Abstract of a thesis doctor of Philosophy in biology: Studying vascular plant diversity and proposing conservation solutions in Pu Hoat Nature Reserve, Nghe An province

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Study and evaluate the diversity of vascular flora (species composition, vegetation) in Pu Hoat Nature Reserve in order to propose solutions for conservation and sustainable development.

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Nội dung Text: Abstract of a thesis doctor of Philosophy in biology: Studying vascular plant diversity and proposing conservation solutions in Pu Hoat Nature Reserve, Nghe An province

MINISTRY OF EDUCATION VIỆT NAM ACADEMY OF AND TRAINING SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY ----------------------------- NGUYEN DANH HUNG STUDYING VASCULAR PLANT DIVERSITY AND PROPOSING CONSERVATION SOLUTIONS IN PU HOAT NATURE RESERVE, NGHE AN PROVINCE Major: Botany Code: 9.42.01.11 ABSTRACT OF A THESIS DOCTOR OF PHILOSOPHY IN BIOLOGY HA NOI, 2020
This Thesis was fulfilled at Graduate University of Science and Technology - Vietnam Academy of Science and Technology Supervisors: 1. Dr. Do Ngoc Dai 2. Assoc. Prof. Dr. Tran Minh Hoi Reviewer 1: Reviewer 2: Reviewer 3 The Thesis will be defended at Graduate Universityof Science and Technology – Viet Nam Academy Science and Technology The Thesis can be found at: The National Library of Vietnam Library of Graduate University of Science and Technology
INTRODUCTION 1. Rationales of study Biodiversity has an extremely important role for humans. People have used this resource for many different purposes: food, medicine and spiritual activities such as customs, art-poetry, painting….are also derived from the relationship between humans and the surrounding creatures. Vietnam is located in the tropical monsoon climate zone. There for having high biodiversity. Vietnam had been known about more than 13,000 species of vascular plants; This number is still increasing every year, having many new species are discovered and added. Pu Hoat Nature Reserve consists of large mountains with an altitude of 2,457 m. This area is in the "Biosphere Reserve of Western Nghe An" recognized by UNESCO on 20/09/2007. It has a total area of 90,741 ha, belonging 9 communes of Que Phong district, include: Thong Thu, Dong Van, Tien Phong, Hanh Dich, Nam Giai, Tri Le, Nam Nhoong, Cam Muon and Chau Thon, in the North West of Nghe An province, with the geographical coordinates 19027’46”-19059’55” North latitude, 104037’-104014’ longitude. Despite having abundant flora but there is very little research on them. Some previous studies of Do Ngoc Dai et al. (2012), Nghe An Forestry Planning Survey Team (2013), Department of Science and Technology of Nghe An (2017). However, these studies are not systematic and fully updated on vascular flora. So, I chose the topic: "Studying vascular plant diversity and proposing conservation solutions in Pu Hoat Nature Reserve, Nghe An province". 2. Objective of study Study and evaluate the diversity of vascular flora (species composition, vegetation) in Pu Hoat Nature Reserve in order to propose solutions for conservation and sustainable development. CHAPTER 1 GENERAL OVERVIEW 1.1. Perspective on biodiversity Biodiversity and conservation issues have become a worldwide strategy. Many international organizations have established to guide, assist and organize the assessment, conservation and development of biodiversity throughout the 1
