964 resultados para ENVIRONMENTAL DEGRADATION


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Following the 1998 National Forest Policy and Forest Act of 2002, participatory forest management (PFM) is being introduced in Tanzania. PFM has two key objectives: to reduce forest degradation thereby increasing ecosystem services, and to improve the livelihoods of local villagers. A unique data set collected in 2006 suggests that significant challenges remain with respect to communicating the new forest policies if the objectives of PFM are to be achieved. First, villagers as a group are much less well informed than other stakeholders, and their knowledge is often inaccurate. Second, women are less likely than men to have heard of the changes. Third, how PFM will contribute to poverty reduction (a key objective of PFM) is not always clear. Fourth, environmental degradation may not be reduced as much as anticipated – without alternatives sources, villagers often continue to cut trees for charcoal and firewood in the protected forests. Finally, several mismatches in perceptions are identified that could lead to difficulties in implementing PFM.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The majority of the world’s population now live in cities. This poses great challenges, but also great opportunities in terms of tackling climate change, resource depletion and environmental degradation. Policy agendas have increasingly focused on how to develop and maintain ‘integrated sustainable urban development’, and a number of theoretical conceptualisations of urban transition have been formulated to help our thinking and understanding in both developed and developing countries. Drawing on examples around the world the paper aims to examine the key ‘critical success factors’ that need to be in place for cities to traverse a pathway to a more sustainable future in urban development terms by 2050. The paper explores how important the issues of ‘scale’ is in the context of complexity and fragmentation in the city’s built environment, identifies the lessons that can be learned for future sustainable urban development, and the further research which is needed to address future urban transitions to 2050.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Societal concern is growing about the consequences of climate change for food systems and, in a number of regions, for food security. There is also concern that meeting the rising demand for food is leading to environmental degradation thereby exacerbating factors in part responsible for climate change, and further undermining the food systems upon which food security is based. A major emphasis of climate change/food security research over recent years has addressed the agronomic aspects of climate change, and particularly crop yield. This has provided an excellent foundation for assessments of how climate change may affect crop productivity, but the connectivity between these results and the broader issues of food security at large are relatively poorly explored; too often discussions of food security policy appear to be based on a relatively narrow agronomic perspective. To overcome the limitation of current agronomic research outputs there are several scientific challenges where further agronomic effort is necessary, and where agronomic research results can effectively contribute to the broader issues underlying food security. First is the need to better understand how climate change will affect cropping systems including both direct effects on the crops themselves and indirect effects as a result of changed pest and weed dynamics and altered soil and water conditions. Second is the need to assess technical and policy options for either reducing the deleterious impacts or enhancing the benefits of climate change on cropping systems while minimising further environmental degradation. Third is the need to understand how best to address the information needs of policy makers and report and communicate agronomic research results in a manner that will assist the development of food systems adapted to climate change. There are, however, two important considerations regarding these agronomic research contributions to the food security/climate change debate. The first concerns scale. Agronomic research has traditionally been conducted at plot scale over a growing season or perhaps a few years, but many of the issues related to food security operate at larger spatial and temporal scales. Over the last decade, agronomists have begun to establish trials at landscape scale, but there are a number of methodological challenges to be overcome at such scales. The second concerns the position of crop production (which is a primary focus of agronomic research) in the broader context of food security. Production is clearly important, but food distribution and exchange also determine food availability while access to food and food utilisation are other important components of food security. Therefore, while agronomic research alone cannot address all food security/climate change issues (and hence the balance of investment in research and development for crop production vis à vis other aspects of food security needs to be assessed), it will nevertheless continue to have an important role to play: it both improves understanding of the impacts of climate change on crop production and helps to develop adaptation options; and also – and crucially – it improves understanding of the consequences of different adaptation options on further climate forcing. This role can further be strengthened if agronomists work alongside other scientists to develop adaptation options that are not only effective in terms of crop production, but are also environmentally and economically robust, at landscape and regional scales. Furthermore, such integrated approaches to adaptation research are much more likely to address the information need of policy makers. The potential for stronger linkages between the results of agronomic research in the context of climate change and the policy environment will thus be enhanced.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Nature conservation may be considered a post-normal science in that the loss of biodiversity and increasing environmental degradation require urgent action but are characterised by uncertainty at every level. An ‘extended peer community’ with varying skills, perceptions and values are involved in decision-making and implementation of conservation, and the uncertainty involved limits the effectiveness of practice. In this paper we briefly review the key ecological, philosophical and methodological uncertainties associated with conservation, and then highlight the uncertainties and gaps present within the structure and interactions of the conservation community, and which exist mainly between researchers and practitioners, in the context of nature conservation in the UK. We end by concluding that an openly post-normal science framework for conservation, which acknowledges this uncertainty but strives to minimise it, would be a useful progression for nature conservation, and recommend ways in which knowledge transfer between researchers and practitioners can be improved to support robust decision making and conservation enactment.