Tài liệu Study, assessement of bioclimatic resources in the northeast region of vietnam for development of a few agricultural crops and forest trees that have economic value

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VIETNAM ACADEMY OF SCIENCE AND TECHNOLOGY MINISTRY OF EDUCATION AND TRAINING INSTITUTE OF GEOGRAPHY  DO THI VAN HUONG STUDY, ASSESSEMENT OF BIOCLIMATIC RESOURCES IN THE NORTHEAST REGION OF VIETNAM FOR DEVELOPMENT OF A FEW AGRICULTURAL CROPS AND FOREST TREES THAT HAVE ECONOMIC VALUE Chuyên ngành: Speciality: Geographical and environmental resources Code: 62 44 02 19 SUMMARY OF Ph.D DISSERTATION IN GEOGRAPHY Ha Noi – 2014 Dissertation has been completed at: Institute of geography, Viet Nam academy of science and technology Advisors: 1. Associate professor Dr. Nguyen Khanh Van 2. Dr Do Huu Thu Reviwer 1: Associate professor Dr. Tran Van Con Reviwer 2: Professor Dr. Tran Thuc Reviwer 3: Associate professor Dr. Nguyen Thi Hong The dissertation is defended in front of board of examination of dissertation at institute level held at the institute of geography in 18 Hoang Quoc Viet, Cau Giay, Ha Noi at……… on……… 2014 The dissertation can be found in: - National library - Library of institute of geography, Viet Nam academy of science and technologchnology -1INTRODUCTION 1. Reasons for choosing project Climate is the first natural factor, the condition of all regular development process, natural metabolism. Study on assessement of bioclimatic conditions of vegetation covers provides essential information needed about characteristics of bioclimate as a basis for serving orientation of development planning of agriculture and forestry to help managers make the structure of agricultural crops and forest trees reasonable to fully utilize the strengths of each territory in order to achieve high efficiency and sustainability.. Northeast region of Vietnam is one of the mountainous and midland areas of our country, the natural geographical region has an important significance both in terms of nature, economy and politics. During the past several years, the area has always been regarded as a rich potential for developing agro- forestry and areas specializing in the growing of special crops with high economic value. Agricultural and Forestry economimy always account for high proportion of the economic structure of Northeast region, especially playing an important role in the economic development of the region . However, currently Northeast region is still underdeveloped, agricultural and forestry production in the region has not developed commensurating with the level that it may be , people's life faces a lot of difficulties. Identifying areas that are able to expand agricultural and forestry production, afforestation, promote protection and development of forest resources and selection of tree group for development in accordance with the climatic conditions of the region is the critical issues. Assessment of bioclimatic conditions in a scientific way for the development of sustainable agriculture and forestry are necessary, having high practical significance. We believe that selection of study and asessement of bioclimatic resources for the development of agricultural crops, forestry trees , perennial crops, medicinal plants with economic value is very necessary. Individually, as a graduate student with the practical needs and the desire to contribute to sustainable development of socio-economics of Northeast region of Viet Nam, the author has chosen the project: "Study on -2assessement of bioclimatic resources in Northeast region of Vietnam for development of agricultural crops and forest trees with economic value "to perform PhD dissertation in geography. 2. Objectives and study tasks 2.1. Objectives - Study on characteristics of bioclimatic resouces in Northeast region to elucidate the potential of bioclimate to establish the scientific basis for exploitation of bioclimatic resources for sustainable development of agricultural and forestry production. - Recommendation of rational using bioclimatic units for sustainable development of agricultural crops and forestry trees in Northeast region. 2.2. Tasks - Overview of documents of bioclimate, studies on bioclimate assessment and other documents related to the place of study, designing rationale for the use of the project. - Analyzing factors that shape the climate, mapping of bioclimatenatural vegetation covers in Northeast region on scale of 1: 500.000; Analysis of bioclimatic characteristics to clarify rules of differentiation of bioclimatic resources, distribution law, the structure of external appearance, ecological processes and vegetation cover types on studied territor. - Assessment of bioclimatic resources for the development of a number of agricultural crops and forest trees; assessment of appropriate levels of bioclimatic types for acacia hybrid (assessment for total Northeast region at map on scale 1: 500,000), tea plant (Thai Nguyen Province on scale 1: 100,000), star anise (in Lang son province on scale of 1: 100,000), black cardamom (Sa Pa district, Lao Cai province on scale of 1: 50,000) and recommendation of orientations of rational exploitation and use of bioclimatic resources and sustainable development of agricultural crops and forest trees. 3. Limited scope of study - Limited scope of territory :Studied territory is limited within Northeast region with natural area of 64 952 km ² (accounting for 20% of total area of the country), including 11 provinces. Geographical studied places focused on mainland, not included part of the sea and islands. - Limited scientific scope: The dissertation only focuses on characteristics, differentiation of bioclimatic conditions and assessment of bioclimatic adaptation for developing a number of agricultural crops and forest trees with economic value in Northeast region ( Acacia hybrid -3tree, midland tea plant, star anise and black cardamom);orientation of spatial rational use of bioclimatic resources in agricultural and forestry production in Northeast region. 