world. They are the International Union for Conservation of Nature and Natural Resources (IUCN), the United Nations Environment Program (UNEP), the World Wide Fund For Nature (WWF), the International Plant Genetic Resources Institute (IPGRI) ... Biodiversity conservation is at the heart of conservation biology, but the term "biodiversity" has many definitions. The definition proposed by the World Wide Fund For Nature WWF (1989) is as follows: Biodiversity is the prosperity of life on earth, is the millions of plants, animals and microorganisms, is the genes contained in species and extremely complex ecosystems coexist in the environment. ” So biodiversity must be calculated on three levels: Species diversity, ecosystem diversity and genetic diversity. 1.2. Research on plants in the world 1.2.1. Research on flora In European and American countries, the study of flora throughout the territory has been completed long ago. Most of the specimens were collected and stored in Herbarium such as: Kew (England), Paris Museum of Natural History (France), New York (USA), St. Petersburg (Russia) ... So when building nature reserves and national parks is very convenient and simple for them. Some typical works of some Asian countries such as Flora of India, Flora of Malaysia (1948-1972), Flora of Thailand (1970-2012), Flora of Hainam (1971-1980) ), Flora of Yunnan (1997-1997), Flora of China (1994-2013), (1968-2000), Flora of Hong Kong (2007-2009), Flora of Taiwan (1993-2000) ), ... 1.2.2. Research vegetation Research on vegetation, there are a huge amount of different perspectives, each of which offers specific ways of classifying such purposes as forest classification based on structure and appearance. This is a classic direction applied by many researchers such as A. F. Schimper (1903), Champion (1936), A. Aubréville (1949), Schimithusen (1959), UNESCO (1973), ... 1.3. Research on plants in Vietnam 1.3.1. Research the flora Research on flora in Vietnam is mainly by the authors of J. Loureiro (1793), J.B.L. Pierre (1880), H. Lecomte et al (1907-1952), A. Aubréville (1960-1996), Le Kha Ke et al (1971-1989), Pham Hoang Ho (1991-1993; 1999- 2000), Collective of Vietnamese plant researchers (2001, 2003, 2005). In addition, there are a number of separate family published documents such as 2
Orchidaceae Vietnam (L. Averyanov, 1994), Euphorbiaceae (Nguyen Nghia Thin, 1999), Annonaceae (Nguyen Tien Ban, 2000), Lamiaceae (Vu Xuan Phuong, 2000), Myrsinaceae (Tran Thi Kim Lien, 2002), Cyperaceae (Nguyen Khac Khoi, 2002), ... Some studies on species composition diversity: T. Pócs (1965), Phan Ke Loc (1969, 1980), Thai Van Trung (1978), Nguyen Nghia Thin (1997), Le Tran Chan et al. (1999), Nguyen Tien Ban et al. (2005),…. 1.3.2. Research vegetation Some studies on the vegetation of foreigners such as Chevalier (1918), Maurand (1943), Duong Ham Nghi (1956), Rollet, Ly Van Hoi and Neay Sam Oil (1958), Loschau (1960), Schmid M. (1974), .... In the country, there are a number of research works by the authors: Vu Tu Lap (1976), Thai Van Trung (1978, 2000), Vu Dinh Hue (1984), Phan Ke Loc (1985). In addition, there are a number of other studies such as Phung Ngoc Lan (1996), Nguyen Nghia Thin (2004), .... 1.4. Research plant geographic factors Studies on the lifeform spectra of the flora in Vietnam in general and the flora systems of localities in particular have been applied according to the plant life classification system of C. Raunkiær (1934). Some studies such as: T. Pócs (1965) studied the life form spectrum of the flora of North Vietnam, Thai Van Trung (1978) also applied other symbols for shoots and leaves according to the season and sign conditions. of canopy shape, vines material, Le Tran Chan (1999) ... 1.5. Studying life forms spectrum Gagnepain was the first person to study, analyze and evaluate the plant geographic factors of the Vietnamese flora (1926, 1944), T. Pócs (1965) analyzed and sorted the plants in the North. Vietnam constitutes a group of factors on the basis of the current distribution area without analyzing their origin. Thai Van Trung (1978), Nguyen Nghia Thin (1999), .... 1.6. Studying plants in Pu Hoat Nature Reserve Researching plants in Pu Hoat Nature Reserve before and later establishing a management board had a number of works such as: Hoang Danh Trung et al (2010) “Study on plant diversity in the buffer zone of Pu Hoat Nature Reserve , Nghe An"; Do Ngoc Dai and Le Thi Huong (2012) initially assessed the diversity of flora in Pu Hoat Nature Reserve, Nghe An announced 925 species; In 2013, the Forest Inventory and Planning Institute assessed biodiversity to establish Pu Hoat Nature Reserve to announce 776 species. In 3