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Direct contact with biodiversity is culturally important in a range of contexts. Many people even join conservation organisations to protect biodiversity that they will never encounter first-hand. Despite this, we have little idea how biodiversity affects people's well-being and health through these cultural pathways. Human health is sensitive to apparently trivial psychological stimuli, negatively affected by the risk of environmental degradation, and positively affected by contact with natural spaces. This suggests that well-being and health should be affected by biodiversity change, but few studies have begun to explore these relationships. Here, we develop a framework for linking biodiversity change with human cultural values, well-being, and health. We argue that better understanding these relations might be profoundly important for biodiversity conservation and public health.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Artisanal and small-scale mining (ASM) is an activity intimately associated with social deprivation and environmental degradation, including deforestation. This paper examines ASM and deforestation using a broadly poststructural political ecology framework. Hegemonic discourses are shown to consistently influence policy direction, particularly in emerging approaches such as Corporate Social Responsibility and the Forest Stewardship Council. A review of alternative discourses reveals that the poststructural method is useful for critiquing the international policy arena but does not inform new approaches. Synthesis of the analysis leads to conclusions that echo a growing body of literature advocating for policies to become increasingly sensitive to local contexts, synergistic between actors at difference scales, and to be integrated across sectors.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The concern related to the environmental degradation and to the exhaustion of natural resources has induced the research on biodegradable materials obtained from renewable sources, which involves fundamental properties and general application. In this context, we have fabricated thin films of lignins, which were extracted from sugar cane bagasse via modified organosolv process using ethanol as organic solvent. The films were made using the vacuum thermal evaporation technique (PVD, physical vapor deposition) grown up to 120 nm. The main objective was to explore basic properties such as electrical and surface morphology and the sensing performance of these lignins as transducers. The PVD film growth was monitored via ultraviolet-visible (UV-vis) absorption spectroscopy and quartz crystal microbalance, revealing a linear relationship between absorbance and film thickness. The 120 nm lignin PVD film morphology presented small aggregates spread all over the film surface on the nanometer scale (atomic force microscopy, AFM) and homogeneous on the micrometer scale (optical microscopy). The PVD films were deposited onto Au interdigitated electrode (IDE) for both electrical characterization and sensing experiments. In the case of electrical characterization, current versus voltage (I vs V) dc measurements were carried out for the Au IDE coated with 120 nm lignin PVD film, leading to a conductivity of 3.6 x 10(-10) S/m. Using impedance spectroscopy, also for the Au IDE coated with the 120 nm lignin PVD film, dielectric constant of 8.0, tan delta of 3.9 x 10(-3)) and conductivity of 1.75 x 10(-9) S/m were calculated at 1 kHz. As a proof-of-principle, the application of these lignins as transducers in sensing devices was monitored by both impedance spectroscopy (capacitance vs frequency) and I versus time dc measurements toward aniline vapor (saturated atmosphere). The electrical responses showed that the sensing units are sensible to aniline vapor with the process being reversible. AFM images conducted directly onto the sensing units (Au IDE coated with 120 nm lignin PVD film) before and after the sensing experiments showed a decrease in the PVD film roughness from 5.8 to 3.2 nm after exposing to aniline.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Nessa tese relaciona-se a problemática ambiental com a problemática social tal como esta se apresenta em áreas urbanas de sociedades do Sul, particularmente no Brasil. Faz-se um esforço de não confundí-las, apontando suas especificidades e as possibilidades, que a primeira traduz, no sentido de repensar, em termos teóricos, o planejamento e a gestão das cidades. Discute-se o papel do Estado capitalista nessas sociedades, enquanto mediador de conflitos sociais resultantes de políticas públicas excludentes. Discute-se ainda o significado, limites e possibilidades da participação pública na definição e/ou implementação de tais políticas e o papel que a educação ambiental pode assumir neste sentido. Apresenta-se dois estudos de caso tratando da degradação ambiental de bacias hidrográficas localizadas na Região Metropolitana de São Paulo, nos quais a participação pública tem se dado em algum nível, contribuindo para a tomada de decisões. Num caso, esta se dá numa conjuntura política onde as decisões tecnocráticas são determinantes; em outro, está relacionada com a tentativa, por parte do Estado, de implantação de uma gestão mais democrática, que implica no diálogo deste com as organizações civis visando a realização de negociações.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A mandioca (Manihot esculenta Crantz) é uma planta cultivada predominantemente para a subsistência dos trabalhadores rurais sendo uma das principais fontes de carboidratos disponíveis aos estratos sociais de baixa renda e tem importante participação na geração de emprego e renda. O Estado do Pará destaca-se pelo volume de produção de mandioca, mas o cultivo ainda está voltado essencialmente para a subsistência sendo pouco explorado como matéria prima em derivados industriais e insumo para enfrentar problemas globais como a fome, a degradação ambiental e a produção de energia, gerando emprego e renda para comunidades locais e rurais. Este estudo tem como objetivo avaliar como está se desenvolvendo a organização de produtores rurais de mandioca da Associação de Desenvolvimento Comunitário e Rural Bom Jesus, através do modelo de gestão de cadeia produtiva e compreender em que medida se justifica economicamente o cultivo de mandioca. A pesquisa é de natureza exploratória e descritiva e por meio do questionário e entrevista aplicado a 17 produtores rurais juntamente com a fundamentação teórica sobre o entendimento contemporâneo de cadeia produtiva foram percebidos evidências que justificam economicamente, em parte, o cultivo da mandioca. A geração de postos de trabalhos para as mulheres, a utilização de resíduos como incremento no arranjo produtivo, a apoio da extensão e do crédito rural, e as vantagens advindas da organização dos produtores rurais proporcionando renda e produção constantes no campo, foram os fatores considerados. Porém, a necessidade de inovações tecnológicas, parcerias com os setores industriais, arranjos produtivos mais rentáveis, mecanização do plantio e da colheita, os problemas ambientais (resíduos tóxicos e desmatamento) e de acesso à pesquisa, o nível de escolaridade, e a cooperação entre os agricultores, são desafios reais a serem enfrentados e o fator decisivo é o apoio governamental. Este estudo demonstra a realidade de uma sociedade quase sempre marginalizada e esquecida pelas políticas públicas. Além da variável econômica, a avaliação das culturas produtivas deve passar pelos filtros de análise social e ambiental, pois assim, nos permite com maior exatidão compreender os problemas reais da nossa sociedade, em especial da vida na Amazônia.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

