THAI NGUYEN UNIVERSITY UNIVERSITY OF EDUCATION HOANG VAN HAI STUDY SOME BASIC CHARACTERISTICS AND PROPOSE MEASURES TO CONSERVE AND DEVELOP SUSTAINABLY THE VEGETATION ON LIMESTONE MOUNTAIN AREA IN CAM PHA CITY, QUANG NINH PROVINCE Speciality: Ecology Code: 9420120 DISSERTATION SUMMARY THAI NGUYEN - 2019 The dissertation was finished at: THAI NGUYEN UNIVERSITY - UNIVERSITY OF EDUCATION Supervisors: Assoc Prof Ph.D Nguyen The Hung Assoc Prof Ph.D Le Ngoc Cong Reviewer 1:……………………………………………… Reviewer 2:……………………………………………… Reviewer 3:……………………………………………… The dissertation will be defended in the university committee: THAI NGUYEN UNIVERSITY - UNIVERSITY OF EDUCATION At ……………… , 2019 The dissertation can be read at: - National library of Vietnam; - Thai Nguyen University - Learning Resource Center; - Library of University of Education LIST OF PUBLICATIONS RELATED TO THE THESIS Hoang Van Hai, Nguyen The Hung, Le Ngoc Cong (2016), “Diversity of vegetation and flora in Bai Tu Long bay, Quang Ninh Province”, Journal of Science and Technology, Thai Nguyen University, vol (2016): 89-94 Hoang Van Hai, Nguyen The Hung, Le Ngoc Cong, Do Thi Ha (2017), “Features of vegetation structure on the limestone in Cam Pha, Quang Ninh”, Journal of Agriculture and Rural Development, vol 306+307 (2017): 210-216 Hoang Van Hai, Nguyen The Hung, Do Thi Ha (2017), “Characteristics on regeneration of the wood- species of limestone vegetation in Cam Pha City (Quang Ninh province)”, Journal of Science and Technology, Thai Nguyen University, vol 161(2017): 133-138 Hoang Van Hai, Bui Manh Hung (2017), “Forecasting the tree growth for forests on limestone mountains in Cam Pha, Quang Ninh Province”, Journal of Forestry Science and Technology, vol (2017): 54-63 PREAMBLE The urgency of the thesis Cam Pha city with Bai Tu Long Bay (buffer zone of Ha Long Bay) is one of Quang Ninh's tourism areas, currently limestone mountain vegetation is being degraded in both area and quality due to some causes such as exploiting plant resources used as firewood, limestone exploitation for the industry of construction material production, encroaching on sea, expanding residential land fund To contribute to improving the effectiveness of management, conservation and sustainable development of vegetation on limestone mountains in Cam Pha city, Quang Ninh province, the thesis "Study some basic characteristics and propose measures to conserve and develop sustainably the vegetation on limestone mountain area in Cam Pha city area, Quang Ninh province ” was performed Objectives of the study Determining the basic characteristics of vegetation on limestone mountains in Cam Pha city area, Quang Ninh province Proposing the directions of reasonable use and protection, meeting economic, social and environmental development needs The meaning of the thesis Quantifying the structural characteristics and growth capacity of timber trees in the vegetation on limestone mountains in Cam Pha city, Quang Ninh province The research results are the basis to orient conservation solutions in order to sustainably develop the vegetation on limestone mountains in Cam Pha city New contributions of the thesis - In terms of theory: Provide scientific data on species composition, structural characteristics, geographical factors, growth and regeneration capacity of woody trees, and the distribution of the vegetation on limestone mountains in Cam Pha city, Quang Ninh province - In terms of practicality: Contributing solutions for conservation and sustainable development of the vegetation on limestone mountains in Cam Pha city area in particular and Quang Ninh province in general Chapter OVERVIEW 1.1 Studies on the vegetation on limestone mountains 1.1.1 In the world In the world, limestone mountains account for about 10% of the total land area Limestone mountains play an important role for humans, a quarter of the world's population living depends on groundwater originated from the limestone mountains Many limestone mountains in the world and in the country are recognized as landscapes or world heritage such as: Port Campbel National Park (Australia), a group of Buddha worship caves in Pak Ou (Laos), Que Lam in Guangxi province (China), Thach Lam in Van Nam province (China) Hon Phu Tu (Kien Giang), Ha Long Bay (Quang Ninh), Non Nuoc (Da Nang), Phong Nha (Quang