2017, the Department of Science and Technology has implemented the topic "Surveying and assessing biodiversity in Pu Hoat Nature Reserve and proposing conservation solutions" has recorded 1159 species, 469 genera and 122 families in 5 vascular plant branches. In 2018, Xin Hong et al announced the Be species (Didymocarpus puhoatensis) in Pu Hoat Nature Reserve. 1.7. Natural and socio-economic conditions in Pu Hoat Nature Reserve 1.7.1. Natural conditions of Pu Hoat Nature Reserve Pu Hoat Nature Reserve has a total natural area of 90,741 hectares, of which 39,221 hectares of special use forest and 51.52 hectares of protection forest. Located in 9 communes of Que Phong district: Tri Le, Tien Phong, Thong Thu, Hanh Dich, Nam Giai, Dong Van, Nam Nhoong, Plug Muon and Chau Thon. 1.7.2. Social and economic conditions - Thai ethnic group has 8,148 people, accounting for 83.7%; The H’Mong ethnic group has 3,310 people, accounting for 7.3%; Kho Mu ethnic group has 412, accounting for 4.5%; The Kinh ethnic group has 1,832 people, accounting for 4.1%; CHAPTER 2 MATERIALS, CONTENTS AND METHODOLOGY OF STUDY 2.1. Materials and scope of study All vascular plant species and vegetation statuses in Pu Hoat Nature Reserve, Nghe An province. 2.2. Duration of study This study was conducted from March of 2017 to August 2019. Sampling was conducted in 6 times with 7 days per time. 2.3. Content of study + Making a species list in Pu Hoat Nature Reserve. + Assessing the diversity of taxa plant, life forms, geographic factors, use values, rare plant species and conservation issues. + Classifying and describe the structure of vegetation types in Pu Hoat Nature Reserve. + Proposing solutions to conservation of plant diversity in Pu Hoat Nature Reserve. 2.4. Study methodology 2.4.1. Inheriting data method 4
This section has described the geographical, topographical, climatic, social and floristic characteristics of study site, sample in Museum national and international and previously published works. 2.4.2. Field survey methods Field survey methods were adapted from “Plants research methods” by Nguyen Nghia Thin (2008), Thai Van Trung (1999) and Klein R.M., Klein D.T. (1975). - Investigate the route: Based on a selection map of research routes. The survey routes with different length are determined to go through all forest states.The survey tour routes is marked on the map and marked in the field with easily identifiable paint or nylon. Identify key survey routes to identify all vascular plant species according to the proposed content. Investigation in plots: Area of each standard plot is 2000m² with dimensions of 40x50m. In each standard plot, 5 small standard plot are made in 4 corners and 1 middle plot, the area of the small standard plot is 25m² with the size 5x5m. Then Detail descriped in each standard plot - Sample collection At least two or three specimens per individual per species were collected from the same study site. Size must reach 29 x 41cm and can prune branches and leaves. All traits such as color, resin, characteristics of flower, fruit and leaf, which may change due to subsequent procedures of sample processing (e.g. drying), were documented in details. The plants were also pictured by a digital camera (Canon). 2.4.3. Processing and presentation of samples These samples were dried and stored in botany lab of Faculty of Agriculture, Forestry and Fishery, Nghe An College of Economics 2.4.4. Species identification methods The scientific species is determined by the comparative morphological method, This is a traditional method used in plant classification research ever. The species identification based on following documents: - An Illustrated Flora of Vietnam (Pham Hoang Ho, 1991 - 1993, 1999 - 2000); - Handbook to reference and identification of the families of angiospermae plants in Vietnam (Nguyen Tien Ban, 1997); - Vietnam forest trees (1971-1989); - Flora of Iindochina (1907); - Flora of China (1994-2002); - Flora of Viet Nam (volume 1-21) Check scientific name: The scientific names of the species have been identified, check scientific names to ensure the systematic, avoid confusion and errors, based on the Vietnam Plant List, I-III. and Website: http: // www. 5