A água é um bem escasso, com demanda crescente tanto pelo crescimento das populações como pelo maior uso da água pelos novos processos e produtos impostos pelos padrões de conforto e bem estar da vida moderna e na produção de alimentos. Ao mesmo tempo em que aumenta a demanda de água,com seus usos múltiplos, a sua qualidade vem diminuindo pela degradação ambiental. Ouso racional da água deve ser tratado comointeresse público que se traduz na busca sistemática de diminuição dos desperdícios de água. No Brasil existem políticas públicasfederais que incluem esta preocupação, mas que devem ser aprimoradas, pois não exigem uma gestão por desempenho dos operadores dos sistemas de água. O governo local, municipal, tem dupla responsabilidade: como produtor de água, via sistemas públicos de águaecomo grande consumidor, através da rede de sistemas prediais públicos. A gestão dos desperdícios de água é focadono incentivo à cultura da medição, na prática do Balanço Hídrico dos sistemas de água, na gestão do consumo descentralizado nas unidades públicas consumidoras, e incentivos motivacionais para o melhor uso, com ênfase na transparência das informações.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Com o fim da Guerra Fria e os acontecimentos que marcaram o “onze de setembro”, novas ameaças surgiram, impactando negativamente a percepção de segurança coletiva, e impondo profundas modificações nas estruturas e no modo de atuação do Poder Militar de diversas nações. A marginalidade social, o narcotráfico, o crime organizado, a degradação do meio ambiente e outras tantas ameaças, fizeram com que algumas nações se vissem motivadas a empregar suas Forças Armadas, prioritariamente, no combate a estas mazelas, ou seja, nas operações de não-guerra. Este fenômeno vem causando uma ebulição nas ciências militares, com reflexo no campo social, político e econômico, provocando um processo conhecido como “Transformação da Defesa”, que só é viável com a ruptura de alguns modelos tradicionais de administração e com a introdução de uma nova cultura organizacional que promova um ambi-ente adequado ao processo de inovações no setor de Defesa. Para fazer gestão deste processo, deve haver um sistema de inovação setorial de Defesa, já que o atual modelo, conforme apon-tou a investigação, é fragmentado e desarticulado, que produz, fundamentalmente, inovações incrementais e, raramente as de ruptura. Trata-se de um sistema virtual, que não existe for-malmente como tal, mas que possui toda a infraestrutura necessária para funcionar como um sistema formal e gerenciável. A pesquisa, de caráter epistemológico estruturalista, teve por objetivo desenvolver um modelo conceitual para gestão do sistema de inovação do setor de Defesa (segmento de não-guerra), com base em uma estrutura subjacente desvelada, que, de forma oculta, dá suporte ao sistema atual. O desvelamento desta estrutura permitiu concluir que, no campo estudado, os agentes do sistema de inovação, agindo de acordo com seus inte-resses, mobilizam, de forma consciente ou inconsciente, os fatores valorativos da inovação presentes na cultura organizacional em que estão imersos, os quais, juntamente com a influên-cia dos fatores de suporte (o Capital), são fundamentais para a formação de alianças e, em consequência, para o processo de inovação no segmento de não-guerra do setor de Defesa. Como era esperado, o desvelamento da estrutura subjacente propiciou a realização de um di-agnóstico preciso do sistema estudado, permitindo ao pesquisador o lançamento de um olhar crítico sobre o mesmo, o que contribui para a proposição de uma intervenção segura no modelo vigente. O modelo proposto buscou incentivar, também, a criação, o avanço e a difusão das inovações não-tecnológicas, contrapondo-se ao atual, que privilegia fundamentalmente a abordagem tecnológica. Adicionalmente, foram sugeridas algumas medidas, no sentido de incrementar as interações entre os principais agentes do sistema.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