4. Scentific signìficance of the dissertation - The dissertation has elucidated nature of characteristics and differentiation of bioclimatic resources on the territory from which recommends orientation of rational exploitation and use of territorial bioclimatic resources for sustainable socioeconomic development - Practical signìficance of the dissertation: In order to orientate sustainable development of agricultural and forestry production, the results of the dissertation will be the scientific basis for reasonable maintenance, restoration, protection and development of vegetation covers in natural forest and planted forest, contributing to recommendation of structure of agricultural crops and forest trees, areas spicializing in growing industrial trees, medicinal plants that have high economic value in accordance with specific characteristics of bioclimatic resources on territory of northeast region of Vietnam. : 5. New contribution of the dissertation Indicator System and bioclimatic- vegetation maps of Northeast region on scale of 1:500.000 has reflected bioclimatic characteritics and differentiation characteristics of vegetation covers in Northeast region. Bioclimatic units carry specific characteristics of the studied area.. Assessement of bioclimatic resources and other natural factors for development of agricultural crops and forest trees with economic value is the scientific basis for the rational spartial arrangement of production, contributing to the sustainable development of agricultural and forestry sectors in Northeast region.. 6. Theoretical points for defending - Theoretical point 1: Midland and mountainous area in North East region have diverse natural conditions and bioclimatic natural resouces reflecting diverse aspect, abundant bioclimatic resources and climatic differentation according to its own rules. Bioclimatic classification. It reflects the structure of vegetation mulch -vegetation types of the studied area. - Theoretical point 2: Applying the method of assessing ecological adaptation, assessing the appropriate level of bioclimatic conditions for a few agricultural crops and forest trees, medicinal plants that have high economic value, the dissertation has developed a scientific basis necessary for proper orientation of using bioclimatic resources, spartial arrangement of areas pf producing forest trees and areas specializing in -4the growing industrial plants, medicinal plants on the territory of northeast region of Vietnam. 7. Sources of Document - The results of the study, field survey following routes. - Climatic data of 34 meteorological stations and rain gauge stations of Northeast region - In addition to the documents that have already been published having content related to the dissertation, the graduate student herself collected materials and data from the NAFOSTED project (2012-2014 by Assoc. Dr. Nguyen Khanh Van and the graduate student is a member directly taking part in this project. - Falcilities of maps of special subjects serving for mapping in the dissertation include: Topographic map of Northeast region on scale of 1:500.000; Soil Map of Thai Nguyen, Lang Son on scale of 1:100.000, soil map Sa Pa District, Lao Cai Province on scale of 1:50.000 ; The projects, scientific reports on investigations of natural and socio-economic conditions, , climatic resources in Northeast region. 8. Structure of the disertation The disertation is presented in writing consisting of 150 typed pages in A 4 size, 34 tables, 30 figures, lists of 122 references in Vietnamese and foreign languages. Besides the introduction, conclusion and references, the dissertation has three chapters including: Chapter 1: The theoretical basis for the study and assessement of bioclimatic resources for development of agricultural and forestry production. Chapter 2: Characteristics of climate and bioclimatic resources in Northeast region Chapter 3: Assessment of bioclimatic resources in Northeast region for development of some agricultural crops and forest trees. Chapter 1:THEORETICAL BASIS FOR STUDY AND ASSESSEMENT OF BIOCLIMATIC RESOURCES FOR DEVELOPMENT AGRICULTURAL AND FORESTRY PRODUCTION, 1.1. Some basic terms Climate applications is a science that studies climate in relation to a specific object; analysing, elucidating the positive and negative impact of climate on the object to provide the right, reasonable solutions to take advantage and enhance the positive impacts, prevent negative impacts of climate. The basic direction of study on climate applications such as -5agriculture climate, forestry climate, medicine climate, tourism climate, construction climate, transportation climate, Military climate. Bioclimatology is a subject to study association between climatology and ecology, the effects of climate to living organism. Bioclimatology focuses on study on impact of climatic factors (radiation, temperature, humidity .ect..) for a long time and tracks the impact of weather each day, each month, studying climate within the region and in each small area (micro-climate), in landscape and barn equipment created by humans for plants and animals. Study on bioclimate is the basis for study of living organism’s adaptation to enhance the productivity in a given environment "[87]. Study on some of the main directions of bioclimate (agrobioclimate, natural vegetation bioclimate, human bioclimate) continues to be interested in, promoting both scientific and practical aspects. 