Anthropic Processes and Land-Use Change During 33 Years in Roraima, Northern Amazonia
| Autor: | Thiago Henrique de Castro Araújo, Eliana de Souza, Valdinar Ferreira Melo, Marcelo M. Santiago, Reinaldo Imbrozio Barbosa, Carlos Ernesto Gonçalves Reynaud Schaefer, Soniclay Da S. Maia, Márcio Rocha Francelino, Marcelle A. Urquiza |
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| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
Amazônia - Roraima 010504 meteorology & atmospheric sciences Land use Agroforestry Amazon rainforest business.industry Subsistence agriculture Ecotone Fogo Florestal 01 natural sciences Geography Deforestation Agriculture Human settlement Land use land-use change and forestry business Desmatamento 010606 plant biology & botany 0105 earth and related environmental sciences |
| Zdroj: | Repositório Institucional do INPA Instituto Nacional de Pesquisas da Amazônia (INPA) instacron:INPA |
| ISSN: | 1916-9760 1916-9752 |
| DOI: | 10.5539/jas.v10n7p426 |
| Popis: | The Amazon region has experienced a rapid rate of deforestation and land use change as a result of establishment of agricultural settlements, resulting from public policies designed to promote rural development. We analyzed land use patterns and changes in the central region of Roraima, northern Brazil, testing the hypothesis that the anthropic pressure based on the conversion of natural vegetation (forest ecotone zone and open areas of savanna and campinaranas) on agriculture and pasture, has led to the decline of forest resilience, and has not promoted development in lands converted in agricultural colonization projects, a process exacerbated by practices of burning. Satellite images from between 1984 to 2017, with field-collected data and geoprocessing techniques, allowed interpretation and analysis of seven land-use classes. Agriculturally-based human impacts were greatest in forest areas, with forest loss rates being 6.4 times greater than regeneration rates. The 39.3% reduction in natural non-forest vegetation types exceeded that of forest loss (23.8%). Repeated fires resulted in a 627.1% increase in forest fragmentation in areas heavily impacted by fire. Our study revealed that, over 33 years, deforestation and transitions of land to non-conservation uses did not lead to a system with highly productive agricultural practices, but to extensive impoverished, and degraded subsistence. The main reason was the basic unsuitability of the region´s extremely acidic/dystrophic soils on which settlements have been founded, and the predominance of low-tech, family-based, agriculture and the absence of the required technology for attaining better results. |
| Databáze: | OpenAIRE |
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