Binh), Vong Phu (Lang Son), the old cave in Cuc Phuong (Ninh Binh) Based on the reference of 24 research works of foreign authors, the thesis has reviewed the research results in the world related to this research field, including: (1) Determining name of plant species on limestone mountains; (2) Division of vegetation types on limestone mountains; (3) Determination of vegetation structure on limestone mountains; (4) Evaluating the regeneration capacity of woody trees in vegetation on limestone mountains In general, the authors in the world only focus on naming species and identification of vegetation types on limestone mountains, but no one research on the structure of height and diameter of woody trees in vegetation on limestone mountains 1.1.2 Studies on the vegetation on limestone mountain in the country In Vietnam, the majority of limestone mountains and limestone forest and mountains concentrate mainly in the provinces of the Northeast, Northwest and North Central regions with a total of 1,152,200 ha, limestone mountains account for only 3.5 % of the natural area in the whole country and distributed in the following areas: North West 229,100 ha; Northeast 638,900 ha; Northern Delta 19,200 ha; North Central Region 246,800 ha; Central Coast 3,800 ha; Central Highlands 8,400 ha; Southeast 600 ha; Mekong Delta 300 On the basis of referring to the research results of 15 domestic authors, the thesis has synthesized the research results related to this work: (1) Determining the composition of plant species on limestone mountains; (2) Determination of vegetation type; (3) Determine the group of plants on limestone mountains; (4) Determine the structure of D1.3 and Hvn; (5) Evaluate the regeneration capacity of woody trees Most authors in the country only study the vegetation on limestone mountains in mainland Some authors have also published researches on the vegetation on limestone mountains in the sea, however, those only aimed at the determination of plant species composition, but not research deeply on vegetation structure 1.2 Studies on the vegetation on limestone mountains in Quang Ninh province There are very few authors studying the vegetation on limestone mountains in Quang Ninh province Of them, the research performed by Nguyen Tien Hiep (2005) and reported in the "Proceedings of the conference on biodiversity of Ha Long Bay World Natural Heritage Site" is the most typical He divided the vegetation on limestone mountains in the area of Ha Long Bay and Bai Tu Long Bay into: The vegetation of the coastal sandy beach; Vegetation in the valley; Vegetation on the slopes; Cliff plants; Vegetation growing in rocks and cave gates; Vegetation on the top of the mountain In the world, limestone mountains are mainly concentrated in Asia Therefore, studies on vegetation on limestone mountains are limited Only some Japanese and Chinese researchers published their research on vegetation on limestone mountains However, their works only focused on the identification of plant species There is not any research on the structure of vegetation on the limestone mountains In Vietnam, there are also some scientists studying the vegetation on limestone mountains as Nguyen Nghia Thin (Evaluating the diversity of flora belonging to the drought ecosystem on Vietnam's limestone mountains), or Tran Huu Vien 2004 (Scientific basis for building sustainable forest management solutions on limestone mountains in Vietnam), or Le Tran Tran 2003; (Investigation of biodiversity of the forest on limestone mountains in Thanh Son - Ha Nam) The above researches only focus on evaluating species composition, mosaic type, composition of alive organisms, geographical factors There is not any work studying on the structure of diameter, height and growth capacity of woody trees in the vegetation on limestone mountains to use as a basis for proposing conservation measures and sustainable development Therefore, the thesis will focus on the following issues: - Study on the vegetation structure according to diameter, height, correlation between diameter and height of woody trees in the vegetation at different terrain locations - Evaluating the natural regeneration capacity of woody trees in the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province - Study on the growth ability of woody trees in