1.2. Historical Overview of bioclimate -natural vegetation covers Study of bioclimate-natural vegetation cover has been one of the directions of studies for a long time. Many research works of scientists in the country and foreign countries has high scientific and practical significance. In fact, study results of bioclimate has provided a scientific basis for geographic vegetation in determining the distribution of plant species, as well as the ecological characteristics of generating natural vegetation covers. The climate and vegetation have very close relationships. Natural vegetation is regarded as indicators of climatic conditions corresponding to a climatic type, havings a certain primary vegetation type. 1.2.1. Overview of research works on the world The process of forming a direction of climatic classification on the basis of plant ecology is a long process and are always developed with different scientific advances by plant taxonomists , climatologists supplemented by study results of landscapists. In recent years, study direction of applications of bioclimate-natural Vegetation covers relationship has been promoted having practical significance, especially in the context of climate change.. Currently, scientists in the world are continuing to study and develop this direction of study Application scope of studying bioclimate-natural vegetation does not limit to the study for the purpose of assessing adaptation of crop ecology, but studying forest fire warning, protection of natural forest resources and vegetation covers for purposes of studying adaptation and coping with climate change is also actively promoted 1.2.2. Over view of studies in Vietnam Study of bioclimate in vegetation cover classification and agriculture and forestry in general has been summarized in Thai Van -6Trung ‘s works "forest vegetation cover of Vietnam." In the next studies of Schmid (1962), Duong Huu Thoi, Pham Hoang Ho (1960) . bioclimatic factors were applied to the description, explanation of the formation, differentiation of the types of Vegetation Covers in different regions of our country. A number of subsequent studies, investigations and assessement of climatic resources performed by Lee (1973), Vu Tu Lap (1976), Nguyen Duc Ngu, Nguyen Trong Hieu (1985) Lam Cong Dinh (1992), Nguyen Viet Pho, Vu Van Tuan (1993), Nguyen Duc Ngu, Nguyen Trong Hieu (2004) analyzed the characteristics of climate and resources in Vietnam. In addition, sudies on assessement of climatic resources of Vietnam are also mentioned in some coursebooks of Vietnam natural geography, ecologcal economy , bioclimatic basis written by the authors: Nguyen Duc Chinh, Vu Tu Lap , Le Ba Thao, Nguyen Phap, Nguyen Khanh Van * Northeast region The study of climate in the specific areas, locallities of Northeast region has been integrated in the findings of climate studies in Vietnam, or in specific localities of Northeast region through the results of the studies from the Hydrometeorological stations. However,there are little separate works of study on assessement of bioclimatic resources assessment for development of agricultural crops and forest trees of the region. Realizing that this is the direction of studying climate applications having high practical significance, the author would like to be allowed to inherit and continue developing the previous studies. 1.3. Overview of studies on agricultural crops, forest trees Currently, many studies of forest trees, industrial trees and medicinal plants have been invested and put into practical applications. Some of the main forest trees in our country as Acacia, Pine tree, gum tree (Eucalyptus), Manglietia conifera ... have been studied in many works carried out by authors such as Vu Tien Hinh; Dao Cong Khanh;Vu Nham, Nguyen Ngoc Lung, ... These study results have made important contribution to the process of restoring vegetation covers, development of planted forest in Vietnam. Studies of evaluating and classifying the levels of ecological adaptability of plant groups (especially industrial trees, medicinal plants), specific crops. Many scientists in the agriculture, biology, geography and medicinal plants are interested in these studies and have obtained specific results. The dissertation has listed some studies of agricultural crops, assessment of the level of adaptation to the climatic conditions of industrial trees , medicinal plants performed by Le Trong Cuc Nguyen -7Dai Khanh, Pham Chi Thanh, Do Tat Loi. Analysis of the results of the projects helps the author get more scientific data for studying, analysis, assessement of bioclimatic resources for the development of some valuable Agricultural crops and forest trees in Northeast region of Vietnam. 1.4. Several classification systems, division of bioclimateVegetation cover types in Vietnam. In the study of climate, there have been a number of documents mentioning, analysing, classifying and distributing bioclimate-natural vegetation covers. Typically, there are studies performed by Vu Tu Lap, Thai Van Trung, Lam Cong Dinh, author groups of the Institute of Geography. Inheriting the results, classification, distribution of bioclimatic types obtained by various authors in the country, analyzing the advantages and disadvantages of these methods of bioclimate classfication so that the author can select most appropriate classification method of bioclimatenatural vegetation covers on the territory. In the process of study, classification, bioclimatic mapping in Northeast region, the author applied the classification method by the authors of Institute of Geography, selecting criteria for classifying levels of bioclimatic types in map of bioclimate-natural vegetation covers in Northeast region of Viet Nam… 1.5. General theory of climatic resources assessment for the development of agricultural and forestry production * Objects and assessement unit Objects assessed are the bioclimatic units, bioclimate-resources units, specific crops: Acacia hybrid tree, Midland tea plant star anise, black cardamom. assessement units used when bioclimate is assessed for development of agricultural crops and forest trees in Northeast region (in bioclimatic map on scale of 1: 500,000) are units.of bioclimatic type. Assessment unit of bioclimate for a specific crop (in bioclimatic map on scale of 1: 100.000, 1: 50.000) is bioclimate-soil. Contents of assessement: The contens consist of determining characteristics of climatic resources on the territory, assessement of bioclimatic types for development of specific agricultural crops and forest trees to recommend orientation of rational and efficient use of bioclimatic resources *The dissertation designs various steps of assessement for forest trees (acacia hybrid), industrial trees (tea, star anise), medicinal plant (black cardamom). Assessement of bioclimatic adaptation was performed through the following steps: Selecting and designing assessment indicator system; -8scale, arithmetic mean; identifing methods of assessment and applying them to studied territory. Asessement of bioclimatic resources, bioclimate-esources for the purpose of crop development. The disertation applied the method of calculating componential scores by using the fomular. of calculating arithmetic mean n n Xa = (1/∑ ki) ∑ kiXi (I) i=1 i=1 In which: Xa: scores for general assessement of total area a; ki: weight of i factor; Xi: score for i factor; n: number of assessed factors The assessment results will find out the most appropriate unit of bioclimate-resources for development of agricultural crops and forest trees in Northeast region. * Classification of asessement results and recommendations of their use After the results were obtained, applications to practice must be verified and classified for each bioclimatic unit, bioclimate-resource. That is a combination of bioclimatic group units, with the same appropriate level for crops that were assessed having the same type of resource potential or the same conditions for crop development. 1.6. Points of view and methods of study * The dissertation used points of view such as: systematic point of view, territorial point of view, historical point of view and view of sustainable development. In particular, the views and synthesis system were the key point. * Methodology of study:The dissertation used methods of study as follows: Method of collecting, analyzing and processing data; field survey methods, interviewing experts; method of statistical analysis; Method of typing, climatic classification; Assessment methods of plants that adapt to ecology; Methods of mapping and geographic information systems (GIS). * Procedures of study: After conducting field surveys, collecting data and processing related documents, the author conducted the study following different steps: Step 1: Gathering documents and data, analysis and assesement of natural and socioeconomic conditions of Northeast region; Step 2: Analyzing characteristics of bioclimatic resources, bioclimatic mapping Northeast region; Step 3: Assessing bioclimatic resources in Northeast region for developing some agricultural crops and forest trees that have economic value in this region. -9Subconclusion of chapter 1 1 . The results of the study performed by many authors in the country and foreign countries shows that bioclimate , bioclimate- natural vegetation cover is a direction of study that has a long history , contributed ,enriched , enlightened by the results of many branches of sciences of earth sciences in general. This is a real direction of study having both theorical and practical significance. Currently study of bioclimate is continuing to be studied by many scientists to promote the application to solve practical problems . The findings of agricultural crops and forest trees are regarded as an important document for the author to inherit and promote further study in order to obtain results in the the dissertation. 2. Northeast region has natural area of 63 952 km ² (accounting for about 20% of the country). This is a vast natural geographical area having special bioclimatic resources and diverse complex climatic differentiation.. There are many scientific studies of climate that mention climate in Northeast region but they only limit to the level of general study, not studying the entire contents of northeast region of Vietnam. In contrast, there are a number of projects for a department or a province located in Northeast region. There haven’t been any works analyzing bioclimatic resources in the region specifically and in detail(at the rate of study / 1500.000). Therefore, the study of the dissertation on bioclimatic resources on Northeast territory has sufficient scientific basis to be performed. The results of the analysis in chapter 1, the points of view and methods of study are a theoretical basis for the author to review, select and apply appropriately to study on assessement of bioclimatic resources in order to develop some kind of Agricultural crops and forest trees having economic value, contributing to hunger eradication and Poverty reduction, optimal use of natural resources of Northeast region. CHAPTER 2: CLIMATE AND BIOCLIMATC RESOURCES IN THE NORTH EAST AREA OF VIETNAM 2.1. Factors forming and affecting bioclimatic resources 2.1.1. Natural factors forming climate of North east region of Viet Nam Factors forming climate of the northeast region include three factors: solar radiation, circulation of atmosphere and factorgroup of buffer surface . * Northeast region (20º40’B -23°22’B, 103°31’-108°31’D )covers the whole notheast area with its natural area of 63.952 km² (accounting for 20% area of the whole country), which consists of 11 provinces (Quang Ninh, Lang Son, Cao Bang, Bac Can, Thai Nguyen, Yen Bai, Lao Cai, Ha Giang, Tuyen Quang, Phu Tho, Bac Giang) (map1.1) [65]. With the location and territories -10mentioned above, the area plays an extremely important role in eclology, environment, society, economy, security and national defence. The geographical location has detemined that the north east region has radiation regime with tropic style. Generally, the area is abundant in radiation with more than 200 kcal/cm² per year, Such amount of radiation ensures the