This study intends to establish a relation between environmental degradation, particularly the devastation of the green canopy, and public health. Utilizing a mapping of the trees included in the researched area, each individual tree was analyzed according to its age, taxonomic listing, architecture, shape and size (determined by aesthetic/convenience reasons or deformed by pruning). Initially investigated were the covert reasons lying underneath the constant aggression against trees (which many times seem to contain elements of hatred and contempt) within the urban environment. In addition to that, the aspects concerning environmental modifications and the consequent impact on public health were also assessed. Two main problems promptly emerged as a result of the removal of trees: a) without a canopy to protect the areas, they became subject to winds directly blown from SW Africa and impregnated with aerosol partic les, which are common causes for respiratory disorders and, b) direct UV solar radiation, which causes some types of skin cancers and eye disorders. To reach such results, we studied the origins and formation of UV radiation induced cancers and searched for the UV radiation spectra of action, e.g., usual intensity and quantity reaching clear and shadowed spaces in a certain area and its consequences. In a second instance, we also searched for pertinent data resources in order to confirm the increase of skin cancer cases due to exposure to UV radiation and the relation between the destruction of the green canopy and the above mentioned problems. We believe that a few significant results have been achieved by this study, namely: the relation between a culture based on medieval beliefs and its consequences on the environment; how this culture exploits and deforms nature in pursuit of financial and psychological interests to a point of transforming the landscape into a copy of something devoid of any relation to latitude and altitude; and above all, the indifference concerning the alarming results carried by these modifications

Relevância:

60.00% 60.00%

Publicador:

Resumo:

