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51.
Since the 1990s, successive Governments in Peru have sought to expand the exploration and production of the country's oil and gas resources. This economic agenda poses significant opportunities and risks which are usually considered at the macro‐level and framed by debates regarding the so‐called “natural resource curse”. While risks such as “Dutch disease” are important to consider, a worrying set of short‐term issues surrounds the impacts of rapid changes brought on by oil and gas industrial development at the micro‐level, namely, those that affect local communities and the environment. In the case of Peru, this is especially relevant to the vast areas of ecologically sensitive and previously under‐developed Amazonia that are now under concession to oil and gas companies. Low levels of industry transparency combined with a lack of uniform free, prior and informed consent are exacerbating community‐level grievances, and the conflicts to which they can lead. As the oil and gas industry expands in the Peruvian Amazon, the risk of conflict is likely to prove far harder to minimize or ameliorate than are the challenges of managing industry revenues and the risk of currency appreciation most often associated with the natural resource curse.  相似文献   
52.
Abstract: To examine differences in land use and environmental impacts between colonist and indigenous populations in the northern Ecuadorian Amazon, we combined data from household surveys and remotely sensed imagery that was collected from 778 colonist households in 64 colonization sectors, and 499 households from five indigenous groups in 36 communities. Overall, measures of deforestation and forest fragmentation were significantly greater for colonists than indigenous peoples. On average, colonist households had approximately double the area in agriculture and cash crops and 5.5 times the area in pasture as indigenous households. Nevertheless, substantial variation in land‐use patterns existed among the five indigenous groups in measures such as cattle ownership and use of hired agricultural labor. These findings support the potential conservation value of indigenous lands while cautioning against uniform policies that homogenize indigenous ethnic groups.  相似文献   
53.
Miretzky P  Bisinoti MC  Jardim WF 《Chemosphere》2005,60(11):1583-1589
The sorption of Hg (II) onto four different types of Amazon soils from the A-horizon was investigated by means of column experiments under saturation conditions and controlled metal load. Higher organic matter contents in the soil resulted in higher Hg (II) adsorptions, reaching values as high as 3.8 mg Hg g−1 soil. The amount of mercury adsorbed on a soil column (Q) shows a very poor correlation with soil clay content (r2 = 0.2527), indicating that Hg sorption in these topsoil samples is chiefly governed by the organic matter content. Desorption experiments using Negro River (Amazon) waters were conducted using soil saturated with Hg (II) in order to better understand the metal leaching mechanism. The amount of Hg (II) released from soils was around 30% of the total sorbed mercury upon saturation, suggesting that mercury sorption in the soils present in the catchment area of the Negro River basin is not a reversible process.  相似文献   
54.
In the last decade, large-scale production of soybeans has been a major driver of the enhanced deforestation in the Brazilian Amazon. We show that these soybeans are mainly exported to the EU to substitute for the BSE related banned meat and bone meal in livestock feed. This strongly suggests a link between Brazilian rainforest disappearance and BSE prevention.  相似文献   
55.
Abstract:  Research on local use values of forests across an ecological succession informs land-use decisions and conservation planning. I evaluated use values of three age classes of secondary forest: fallow fields (<5 years old, $8.20/ha/year), young secondary forest (5–20 years old, $20.60/ha/year), and old secondary forest (>20 years old, $6.80/ha/year). I quantified daily forest product use and calculated use values in dollars per hectare per year for three communities in the northern Peruvian Amazon. I made three comparisons between forest types: number of useful species, value based on different use categories, and overall use values. Old secondary forest had the greatest number of total species present and species collected. Wood, food, and medicine were the three most valuable use categories. The value different families extracted from local forests varied enormously, but median forest values were lower for all forest types than potential gains from agricultural land use (e.g., coffee $167/ha/year). Values of different-aged stands on privately owned lands in two communities did not differ significantly, whereas in the third community, young secondary forest had a significantly greater value than other forest types. Old secondary forests were the most valuable source of wood products, and wood was the only use category in which there was any difference in the value of products extracted from different-aged forest stands. The value of all three forest types on open-access (nonprivate) lands was minimal (mean in each forest type, $0/ha/year). Local people can utilize the valuation results to develop land-use strategies that balance forest product use, agricultural productivity, and biodiversity conservation.  相似文献   
56.