existance of tropical rain forest vegetation covers and rain appears in many places of the region in rainy season * North east region is influenced by circulation regime of internal tropical monsoon [49], [71], [72]. In the spere of the region in sumer the prevailing winds blow in the region from the sea ( northeast trade winds that dominates the north hemisphere) have south and southwest direction. In winter the prevailing winds blow from continent northwardly and norhthesterly. Shift of wind regimes causes contrast between heat regimes and between annual precipitation in the place of study . * Factor group of buffer surface include 2 factors: factor group of geology and terrain and factorgroup of hydrography, soils and vegetation covers. - Factor group of geology and terrain: Differentiation of terrain by east west com bination and north south combination plus specific characteristic of the area (mountain, hill and plain) has caused the climate in the northeast region to be divided according to east –west direction and the height (figure 2.1). Topographic structure, interaction of terrain circulation cause climate in the region to divide into climate patterns, climates that have specific features. Factors of geology and terrain have important influence on formation of the climate in the region. - Factor group of hydrography - soils, vegetation cover are illustrated in the figures 2.2, 2.3, 2.4, 2.5: Soil mantle - vegetation and hydrographical factor have contributed to regulation of climate especially in area where there is good soil, abundant hydrological reserves,high development of forest. So this is the important factor of buffer surface affecting formation of climate .The combined impact of buffer surface including terrain, soils, hydrography, living organism and sea combined with factor of monsoon circulation on the tropics has formed featured specific climate pattern and no other places in the world at the same latitude have-11the similar feature. That is the humid tropical monsoon climate with cold winter consisting of 3 cold months that have temperature below 18ºC. 2.1.2. Factors of economy society - exploitation and rational use of bioclimatic natural resources By the end of 2012, population in Northeast region of Viet nam is -119720.2000 (that belong to 30 different races),making up 11% of population of the whole country. Most residents of the region live on agricultural and forestry production (population in rural area accounts for > 80%). Development of agricultural and forestry production will be the precondition for economic and optimal employing surplus labours to contribute to redistribution of residents, focus on development and improve living standards of people in rural and mountainous area, exploit production and enhance the quality of life for the communities in Northeast region. * Economic sectors - In the region a number of forest areas for materials used for industry of processing paper,producing artificial board and, mine pillars have been formed . That is why forest coverage has increased significantly so far. - Industrial sector of processing agricultural and forestry products in the region í still limited in number and size. It í not associated with the manufacturing sector. Procedures of product processing is still rudimentary, having not been equipped with modern equipment. At the present mainly primary products are exported to foreign markets at low prices , . output in consumption of agricultural and forestry products is not guaranteed so specialized activities of the production of goods face a lot of difficulties 2.2. Laws of nature and climatic differentiation of Northeast region 2.2.1. General characteristic: Factors forming the climate have specified general nature of the Northeast Climate: intrinsic properties of tropics, monsoon, natural moisture, diversity and climate fluctuations. 2.2.2. Laws of climatic differentiation Seasonal differentiation in climate of Northeast region is the most important characteristic and has high practical significance, especially in the field of production and economy of our country. Differentiation of dynamics of seasonal climate here is due to the activities of monsoon circulation, with a unique combination of geography.. The rules of the climate division include: differentiation of climate with latitude, longitude, altitude and differentiated according to seasonal climate in which climate rule of differentiation by elevation and seasonal are best expressed in the differentiation of regional climate. -12With rain regime, rainfall, humidity metioned above, Northeast region is differentiated into areas with more rain, less rain very clearly. Generally, it is favorable for the development of crops that prefer moist, adaptive with distinct seasons. The distribution of rainfall over space and time creates ecological diversity of crops.. The special weather phenomenon: In the region, the weather phenomenon particularly like typhoon, local hot dry wind, frost, fog, hail, thunderstorms, snow and ice ..etc… are the phenomena occurring with more frequency and are harmful to development of vegetation covers and crops. 2.4. Mapping bioclimate of natural vegetation covers (based on original source) in Northeast region of Vietnam 2.4.1. Establishment of principles of the bioclimate map of natural vegetation covers Bioclimatic map that is established has to meet the following principles: (i) The map must first reflect the climatic conditions of the studied territories, differentiated according to time and space. (ii) bioclimatic map must reflect ecological characteristics of the territory containing models of vegetation covers available in the territorie studied. (iii) bioclimate map must reflect the needs that serve for production, planning territories studied. 