Item – Thèses Canada

Numéro d'OCLC
1000103216
Lien(s) vers le texte intégral
Exemplaire de BAC
Auteur
Graesser, Jordan,
Titre
The changing scale of agriculture in Latin America
Diplôme
Ph. D. -- McGill University, 2017
Éditeur
[Montreal] : McGill University Libraries, [2017]
Description
1 online resource
Notes
Thesis supervisor: Navin Ramankutty (Supervisor).
Includes bibliographical references.
Résumé
"Modern agriculture has profoundly impacted the global food system through intensification and expansion into non-agricultural land cover. National governments have encouraged mechanized farming to improve cultivation efficiency, increase agricultural production, and advance agricultural trade and non-food crops. As a result, agriculture across the globe has become more efficient; but it has also altered crop dynamics and augmented specialization. In Latin America and the Caribbean (LAC), large-scale, industrialized agriculture has rapidly transformed landscapes during the past few decades. As a result, the region experienced the most rapid increase of agricultural area across the globe during this century. 'Flex' crops---particularly soybeans and sugarcane---were a major driving force behind agricultural expansion into forest and grassland ecosystems. Consequently, agriculture in LAC has become more specialized and mechanized over time. The roles and environmental impacts of different agricultural practices (e.g., crop farmers vs. livestock ranchers) and actors (e.g., smallholders vs. largeholders) is still largely unclear, though. In this dissertation, I explore the transformation of agriculture across LAC. First, in Chapter 2, I evaluate the expansion dynamics between cropland and pastureland across LAC from 2001 to 2013. We used annual data from a coarse resolution satellite (MODIS) to differentiate between the two agricultural systems, and illustrate that not all deforestation in agricultural frontiers was led by livestock ranchers. I follow this work in Chapters 3 and 4 with a field level evaluation of cropland change in a region of South America where agriculture expanded at the fastest rates across the continent. There, cropland production is said to be dominated by large-scale farmers, but the degree of their presence across the landscape is not well known. Therefore, I developed an image processing method to semi-automatically detect individual crop field parcels. The 3rd chapter documents this new approach. In Chapter 4, I apply these methods over 24 years of Landsat imagery and find that large-scale cropland farming increasingly expanded into deforested land. Finally, in Chapter 5, I examine the role of different crops, evaluating the spatial dynamics of 4 major crop groups, analyzed using sub-national agricultural statistics. In summary, my contributions through this work include: 1) the first continental analysis of annual agricultural land cover changes across LAC; 2) development of new methodology to monitor the scale of farming; 3) the quantification of large-scale agriculture's increasing presence at the deforestation frontiers; and 4) identification that soy---the crop with the strongest link to South American deforestation---contributed to more agricultural specialization, but not at the expense of other major crops. The agricultural sector in LAC is rapidly changing, and the results from this thesis advance our understanding of where and how it is changing."--
Autre lien(s)
digitool.Library.McGill.CA
escholarship.mcgill.ca
escholarship.mcgill.ca
Sujet
Geography