theplantlist.org (The Plant List); consult the scientific name on http: // www. ipni.org (The International Plant Names Index). 2.4.5. Making a Checklist of species The list of species name is sorted by family, genus and species by Brummitt (1992). The list also contains information on conservation status in Red Data Book of Vietnam and other information including: life form, geographical element and use value, sample. 2.4.6. Flora diversity assessment methods 2.4.6.1. Assess the diversity of Division , class, families and genus Taxon diversity of flora: usingthe methods of Nguyen Nghia Thin (2008) 2.4.6.2. Assess the life form method Determining and analyzing the life forms of the species according to the Raunkiær life-scale division (1934). 2.4.6.3. Assess the geographical element method The establishment of the geographical element, applying the division of Nguyen Nghia Thin (2007). 2.4.6.4.Methods of assessing the use value and threat levels Statistical calculating of useful species from botanical monograph documents such as: Vietnam dictionary of medicinal plants (2012),“1900 used plant species in Vietnam” (1993),“ Checklist of Vietnam of plant species”(2003, 2005),... 2.4.7. Method of mapping vegetation and system of units Vegetation Step 1. Preparation: Step 2. Processing remote sensing images: Step 3. Establishment of vegetation map: 2.4.8. Method of the proposed construction solutions to manage and conserve plant diversity in Pu Hoat Nature Reserve CHAPTER 3 RESULTS AND DISCUSSION 3.1. Species composition diversity in Pu Hoat Nature Reserve 3.1.1. Taxa diversity 3.1.1.1. Diversity of division Identified 2,367 plant species and 3 varieties belong to 885 genera, 208 families of 6 divisions of vascular plant species (table 3.1). Which has discovered and described 3 new species for science expected to name:Camellia ngheanensis Do N.D., Luong V.D., Ly N.S., Le T.H. & Nguyen D.H, Camellia puhoatensis Luong V.D., Ly N.S., Le T.H., Nguyen D.H. & Do N.D belong to 6
Theaceae family and Loxotigma puhoatensis Ly N.S., Le T.H., Nguyen D.H. & Do N.D. - Gesneriaceae familly. This research, Recording 4 new species to the flora of Vietnam: Zingiber nudicarpum D. Feng, Zingiber neotruncatum T.L. Wu, K. Larsen & Turland, Amomum glabrum S. Q. Tong, Spatholobus pulcher Dunn. Besides, there are 8 recently newly published species for science and new record for the flora of Vietnam in Pu Hoat Nature Reserve: Neolitsea vuquangensis Mitsuyuki & Yahara belong to Lauraceae family, Goniothalamus banii B.H. Quang, R.K. Choudhary & V.T. Chinh of Annonaceae family, Zingiber castaneum Škorničk. & Q.B. Nguyễn, Zingiber nitens M.F. Newman, Alpinia polyantha D. Fang, Amomum velutina X.E.Ye, Škorničk. & N.H. Xia, Zingiber vuquangense Ly N.S., Le T.H., Do N.D., Trinh T.H, Nguyen V.H, Amomum cinnamomeum Škorničk., Luu & H.Đ. Trần belong to Zingiberaceae . Table 3.1. Taxa distribution in Pu Hoat Nature Reserve Family Genus Species Division Number of Number Number % % %) falimilies of genera of species Psilotophyta 1 0.48 1 0.11 1 0.04 Lycopodiophyta 2 0.96 4 0.45 30 1.24 Equisetophyta 1 0.48 1 0.11 1 0.04 Polypodiophyta 27 12.98 83 9.38 233 9.61 Pinophyta 8 3.85 11 1.24 16 0.66 Magnoliophyta 169 81.25 785 88.70 2.144 88.49 Total 208 100 885 100 2.425 100 From table 3.1 and Figure 3.1., we found that most taxa belonged to Magnoliophyta with 2,144 species (88.49%), 785 genera (88.70%) and 169 families (81.25%), following is Polypodiophyta with 233 species (9.61%), 83 genera (9.38%) and 27 families (12.98%). Pinophyta has 16 species (0.66%), 11 genera (1.24%) and 8 families (3.85%). Lycopodiophyta with 30 species (1.24%), 4 genera (0.45%) and 2 families (0.96%). Equisetophyta and Psilotophyta have 1 species (0.04%), 1 genus (0.11%) and 1 family (0.48%). So, Magnoliophyta were mainly found taxa in Pu Hoat which is in agreement with plant evolution, because Magnoliophyta is the most dominant division of vascular plants. 7