2.4.2. Indicator system for bioclimates classification of vegetation covers indicator system of heat and humidity being studied,and built for bioclimatic map must meet the following requirements: (i) indicators selected must be representative, that is, must reflect nature and distribution characteristics of seasons, the hot season, the rainy season, by latitude, altitude and season. (ii) indicators selected must reflect the nature of the ecological climate, i.e, reflect the law of distribution, the growth and development of certain types of natural vegetion covers on studied territory. -System of heat includes average temperature of the year and indicator of lenght of cold season - indicator system of rain and wet including an indicator of total annual rainfall and number of dry months is used for the climate type hierarchy -13-To sum up the criteria mentioned above, the bioclimatic map of natural vegetation covers of the Northeast region is formed with heat and wet indicator system (Table1). 2.4.3. The bioclimatic types of Northeast region Table 1: indicator system of bioclimate of natural vegetation covers of Northeast region wet Heat annual average temperat ure year (Tyear , ºC)t Total annual rainfall (R, mm) Lenght of dry season (n) A – rain a lot R year ≥ 2500mm B - rain a lot 2000mm ≤ R năm < 2500mm C – moderate rain 1500mm ≤ R năm < 2000mm D – litle rain 1200mm ≤ R year < 1500mm b) averag e dry season 3-4 months b) averag e dry season 3-4 months c) long dry season n=5 th months IID2b (10) IID2c (2) a) short dry season n2 monts b) averag e dry season 3-4 th months b) average dry seas 3-4 monthx 4) Cold time period is long, throughout the year 10-12 months IVA4a (4) IVA4b (6) IVB4b (2) 3) cold time period is long,7-9 months IIIA3a (4) IIIA3b (3) IIIB3b (8) IIIC3b (7) II – cool 20ºC > Tnăm ≥ 16ºC 2) Average cold time period 4-6 months IIA2a (1) IIA2b (3) IIB2b (10) IIC2b (36) I–Ha bit hot Tnăm ≥ 20ºC short cold time period 3 months IA1a (1) IA1b (1) IB1b (5) IC1b (4) IV – very cold Tnăm < 12ºC III – L cold 16ºC > Tnăm ≥ 12ºC Lenght of cold season (n) c) long dry season n=5 th months IC1c (3) E – litle rain R<1200 mm c) long dry season n=5 months ID1c (3) On the basis of analyzing the thermal and moisture divergence indicators in the Northeast region combined with analysis of the distribution of 6 types of natural vegetation covers in the studied area.The results of classification show that in North East region, there are 6 t bioclimatic types (described in Table 2) 20 different types of bioclimate of vegetation covers, which have been repeatedly types on the territory of the studied area (116 of 20 separate zoning categories of bioclimate) are illustrated in the bioclimatic map of natural vegetation covers of the Northeast region) (figure 2.13). IE1c (2) -14Table 2: Description of the types of bioclimate of Northeast region Bioclimatic type type 1: bioclimatic type of tropical monsoon at lowland area, which is a bit hot with a short, cold period , there is lots of rain, dry season is from short to medium, including the type of bioclimate IA1a and IA1b. type 2: bioclimatic type of tropical monsoon at lowland area which is a bit hot, cold period is short,there is moderate rainfall, there are moderate to long dry seasons, including the type of bioclimate IB1b, IC1b, IC1c. type 3: Bioclimatic type of tropical monsoon, at lowland area, it is a bit hot with a cic types ID1c, IE1c. type 4: Bioclimatic type of tropical monsoon in low mountainous area(500/600-1400m), it is cool, cold period is average, there is very much rain to little rain. There are medium to long dry seasons, including the type SKH IIA2a, IIA2b, IIB2b, IIC2b , IID2b, IID2c. type 5: bioclimatic type of tropical monsoon in area with medium mountain (1400-2200m), it is cold, there is a long cold period, there is a lot of rain to moderate rain, and moderate short dry season, including the type of bioclimate IIIA3a, IIIA3b, IIIB3b, IIIC3b. type 6: bioclimatic type of tropical monsoon in high mountains (> 2200m),it is very cold, there is a very long cold period and a lot of rain, short to medium dry season, including the bioclimatic types VIA4a, VIA4b, VIB4b. Description Types of bioclimate that correspond bioclimateic type of vegetation covers of evergreen tropical rain forest. This corresponds to the type of bioclimate ofv egetation covers of semi evergreen tropical rain forest corresponding to the bioclimatic type of vegetation covers of tropical deciduous forest This type of bioclimate corresponds to vegetation covers in climate of temperate evergreen forest with lower moist This type corresponds to vegetation covers in climate of Moist Conifer and Evergreen Broad-leaved Forest This type corresponds to Alpine vicinity (vegetation, the bioclimatic type of vegetation covers in climate of high mountainous area, cover types of coniferous forest climate, which has dwarf trees (Phyllostachys) in high mountain). Bioclimatic types of tropical monsoon in the region include : (1) IA1a: bioclimatic type with a bit hight temperature, there is a short cold time period, it is much rainy, dry season is short. (2) IA1b of bioclimatictype with somewhat hot , there is a short cold time period, it rains a lot, dry season is medium; (3) IB1b: bioclimatic type, which is somewhat hot , there is a short cold time period, it rains a lot, dry season is long; (4) IC1b: , there is a short cold time period,moderate rain and long dry season (5) IC1c: : bioclimatic type, which is somewhat hot , there is a short cold time period moderate rain and long dry season; (6) ID1c: : bioclimatic type which is somewhat hot , there is a short cold time period, little rain,and long dry season; (7) IE1c: bioclimatic type, which is somewhat hot ,cold time period is short ,there is little rain and dry season is long; (8) IIA2a: bioclimatic type of low mountainous area,it is cool, cold time period is long, it rains a lot, dry season is short; (9) IIA2b: bioclimatic type of low mountainous area, it is cool, cold time period is long TB, , it rains a lot, dry