the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province - General assessment of the value, management and use situation and determine the risks of degradation of the vegetation on limestone mountains in Cam Pha city, Quang Ninh province - Proposing measures to manage, conserve, use and sustainably develop the vegetation on the limestone mountain in Cam Pha city, Quang Ninh province Chapter 2: SUBJECT, SCALE AND CONTENTS AND RESEARCH METHOD 2.1 Object and scale of the study Natural vegetation on limestone mountains in Cam Pha City, Quang Ninh Province 2.2 Research content 2.2.1 Study on the status of vegetation on the limestone mountains in Cam Pha city, Quang Ninh province - Research on the diversity of the vegetation on the limestone mountains: Study on the diversity of vegetation based on topographical factors and the appearance of plants involved in saltwater intrusion; Diversity of morphology, structure of vegetation; Diversity of taxons and geographic factors on the value of use of plant resources; Identify endemic and rare species; Variety of composition of life forms 2.2.2 Study the structure of vegetation on the limestone mountains through the structure of some indicators of density and growth (N-D, N-H, H-D) 2.2.3 Evaluating the natural regeneration capacity of woody trees in the vegetation on the limestone mountain in Cam Pha city, Quang Ninh province 2.2.4 Study on the growth ability of timber trees in the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province 2.2.5 General assessment of the value, situation of management and use, and identification of degradation risks of the vegetation on limestone mountains in Cam Pha city, Quang Ninh province 2.2.6 Proposing measures to manage, preserve, use and develop the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province 2.3 Research methods 2.3.1 Inheritance method Inheriting the results of previous research on species composition, biological diversity and vegetation types related to the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province 2.3.2 Method of standard plot, method of investigation by route - Method of investigation by route: Applied for the vegetation on the cliff slopes Depending on the terrain of the mountain, we designed routes with a distance of 50-100 m, with a line width of m On the lines, investigating, sampling and measuring were carried out at 18 random survey lines on the cliff slopes in both the sea and mainland in Cam Pha city, Quang Ninh province - Method of standard plot: Applied for the vegetation at the down of mountain and limestone valley Standard plots cover an area of 2500 m2 (50m x 50m), set up 50 standard plots, equally divided into types of terrain: at the down of mountain and valley, each with 25 plots types At the PLOT, investigating, measuring, data recording and sampling were conducted Samples were collected, preserved and processed as reported by Mary Susan Taylor (1990), The Herb Society of America (2005) and Nguyen Nghia Thin (2007) 2.3.3 Method of classifying and determining the coverage of vegetation - Dividing vegetation types based on topographical elements and the occurrence of plant species involved in saltwater intrusion - Coverage is determined by the coverage of the trunk and the canopy - Vegetation structure was drawn by Autocad 2007 software 2.3.4 Identification of species composition and plant life form components - Species classification by morphological comparison method; Nomenclature and arrangement of taxons are processed according to the List of Vietnamese plants The name of the tree was determined by Pham Hoang Ho (1999-2000), Tran Dinh Ly (1995), Nguyen Nghia Thin (1997), Nguyen Tien Ban (2003, 2005,1997) - The rare and precious plant species identified by the Vietnam Red Book (2007) - the plant part, the Red List of IUCN; Decree No 32/2006-CP of the Government on management of endangered and rare forest plants and animals; Circular No 40/2013 / TT-BNNPTNT; The Circular issued a list of wild fauna and flora specified in the annexes to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) - Plant geographic elements are determined as described by Le Tran Chan (1999) - Types of plant life form are divided as described by Raunkiaer (1934) 2.3.5 Method of calculating Sorenssen index Sorenssen index (SI) In which, c is the number of