A remote sensing/GIS-based physical template to understand the biogeochemistry of the Ji-Paraná river basin (Western Amazônia)

Ballester, Maria Victória Ramos; Victoria, D. de C.; Krusche, Alex V.; Coburn, Robert C.; Victória, Reynaldo Luiz; Richey, Jeffrey E.; Logsdon, Miles G.; Mayorga, Emilio; Matricardi, Eraldo Aparecido Trondoli

doi:10.1016/j.rse.2002.10.001

Cited by 77 publications

(70 citation statements)

References 52 publications

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“…The rio Machado is approximately 1,200 km long (Fernandes & Guimarães, 2002) and is formed by the confluence of the Comemoração and Pimenta Bueno rivers. Along its course, it also receives the Rolim de Moura, Urupá, Jaru, Machadinho, and Preto rivers and flows into the right bank of the rio Madeira (Ballester et al, 2003). This region has many terra firme streams, which are intermittent during most of the dry season (Fernandes & Guimarães, 2002).…”

Section: Methodsmentioning

confidence: 99%

Fish complementarity is associated to forests in Amazonian streams

et al. 2015

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The functional structure of communities is commonly measured by the variability in functional traits, which may demonstrate complementarity or redundancy patterns. In this study, we tested the influence of environmental variables on the functional structure of fish assemblages in Amazonian streams within a deforestation gradient. We calculated six ecomorphological traits related to habitat use from each fish species, and used them to calculate the net relatedness index (NRI) and the nearest taxon index (NTI). The set of species that used the habitat differently (complementary or overdispersed assemblages) occurred in sites with a greater proportion of forests. The set of species that used the habitat in a similar way (redundant or clustered assemblages) occurred in sites with a greater proportion of grasses in the stream banks. Therefore, the deforestation of entire watersheds, which has occurred in many Amazonian regions, may be a central factor for the functional homogenization of fish fauna.A estrutura funcional das comunidades é comumente medida através da variabilidade nos traços funcionais, que pode demonstrar padrões de complementaridade ou redundância. Testamos a influência de variáveis ambientais na estrutura funcional de peixes de riachos Amazônicos ao longo do gradiente de desmatamento. Para cada espécie, calculamos seis traços ecomorfológicos relacionados ao uso do hábitat e usamos esses traços para calcular o índice de proximidade de táxon (NRI) e o índice do táxon mais próximo (NTI). Os conjuntos de espécies que usam o hábitat de modo distinto (comunidades complementares) ocorreram em trechos de microbacias com maior proporção de florestas, e os conjuntos de espécies que utilizam o hábitat de forma similar (comunidades redundantes) ocorreram em trechos com maior proporção de gramíneas nas margens. Portanto, o desmatamento de microbacias inteiras, como vem acontecendo em muitas regiões Amazônicas, pode ser o fator principal para a homogeneização funcional da ictiofauna.

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Section: Methodsmentioning

confidence: 99%

Fish complementarity is associated to forests in Amazonian streams

et al. 2015

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“…The importance of Amazon forest in the dynamics of climatic and biogeochemical processes makes the deforestation of the Amazon a frequent subject of study, especially with regard to carbon cycling, global climate and environmental changes (Potter et al 2001, CPTEC/INPE 2003, Roberts et al 2003, Durieux et al 2003, Ballester et al 2003 and the conservation of biodiversity (Fearnside 2001). In contrast, only a relatively small number of researchers are concentrating on the human dimension of the Amazonian occupation.…”

Section: Introductionmentioning

confidence: 99%

DMSP/OLS night‐time light imagery for urban population estimates in the Brazilian Amazon

Amaral

Monteiro

Câmara

et al. 2006

International Journal of Remote Sensing

170

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This article analyses DMSP/OLS night-time imagery as an information source to detect human settlements and to estimate the urban population in the Amazon region. DMSP/OLS single orbits were used to generate a DMSP stable light mosaic for 2002, in which most of the urban settlements with a population higher than 5000 inhabitants were precisely identified. DMSP/OLS night-time mosaic images from 1995, 1999 and 2002 were integrated with the IBGE census data and the correlation between DMSP/OLS night-time light area and the urban population was compared. Coefficients of determination higher than 0.8 were obtained from the linear regression between DMSP/OLS night-time lights and urban population census data. Although the fieldwork showed that DMSP image data could only record urbanized settlements with more than 2.5 km 2 of well-lit surface areas, the initial and final extension of the night-time light foci were actually precisely registered. Therefore, this paper identifies the potential of DMSP night-time light images for estimating urban population as well as the technical limitations of using such images as a means to monitor urban population dynamics annually in a region where data are scarce and the demographic dynamics are unique, as in the Brazilian Amazon.

