Soil biochemical property response to drought effects under land use change in the context of climate change

VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY BUI HANH MAI SOIL BIOCHEMICAL PROPERTY RESPONSE TO DROUGHT EFFECTS UNDER LAND-USE CHANGE IN THE CONTEXT OF CLIMATE CHANGE MASTER’S THESIS VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY BUI HANH MAI SOIL BIOCHEMICAL PROPERTY RESPONSE TO DROUGHT EFFECTS UNDER LAND-USE CHANGE IN THE CONTEXT OF CLIMATE CHANGE MAJOR: CLIMATE CHANGE AND DEVELOPMENT CODE: 8900201.02QTD RESEARCH SUPERVISOR: Dr HOANG THI THU DUYEN Hanoi, 2020 PLEDGE I assure that this thesis is the result of my own research and has not been published The use of results of other research and other documents must comply with regulations The citations and references to documents, books, research papers, and websites must be in the list of references of the thesis Author of the thesis Bui Hanh Mai TABLE OF CONTENT LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS ACKNOWLEDGMENT CHAPTER 1: INTRODUCTION 1.1Background and motivation of the study 1.2Research framework 1.3Drought in the world 1.4Drought in Vietnam 1.5Impact of drought and land use change on soil 1.5.1 Impacts of droug properties 1.5.2 Impacts of land biochemical properties 1.6 Objects and scope of the research 1.7 Research questions and hypothesis 1.7.1 Research questio 1.7.2 Hypothesis CHAPTER METHODOLOGY 2.1 Data collection 2.1.1 Meteorological d 2.1.2 Remote sensing d 2.2 Methods of identifying and calculating drough 2.3 Soil sampling and processing 2.4 Experiment setup 2.5 Determination of MBC and MBN 2.6 Identification of microbial basal respiration 2.7 Statistical analysis CHAPTER 3: RESULTS AND DISCUSSION 3.1 Results 3.1.1 Land use and lan 3.1.2 Drought progres 3.1.3 Basic soil proper 3.1.4Microbial activit 3.2Discussion 3.2.1Land use and lan 3.2.2Drought progres 3.2.3Soil properties a CHAPTER CONCLUSIONS AND RECOMMENDATIONS 4.1Conclusions 4.2Recommendations for future research REFERENCES APPENDIX LIST OF TABLES Table 2.1 Land cover types description 189 Table 2.2 Classification used for K indices 21 Table 2.3 Methodologies to analyze soil physic-chemical properties .22 Table 3.1 The basic properties of forest soil and pineapple soil 30 i LIST OF FIGURES Figure 1.1 Drought concept relevant to climate change Drought releases ecological and socio-economic impacts Figure 1.2 Research framework Figure 1.3 Average monthly sunshine hours (2000 - 2019) in Quang Nam 14 Figure 1.4 Average monthly temperature (2000 - 2019) in Quang Nam 15 Figure 1.5 Average monthly precipitation (2000 - 2019) in Quang Nam .16 Figure 1.6 Average monthly evaporation (2000 - 2019) in Quang Nam 16 Figure 2.1 Soil sampling locations at Phiem Ai Village, Dai Nghia Commune, Dai Loc District, Quang Nam Province 231 Figure 2.2 Experiment setup for drought condition 23 Figure 2.3 Design experiment to analyze soil respiration .24 Figure 3.1 Land-use and land cover maps in Quang Nam (2003 – 2018) .26 Figure 3.2 The total area of each type of land use and land cover in Quang Nam 2003 – 2018 27 Figure 3.3 Drought frequency month during 2000 – 2019 28 Figure 3.4 K indices of mean drought months in dry season 28 Figure 3.5 K indices of drought months during dry season (2000 – 2019) .29 Figure 3.6 MBC of forest soil and pineapple soil 31 Figure 3.7 MBN of forest soil and pineapple soil 32 Figure 3.8 MBC:MBN ratio of two soil types and three treatments .33 Figure 3.9 The ratios of MBC to SOC and MBN to TN of both soils 33 Figure 3.10 The microbial basal respiration in the difference soil moistures of both soil 35 Figure 3.11 The amount of CO2 after three periods incubators at three treatments 35 Figure 3.12 The correlation between MBN and soil respiration of forest soil in incubated with 10% WHC .36 ii LIST OF ABBREVIATIONS ANOVA C ENSO Gt IMHEN IPCC MBC MBN MODIS N SOC SOM TC TN WHC One-way analysis of variance Carbon El Nino Southern Oscillation Gigaton Institute of Meteorology, Hydrology and Climate Change International Panel on Climate Change Microbial biomass carbon Microbial biomass nitrogen Moderate Resolution Imaging Spectroradiometer Nitrogen Soil organic carbon Soil organic matter Total carbon Total nitrogen Water holding capacity iii ACKNOWLEDGMENT To complete this thesis, I would like to express my sincere