13 research outputs found
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
Discriminação de cerrado rupestre por meio de imagens multitemporais do landsat : proposta metodológica
Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, 2010.O Cerrado Rupestre corresponde a uma formação savânica do bioma Cerrado, ocorre em relevos acidentados e em meio a afloramentos rochosos, apresenta elevada biodiversidade e várias espécies endêmicas e funciona como barreira para a expansão agrícola. No estado de Goiás, ocorrências expressivas dessa fitofisionomia são encontradas no Parque Nacional da Chapada dos Veadeiros (PNCV). O objetivo deste estudo foi desenvolver uma nova abordagem metodológica para discriminar Cerrado Rupestre do PNCV com base em imagens multitemporais do satélite Landsat. Sete cenas do referido satélite foram convertidas para reflectância de superfície terrestre com suporte do algoritmo de correção atmosférica denominado FLAASH (Fast Line-of-Sight Atmospheric Analysis of Spectral Hypercubes). Em seguida, os valores de reflectância de cada cena foram somados e as imagens resultantes foram processadas por meio da técnica de segmentação de imagens por crescimento de regiões. Os segmentos foram exportados para o formato shape e os polígonos correspondentes ao Cerrado Rupestre foram identificados por meio de análise visual na tela do computador da composição colorida falsa-cor das bandas 4, 5 e 7. Foram mapeados 24.451 hectares de Cerrado Rupestre, o que corresponde a 37% da área do parque. A exatidão global do mapeamento foi de 83%. Como continuação desta linha de pesquisa, recomenda-se a inclusão de um número maior de cenas, principalmente da estação chuvosa, a integração dos dados de sensoriamento remoto com modelos digitais de elevação e a análise sinergística entre os sensores ETM+ e TM do Landsat com calibração cruzada. _______________________________________________________________________________ ABSTRACTThe Rupestrian Cerrado (Cerrado Rupestre) corresponds to a shrub-like vegetation of the Brazilian tropical savanna biome, occurs mainly over hilly topography and rocky quartzite and sandstone outcrops, presents high biodiversity and several endemic species, and acts as barrier for agricultural expansion. In the State of Goias, large occurrences of this type of vegetation are found in the Chapada dos Veadeiros National Park (PNCV - Parque Nacional da Chapada dos Veadeiros). Rupestrian Cerrado mapping using remotely sensed data is difficult because of the spectral confusion with other phytophysiognomies, especially with Dry Forest in dry season images and with Cerrado strictu sensu in wet season images. The goal of this study was to develop a new approach to discriminate Rupestrian Cerrado based on multitemporal Landsat satellite images. The study area was the PNCV. Seven Landsat scenes were converted into surface reflectances with support of FLAASH (Fast Line-of-Sight Atmospheric Analysis of Spectral Hypercubes) atmospheric correction algorithm. The reflectances from each ETM+ were summed and the resulting images were processed through the image segmentation technique by growing region. The segments were exported into shapefile format and the polygons related to the Rupestrian Cerrado were identified by visual analysis of the false color composite of 4, 5 and 7 in the computer screen. We found 24,451 hectares of Rupestrian Cerrado, which corresponds to 37% of total area of the park. The global accuracy of the mapping was 83,19%. As ongoing research, we recommend the inclusion of a higher number of scenes, mainly from wet season, the data integration of satellite images with digital elevation models, and the synergistic analysis of cross-calibrated Landsat ETM+ and TM data sets
Discriminação de Cerrado Rupestre no Parque Nacional da Chapada dos Veadeiros: uso de imagens multitemporais do Landsat
The Rupestrian Cerrado (Cerrado Rupestre) corresponds to a shrub-like vegetation of the Brazilian tropical savanna biome, occurs mainly over hilly topography and rocky quartzite and sandstone outcrops, presents high biodiversity and several endemic species, and acts as barrier for agricultural expansion. In the State of Goias, large occurrences of this type of vegetation are found in the Chapada dos Veadeiros National Park (PNCV Parque Nacional da Chapada dos Veadeiros). Rupestrian Cerrado mapping using remotely sensed data is difficult because of the spectral confusion with other phytophysiognomies, especially with Dry Forest in dry season images and with Cerrado strictu sensu in wet season images. The goal of this study was to develop a new approach to discriminate Rupestrian Cerrado based on multitemporal Landsat satellite images. We found 24,451 hectares of Rupestrian Cerrado, which corresponds to 37% of total area of the park. The global accuracy of the mapping was 83,19%.Pages: 1757-176
Temporada de incêndios florestais no Brasil em 2010: análise de série histórica de 2005 a 2010 e as influências das chuvas e do desmatamento na quantidade dos focos de calor
The paper studied the relationship between the rainfall and deforestation polygons respectively with the amount and spatial distribution of hotspots in Brazil, from 2005 to 2010. The results allow concluding that the hotspots, indicators of forest fires, have a high correlation with deforestation in terms of spatial distribution, and also show a high correlation with the amount of rainfall in terms of the total amount of the hotspots.Pages: 7902-790
Brigadas do Prevfogo em municípios críticos: uso de tecnologia geoespacial na seleção de municípios
Forest fires are among the most damaging event in the environment. Especially in low tolerance to fire ecosystems, such events cause effects that can lead to loss of biodiversity in remnants of native vegetation. The prevention manuals indicate, among other actions, that the implementation of prevention and combat brigades allows the reduction of magnitude forest fire, contributing to biodiversity conservation. Since 2001, Ibama/Prevfogo trains, selects and hires firefighters to protect threatened areas. In 2008, to extend the activity to the critical municipalities, through the program Prevfogo brigades in critic municipalities, Prevfogo had used geospatial tools to perform a selection of locales supported by brigades. The objective criteria involved the lifting of hotspots in areas of remnant native vegetation, protected areas and indigenous lands. Through an algebraic formula, it was possible to weigh these factors and, therefore, give transparency to the performance of prevent and combat teams that component of such federal program. This paper aims at sharing with the scientific community the technical criteria that selected municipalities covered by the program. The main conclusion is that the use of remote sensing and space technologies allow greater precision in the formulation of public policies on the environment and transparency in decision-making by public managers.Pages: 7895-790