It is important to evaluate the quality of water for proper management of these resources, since the increase of environmental degradation and the multiple use of water resources are decreasing the quality of water consumed by living beings. The objective of this study was to characterize the phytoplankton community and its variations during periods of dray and rain in Jiqui Lake located in Parnamirim, RN. It was also aimed to analyze the physical and chemical factors of this environment, in order to contribute to the knowledge of water quality used for human consumption. The collection of water samples were carried out in September 2008 to August 2009. The collection of the phytoplankton community was carried out in four sampling sites (surface, bottom, margin of the lake without macrophytes and site dominated by macrophytes). Phytoplankton was collected using plankton net of 20m. The analysis of nutrients and identification of phytoplankton were performed in the laboratory. The results indicate that concentration of chlorophyll a was high in the bottom with mean value of 1.07 μgL-1 (SD ± 1.61). During the study period there was a dominance of the following species: Euglena gracilis, Trachelomonas sp, Cyclotellas sp, Gomphonema apuncto, Navicula cuspidata var. cuspidata, Navicula sp, Rhopalodia gibba. There was homogeneity between limnological values in the four study sites, with significant difference between the periods of drought and rain. The Jiqui Lake is considered oligotrophic due to its low concentrations of chlorophyll a, high transparency and low levels of nutrients. The values of BOD and chlorophyll a concentration remained below the permitted standards existing for freshwaters in Brazil, thus the water from Lake Jiqui is of good quality, suitable for human consumption.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Marine shrimp farming has grown exponentially during the last years in Brazil. In spite of the promising economical situation, this activity is facing an increasing criticism due to its environmental impact. Thus, the necessity of alternatives to mitigate environmental degradation caused by this activity. An alternative that is being studied is the policulture that is the integrated culture of two or more organisms, normally one of them a filtering organism. Among filtering organisms, macroalgae are very practicable because they are efficient in the removal of the exceeding nutrients of the water and do not leave residues in the water. Besides, the integrated culture with macroalgae allows the economical exploration of the seaweed (for the manufacture of jelly and jam, for the dairy industry, pharmaceuticals, etc.) along with possibility of a sustainable aquaculture. In the present experiment, the development of the seaweed Gracilaria birdiae, the influence and tolerance of this species to the environmental parameters, and its absorption efficiency in relation with the three kinds of macronutrients (NH4+, NO3- and PO4-3) found in the effluents of marine shrimp farming was studied. The experiment was divided in two parts: a laboratorial part and one part carried under natural conditions. The water used in the laboratory trial was collected in the shrimp ponds of Tecnarão farm and distributed in aquaria containing 20 g of G. birdiae. In the field trial, 0.5 kg of G. birdiae was inserted in PVC cages cultivated in the farm. The results of the study showed a modest growth of G. birdiae, probably due to its low tolerance to highly eutrophicated environments. However, the removal of nutrients was very expressive. Ammonia was reduced in approximately 34 %. Ortho-phosphate showed a reduction of 93.5 %. The capacity of biofiltration of the NO3- by the macro algae was of 100 %, showing that G. birdiae is a seaweed-filtered with a high level of removal for this nutrient under laboratorial conditions. In spite of the low growth of the macro algae in the experiment, the results in relation to the removal of nutrients of the water was encouraging, suggesting that this species can be an efficient biofilter and thus, a strong candidate to be used in a sustainable aquaculture

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Despite the importance of coral reefs to humanity, these environments have been threatened throughout the world. Several factors contribute to the degradation of these ecosystems. The Maracajaú Reef Complex, in Rio Grande do Norte state is part of the Coral Reefs Environment Preservation Area in northeastern Brazil. This area has been receiving an increasing influx of tourism and the integrity of the local reefs is a matter of concern. In this study, the reef macroalgae communities were studied and compared within two areas distinguished by the presence or absence of tourism activities. Two sample sites were chosen: the first one, where diving activities are intense; and the other, where these practices do not occur. Samples were collected at both sites within a quadrate of 625 cm2 of area randomly thrown 5 times along a 10 meters transect line. Richness, Shannon-Hill diversity and Simpson dominance indices were determined based on biomass data. Similarity between sites was analyzed with Bray-Curtis similarity and distance index. Fifty-eight macroalgae species were observed, including 7 Chlorophyta, 13 Phaeophyta and 38 Rhodophyta. In the non-disturbed site, 49 species were found, while at the disturbed site, there were 42 species. Dictyotaceae and Corallinaceae were the most representative families at the non-disturbed site, and Rhodomelaceae and Dictyotaceae at the disturbed site. The non-disturbed site presented a higher biomass and the greatest richness and diversity indices. In the disturbed site the dominance index was greater and Caulerpa racemosa was the dominant species. The dendogram based on similarity index showed two major clusters, and an isolated element at the center that corresponds to a sample from the disturbed site. In the first cluster, samples from the non-impacted site were predominant and fleshy brown algae were more conspicuous. The second cluster was composed primarily of samples from the impacted site, where C. racemosa and red filamentous and erect calcareous algae associations (turf forming) were observed covering large extensions. These associations are represented by groups of algae adapted to environments where disturbances are frequent. They can grow rapidly on substrate where benthic community was removed and do not allow the establishment of other species. The results of the present study show that tourism activity is an impacting factor that has been causing shifts in macroalgae communities in the Maracajaú Reef Complex