thanks to the lecturers and staff of Program of Climate Change and Development, Vietnam Japan University, Vietnam National University, Hanoi, and other lecturers and students of Soil Sciences Department of Vietnam National University of who guided and facilitated me to complete my thesis on time I would like to express my deepest and most sincere thanks to my supervisor Dr Hoang Thi Thu Duyen, advisor - Dr Kotera Akihiko, Prof Phan Van Tan and Dr Nguyen Van Quang - Lecturers of Climate Change and Development program, Vietnam Japan University, VNU for their dedication and valuable comments on thesis In addition, the research has also received support and help from leaders and staff of Quang Nam Crop Production and Plant Protection Subdepartment and Department of Agriculture and Rural Development Dai Loc District so that I could collect information related to the thesis Last but not least, the author also appreciates financial support of VNU project (code QG.20.63, No 1086/QĐ-ĐHQGHN), without this support the implementation is impossible Finally, I would like to dedicate this thesis to my parents and friends as a gesture of my thanks for their constant support and belief in me iv CHAPTER INTRODUCTION 1.1 Background and motivation of the study Climate change is a natural process but it is boosted by anthropogenic activities (IPCC, 2012) and the rapid increases in CO concentrations over the last few centuries, which leads to a series of unpredictable weather events Drought/severe drought is one of the consequences of climate change, which is projected to increase unprecedentedly in prone areas (IPCC, 2019) The world temperature is supposed to increase over 1.5 to oC in the period of 2081 to 2100 (Collins et al., 2013) Each increase of atmospheric temperature results in 7% increase of atmospheric moisture holding capacity (Sun et al., 1996) Therefore, precipitation becomes more condensed, and hence, prolonged dry season over a year In drought-sensitive areas, such as the Mediterranean, north-eastern Asia, West Asia, many regions of South America and the majority of Africa (IPCC, 2019), global warming exacerbates drought severity by accelerating evaporation, enhancing shortage of soil moisture (Figure 1.1) Levene's Test for Equality of Variances F 10 Equal variances not assumed 75 Sig Table C.5: Results of the Correlation Analysis – Forest soil MBNi Pearson Correlation Sig (2-tailed) N MBCi Pearson Correlation Sig (2-tailed) N Moi Pearson Correlation Sig (2-tailed) N pH Pearson Correlation Sig (2-tailed) N BRi Pearson Correlation Sig (2-tailed) N MBC: Pearson Correlation MBN Sig (2-tailed) N TC Pearson Correlation Sig (2-tailed) N TN Pearson Correlation Sig (2-tailed) N C:N Pearson Correlation Sig (2-tailed) N * Correlation is significant at the 0.05 level (2-tailed) 77 Table C.6: The Correlation Analysis results of MBC, MBN and soil respiration – Forest soil MBNi Pearson Correlation Sig (2-tailed) N MBCi Pearson Correlation Sig (2-tailed) N MBN60 Pearson Correlation Sig (2-tailed) N MBN10 Pearson Correlation Sig (2-tailed) N MBC60 Pearson Correlation Sig (2-tailed) N MBC10 Pearson Correlation Sig (2-tailed) N BRi Pearson Correlation Sig (2-tailed) N BR60 Pearson Correlation Sig (2-tailed) N BR10 Pearson Correlation Sig (2-tailed) N * Correlation is significant at the 0.05 level (2-tailed) ** Correlation is significant at the 0.01 level (2-tailed) 79 Table C.7: Results of the Correlation Analysis – Pineapple soil MBNi Pearson Correlation Sig (2-tailed) N MBCi Pearson Correlation Sig (2-tailed) N Moi Pearson Correlation Sig (2-tailed) N pH Pearson Correlation Sig (2-tailed) N BRi Pearson Correlation Sig (2-tailed) N MBC: Pearson Correlation MBN Sig (2-tailed) N TN Pearson Correlation Sig (2-tailed) N TC Pearson Correlation Sig (2-tailed) N C:N Pearson Correlation Sig (2-tailed) N 81 Table C.8: The Correlation Analysis results of MBC, MBN and soil respiration – Pineapple soil MBNi Pearson Correlation Sig (2-tailed) N MBCi Pearson Correlation Sig (2-tailed) N MBN60 Pearson Correlation Sig (2-tailed) N MBN10 Pearson Correlation Sig (2-tailed) N MBC60 Pearson Correlation Sig (2-tailed) N MBC10 Pearson Correlation Sig (2-tailed) N BRi Pearson Correlation Sig (2-tailed) N BR60 Pearson Correlation Sig (2-tailed) N BR10 Pearson Correlation Sig (2-tailed) N * Correlation is significant at the 