57.
The need to design measures for adapting to climate change is increasingly recognized as important and has encouraged research on the role of local ecological knowledge (LEK) in supporting adaptation. Studies of how LEK can help adapt to increasing climate variability remain limited. This article develops an approach through which the process of adaptation can be tracked at a community level. We describe how community residents in the Amazon floodplains incorporate natural hydrologic and ecological processes into their management systems to optimize ecosystem functioning.We describe two case studies where LEK is used as a resource by small-scale fisher-farmers in the Amazon floodplains to adapt to the increasing impacts on their livelihoods generated by changing climate patterns. This article draws on local histories and seeks to identify the critical factors that either facilitate or impede household ability to reduce their vulnerability. We found that the LEK of small fisher-farmers has facilitated the adaptation of a resource management system to optimize production across a broad range of floodplain habitats and conditions. There are, however, significant challenges to operationalizing these approaches, including an absence of systematically collected data on adaptation strategies and outcomes. In addition, local people must be integrated into policymaking processes so their knowledge can contribute to the design of locally appropriate policies for adapting to the impacts of climate related events.  相似文献   
58.
NO production and the rate constant of NO consumptionin soil samples from Amazonian forest and pasturesites were determined in the laboratory. The purposewas to study NO production and consumption in soilsfrom both types of land use as functions of soiltemperature and soil moisture. NO productionincreased exponentially with soil temperature. Thedegree of increase depended on soil moisture,indicating that the response of NO production to achange in soil temperature is most pronounced at acertain intermediate soil moisture. NO productionpeaked at a soil moisture of 0.10 g g-1, correspondingto 0.27 and 0.38 water-filled pore space for forestand pasture soils, respectively. The optimum soilmoisture for which maximum NO release was observedwas independent of soil temperature. NO consumptionwas most efficient at high soil temperatures andunder dry soil conditions. NO release wasapproximately 10 times larger for forest than pasturesoil. The difference may be related to the higherNO3 - content in forest soil.  相似文献   
59.
This paper discusses the linkages between population change, land use, and deforestation in the Amazon regions of Brazil, Bolivia, Colombia, Ecuador, Perú, and Venezuela. We begin with a brief discussion of theories of population–environment linkages, and then focus on the case of deforestation in the PanAmazon. The core of the paper reviews available data on deforestation, population growth, migration and land use in order to see how well land cover change reflects demographic and agricultural change. The data indicate that population dynamics and net migration exhibit to deforestation in some states of the basin but not others. We then discuss other explanatory factors for deforestation, and find a close correspondence between land use and deforestation, which suggests that land use is loosely tied to demographic dynamics and mediates the influence of population on deforestation. We also consider national political economic contexts of Amazon change in the six countries, and find contrasting contexts, which also helps to explain the limited demographic-deforestation correspondence. The paper closes by noting general conclusions based on the data, topics in need of further research and recent policy proposals.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue  相似文献   
60.
Lima IB 《Chemosphere》2005,59(11):1697-1702
Biogeochemical distinction of methane emissions to the atmosphere may essentially rely on the surface area and morphometry of Amazon hydroreservoirs. Tucuruí (deep) and Samuel (shallow) reservoirs released in average 13.82 ± 22.94 and 71.19 ± 107.4 mg CH4 m−2 d−1, respectively. δ13C–CH4 values from the sediments to the atmosphere indicate that the deep reservoir has extended methanotrophic layer, oxidizing large quantities of light isotope methane coming from the sediments, while sediment-generated methane can easily evade the shallow reservoir.  相似文献   
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