Land-Use Dynamics of Kerala's Agroforestry Systems
Total Page:16
File Type:pdf, Size:1020Kb
1 Land-use dynamics of Kerala’s agroforestry systems Thomas Arcadius Fox Department of Geography McGill University Montreal, Quebec March 2015 A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Masters of Science © Thomas Fox 2 Table of Contents Title Page ........................................................................................................................................ 1 Table of Contents ............................................................................................................................ 2 Abstract ........................................................................................................................................... 4 Résumé ............................................................................................................................................ 5 Acknowledgements ......................................................................................................................... 6 List of Figures ................................................................................................................................. 8 List of Tables .................................................................................................................................. 9 Chapter 1 Introduction, literature review, and general objectives .............................................. 10 1.1 The importance of agricultural land use .............................................................................. 10 1.2 Tropical homegardens ......................................................................................................... 11 1.3 General description of Kerala, India ................................................................................... 13 1.4 A brief history of agriculture in Kerala ............................................................................... 14 1.5 Thesis objectives and structure ........................................................................................... 17 Chapter 2 Kerala‟s transitioning agricultural landscapes ............................................................ 19 2.1 Introduction ......................................................................................................................... 19 2.2 Methods ............................................................................................................................... 21 2.2.1 Study Areas .............................................................................................................................. 21 2.2.2 Data Description and Preprocessing ................................................................................... 21 2.2.3 Pixel-based vs. Manual Classification................................................................................. 24 2.2.4 Class Selection ........................................................................................................................ 26 2.2.5 Classification Methodology and Rule Set ........................................................................... 28 2.2.6 Change Detection ................................................................................................................... 30 2.3 Results ................................................................................................................................. 30 2.4 Discussion & Conclusion .................................................................................................... 34 Segue connecting chapters two and three ..................................................................................... 39 3 Chapter 3 The changing face of homegarden agriculture ........................................................... 40 3.1 Introduction ......................................................................................................................... 40 3.2 Methods ............................................................................................................................... 43 3.2.1 Study Site, Participants, and Research Team ..................................................................... 43 3.2.2 Surveys ..................................................................................................................................... 45 3.2.3 Semi-structured Interviews .................................................................................................... 47 3.3 Survey Results ..................................................................................................................... 48 3.3.1 Characteristics of Homegardens and Homegardeners ..................................................... 48 3.3.2 Trends in Crop and Livestock Production .......................................................................... 51 3.4 Discussion of Survey Results .............................................................................................. 54 3.5 Discussion of Interview Outcomes ..................................................................................... 57 3.5.1 Land-use Change: Further Insights ..................................................................................... 57 3.5.2 Drivers of Land-use Change ................................................................................................. 61 3.5.3 Coping Strategies ................................................................................................................... 68 2.5.4 Perceived Implications .......................................................................................................... 69 2.5.5 Overview of interview outcomes ........................................................................................... 72 Chapter 4 Concluding Discussion ............................................................................................... 73 References ..................................................................................................................................... 78 Appendix A: Pixel-based classification results............................................................................. 83 Appendix B: Consent form ........................................................................................................... 86 Appendix C: Questionnaire........................................................................................................... 88 4 Abstract Kerala‟s homegardens are ancient agroforestry systems celebrated for their ecological sustainability, their subsistence potential, and their high diversity of cultivated species. While homegardens have occupied Kerala‟s landscapes for thousands of years, some are worried that these systems are under threat from comparatively profitable plantations of rubber and other monoculture-based tree crops. Thus, the aim of this thesis is to examine the land-use dynamics in Kerala‟s agroforestry systems between 2001 and 2013. In Chapter 2, I analyze high resolution satellite imagery in order to broadly characterize agricultural and non-agricultural land-use changes in three panchayats (counties) of Kerala. The results indicate that: 1) wetlands (mostly paddy rice) are decreasing in all study regions; 2) built surfaces are increasing dramatically in all regions; and 3) agroforestry exists in a dynamic equilibrium with other land covers. In Chapter 3, I use a combination of quantitative surveys and semi-structured interviews to identify land-use changes and their drivers at the homegarden scale for 115 homegardens in 8 panchayats. Results indicate that almost all commercial and food crops, as well as livestock, are decreasing in production on homegardens, and that no crops are increasing. Nearly every farmer interviewed perceived a decline in agriculture in their region, and offered numerous interrelated explanations for why this might be so. Overall, Kerala‟s landscapes are undergoing a dynamic, multi-scale transition away from both homegarden- and plantation-based agriculture. 5 Résumé Les jardins familiaux du Kerala sont de ancients systèmes agroforestiers célébrés pour leur durabilité écologique, leur potentiel de subsistance, et pour leur grande diversité d‟espèces cultivées. Bien que les jardins familiaux ont occupé les paysages du Kerala depuis des milliers d'années, certains s‟inquiètent que l'existence de ces systèmes soit menacée par des plantations relativement rentables telles que celles de caoutchouc ou d'autres arbres de monoculture. Ainsi, l'objectif de cette thèse est de quantifier, de décrire et d‟expliquer la dynamique d'utilisation des terres des systèmes agroforestiers du Kerala de 2001 à 2013. Dans le deuxième chapitre, j‟analyse une imagerie satellite de haute résolution pour caractériser les changements des paysages agricole et non agricole dans trois panchayats (comtés) du Kerala. Les résultats indiquent que: 1) les zones humides sont en baisse dans toutes les régions étudiées; 2) les constructions humaines augmentent considérablement dans toutes les régions; et 3) l'agroforesterie existe en équilibre dynamique avec le reste du couvert terrestre. Dans le chapitre 3, j‟utilise une combinaison d'enquêtes quantitatives et d‟entrevues semi-structurées pour identifier les changements d'utilisation des terres et de leurs origines à l'échelle des jardins familiaux pour 115 jardins familiaux dans 8 panchayats. Les résultats indiquent que la quasi- totalité des cultures commerciales et alimentaires, ainsi que