species appearing in both area a and b, a is the number of species in area a, b is the number of species in the area b 2.3.6 Methods of determining structural elements - Vegetation in the valleys: The elements of the IVIi% value (Importance Value Index) is calculated according to the formula below (Pham Xuan Hoan, 2003): IVIi % In which: IVIi is the important level index (rate of composition) of the species i Ai is the relative abundance of the species i Di is the relative superiority of the species i With: Ai % (Ni is the number of individuals of the species i; s is the number of species in the population) Di % (Gi is the stem section of the species i; s is the number of species in the population) In which, Gi is calculated according to the formula : Gi (cm2) (D1.3 is 1.3m diameter of the tree i) - The vegetation at the foot of mountain and cliff slopes: The composition is calculated according to the formula (described by Tran Huu Vien) [94]: In which: Ci is IVI%, Ni the individuals number of species i; s is the number of species in the vegetation Conclusion: Which species has the value of Ci% ≥ 5, that species participates in the formula of composition 2.3.7 Simulation method rules law of tree diameter and height Data were analyzed by software described by Bui Manh Hung (2005): The appropriateness between theoretical distribution and empirical distribution was evaluated by criteria 2 m   In which:  ft  fll  fll ft is the experimental frequency fll is the theoretical frequency m is the number of teams If any team has a theoretical frequency of less than 5, then match the previous or next team so that f ll> If    052 which is looked up in the table with degree of freedom k = m-r-1 (m is the number of teams after pooling, r is the number of parameter of the theory distribution), then the theory distribution is consistent with the experimental distribution (H0+) In contrast, if looking up tables with degrees of freedom k, then hypothesis H0 is rejected (H0-) 2.3.8 Simulation method of the correlation rule between height and diameter (Hvn/D1.3) Simulation of the correlation between height and diameter according to Bui Manh Hung's software (2005) 2.3.9 Evaluation method of growth capacity of the woody trees in the limestone mountain vegetation In order to make an assessment of growth capacity of timber trees in the vegetation on the limestone mountain in Cam Pha city, the author used simulation method with mathematical expressions to represent the growth through two indicators: diameter growth (D1.3) and height (Hvn) The study was conducted with three common functions, including: Gompertz, Johnson-Schumacher and Verhults, to simulate the growth of timber tree species in the vegetation on the limestone mountains 11 4.4 Characteristics of geographical factors in the vegetation on the limestone mountain in Cam Pha city, Quang Ninh province The vegetation on limestone mountain in Cam Pha city were effected of the characteristics of Asia tropical flora, which has the mixture nature of many plant types Compared to the flora of Vietnam (20 plant geographic factors), the flora on Cam Pha limestone mountain only lacks elements: Central endemic element and Southern endemic element The diversity of plant geographic factors of limestone mountain flora in Cam Pha city plays a very important role for landscape ecology and geological and geomorphological values 4.5 Characteristics of vegetation structure on the limestone mountains in Cam Pha city, Quang Ninh province 4.5.1 Characteristic of structure - Vegetation in limestone mountain valley: Research results at plots in Buom island, Vung Gieng island, etc show that, in 25 plots, 42 species of timber trees participate in the formula of composition, in each plot the dominant woody species range from to species Figure 4.3 The vegetation in limestone mountain valley in Cam Pha city (2016) Note: Shl-Sung Ha Long; Trbđ- Tra bo đe; Trq- Trom quy; Vđmc- Vong đo mun coc; Vg- Vai guoc; Sa- Sang; Sqnh- Si qua nho; Sb- Sung bau; Sltr- Soi la tron; Trli- Trai li; Bbnh- Ba bet nhung;Blnh- Boi loi nhot; Ngph- Ngai phun; Ngml- Ngoai moc la; Sgđ- Sung gan đung; Chth- Cheo thuc; Mc- Mang cut;Thm- Thung muc - Vegetation at the down of limestone mountain: The results show that, of total 25 plots surveyed in Beo Cay Ngo, Ong Be Con, there are 49 species