season is medium; (10) IIB2b: bioclimatic type of low mountainous area, it is cool, cold time period is average long , it rains a lot,, dry season is moderate long ; (11) IIC2b: bioclimatic type of low mountainous area,it is cool, cold time period is moderate long, it rains moderately,dry season is moderate long; (12) IID2b: bioclimatic type of low mountainous area it is cool, cold time period is moderate long, there is little raint,dry season is moderate long; (13) IID2c: bioclimatic type of low mountainous area, it is cool, cold time period is moderate long, there is little raint,dry season is long; (14) IIIA3a bioclimatic type of medium mountainous area, it is cold, cold time period is long, it rains a lot, dry season is short; (15) IIIA3b: bioclimatic type of medium mountainous area , it is cold, cold time period is long it rains a lot dry season is moderately long; (16) IIIB3b: bioclimatic type of medium mountainous area, , it rains a lot, dry season is moderately long; (17) IIIC3b: bioclimatic type of medium mountainous area, it is cold, cold time period is long, there is moderate rain, dry season is moderately long (18) IVA4a: bioclimatic type of high mountainous area, , it is very cold, cold time period is very long, it is cold throughout the year,it rains a lot and dry season is short; (19) IVA4b: bioclimatic type of high mountainous area , it is very cold, cold time period is very long, it is cold throughout the year,it rains a lot and dry season is moderately long; (20) IVB4b: -15bioclimatic type of high mountainous area , it is very cold, cold time period is very long, it is cold throughout the year,it rains a lot and dry season is moderately long. In terms of area bioclimatic type IC1b makes up largest area of 20 categories (21832.22 km²), the second largest is the type IIC2b (10122.37 km²) The bioclimatic type SKH IVB4b accounts for the smallest area (32.46 km²). Regarding the number of repetitions , type SKH IIC2b has the most number of repetitions 36 times), followed by IIB2b, IID2b 10 times). The other remaining bioclimatic types account for medium area and number of repetitions is from 1 - 10 times. Characteristics of each bioclimatic type in Northeast region are described in Appendix 3. Overall, the Northeast bioclimatic resources are rich and diverse . On the studied area there are 20 bioclimatic types with different features. Biolimatic resources in the region also have a clear differentiation based on the heat,. It is from hot, cool, a bit cold to very cold . Rainfall in some places reaches over 4000mm/year (Bac quang), some places raifall is less than 1200mm/year (Ky Cung River Valley, Bang Giang), There is differentiation between the length of cold season and between the length of dry season. 2.4.4. Bioclimatic mapping natural vegetation covers of Thai Nguyen and Lang Son province and Sa Pa district of Lao Cai province On the basis of bioclimatic map of natural vegetation covers in Northeast region, based on the ecological characteristics of crops, indicator system for classification of bioclimatic natural vegetation covers, bioclimatic maps of vegetation covers.inThai Nguyen, Lang Son provinces and Sa Pa district of Lao Cai provinces are determined and set up in accordance with the ecological threshold of each selected crop for assessment..Bioclimatic maps of Thai Nguyen, Lang Son on scale 1:100 000 (corresponding to 7 and 9 bioclimatic units) shown on figures 2.14, 2:15 and bioclimatic map of Sa Pa district of Lao Cai provine on scale 1:50 000 (10 bioclimatic units) (figure 2.16) are established as a basis for the dissertation to assess bioclimatic adaptation for development of industrial trees, medicinal plants mentioned in chapter 3. 2.5. Consistency and close relationships of cause and effect between bioclimates of territory and distribution of natural vegetation covers inNortheast region On being considered, the relationships between climate and vegetation covers. in nature are easy to reccognize. With a certain condition of climate and soil, a certain type of natural vegetation cover will appear respectively. If there are the same bioclimatic conditions, zonal soil type or non- zonal traits will inevitably generate, essentially carrying the same characteristics, properties and processes. Generally -16factors "bioclimate - vegetation - soil are regarded" as being unified in general. That means in Northeast region of Vietnam may not appear elsewhere characterized climate which is basically subtropical but forest vegetation covers consist of tropical forest types [74] .Studying arising and development of vegetation covers only based on soil, climate. Ignoring climatic effects will lead to inaccurate results. In fact, every bioclimatic type is characterized by a basic type of vegitation cover. Type of vegetation cover arising will occupy a key area, laying a gound for the layout orientation, development of economic forests, agricultural crops and forest trees - the main object of the production and help guide further study to serve for-production and business. Subconclusion of chapter 2 1. Bioclimatic characteristics of Northeast region have been analyzed in great detail. It shows that the Northeas region has typical climate:of tropical monsoon climate with cold winter. Due to the influence of geological structure, topography, circulation factor and sea, the climate differentiation is in accordance with its own law. Bioclimatic map of the Northeast region of Viet Nam on a scale of 1: 500,000 shows that there are 6 bioclimatic types, 20 different bioclimatic types, with 116 separate zones. The map also shows the rules of differentiation on territorial bioclimatic resources of the Northeast region. It can be used as a basis for assessing adaptation for bioclimate. Adaptation of bioclimate -resources for development of agricultural crops and forest. Bioclimatic unit , bioclimate- soil resources are selected as evaluation units. The bioclimatic maps at provincial level and district level have been designed such as Bioclimatic map of Thai Nguyen province (on scale 1: 100,000) with 7 bioclimatic units, bioclimatic map of Lang Son province (on scale 1: 100,000) with 11bioclimatic units, the bioclimatic map of Sa Pa district (on scale 1: 50,000) with 15 different bioclimatic units. This is the basis for the author toasess the level of adaptation of bioclimate-soil resouces in detail in order to develop midland tea plants, llicium verum (Star anise), Black cardamom metioned in chapter 3. 