Tóm tắt Luận án Studying vascular plant diversity and proposing conservation solutions in Pu Hoat nature reserve, Nghe An province

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 7 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 Division Family Genus Species Number of falimilies % Number of genera % Number 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. 8 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 Class Family Genus Species Number of falimilies % Number of genera % Number of 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. 9 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 10 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). 11 Table 3.13. The value of use of plant species in Pu Hoat Nature Reserve TT The value of use Symbol Number of species Percentage (%) 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 12 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 Life form Symbol Number of species Percentag 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%). 13 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 Phanerophytes Symbol Number of species Percentage (%) 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 14 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 15 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 bol Element Number of species % Number 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 70 2.89 2.2 Asia, Africa, AmericaTropical 5 0.21 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 16 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 0.00 115 4.74 5.2 The ancient world Temperate 1 0.04 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 17 - 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 <30%. It is also consistent with the research results of Thai Van Trung (1978), Le Tran Chan et al. (1999) suggested that Vietnam's flora has over 30% of endemic and near endemic species. In particular, there are 3 new species discovered for science and recently recorded for distribution in Pu Hoat Nature Reserve such as: Camellia ngheanensis Do N.D., Lương 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 Theaceae family and Loxotigma puhoatensis Ly N.S., Le T.H., Nguyen D.H. & Do N.D. of family Gesneriaceae. 3.1.5. Diversity of rare genetic resouce and preservation Based on the Red Data Book of Vietnam (2007), IUCN (2017), in Decree 06/2019 by Government (2019). This study has identified 129 species in Pu Hoat Nature Reserve, Nghean province which are under extinct risk. Among 129 species which were identified as under extinct risk at different levels, 112 species are listed in Red Data Book of Vietnam (2007) with 5 species at CR level, 37 species at EN level and 69 species at VU level. 1 species at LR level. Such as some species: Cunninghamia konishii, Fokienia hodginsii, Amentotaxus yunnanensis, Asarum glabrum, Goniothalamus tamdaoensi,... 18 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 (2007) 5 37 69 1 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 19 The area surveyed and developed the vegetation map of Pu Hoat Nature Reserve was implemented at: Tri Le, Cam Muon, Nam Giai, Hanh Dich, Tien Phong, Thong Thu and Dong Van. Total routes: 33 routes, total length of survey routes is about: 537 km; The total investigated acreage is about: 1075 ha; Total number of standard box: 30 standard box. Routes and Standard box in the study areas are as follows: Tri Le, Number of routes: 8 routes (Cắm Muộn, Du sam núi đất, Sa mộc dầu, Đỉnh Pù Hoạt), total length of survey routes is about: 130 km; The total investigated acreage is about: 261 ha; Total number of standard box: 9 standard box. Nậm Giải - Hạnh Dịch – Tiền Phong, Number of routes: 15 routes, total length of survey routes is about: 245 km; The total investigated acreage is about: 489 ha; Total number of standard box: 11 standard box. Thông Thụ, Number of routes: 07 routes, total length of survey routes is about: 114 km; The total investigated acreage is about: 228 ha; Total number of standard box: 06 standard box. Đồng Văn, Number of routes: 03 routes, total length of survey routes is about: 49 km; The total investigated acreage is about: 98 ha; Total number of standard box: 04 standard box. 3.2.1. Vegetation types in Pu Hoat Nature Reserve Identified Pu Hoat Nature Reserve as having 6 Vegetation types , including: - Tropical moist closed evergreen forests, rain forest (<700 m), - Tropical moist closed-leaved forests (<700 m); - Grassland, shrubs, trees scattered (<700 m); - Evergreen broad leaved forests, subtropical low rain forests (700- 1.800m); - The subtropical moist mixed broad- leaved and conifer low mountain forest (700-1.800m); - Pants cold upland vegetation (mountain pinnacle >1.800m). Area and distribution value of vegetation types are summarized in Table 3.21. Table 3.21. Area of vegetation types in Pu Hoat Nature Reserve N o Vegetables types Ha 1 Tropical moist closed evergreen forests, rain forest (<700 m) 25,562,97 2 Grassland, shrubs, trees scattered (<700 m) 2,640,05 3 Tropical moist closed-leaved forests (<700 m) 56,89 4 Evergreen broad leaved forests, subtropical low rain forests (700-1.800 m) 41,761,19 5 The subtropical moist mixed broad- leaved and conifer low mountain forest (700-1.800 m) 13,336,09 20 6 Pants cold upland vegetation (mountain pinnacle >1.800m). 1,105.60 7 Water surface area 96,11 8 Other area 6,182.1 Total 90,741.00 There are 3 types of carpet occupying the main area of Pu Hoat Nature Reserve: Evergreen broad leaved forests, subtropical low rain forests (700- 1,800 m), tropical moist closed evergreen forests, rain forest (<700 m), The subtropical moist mixed broad- leaved and conifer low mountain forest (700- 1,800 m) 3.2.3. Characteristics of carpet types in Pu Hoat Nature Reserve 3.2.3.1.Tropical moist closed evergreen forests, rain forest (<700 m) The forest consists of 3 layer of wood trees, 1 layer of low shrubs, 1 layer of deciduous grass and extra-terrestrial plants; This type of vegetation is quite common in the natural forest types in Hanh Dich, Thong Thu, Tien Phong, Nam Giai and Tri Le of Pu Hoat Nature Reserve at elevations below 700 m. 3.2.3.2. Tropical moist closed-leaved forests (<700 m) This type of secondary forest, pure plantations forest or scrubs narrow distribution and scattered in areas of Pu Hoat including Tri Le, Hanh Dich, Chau Thon and Dong Van areas. Forest structure consists of 2-5 layer. 3.2.3.3. Grassland, shrubs, trees scattered (<700 m) This type of vegetation is very narrow in Pu Hoat, mainly in areas where people cultivate land and fallow land. Forests usually consist of 2-3 layer, small trees, shrubs and grasses with regenerated and light demanding species. Small trees: Grewia glabra Blume, Sterculia hymenocalyx K. Schum,