of plants participating in the formula of composition, in each plot the dominant tree species range from to species 12 Figure 4.4 The vegetation in limestone mountain foot in Cam Pha city (2016) Note: Blnh- Boi loi nhot;Sltr- Soi la tron;Sa- Sang;Mt- May teo; TrbđTra bo đe; Trlch- Tra lam chieu;R- Rang; Vc- Vong cach; St- Son ta;SiqnhSi qua nho; Gi- Gia; Đm- Đon mong; Thmđ- Thien mon đong; Thh- Thanh Huong; Đo- Đom; Phđ- Phen đen - Vegetation on cliff slopes: The combined results from the survey lines on Cay May island, Cu Cai island and Cai Bua island, show that of total 18 investigated routes, 31 species participate in the formula of composition, in each investigated routes dominant tree species range from to species Figure 4.5 The vegetation on the limestone cliff slopes in Cam Pha city (2016) Note: Gnb- Gang nam bo;Sa- Sang; Siqnh- Si qua nho; So- Sop;Thh- Thanh Huong; Sltr- Soi la tron; Trq- Trom quy; Sung gan đung; Ma- Mang; Vđmc- Vong đo mun coc; Shl- Sung long; Ngbhl- Ngu gia bi long;Qg- Quyt gai; Bm- Bong moc 4.5.2 Characteristics of density structure The results show that the vegetation at the down of mountain has the highest density (8,410 trees/ha), 1.6 times higher than the vegetation in the valley and 20 times higher than the vegetation on the cliff slope The vegetation on the slopes and cliffs has the lowest density of trees (413 trees/ha) 13 4.5.3 Structure N/D1.3 The N/D1.3 distribution alignment according to three common theoretical distributions, like Distance, Meyer and Weibull was tested As test with Weibull function, 24/25 plots hypotheses H were accepted, so Weibull function is the best simulation function of N/D 1.3 structure for the vegetation of limestone mountain valley in Cam Pha city 4.5.4 Structure N/Hvn The results show that, when test with Weibull function, 22/25 plots hypotheses H0 were accepted, so Weibull function is the best simulation function of N/Hvn structure for the vegetation of limestone mountain valley in Cam Pha city 4.5.5 Rules of correlation between height and diameter (H vn/D1.3) in the vegetation of limestone mountain valley in Cam Pha city, Quang Ninh province The analytical results show that only Power function is suitable to simulate Hvn/D1.3 correlation, with the highest R2 coefficient ranging from 0.4 to 0.958 4.6 Growth ability of woody trees in the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province 4.6.1 Growth capacity of woody trees in vegetation on the limestone mountains in Cam Pha City according to diameter variation (D1.3) The diameter data (D1.3) of the woody tree were analysed by R software, the results are shown in Table 4.13 Table 4.13 Results of estimating parameters of growth function for diameter (D1.3) Function Gompertz Johnson-schumacher Verhulst Parameter a 3-18 3-18 3-18 Parameter b0 13.521 19.368 12.805 Parameter b1 0.577 35.322 0.683 Parameter b2 0.041 37.572 0.056 R2 0.99507 0.995261 0.994921 AIC -44.84719 -45.47957 -44.36834 The results show that the correlation coefficient R2 of the functions is equivalent (0.995), so Gompertz, Johnson-schumacher and Verhulst functions describe well the growth rate of the trunk diameter in the vegetation on the limestone mountains in Cam Pha city 4.6.2 Growth capacity of timber trees in the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province, according to the variable of the height (Hvn) Completely similar to diameter variable, data measured from PLOT, surveyed lines and data inherited from bay management over 14 the years are used to analyse nonlinear correlation for Gompertz, Schumacher and Verhulst The analytical results are shown in the following table Table 4.16 Parametric equations simulating the height (H vn) Function Parameter a Parameter b0 Parameter b1 Parameter b2 R2 AIC Gompertz 3-18 11.248 0.698 0.045 0.99501 -44.65503 Johnson-schumacher 3-18 17.043 37.017 33.084 0.995246 -45.42845 Verhulst 3-18 10.483 0.865 0.065 0.99479 -43.97494 The results show that all three growth functions are well simulated for the height growth according to age Based on that, three growth functions including Gompertz, Schmacher and Verhulst were used to simulate the growth for the variables of diameter and height of woody trees in the limestone mountain vegetation in Cam Pha city The results show that all three functions can simulate well the growth