The Socioecological Significance of Dispersed Farmland Trees in Northern Ethiopia
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Colby College Digital Commons @ Colby Honors Theses Student Research 2016 Missing the Trees for the Forest: The Socioecological Significance of Dispersed Farmland Trees in Northern Ethiopia Jacob A. Wall Colby College Follow this and additional works at: https://digitalcommons.colby.edu/honorstheses Part of the Environmental Studies Commons, Geographic Information Sciences Commons, Natural Resources and Conservation Commons, Natural Resources Management and Policy Commons, Nature and Society Relations Commons, Other Environmental Sciences Commons, Remote Sensing Commons, Spatial Science Commons, and the Sustainability Commons Colby College theses are protected by copyright. They may be viewed or downloaded from this site for the purposes of research and scholarship. Reproduction or distribution for commercial purposes is prohibited without written permission of the author. Recommended Citation Wall, Jacob A., "Missing the Trees for the Forest: The Socioecological Significance of Dispersed Farmland Trees in Northern Ethiopia" (2016). Honors Theses. Paper 950. https://digitalcommons.colby.edu/honorstheses/950 This Honors Thesis (Open Access) is brought to you for free and open access by the Student Research at Digital Commons @ Colby. It has been accepted for inclusion in Honors Theses by an authorized administrator of Digital Commons @ Colby. Missing the Trees for the Forest: The Socioecological Significance of Dispersed Farmland Trees in Northern Ethiopia Jacob A. Wall Environmental Studies Program Colby College Waterville, Maine May 16, 2016 A thesis submitted to the faculty of the Environmental Studies Program in partial fulfillment of the graduation requirements for the Degree of Bachelor of Arts with honors in Environmental Studies. ________________________ _______________________ ____________________ Travis W. Reynolds, Advisor Manny Gimond, Reader Bruce Rueger, Reader i Copyright © 2016 by the Environmental Studies Program, Colby College. All rights reserved. ii ABSTRACT Scattered trees are prominent features in the agricultural landscape of the Ethiopian highlands. The dry Afromontane forests of the Amhara Region in northern Ethiopia have faced centuries of deforestation - the FAO estimates only 3% of the region is forested today. The remaining landscape has been largely converted into agricultural and grazing lands, with the exception of some limited government-protected lands, as well as thousands of small forest fragments left around Orthodox Churches (“church forests”). But while a growing body of scholarship has highlighted the ecological and cultural importance of church forests and other natural forest fragments, the roles of scattered remnant trees left in actively cultivated agricultural systems remains understudied. The ecological and socio- cultural benefits of scattered trees is widely acknowledged in some human-modified landscapes, including in the context of agroforestry where such trees provide important ecosystem services such as carbon sequestration, erosion control, water quality enhancement, biodiversity conservation, pollination, and topsoil enrichment, as well as numerous economic benefits including food, fodder, and fuel. This study examines the measured and perceived temporal change in scattered tree abundance in non-agroforestry systems, through Geographic Information Systems (GIS) analyses and social survey data collection in croplands in the Amhara Region. Findings from GIS analyses indicate a surprising increase in scattered tree abundance since the 1960s and ground-truthing indicates that remnant tree scattered tree species are very diverse. In social surveys, farmers also report a perceived increase in tree numbers on cropland in recent decades – with social survey responses emphasizing the considerable economic importance and perceived ecosystem services of tree species as justification for why scattered trees are retained even when they interfere with crops. The study results highlight the importance of scattered trees on farmland and suggest policy interventions for single tree-scale conservation and scattered tree restoration across northern Ethiopia. i ii ACKNOWLEDGMENTS I would like to sincerely thank my thesis advisor, Assistant Professor of Environmental Studies Travis W. Reynolds for all his valuable guidance, persistent enthusiasm, and constant mentorship throughout this project. I would like to thank my reader, GIS and Quantitative Analysis Specialist and Research Scientist in Environmental Studies Manny Gimond, for helping me implement spatial analyses and answering my unrelenting questions. I would also like to thank Manny for being such a warm and welcoming presence in Diamond and allowing me to live in the GIS lab. Thank you also to my third reader Bruce Rueger for his time and insightful suggestions. I can’t thank Hannah Peters ’19 enough for all of the incredibly hard work she put into helping me with all of the Google Earth work. This project would not have been possible without Dr. Alemayehu Wassie who has provided constant support for the past three years and the Clare Boothe Luce Assistant Professor of Biology Cat Collins for the incredible mentorship throughout this project. I would also like to thank Gezahegn Ayinie for helping me implement the social surveys and for being a good friend. Janice Liang, a huge thanks goes out to you for making all of the trips to Ethiopia a blast and putting up with me for months on end. Thank you also to Tizezew Shimekach Sisay, Sam Lovell, and all of the REU students: Ralph Olacio, Chloe Geffken, Annika Min, Wilford Briggs, Klaus DeBoer, Tracy Gatumu, Dawn Brown, Yenesew, Walelign Alemu, Kilash Kifili, and Zeneb Awoke. This project would not have been possible without you. Finally, a huge heartfelt thank you to all of the respondents who so willingly took my survey and welcomed me into their homes. I will never forget those wonderful moments. iii iv TABLE OF CONTENTS Abstract ................................................................................................................................ i Acknowledgments.............................................................................................................. iii Table of Contents .................................................................................................................v Chapter 1: Deforestation and Forest Governance in the Northern Ethiopian Highlands ....1 Introduction ..................................................................................................................... 1 Background: Land Cover Changes in Ethiopia .............................................................. 3 Deforestation in Ethiopia .............................................................................................................. 3 Causes and Consequences of Deforestation in Northern Ethiopia ................................... 5 Institutions Governing Forests in Ethiopia .............................................................................. 7 Thesis Overview ........................................................................................................... 11 Chapter 2: Missing the Trees for the Forest – National Forest Cover Estimates Understate Tree Cover Change over Time ...........................................................................................13 Introduction ................................................................................................................... 13 Background: Tree Cover in the Amhara Region of Northern Ethiopia ........................ 14 Methods......................................................................................................................... 16 Study Sites ...................................................................................................................................... 17 GIS Methods .................................................................................................................................. 24 Results ........................................................................................................................... 31 How Scattered Tree Landscapes Are Defined ..................................................................... 31 Scattered Tree Cover Change over Time (1960s to Present) .......................................... 33 NDVI as a Proxy for Scattered Tree Cover .......................................................................... 34 NDVI Change Over Time (1985 to Present) ........................................................................ 36 Study Limitations ......................................................................................................................... 40 Discussion ..................................................................................................................... 43 Conclusions ................................................................................................................... 44 Chapter 3: The Social Significance of Scattered Remnant Trees in northern Ethiopia .....45 Introduction ................................................................................................................... 45 Methods......................................................................................................................... 45 Study Sites ...................................................................................................................................... 45 Survey Methods ...........................................................................................................................