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1.
Nat Plants ; 6(12): 1418-1426, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33299148

RESUMO

Delivering the Sustainable Development Goals (SDGs) requires balancing demands on land between agriculture (SDG 2) and biodiversity (SDG 15). The production of vegetable oils and, in particular, palm oil, illustrates these competing demands and trade-offs. Palm oil accounts for ~40% of the current global annual demand for vegetable oil as food, animal feed and fuel (210 Mt), but planted oil palm covers less than 5-5.5% of the total global oil crop area (approximately 425 Mha) due to oil palm's relatively high yields. Recent oil palm expansion in forested regions of Borneo, Sumatra and the Malay Peninsula, where >90% of global palm oil is produced, has led to substantial concern around oil palm's role in deforestation. Oil palm expansion's direct contribution to regional tropical deforestation varies widely, ranging from an estimated 3% in West Africa to 50% in Malaysian Borneo. Oil palm is also implicated in peatland draining and burning in Southeast Asia. Documented negative environmental impacts from such expansion include biodiversity declines, greenhouse gas emissions and air pollution. However, oil palm generally produces more oil per area than other oil crops, is often economically viable in sites unsuitable for most other crops and generates considerable wealth for at least some actors. Global demand for vegetable oils is projected to increase by 46% by 2050. Meeting this demand through additional expansion of oil palm versus other vegetable oil crops will lead to substantial differential effects on biodiversity, food security, climate change, land degradation and livelihoods. Our Review highlights that although substantial gaps remain in our understanding of the relationship between the environmental, socio-cultural and economic impacts of oil palm, and the scope, stringency and effectiveness of initiatives to address these, there has been little research into the impacts and trade-offs of other vegetable oil crops. Greater research attention needs to be given to investigating the impacts of palm oil production compared to alternatives for the trade-offs to be assessed at a global scale.


Assuntos
Agricultura/tendências , Arecaceae/crescimento & desenvolvimento , Biodiversidade , Conservação dos Recursos Naturais/tendências , Produtos Agrícolas/crescimento & desenvolvimento , Óleo de Palmeira , Crescimento Sustentável , Agricultura/estatística & dados numéricos , Previsões
2.
PLoS One ; 15(9): e0239006, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960903

RESUMO

To prevent and control non-point source pollution, many policies have been carried out by government in China. However, the effectiveness of these policies has rarely been evaluated. In this study, the potential and spatial distribution of agricultural non-point source pollution in the Baiyangdian Basin are reported. This investigation considers multiple parameters under various policies with county as a basic unit. The results for the potential pollution from chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen (TN) and total phosphorus (TP) are 60.89×104, 3.93×104, 87.05×104 and 15.10×104 Mg, with corresponding intensities of 190, 12, 272 and 47 kg ha-1 for the Baiyangdian Basin in 2016. The highest pollution from COD is attributed to livestock and poultry breeding, whereas TN and TP are dominantly produced by rural domestic sources, and NH3-N is mostly derived from planting. Spatially, distribution of the counties producing larger non-point source pollution presented a northeast to southwest direction, consistent with the Taihang mountain alignment in the basin. The counties with high pollution intensities are mostly in the south and east of the basin. Agricultural non-point source pollution control and prevention policies contributed in pollution reduction. Compared with 2016, the total potential pollution of COD, NH3-N, TN and TP in 2020 decrease by 45.1%, 14.7%, 37.9% and 37.4%, respectively, whereas for an assumed future time (F2), the decreases are 59%, 51.4%, 56.2% and 55.7%, respectively. Prevention measures should focus on reducing pollution from livestock and poultry breeding as well as planting.