0.05 level (2-tailed) 83 Where: F = forest soil P = pineapple soil MBNi = microbial biomass nitrogen initial period MBN60 = microbial biomass nitrogen incubated with 60% WHC MBN10 = microbial biomass nitrogen incubated with 10% WHC MBCi = microbial biomass carbon initial period MBC60 = microbial biomass carbon incubated with 60% WHC MBC10 = microbial biomass carbon incubated with 10% WHC Moi (moi) = moisture pH = pH (H2O) BD = bulk density BRi = soil respiration initial period BR10 = soil respiration incubated with 60% WHC BR60 = soil respiration incubated with 10% WHC MBC:MBN = microbial biomass carbon to microbial biomass nitrogen ratio TN = total nitrogen TC = total carbon TP = total phosphorus C:N = carbon to nitrogen ratio 78 Appendix D: The activities during the master thesis implementation Interview local authorities Soil sampling Soil processing 79 Setup experiments 80 Appendix E: Learning outcome Program Learning Outcomes (PLOs) of MCCD PLO1: Accumulating and mastering the basic knowledge on principles of Marxism - Leninism, Political Theory and Ideology of Ho Chi Minh; and general knowledge about administration and management PLO2: Mastering the fundamental, interdisciplinary knowledge and methodologies to assess and address actual problems (fate and features) related to CC mitigation, adaptation for sustainable development at global, national and local levels PLO3: Understanding and developing systematic thinking; necessary knowledge on science, technology, innovation and governance related to CC response for development; identifying, analyzing, assessing and forecasting the issues related to CC and CCR; predicting the developing trend of CC science PLO4: Applying knowledge to solve the problems in CC and CCR: planning and approaching the works in field of CC; proposing the initiatives as well as the researches on CC; implementing the solutions on science, technology, mechanism, policy and finance for CCR and development PLO5: Having skills of cooperation with personal, agencies, organizations domestically and internationally to solve the CC 81 Program Learning Outcomes (PLOs) of MCCD issues, communication in works, projects on CC; and organizing, managing and administrating advanced career development PLO6: Accumulating soft skills to self-directed and adapt to competitive working environment such as English proficiency (at level 4/6 according to English competencies Framework for Vietnam), Japanese communication skills; having skills on time management; using the basic computer skills proficiently; working and researching independently; having skills of research and development; and using technologies creatively in academic and professional fields PLO7: Dynamic, confident, persistent, enthusiastic, and risktaking and management PLO8: Having social/community’s responsibility and professional morality, especially for the scientific research results; being able to adapt to multicultural environment, ensure the harmony between the stakeholders, CCR and development; having good social morality, assist the vulnerable people to climate change; compliance with the law; discipline at work and positive lifestyle; having good attitude to their career in climate change response for sustainable development PLO9: Having responsibility for researching, creating new Program Learning Outcomes (PLOs) of MCCD knowledge, and offering new ideas on climate change response in different complex situations; adapting and guiding other people and making expert decisions on climate change response; managing research, having high responsibility in learning in order to develop professional knowledge, and creating new ideas in new process; and having good life-long learning capacity 83 ... with the total coverage of wet ecosystems around the world (Ramesh et al., 2019) Therefore, the study ? ?Soil biochemical property response to drought effects under the land- use change in the context. .. VIETNAM JAPAN UNIVERSITY BUI HANH MAI SOIL BIOCHEMICAL PROPERTY RESPONSE TO DROUGHT EFFECTS UNDER LAND- USE CHANGE IN THE CONTEXT OF CLIMATE CHANGE MAJOR: CLIMATE CHANGE AND DEVELOPMENT CODE: 8900201.02QTD... 2019) Land- use change, as well as drought, have an impact on the biochemical properties of the soil Increasing frequency, intensity and timing of drought is predicted to lead to reduce the functions