Figure 3.1. Taxa distribution in Pu Hoat Nature Reserve The ratio between two classes in Magnoliophyta: The unequal distribution of taxon level was found not only in division but also between two classes in Magnoliophyta. The result was shown in Table 3.2. Table 3.2. Distribution in two classes of Magnoliophyta Family Genus Species Class Number of Number Number of % % % falimilies of genera species Magnoliopsida 132 78.11 608 77.32 1.682 78.45 Liliopsida 37 21.89 177 22.68 462 21.55 Total 169 100 785 100 2.144 100 Ratio Mag./Li. 3.57 3.41 3.64 The Magnoliopsida was more abundant with > 70% of families, genera and species of division; the Liliopsida only accounted for 37 families (21.89%) of which including 177 genera (22.68%) and 462 species (21.55%). This is reasonable because Magnoliopsida is alway dominated compared to Liliopsida and in agreement with previous studies of Phung Ngoc Lan et al. (1996), Nguyen Nghia Thin et al. (2004) which investigated different flora in Vietnam. 8
Figule 3.2. Percentage of Magnoliopsida class compared to Liliopsida class in Magnoliophyta The ratio of comparable taxa between Magnoliopsida and Liliopsida was always greater than 3. Thus, the flora characteristics of flora in Ph Hoat Nature Resever in particular, and in Vietnam in general, represent for tropical-monsoon flora types. This result is in greement with the prediction of Nguyen Nghia Thin (2008) which stated that the ratio between Magnoliopsida and Liliopsida in tropical areas is always greater than 3. 3.1.1.2. Diversity of family Among 208 families which have been identified in Pu Hoat, most of them belongs to Magnoliophyta which includes 169 families (account for 81.25 % of families), Polypodiophyta having 27 families (12.98%), Pinophyta consists of 8 families (3.85%). Lycopodiophyta including 2 families, Psilotophyta and Equisetophyta having only 1 species. Among 208 families, 49 families have only 1 species, 34 families have 2 species. Per family, 15 families have 3 species per family, 6 families have 4 species per family, 37 families have 5-9 species per family and 67 families have more 10 species per family. When assessing the diversity of a flora, people often analyze the 10 most diverse families of that flora. Because the percentage (%) of the 10 most diverse families compared to the total species of the whole system is considered the face of each flora and a reliable comparison indicator. In Pu Hoat Nature Reserve10 families most diverse have 787 species (32.19%). The most diverse families of the flora Pu Hoat Nature Reserve (more 9
than 100 species): Euphorbiaceae having 119 species (4.91%); following Lauraceae including 113 species (4.66%); Rubiaceae consist 102 species (4.21%). 7 famiies having from 50 to 78 species (2.06% - 3.22%). Thus, the total number of species of the 10 most diverse families in Pu Hoat Nature Reserve accounts for 32.45% in accordance with A.I. Tonmachop (1974) considers that the 10 most diverse families of tropical flora usually account for no more than 40-50% of the total species of flora and very few families account for more than 10% of the species of the whole system. This result is also consistent with some published results of flora study authors in different regions such as Xuan Lien Nature Reserve (27.18%), Ben En Nature Reserve (40.3%). , Pu Mat National Park (32.81%), Pu Luong Nature Reserve (27.83%). 3.1.1.3. Diversity of genus Among of 885 genera had known, the 10 genera (although account for only 1.13% of the total number of genera) but have 229 species, accounting for 9.44% of the total species of Pu Hoat Nature Reserve. Genus Ficus is the most abundant with 43 species (1.77%). This genus is considered a typical genus for tropical rain forests, they are widely distributed from low to medium belts. Following genus Litsea having 31 species (1,28%), Cinnamomum with 24 species (0.99%). Asplenium including 21 species (0.87%). 