of forest trees in the study area Correlation coefficients for both diameter variable and height variable are very high (0.995) However, if considering more accurately, the Schumacher function has the highest compatibility, because the AIC value is the lowest in the three models, which is true for both diameter and height variables All parameters of the regression model exist in the whole, since the Pr values are much less than 0.05 This shows that the models are really meaningful and can be applied to other areas with the same characteristics of plants and other natural conditions 4.7 The regeneration capacity of timber trees in the vegetation on the limestone mountains in Cam Pha city, Quang Ninh province 4.7.1 The structure and density of regenerated woody trees The results show that the number of regenerated tree species appearing in the vegetation of limestone mountain valley is 40 species, of which species participate in the formula of composition such as Ficus alongensis, Ficus microcarpa, Litsea glutinosa, Sterculia lanceolata (Vung Gieng island, Cay Nua island, Cua Vong island), in which Ficus alongensis is the species that accounts for the highest proportion of 11,16% 4.7.2 Origin and quality of regenerated woody trees The survey results on the quality and origin of regenerated trees in limestone mountain vegetation in Cam Pha are shown in Table 4.20 15 Table 4.20 The origin and quality of regenerated woody trees in limestone mountain vegetation in Cam Pha city Origin Quality (%) Location of No of Per Per vegetation tree/ha Seed Shoot Good Medium Bad (%) (%) In the valley 2938 2304 78.45 634 21.6 49 30 21 At the foot of 3880 2898 74.7 982 25.3 58 26 16 mountain On the cliff 820 612 74.65 208 25.3 30 45 25 slopes Average 2546 1938 76.24 608 23.8 45.7 33.7 20.7 The table shows that regenerated seedlings vary from 74% to 78%, on average of 76% 4.7.3 Distribution of regenerated woody trees according to the height Distribution of regenerated timber tree according to the height is presented in Table 4.21 Table 4.21 Distribution of regenerated timber trees according to the height in limestone mountain vegetation in Cam Pha City Number of regenerated trees according to the Location of No of height (No of tree/ha) tree/ha vegetation 150 cm In the valley 2938 1211 987 546 194 At the down of 3880 1475 1264 798 343 mountain On the cliff 820 368 213 145 94 slopes Average 2546 1018 821 496 210 The results showed that the density of regenerated trees was the highest at the height of 150 cm, regeneration density varies from 145 to 798 trees/ha, on average of 496 trees/ha 4.7.4 Distribution of regenerated timber trees in horizontal plane Results of distribution of regenerated woody trees are summarized in the following table: Table 4.22 Distribution of regenerated woody trees in 16 horizontal plane No Location Vegetation in the valley Vegetation at the down of mountain Vegetation on the cliff slopes λ 0.4408 r 0.84 U 1.39 Distribution type Random 0.582 0.55 -2.07 Cluster 0.1231 0.19 -10.9 Cluster The table shows that the distribution of regenerated timber trees in the valley vegetation is random The distribution of regenerated timber trees in vegetation at the foot of the mountain and cliff slopes is distributed in clusters This distribution is consistent with the terrain of limestone mountain The vegetation in the valley has relatively flat terrain and thick layer of soil, so when the fruits and seeds fall down, they are distributed randomly on the ground For vegetation at the down of mountains and cliff slopes, due to steep terrain, when fruits and seeds fall down, they tend to slip to the same position leading to the regenerated trees distributed in clusters 4.7.5 Factors affect the regeneration capacity of seedlings 4.7.5.1 Effect of terrain factors The results on the influence of limestone mountain topography on the quality and density of regenerated trees are shown in the following Table 4.24: Table 4.24 Effect of topographic factors on the regeneration capacity of trees in the vegetation on the limestone mountains in Cam Pha City Height Terrain No of tree/ha Valley 1211 Foot of mountain 1475 Cliff slopes 368 Valley 987 Down of 50-100 cm mountain 1264 Cliff slopes 213 Valley 546 100-150 Down of cm mountain 798 Cliff slopes 145 >150 cm Valley 194 Down of 343 mountain