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 i LIST OF FIGURES ii LIST OF ABBREVIATIONS iii ACKNOWLEDGMENT iv CHAPTER 1: INTRODUCTION 1.1 Background and motivation of the study 1.2 Research framework 1.3 Drought in the world 1.4 Drought in Vietnam 1.5 Impact of drought and land use change on soil properties 10 1.5.1 Impacts of drought on soil microbial activities and biochemical properties 10 1.5.2 Impacts of land use change on soil microbial activities and biochemical properties 11 1.6 Objects and scope of the research 13 1.7 Research questions and hypothesis 17 1.7.1 Research questions 17 1.7.2 Hypothesis 17 CHAPTER METHODOLOGY 18 2.1 Data collection 18 2.1.1 Meteorological data 18 2.1.2 Remote sensing data 18 2.2 Methods of identifying and calculating drought indicators 20 2.3 Soil sampling and processing 21 2.4 Experiment setup 22 2.5 Determination of MBC and MBN 24 2.6 Identification of microbial basal respiration 24 2.7 Statistical analysis 25 CHAPTER 3: RESULTS AND DISCUSSION 26 3.1 Results 26 3.1.1 Land use and land cover maps 26 3.1.2 Drought progress characteristic 27 3.1.3 Basic soil properties 30 3.1.4 Microbial activities 31 3.2 Discussion 37 3.2.1 Land use and land cover maps 37 3.2.2 Drought progress characteristics 37 3.2.3 Soil properties and microbial activities 37 CHAPTER CONCLUSIONS AND RECOMMENDATIONS 42 4.1 Conclusions 42 4.2 Recommendations for future research 43 REFERENCES 45 APPENDIX 53 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 CO2 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 Sig t-test for Equality of Means t 9.619 Sig (2tailed) 2.861 003 df Mean Difference Std Error Difference 972.0927840 101.0552327 75 95% Confidence Interval of the Difference Lower Upper 641.4415489 1302.7440191 Table C.5: Results of the Correlation Analysis – Forest soil MBNi MBNi Pearson Correlation TC TN C:N -.308 980 218 181 514 895 981 245 800 128 860 884 3 3 3 3 Pearson Correlation 692 826 -.702 -.912 474 822 -.554 836 Sig (2-tailed) 514 381 505 269 686 386 626 370 3 3 3 3 Pearson Correlation 164 826 -.981 -.522 888 358 -.927 578 Sig (2-tailed) 895 381 124 651 304 767 245 422 3 3 3 3 Pearson Correlation 030 -.702 -.981 347 -.960 -.171 982 -.978 Sig (2-tailed) 981 505 124 774 181 891 121 135 3 3 3 3 -.927 -.912 -.522 347 -.071 -.983 164 -.537 245 269 651 774 955 117 895 639 3 3 3 3 -.308 474 888 -.960 -.071 -.112 -.996 880 N Pearson Correlation Sig (2-tailed) N MBC: MBC:MBN -.927 N BRi BRi 030 N pH pH 164 N Moi Moi 692 Sig (2-tailed) MBCi MBCi Pearson Correlation 76 MBNi MBN Sig (2-tailed) BRi MBC:MBN 304 181 955 3 3 Pearson Correlation 980 822 358 -.171 Sig (2-tailed) 128 386 767 3 Pearson Correlation 218 Sig (2-tailed) TC TN C:N 928 060 316 3 3 -.983 -.112 019 374 891 117 928 988 756 3 3 3 -.554 -.927 982 164 -.996 019 -.920 860 626 245 121 895 060 988 3 3 3 3 Pearson Correlation 181 836 578 -.978 -.537 880 374 -.920 Sig (2-tailed) 884 370 422 135 639 316 756 256 3 3 3 N C:N pH 686 N TN Moi 800 N TC MBCi N * Correlation is significant at the 0.05 level (2-tailed) 77 256 Table C.6: The Correlation Analysis results of MBC, MBN and soil respiration – Forest soil MBNi MBNi Pearson Correlation BRi BR60 BR10 692 501 910 -.876 -.003 -.927 026 -.880 514 666 272 320 998 245 983 314 3 3 3 3 Pearson Correlation 692 972 330 -.258 720 -.912 -.704 -.266 Sig (2-tailed) 514 152 786 834 488 269 503 828 Sig (2-tailed) N MBCi MBCi MBN60 MBN10 MBC60 MBC10 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 3 3 3 3 501 972 097 -.022 864 -.789 -.852 -.030 666 152 938 986 336 422 350 981 3 3 3 3 910 330 097 -.997* -.417 -.688 438 -.998* 272 786 938 048 726 517 711 042 3 3 3 3 -.876 -.258 -.022 -.997* 484 632 320 834 986 048 678 564 664 005 3 3 3 3 -.003 720 864 -.417 484 -.372 -.992** 477 78 -.504 1.000** MBNi Sig (2-tailed) 998 488 336 726 678 3 3 -.927 -.912 -.789 -.688 245 269 422 3 Pearson Correlation 026 Sig (2-tailed) N BRi Pearson Correlation Sig (2-tailed) N BR60 N BR10 MBCi MBN60 MBN10 MBC60 MBC10 Pearson Correlation Sig (2-tailed) N BRi BR60 BR10 757 008 684 3 632 -.372 350 639 517 564 757 772 559 3 3 3 -.704 -.852 438 -.504 -.992** 350 -.497 983 503 350 711 664 008 772 3 3 3 -.880 -.266 -.030 -.998* 1.000** 477 639 -.497 314 828 981 042 005 684 559 669 3 3 3 3 * Correlation is significant at the 0.05 level (2-tailed) ** Correlation is significant at the 0.01 level (2-tailed) 79 669 Table C.7: Results of the Correlation Analysis – Pineapple soil MBNi MBCi MBNi Pearson Correlation MBCi Pearson Correlation Sig (2-tailed) N Moi MBC:MBN TN TC C:N -.593 995 -.989 -.778 996 -.046 -.837 483 596 065 093 432 056 971 369 3 3 3 3 -.726 -.123 -.792 818 997 -.662 721 984 921 418 390 051 539 488 114 483 3 3 3 3 -.593 -.123 -.508 470 -.044 -.662 -.777 055 596 921 661 689 972 540 434 965 3 3 3 3 Pearson Correlation 995 -.792 -.508 -.150 -.838 982 -.147 -.888 Sig (2-tailed) 065 418 661 850 367 121 906 304 3 3 3 3 -.989 818 470 -.150 861 -.973 191 907 093 390 689 850 339 149 878 276 3 3 3 -.778 997 -.044 -.838 861 -.720 663 995 Pearson Correlation N N BRi BRi Sig (2-tailed) pH pH -.726 Sig (2-tailed) N Moi Pearson Correlation Sig (2-tailed) N MBC: Pearson Correlation 80 MBNi MBCi MBN Sig (2-tailed) MBC:MBN 972 367 339 3 3 Pearson Correlation 996 -.662 -.662 982 Sig (2-tailed) 056 539 540 3 -.046 Pearson Correlation Sig (2-tailed) N C:N BRi 051 N TC pH 432 N TN Moi Pearson Correlation Sig (2-tailed) N TN TC C:N 488 539 063 3 3 -.973 -.720 042 -.785 121 149 488 973 425 3 3 3 721 -.777 -.147 191 663 042 586 971 488 434 906 878 539 973 3 3 3 3 -.837 984 055 -.888 907 995 -.785 586 369 114 965 304 276 063 425 602 3 3 3 3 81 602 Table C.8: The Correlation Analysis results of MBC, MBN and soil respiration – Pineapple soil MBNi MBNi Pearson Correlation 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 BRi BR60 BR10 -.726 998* 400 549 361 -.989 -.237 -.034 483 043 738 630 765 093 848 979 3 3 3 3 -.726 -.770 340 176 380 818 -.496 712 440 779 887 752 390 669 496 Sig (2-tailed) N MBCi MBN60 MBN10 MBC60 MBC10 483 3 3 3 3 998* -.770 338 492 298 -.997 -.171 -.100 043 440 781 672 808 050 890 936 3 3 3 3 400 340 338 986 807 -.263 -.985 903 738 779 781 108 193 831 110 283 3 3 3 549 176 492 986 978 -.422 -.942 817 630 887 672 108 135 723 218 392 3 3 3 3 361 380 298 807 978 -.222 -.992 920 82 MBNi 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 MBCi MBN60 MBN10 MBC60 MBC10 765 752 808 193 135 3 -.989 818 -.997 -.263 093 390 050 3 -.237 BRi BR60 BR10 858 083 256 3 3 -.422 -.222 093 178 831 723 858 941 886 3 3 3 -.496 -.171 -.985 -.942 -.992 093 -.963 848 669 890 110 218 083 941 3 3 3 3 -.034 712 -.100 903 817 920 178 -.963 979 496 936 283 392 256 886 174 3 3 3 3 * Correlation is significant at the 0.05 level (2-tailed) 83 174 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 Results of the Master’s thesis 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 Maps Soil Other outcomes of the Master’s thesis Laboratory skills analysis x x x x x x x 81 x Results of the Master’s thesis 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 Maps Soil Other outcomes of the Master’s thesis Laboratory skills analysis x x x x x x x x x x 82 x Results of the Master’s thesis Program Learning Outcomes (PLOs) of MCCD Maps 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 Soil analysis Other outcomes of the Master’s thesis Laboratory skills ... 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. .. added to the soil, always causes soil acidification, because the nitrification of NH4+ increases H+ ions in the soil (White, 2015) Moreover, the leaching of bases from the soil profile due to pineapple... 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