6 genera have 17-20 species (0.70-0.82%). The genera which are most abundant in species are Syzygium, Litsea, Piper and Cinnamomum. The rest genera have 6-12 species per genus. Notably, the genera Litsea, Cinnamomum, Syzygium are typical, taking part in the structure of the main vegetation of Pu Hoat Nature Reserve. 2 genera Asplenium and Selaginella have characteristic properties of the grass. This shows that the nature of the flora in Pu Hoat Nature Reserve is tropical monsoon. 3.1.2. Diversity of use value Based on available information from botanical monograph documents such as: Vietnam dictionary of medicinal plants (2012),“ 1900 used plant species in Vietnam” (1993),“ Checklist of Vietnam of plant species” (2003, 2005),... combined with the results of interviewing the community during the field survey, it is possible to arrange the plant species in Pu Hoat Nature Reserve into 13 different use value groups (table 3.13). 10
Table 3.13. The value of use of plant species in Pu Hoat Nature Reserve TT The value of use Symbol Number of Percentage species (%) 1 Medicinal THU 1103 45.48 2 Woody LGO 348 14.35 3 Edible ANĐ 263 10.85 4 Ornamental CAN 205 8.45 5 Essential oil CTD 197 8.12 6 Fodder AGS 38 1.57 7 Tannin TAN 30 1.24 8 Fat oil CDB 29 1.20 9 Yarn SOI 39 1.61 10 Spice GVI 21 0.87 11 Dyeing NHU 13 0.54 12 Toxic DOC 12 0.49 13 Sap CNH 7 0.29 * A species may have one or more different uses Figure 3.6. The value of use of plant species in Pu Hoat Nature Reserve The result of statistics is 1,513 species with use value, accounting for 62.39% of the total species. Among them, the group of plants most used is 11
medicinal plants with 1,103 species, accounting for 45.48% of the total number of species; followed by trees for wood with 348 species, accounting for 14.35%; edible plants with 263 species, accounting for 10.85%; ornamental plants with 205 species, accounting for 8.45%; essential oil plants with 197 species, accounting for 8.12%; The remaining user groups have from 5 to 38 species, accounting for 0.21% to 1.57% as shown in Figure 3.6. 3.1.3. Diverse life form A plant community is characterized structurally by the life forms of the species that make up that flora. Each species has certain morphological characteristics distinguished from other species, which is the result of evolution, long-term process of adaptation to external conditions. Therefore, for a flora, it is very important to establish a lifeform spectrometer, which helps to determine the morphological structure of the system and thereby offer optimal measures for conservation and exploitation. Applying the life-form classification system of Raunkiaer (1934) when analyzing the lifeform spectrum the flora of Pu Hoat, 2.425 species were identified, the results are shown in Table 3.15. Table 3.15. Life forms of plants species in Pu Hoat Nature Reserve Number Percentag Life form Symbol of species e (%) Phanerophytes Ph 1.781 73.44 Chamaephytes Ch 359 14.80 Hemicryptophytes Hm 51 2.10 Cryptophytes Cr 85 3.51 Therophytes Th 149 6.14 Total 2,.425 100 The results in Table 3.15 show that the Phanerophytes (Ph) dominated with 1,781 species, accounting for 73.44% of the total number of species. Mainly their families: Annonaceae, Magnoliaceae, Lauraceae, Fagaceae, Theaceae, Rutaceae, Euphorbiaceae, Sapindaceae, Myrtaceae, Meliaceae),…; followed Chamaephytes (Ch) with 359 species accounting for 14.80%. Families belong to Chamaephytes: Poaceae, Lamiaceae, Euphorbiaceae,… Therophytes (Th) having 149 species (6.14%). Cryptophytes (Cr) with 85 species (3,51%). Hemicryptophytes is the lowest with 51 species (2.10%). 12