Assuntos
Monitoramento Ambiental/métodos , Poluição Difusa/análise , Poluição Difusa/economia , Agricultura , Amônia/análise , Animais , Análise da Demanda Biológica de Oxigênio/métodos , China , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/tendências , Política Ambiental/tendências , Poluição Ambiental/análise , Poluição Ambiental/economia , Gado , Nitrogênio/análise , Fósforo/análise , Aves Domésticas , Rios , Poluentes Químicos da Água/análise
3.
Curr Pharm Biotechnol ; 20(14): 1172-1180, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31424366

RESUMO

There has been significant growth in the herbal drugs market around the world, over the last few decades due to growing awareness among people about the rising cost as well as side effects related to the use of synthetic drugs. Herbal medicine has been used in traditional medicinal systems around the world, especially India where the oldest systems of medicine namely Ayurveda, Siddha, and Unani make use of more than 90% plant-based formulations. India is rich in medicinal and herbal plants resources that provide for both the health care needs of rural India as well as the source of raw material for therapeutic agents required in the production of traditional and modern medicine. This review article presents an overview of the knowledge of Indian herbal plants based medicine in the national and international market and the trends in its production, sustainability, and promotion.


Assuntos
Conservação dos Recursos Naturais/tendências , Marketing de Serviços de Saúde , Preparações de Plantas/economia , Plantas Medicinais/crescimento & desenvolvimento , Biodiversidade , Conservação dos Recursos Naturais/legislação & jurisprudência , Regulamentação Governamental , Humanos , Índia , Marketing de Serviços de Saúde/tendências , Ayurveda , Fitoterapia , Preparações de Plantas/normas , Preparações de Plantas/provisão & distribuição
4.
J Ethnopharmacol ; 213: 302-310, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29113957

RESUMO

ETHNOBOTANICAL RELEVANCE: Trillium govanianum Wall. ex D. Don (Melanthiaceae) is valued as a traditional medicinal herb in the Himalayan region. Applications include treatment of cancer, hypertension, neurasthenia, giddiness, arthritis, dysentery, inflammation, sepsis and reproductive disorders. Its range is highly specific, and limited to cold, shaded and moist habitats at 2400-3500 m a.s.l. Rhizomes are gathered from wild populations for trade, and this has recently emerged as a significant source of income among indigenous people of the Indian Himalayan region. AIM: To assess the impact of changing rhizome prices on T. govanianum in the Indian Himalayan region by observing the status of existing populations and assessing the typical methods used for gathering and trade of rhizomes. MATERIAL AND METHODS: Ecological attributes were assessed in 17 sites from Tirthan Valley (Himachal Pradesh), Munsiyari and Tunghnath (Uttarakhand). Socio-economic attributes assessed through communal focus groups and interviews with 579 medicinal plants gatherers and 19 traders, using semi-structured open ended questionnaires. RESULTS: Population decline was highest in Munsiyari, followed by Tirthan Valley and Tunghnath, indicating that the species may become locally extinct in some areas. Methods used for gathering did not consider regeneration. CONCLUSION: Gathering of T. govanianum from wild populations is unselective and unmanaged, raising the potential threat of local extinctions. Sustainable utilization and effective conservation is needed to protect the species and maintain community incomes. A status of 'threatened' is justified for the species in the Indian Himalayan region, due to its slow life cycle, specific habitat requirement, low population density, and commercial value.


Assuntos
Agricultura/métodos , Conservação dos Recursos Naturais/tendências , Trillium , Humanos , Plantas Medicinais , Fatores Socioeconômicos
5.
Int J Food Sci Nutr ; 68(1): 117-120, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27580817

RESUMO

The Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico is a five-century institution that, besides the unique clinical role in the center of Milan, may rely on benefactor donations such as fields and farming houses not far from the city, for a total of 8500 ha, all managed by the "Sviluppo Ca' Granda' Foundation". Presently, the main products of these fields are represented by rice and cow's milk. During the latest years, farmers and managers have developed a model of sustainable food production, with great attention to the product quality based on compositional analysis and functional nutritional characteristics. This experience represents a new holistic model of food production and consumption, taking great care of both sustainability and health.