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“…Moreover, infrastructure implementation and government policy are the primary drivers controlling time and spatial scales of deforestation in most cases (Ballester et al, 2003). In general, this process begins with official or unofficial roads opening and paving in a preserved region, which in turn allow access to illegal wood exploitation, followed by conversion to pasture for cattle and crops (Ferreira et al, 2005;Yoshikawa & Sanga-Ngoie, 2011).…”

Section: Discussionmentioning

confidence: 99%

“…The presence of native vegetation in Amazon is mainly motivated by isolation and existence of protected areas (Bruner et al, 2001), while deforested regions are related to roads and cities proximity (Alves et al, 1999;Ballester et al, 2003;Batistella & Moran, 2005). Therefore, to identify drivers of pristine vegetation remnants in our study area, we selected six factors: 1) roads distances; 2) cities distances; 3) terrain slope; 4) land tenure; 5) fertility; and 6) presence of flooding areas (Figure 2).…”

Section: Driving Factors For Native Vegetation Conservationmentioning

confidence: 99%

“…As a complex phenomenon, the origin of deforestation can be attributed to a series of factors , related to local, regional and global scale processes. In the Amazon, many studies have shown that increasing in deforestation was related to tax incentives (Mahar, 1989;Nepstad et al, 2001), national economy , wood industry, agriculture and cattle raising expansion Asner et al, 2009;Margulis, 2004;Walker et al, 2009), roads construction (Alves et al, 2009;Ballester et al, 2003), low slope, soil properties, among others. In this scenario, an important strategy to decrease deforestation is the public conservation policies aiming the creation of conservation units of integral preservation, sustainable use of natural resources and indigenous lands .…”

Section: Introductionmentioning

confidence: 99%

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The Role of Physical and Political Factors on the Conservation of Native Vegetation in the Brazilian Forest-Savanna Ecotone

Sawakuchi¹,

Ballester²,

Ferreira³

2013

OJF

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The Araguaia River Basin covers a considerable extent of Brazilian Savanna (locally called Cerrado) and part of Amazon Tropical Rainforest, embracing high biodiversity and a vast flooding area. This region has been converted to agricultural lands since 1970s, for the past four decades, leading to a fragmented landscape that holds one of the few large remaining blocks of Cerrado primary vegetation. Therefore, to assess the degree of preservation of this area a 2007 primary vegetation map was derived through Boolean operations using land use and land cover maps from 1975, 1985, 1996 and 2007, from digital classification of Landsat MSS and TM images. To evaluate the role of driving factors on the presence of pristine vegetation, a logistic regression analyses was performed. Tested factors were: distance from roads and cities, terrain slope, land tenure, soil fertility and flooding. We found statistical significant values (p < .05) showing that distance from roads and cities, the increase in slope, the presence of protected areas, indigenous lands, wetlands and areas with low fertility have positive influence on the presence and maintenance of these pristine areas. The occurrence of original vegetation in many cases is associated with environmental constraints that difficult or do not allow agricultural use. Analysis of physical and political factors, which may have direct or indirect influence on the conservation and degradation of native vegetation are very important for the comprehension of the dynamics of regional land use, and provide supporting information for a more efficient and sustainable regional landscape planning.

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A remote sensing/GIS-based physical template to understand the biogeochemistry of the Ji-Paraná river basin (Western Amazônia)

Cited by 77 publications

References 52 publications

Fish complementarity is associated to forests in Amazonian streams

Fish complementarity is associated to forests in Amazonian streams

DMSP/OLS night‐time light imagery for urban population estimates in the Brazilian Amazon

The Role of Physical and Political Factors on the Conservation of Native Vegetation in the Brazilian Forest-Savanna Ecotone

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