From the results of the study, the life form of the Pu Hoat Nature Reserve was established: SB = 73.44% Ph + 14.80% Ch + 2.10% Hm + 3.51% Cr + 6.14% Th. Figure 3.7. The life form of the flora of Pu Hoat Nature Reserve Analysis of the number of species belonging to the above Phanerophytes (Ph), among the life forms is shown in table 3.17. Table 3.17. Survival rate of Phanerophytes (Ph) in flora of Pu Hoat Nature Reserve Number Percentage Phanerophytes Symbol of species (%) Magaphanerophytes > 30 m Mg 82 4.60 Mesphanerophytes: 8-30 m Me 403 22.63 Microphanerophytes 2-8 m Mi 459 25.77 Nanophanerophytes Na 260 14.60 Epiphytes Ep 34 1.91 Phanerophytes Hp 146 8.20 Lianes phanerophytes Lp 383 21.50 Parasite and Hemiparasite Pp 5 0.28 Hydrophytes Hy 8 0.33 Succulentes Suc 1 0.06 Total 1,773 100 13
From the results obtained in the above table, a life form spectrum has been established as follows: Ph = 4.60%Mg + 22.63%Me + 25.77%Mi + 14.60%Na + 21.50%Lp + 1.91%Ep + 8.20%Hp + 0.28%Pp + 0.06%Suc + 0.45%Hy. In the group of Phanerophytes, Microphanerophytes (Mi) accounted for the highest proportion with 25.77%, mainly species belonging to families: Rubiaceae, Euphorbiaceae, Lauraceae, Verbenaceae, Ebenaceae, Moraceae, Rutaceae. Following Mesophanerophytes (Me) accounting for 22.63%. Families belonging to this group: Magnoliaceae, Lauraceae, Fagaceae, Fabaceae, Rubiaceae, Myrtaceae, Sapindaceae, Theaceae, Caesalpiniaceae,… Families belonging to Lianophanerophytes (Lp) (21.50%): Annonaceae, Connaraceae, Vitaceae, Asclepiadaceae, Menispermaceae,… Nanophanerophytes (Na) (14.60%). Belonging to have families: Euphorbiaceae, Moraceae, Verbenaceae, Rutaceae, Rubiaceae,… Phanerophytes (Hp) mainly belongs to families in the Division: Polypodiophyta, Lycopodiophyta and families: Poaceae, Lamiaceae,… Magaphanerophytes accounts 4.60%. Belongs to this group are large tree species of families: Podocarpaceae, Myrtaceae, Dipterocarpaceae, Fabaceae, Magnoliaceae, Fagaceae, Meliaceae, Sapindaceae,… Epiphytes Group account 1.91%, belong to Araceae, Orchidaceae, Asclepiadaceae,… Group Hydrophytes (Hy), Parasite and Hemiparasite (Pp) and Succulentes (Suc) accounting low percentage corresponding: 0.45%; 0.28% and 0.06% . Figure 3.8. Life form of Phanerophytes in Pu Hoat Nature Reserve 14
From the above data, it shows that in humid tropical area, Phanerophytes is often dominant and characteristic of flora. This was also confirmed through the works of Raunkiaer (1934), Richard (1969), Nguyen Nghia Thin (2004, 2006), Le Tran Chan et al. (1999), Le Thi Huong et al. (2015), Dau Ba Thin et al. (2016), Nguyen Thanh Nhan (2017),… 3.1.4. Diverse geographical element The geographical element of plants show us that a species is endemic or migratory and to know the extent of similarity or difference in the distribution of plant species. Therefore, it is necessary to study the geographic element of flora. When studying the geographical element of flora in Pu Hoat Nature Reserve, based on the classification framework of Nguyen Nghia Thin (2007) has been divided into 8 main element. Among of 2,425 vascular plant species in Pu Hoat Nature Reserve, geographic element of 2,409 species have been identified, and 16 species have not enough information to identify (this group is classified into 8 geographic element). Among the identified species, they can be classified into geographical element and summarized in Table 3.18 and Figure 3.9. Table 3.18. The Geographical element of plant species in Pu Hoat Nature Reserve Sym Number Number Element % % bol of species of species 1 All world 6 0.25 6 0.25 2 Inter Tropical 60 2.47 Inter Tropical 2.1 Asia, AmericaTropical 2 0.08 2.2 Asia, Africa, AmericaTropical 5 0.21 70 2.89 2.3 Tropical Asia, Australia, the US and the Pacific Islands 3 0.12 3 Old Tropical 17 0.70 Old Tropical 3.1 Asia-Australia Tropical 120 4.95 160 6.60 3.2 Asia-Africa Tropical 23 0.95 4 Asian Tropical 436 17.98 Asian Tropical 4.1 Southeast Asia-Malêsia Continent 241 9.94 1281 52.82 4.2 Southeast Asia Continent 218 8.99 15
