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: Assoc Prof Dr Nguyen Đang Hoi 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 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 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 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 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 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 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 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 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 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 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 STRUCTURE OF THE THESIS The thesis has 142 pages , includes: Introduction (4 pages); Chapter Overview (35 pages); Chapter Contents and Methods (27 pages); Chapter 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 Website) Chapter 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 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 types: rainforest, subtropical, temperate and alpine Beard (1938) studied on tropical forests and showed that: tropical forests jungle consists of 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 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 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 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 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 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 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 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 different plant dominions, complex for the state IV and IIIB - Research to quantify forest structure using mathematical functions: Bao Huy (1988, 1993) tested 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 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 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 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 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 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 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 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 Chapter 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 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 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 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 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 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