2. The contents of chapter2 also have elucidated the close relationships, cause and effect between the bioclimatic conditions, bioclimatic resources with formation, arising of natural vegetation covers of the Northeast region. Close relationships between the climate system and living organism is shown in the differentiation, the vegetation covers that are differenciated by space, by elevation and through spectrum of life -17forms of the main types of natural vegetation covers available on the territory studied. The results of study will be the suggestion for study, assessment of bioclimatic resource for development of some agricultural crops and forestry trees that have economic value, protecting natural conservation of natural vegetation covers in Northeast region of Viet Nam Chapter 3: ASSESSEMENT OF BIOCLIMATIC NATURAL RESOUCES OF THE NORTHEAST REGION FOR DEVELOPMENT OF A FEW AGRICULTURAL CROPS AND FOREST TREES 3.1. Ecological characteristics of agricultural crops * Acacia hybrid: Acacia hybrid is a tropical tree, which is adapted to the temperature ranging 22-28°C. Requirements.The trees require rainfall ranging 1200 - 2000mm/year.They can survive in dry season that last from 3-4 months. The trees are capable of rapid growth, the roots are strong, capable of retaining and improving soil, water regulation and mixed cross breeding with many other tree species. * Midle tea plans: Tea plant belongst osubtropical group of plants,which is best adapted to temperatures between 20-28ºC. The plants requires average annual rainfall ranging from 1500mm to 2000mm and evenly distributed rainfall in the month. The tea plant requires high air humidity, during the growth period appropriate air humidity ranging from 80-85%. The tea plants is adaptive to high terrain from 200 - 600m, less than 15º slope. Soil for growing the tea plant has to be acidic. Its pHKCl ranges from 4.0 to 5.5 with more than 1 meter deep soil and drainage.. *Illicium verum (Star anise): Illicium verum is adaptive to subtropical climatic conditions of mountainous area. The tree requires annual average temperature from 20-22ºC, cold winter but little frost, suitable raifall from 1200-1500mm/year. Illicium verum is less heat tolerant. Ảppropiate height above sea level for growth of Illicium verum is about (200-600) m. The Illicium verum likes good soil and fertile acidic soil with pHKCl from 4,0-5,5 and in soil layer with thickness of > 100cm. * Black cardamom: The tree is originated from temperate and subtropical areas, very adaptable to average temperatures between 1216ºC. At low temperature (below 10ºC) or high (above 22ºC) the tree starts poorly developing and is no longer adaptive. Length of cold season best adapted for cardamom is from 5-7 months. Cardamon particularly likes moisture, requiring rainfall about 2000mm/year, air humidity in -18forests from 85% to saturation, dry season length not exceeding 2 months.The worst conditions for cardamom is frost and snow, If this phenomena occurs the tree will die. 3.2. Bioclimatic - soil map of Thai Nguyen, Lang Son provinces (scale: 100.000) và and Sa Pa district of Lao Cai province (scale 1: 50.000) Map of bioclimate - soil resouces of Thai Nguyen province designed consisted of 27 units of bioclimate- soil resources, Map of bioclimate - soil resouces of Lang son province designed expressed 38 units of bioclimate- soil resources and Map of bioclimate-soil resouces of Sa Pa district of Lao Cai province showed 33 units of bioclimate- soil resources. Each unit of bioclimate- soil resources could be seen from once to many times. Characteristics of bioclimate- soil resources units are described in detail in the appendix. 3.3. Assessement of favourite level of climate and organizational problems for development of agricultural and forestry production 3.3.1.The asessement critteria Object selected for assesement of bioclimatic adaptation for developing agricultural crops and forest trees t is the bioclimatic type unit of bioclimate- soil resources. However, in order to evaluate the results more accurately, the author used two groups of assessement criteria: Group key criteria (the main factors): (mean annual temperature, mean annual precipitation, length of the cold season, dry season length). This group was applied for resource assessment for development of crops. Group of other criteria (sub-elements):such as elevation, terrain slope, soil characteristics, limiting climate factors: maximal temperature, monthly average temperature, monthly average rainfall were used to assess. 3.3.2. Evaluation of results of bioclimatic adaptation in the Northeast region of Vietnam for development of Acacia hybrid Based on a Liebig's Law of the minimum (1840) and Shelford’ law of toletance (1913), based on the ecological limitation and amplitude of Acacia hybrid that is presented in the work of Le Dinh Kha (1999 ) and forestry handbook (2004) on the distribution, ecology and growth of planted forest to divide and determine the appropriate level for developing bioclimatic type of Acacia hybrid. The author herselt has evaluated as follows. The resuls of the author’s own assessment of the ecological requirement of acacia hybrid to bioclimatic conditions showed (figure 3.4): The bioclimatic type of total rate adaptation was IC1b at highest elevations
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