4.3 Southeast Asia - Himalaya Continent 122 5.03 4.4 Indochina-South China 130 5.36 4.5 Indochina Endemic 134 5.53 5 Temperate zone 1 0.04 Temperate zone 5.1 Asia-North America Temperate 0 0.00 5.2 The ancient world Temperate 1 0.04 115 4.74 5.3 Temperate in the Mediterranean 6 0.25 5.4 East Asia 107 4.41 6 Endemic of Vietnam 396 16.33 Endemic of Vietnam 6.1 Close endemic Vietnam 313 12.91 709 29.24 7 Crop element 68 2.80 68 2.80 8 Unknown element 16 0.66 16 0.66 Tổng số 2425 100 2425 100 - Asian Tropical element with 1,281 species (52.82%) is a dominant element group compared to the remaining groups of the Pu Hoat Nature Reserve. - Old Tropical element having 160 species (6.60% ). This is the element that the species spread from Australia to Asia and Africa. Figure 3.9. The main geographical element of Pu Hoat 16
- Temperate zone element including 115 species (4.74%), They are distributed mainly in old temperate zone of the world with 1 species, Eurasian temperate zone with 6 species and Northeast Asia to Japan with 107 species. - Global element with 6 species, accounting for 0.25%. These species are widely distributed in the world. - Crop element with 68 species (2.80%). These species have been acclimatized and are now widely distributed in the wild. - Among tropical elements, the Asian tropical element is the largest with 436 species (17.98%), followed by Southeast Asia-Malezi with 241 species, accounting for 9.94%; Southeast Asia-India with 218 species (8.99%); Indochina Endemic factor with 134 species, accounting for 5.53%; Indochina- South China with 130 species, accounting for 5.36% and the lowest is Southeast Asia-Himalaya with 112 species, accounting for 5.03%. - Endemic and close Endemic element with 709 species, accounting for 29.24% of the total species; of which, the Endemic element with 396 species, accounting for 16.33% of the total number of species; close endemic element with 313 species, accounting for 12.91%. The percentage of endemic and semi-endemic elements in Pu Hoat
In addition, the trade of 25 species are banned in Vietnam marked according to regulation of in Decree 06/2019/NĐ-CP by Government (2019). These are medicinal plants, ornamental plants and wood plants which are exploited hardly. Thus, their reserves remain only little and their habitats are narrowing in which currently only some species are found in some places in the park. Such as: Paramichelia baillonii, Nervilia aragoana, Acorus macrospadiceus, Polygonatum kingianum, Dendrobium chrysanthum,... According to IUCN (2017), there are 15 species. 3 species at EN level: Cunninghamia konishii Hayata, Hopea pierrei Hance, Cinnamomum balansae Lecomte, , 6 species at VU level: Madhuca pasquieri (Dub.) Lam, Dalbergia cochinchinensis Pierre, Dipterocarpus retusus Blume, Fokienia hodginsii (Dunn) A. Henry & H. H. Thomas, Keteleeria evelyniana Mast, Amentotaxus yunnanensis H.L.Li and 6 species at LR level: Calocedrus macrolepis Kurz, Cycas dolichophylla K.D.Hill, T.Nguyen & P.K.Lôc, Gnetum montanum Markgr, Dacrycarpus imbricatus (Blume) de Laub., Nageia fleuryi (Hickel) de Laub., Aglaia edulis (Roxb.) Wall. (. The results are shown in Table 3.19. Table 3.19. Distribution of species according to the degree of threat in Pu Hoat Nature Reserve Threatearned levels CR EN VU LR IA IIA Red Data Book of Vietnam 5 37 69 1 (2007) Decree 06/2019 2 23 IUCN (2017) 3 6 6 Total 5 40 75 7 2 23 As such, the genetic resources of plant threatened with extinction in Pu Hoat Nature Reserve are diverse, belonging to many different groups. Based on the research results, a map of the distribution of endangered plant species in Pu Hoat Nature Reserve has been made. Therefore, this is a scientific basis for the authorities to have intensive and rational research policies to conserve and sustainably develop them in the future. 3.1.6. Some new findings for science and theVietnamese flora in Pu Hoat Nature Reserve The research results have discovered and described three new species for science: Camellia ngheanensis ND Do, VD Luong, NS Ly, TH Le & DH Nguyen, Camellia puhoatensis Luong VD, Ly NS, Le TH, Nguyen DH & Do ND and Loxotigma puhoatensis Ly NS, Le TH, Nguyen DH & Do ND. Adding 4 new species to the Vietnamese flora: Zingiber nudicarpum D. Feng, Zingiber neotruncatum TL Wu, K. Larsen & Turland, Amomum glabrum SQ Tong, Spatholobus pulcher Dunn. 3.2. Diversity of vegetation in Pu Hoat Nature Reserve 18