, cover of shrubs and
vegetation ranged from 13.7 to 14.6%. In particular, the values about cover of
shrubs and vegetation value, thickness of dry litterfall layer, thickness of decay
litter outside the canopy were lower than inside the canopy, or the conditions of

338


regeneration of the species outside mother tree’s canopy were more
advantageous than inside mother tree’s canopy.
3.5. Oriented solutions to conserve species and QXRK
3.5.1. Viewpoint
The implementation of these species as well as QXRK conservation
solutions at Bidoup - Nui Ba was very essential. With the approach at the level
of communities, species conservation solutions were proposed in view of
communities conservation where the species distributed. All of the solutions
must be considered, to minimize adverse effects on the stability and
development of the whole community. On the basis of viewpoit as well as the
obtained results, conservation solutions were proposed to focus mainly for
management and protection of the mature coniferous trees and promotion of

natural regeneration of coniferous trees species.
3.5.2. Conservation spatial orientation
a. Basis
Conservation spatial orientation based on basic elements: (i) Location of
the spatial distribution of the QXRK compared to other plant communities and
infrastructure, economic and social; (2i) Size and shape of the QXRK; (3i)
Elevations where the QXRK distributed mainly; (4i) Structural and natural
regeneration characteristics of the QXRK.
b. Rule
Similarly partition function, defining space conservation priorities also
adheres to the following principles: the principle of relative homogeneity;
principle of general territory; principle of QXRK conservation priority.
c. Criteria for evaluating conservation priorities
The order of conservation priority groups were evaluated by two criteria:
distribution location of QXRK and emergency level well as the natural
resilience of the conifers. QXRK were taken firstly solutions for the
conservation priorities, including: the communities have concentrated many
individuals conifers (≥ 20 individuals ha-1) or structures N/Dbh of conifer had
peaks form, with many old trees; the communities had coniferous species
(Keteleeria evelyniana, P. krempfii) with high natural recovery and regeneration
ability or very unlikely to natural regeneration (with Fokienia hodginsii, P.
dalatensis) and QXRK distributed concentratly in vulnerable locations.
Accordingly, the QXRK conservation priority were communities with a
total score > 12. The assessment results showed that QXRK with the
participation of Keteleeria evelyniana (sub-zones 125, 128), QXRK with
participation of Pinus Krempfii and Fokienia hodginsii (sub-zones 88, 89, 102A,
127A, 127B) - the communities were suggested firstly conservation priority.


3.5.3. Some conservation solutions

a. Solutions in engineering, science and technology
Some silvicultural measures
- Technical measures of the first group: (To apply to QXRK had similar
characteristics to Pm, Tnl and Tld + Pm communities): Strict protection; Selection
mother trees sow good seed crops; slashing and thinning vegetation, shrubs; plow
soil, thinning canopy surrounding area of mother trees; Regeneration and taking
care seedlings, saplings, small regeneration trees and advanced reganeration trees
by these techniques, such as: earthing up around the base, slashing and thinning
shrubs, replacing decay litter layer by natural forest soil within ½ diameter of the
regeneration tree’s canopy to increase exposure of the regeneration roots with soil,
and ex-planting regeneration individuals distributed in unfavorable conditions:
roadside, rocks, in trees, on the roots of large trees, on the litter layer too thick
etc.
- Technical measures of the secand group: (To apply to QXRK had similar
characteristics to Ds, Tld and Tld + Tnl communities,): natural regeneration
promotion by these techniques: slashing or thinning vegetation, shurbs and less
cleaning dry litter layer; plow soil around the base, decreasing thickness of decay
litter layer or replacing them by natural forest soil within 1/2 diameter of the
regeneration tree’s canopy; disease prevention; Adjusting the distribution of
regeneration trees, and ex-planting regeneration individuals distributed in
unfavorable conditions: roadside, rocks, in trees, on the roots of large trees, on
the litter layer too thick etc.
- Technical measures of the thỉd group: (To apply to other QXRK):
Monitoring dynamics, succession of the communities.
QXRK conservation model by natural generation promotion
measures (In case with Ds communities): Administration recovery processes of
species and the communities (where the species distributed) by zoning and
promotion natural regeneration according Legislation-Sector 21-98.
Some science and technology solutions
- Continue to develop the full data on biodiversity, biological and

ecological characteristics of several species of rare, valuable economic and
science in the mixed broad-needle leaf forest plant communities for conservation
and development strategy in Bidoup - Nui Ba national park;
- Application of information technology, GIS and remote sensing in the
management of data and monitoring changes in species, successional species
populations, communities and mixed broad-needle leaf forest types in Bidoup Nui Ba. On that basis, the programs of investigation and supervision of plant
diversity in long-term, regular and systems need be setuped. Applications


modern devices for surveillance and monitoring of biological characteristics and
growth stages of conifers at some typical QXRK (in the sub-zones: 89, 90, 91,
125, 127, 128 etc);
- Collecting, storing seeds, vegetative propagation studies, sexual species
of rare, endemic plants species and the species have poor natural regeneration
ability such as: Fokienia hodginsii, P.dalatensis etc.
b. Policy, management solutions
- Strengthening proficiency of management and protection forest resources for
the task force;
- Further promote the role and responsibilities of local communities in
forest protection. Encourage and support the implementation of agro - forestry,
sustainable development of the buffer zone and the area of arable land exists in
the core area;
- Raise awareness of the meaning and role of forests, endangered species
of coniferous trees for the community, should strengthen propaganda and
education to raise awareness of the community in many different forms such as:
(1) Bringing awareness education programs for forest protection, identification
of rare tree species, need be protected in teaching at local schools; (2)
Coordinate with organizations and associations in order to integrate the content
of propaganda and educational awareness of environmental and forest protection
in meetings or regular meetings etc.

CONCLUSION, CONSIST, RECOMMENDATION
1. Conclusions
1. Forests in Bidoup - Nui Ba national park include the following forest
types: Forest type of closed evergreen broadleaf rain moisture tropical,
subtropical low mountain; Forest type of closed evergreen broadleaf rain
moisture subtropical medium mountain; Forest type of mixed evergreen broadneedle leaf moisture tropical, subtropical low mountain; Forest type of mixed
evergreen broad-needle leaf moisture subtropical medium mountain; Woodlands
of evergreen rather dry coniferous tropical, subtropical low mountain forest
type; Woodlands of evergreen rather dry coniferous subtropical medium
mountain forest type; mixed Bamboo - broadleaf trees or pure bamboo forest
type; Plantation forests.
2. QXRK types had a total area of 2,277.95 hectares, the communities
distributed in clusters, sometimes appeared scatterly at ridges top or slopes
location, slopes positive direction, focusing in elevation from 1,500 to 1,700 m,
on humus yellow red soil; red yellow soil.
3. Structural characteristics of typical QXRK: