Transformações da terra: para uma perspectiva agroecológica na história.

O artigo discute a constituição do campo da história ambiental, que se deu nos anos 70 em meio aos debates sobre a crise ecológica e a eclosão do movimento ambientalista. Esta história não aceita a noção de que as sociedades humanas não produzem alterações ambientais significativas, e interpela as condições específicas dessa interação recorrente. O sistema agroecológico representa um dos casos mais típicos de rearranjo da atividade humana sobre os ecossistemas naturais, em uma relação complexa de interação entre plantas nativas, vegetação forasteira, fertilidade dos solos e diversas práticas agrícolas. O itinerário dessas mudanças é essencial para se compreender a história do ponto de vista ambienta

A New Science for a Post-Frontier World

The driving force behind the North American frontier were waves of economic migrants from Europe and their offspring, competing against the indigenous people and eventually replacing them. But those waves were backed up by the power of the American and Canadian nation states, with their well-armed military, their well funded railroads, and other technology and capital. Science too was initially on the side of the invaders. But after World War One that frontier began to run out of free, abundant land. Then began what I will call a “post-frontier” science, especially ecological in content, that represented a very different attitude toward the white man’s conquest. Scientists like Frederick Clements, John C. Weaver, Paul Sears, and Stan Rowe, all natives to the Great Plains, laid the foundations for what is now a powerful critique of frontier agriculture. This article aims to summarize that critique briefly but focus mainly on the more recent work of Wes Jackson, founder and longtime president of the Land Institute. He has strongly criticized the frontier ethos for its the lack of understanding of the native ecology of the grasslands. In its place he has offered a vision of “perennial polyculture,” using nature as a model for agriculture in an era of limits. That model has not only been making a growing impact on American thinking but has now spread to other continents. Will the end of this frontier cycle and scientific reappraisal turn out to be what Jackson calls a “new agriculture,” one based on learning from the past and one that can change farming all over the world?The driving force behind the North American frontier were waves of economic migrants from Europe and their offspring, competing against the indigenous people and eventually replacing them. But those waves were backed up by the power of the American and Canadian nation states, with their well-armed military, their well funded railroads, and other technology and capital. Science too was initially on the side of the invaders. But after World War One that frontier began to run out of free, abundant land. Then began what I will call a “post-frontier” science, especially ecological in content, that represented a very different attitude toward the white man’s conquest. Scientists like Frederick Clements, John C. Weaver, Paul Sears, and Stan Rowe, all natives to the Great Plains, laid the foundations for what is now a powerful critique of frontier agriculture. This article aims to summarize that critique briefly but focus mainly on the more recent work of Wes Jackson, founder and longtime president of the Land Institute. He has strongly criticized the frontier ethos for its the lack of understanding of the native ecology of the grasslands. In its place he has offered a vision of “perennial polyculture,” using nature as a model for agriculture in an era of limits. That model has not only been making a growing impact on American thinking but has now spread to other continents. Will the end of this frontier cycle and scientific reappraisal turn out to be what Jackson calls a “new agriculture,” one based on learning from the past and one that can change farming all over the world?The driving force behind the North American frontier were waves of economic migrants from Europe and their offspring, competing against the indigenous people and eventually replacing them. But those waves were backed up by the power of the American and Canadian nation states, with their well-armed military, their well funded railroads, and other technology and capital. Science too was initially on the side of the invaders. But after World War One that frontier began to run out of free, abundant land. Then began what I will call a “post-frontier” science, especially ecological in content, that represented a very different attitude toward the white man’s conquest. Scientists like Frederick Clements, John C. Weaver, Paul Sears, and Stan Rowe, all natives to the Great Plains, laid the foundations for what is now a powerful critique of frontier agriculture. This article aims to summarize that critique briefly but focus mainly on the more recent work of Wes Jackson, founder and longtime president of the Land Institute. He has strongly criticized the frontier ethos for its the lack of understanding of the native ecology of the grasslands. In its place he has offered a vision of “perennial polyculture,” using nature as a model for agriculture in an era of limits. That model has not only been making a growing impact on American thinking but has now spread to other continents. Will the end of this frontier cycle and scientific reappraisal turn out to be what Jackson calls a “new agriculture,” one based on learning from the past and one that can change farming all over the world

Frontier and Western History in Central Brazil

Frontier and Western History in Central Brazil Dutra e Silva, S. No Oeste, a terra e o céu: a expansão da fronteira agrícola no Brasil Central (Rio de Janeiro: Mauad X, 2017

Ecosystems as Commodity Frontiers - Challenges Faced by Land Set Aside as Protected Areas (PAs) in the Dubai Emirate, United Arab Emirates (UAE)

This chapter examines natural habitats in Dubai, UAE that the state has demarcated as protected areas (PAs) in an attempt to utilize them for recreational/economic purposes while also mitigating habitat fragmentation. The authors employ the concept of the ‘commodity frontier’ to demonstrate how these PAs have contributed to the ongoing commodification of land that began with the rise of modern agriculture in the mid-twentieth century. The rise of the oil economy in the mid-twentieth century stimulated significant development that, over time, has resulted in ecological degradation. In line with state conservation agendas aimed at greening the desert and preserving biodiversity, PAs also serve as a mechanism for promoting tourism. Ironically, these activities have in turn put further pressure on the country’s natural resources and desert ecology. The authors also present an example of a PA that has been effectively managed and could serve as a model of sustainable development

Recruitment and Retention of Patients into Emergency Medicine Clinical Trials

The emergency medicine (EM) and prehospital environments are unlike any other clinical environments and require special consideration to allow the successful implementation of clinical trials. This article reviews the specific issues involved in EM clinical trials and provides strategies from EM and non-EM trials to maximize recruitment and retention. While the evidence supporting some of these strategies is deficient, addressing recruitment and retention issues with specific strategies will help researchers deal with these issues in their funding applications and in turn develop the necessary infrastructure to participate in EM clinical trials.ACADEMIC EMERGENCY MEDICINE 2010; 17:1104–1112 © 2010 by the Society for Academic Emergency MedicinePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79223/1/j.1553-2712.2010.00866.x.pd