Assuntos
Conservação dos Recursos Naturais , Produção Agrícola/métodos , Indústria de Laticínios/métodos , Qualidade dos Alimentos , Nível de Saúde , Modelos Biológicos , Animais , Bovinos , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/tendências , Produção Agrícola/economia , Produção Agrícola/educação , Produção Agrícola/tendências , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Indústria de Laticínios/economia , Indústria de Laticínios/educação , Indústria de Laticínios/tendências , Fundações , Saúde Global , Índice Glicêmico , Promoção da Saúde , Humanos , Itália , Leite/química , Estudos de Casos Organizacionais , Oryza/química , Oryza/crescimento & desenvolvimento , Avaliação de Programas e Projetos de Saúde , Sementes/química , Sementes/crescimento & desenvolvimento
6.
J Sci Food Agric ; 97(3): 733-742, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27558451

RESUMO

The global expansion in aquaculture production implies an emerging need of suitable and sustainable protein sources. Currently, the fish feed industry is dependent on high-quality protein sources of marine and plant origin. Yeast derived from processing of low-value and non-food lignocellulosic biomass is a potential sustainable source of protein in fish diets. Following enzymatic hydrolysis, the hexose and pentose sugars of lignocellulosic substrates and supplementary nutrients can be converted into protein-rich yeast biomass by fermentation. Studies have shown that yeasts such as Saccharomyces cerevisiae, Candida utilis and Kluyveromyces marxianus have favourable amino acid composition and excellent properties as protein sources in diets for fish, including carnivorous species such as Atlantic salmon and rainbow trout. Suitable downstream processing of the biomass to disrupt cell walls is required to secure high nutrient digestibility. A number of studies have shown various immunological and health benefits from feeding fish low levels of yeast and yeast-derived cell wall fractions. This review summarises current literature on the potential of yeast from lignocellulosic biomass as an alternative protein source for the aquaculture industry. It is concluded that further research and development within yeast production can be important to secure the future sustainability and economic viability of intensive aquaculture. © 2016 Society of Chemical Industry.


Assuntos
Ração Animal/análise , Aquicultura , Peixes/crescimento & desenvolvimento , Abastecimento de Alimentos , Proteínas Fúngicas/administração & dosagem , Saúde Global , Leveduras/isolamento & purificação , Aminoácidos/análise , Ração Animal/economia , Animais , Aquicultura/economia , Aquicultura/tendências , Biomassa , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/tendências , Produção Agrícola/economia , Digestão , Fermentação , Peixes/metabolismo , Abastecimento de Alimentos/economia , Agricultura Florestal/economia , Proteínas Fúngicas/biossíntese , Proteínas Fúngicas/química , Proteínas Fúngicas/economia , Humanos , Resíduos Industriais/análise , Resíduos Industriais/economia , Lignina/química , Lignina/isolamento & purificação , Lignina/metabolismo , Desnutrição/economia , Desnutrição/prevenção & controle , Ciclo do Nitrogênio , Leveduras/química , Leveduras/crescimento & desenvolvimento , Leveduras/metabolismo
8.
PLoS One ; 11(3): e0151446, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26987057

RESUMO

Artificial vegetation restoration can induce variations in accumulation and distribution of soil carbon (C), nitrogen (N) and phosphorus (P). However, little is known about variations in soil C, N and P nutrient fraction stratification following artificial vegetation in Loess Plateau China. Based on the hypothesis that re-vegetated can improve soil quality and stratification ratios (SR) can be used as an indicator to evaluate soil quality. This study measured contents and storages of soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP) and their SRs in topsoil (0-20 cm) and subsoil (20-60 cm) in three 30-year re-vegetated lands that had been converted from arable land (Robinia pseudoacacia L., Caragana Korshinskii Kom. and abandoned cropland with low interferences and few management measures) and one slope cropland (SC) as a control for three soil profiles(0-20 cm, 20-40 cm and 40-60 cm) from June 2009 to June 2013. The results showed that the contents and storages of SOC, TN and TP in re-vegetated land were significantly higher than those in the SC in both topsoil and subsoil. The storages of SOC, TN and TP in the topsoil (0-20 cm) of the re-vegetated lands increased by 16.2%-26.4%, 12.7%-28.4% and 16.5%-20.9%, respectively, and increased by smaller but significant amounts in subsoil from 2009 to 2013. The SRs for SOC, TN and TP in the re-vegetated lands were mostly >2 (either for 0-20:20-40 cm or 0-20:40-60 cm) and greater than that in the SC. The SRs showed an increasing trend with increasing restoration age. The results also showed that the land use type and soil depth were the most influential factors for the SRs and storages, and the SRs of SOC and TN had significantly positive correlations with their storages. The SRs were concluded to be a good indicator for evaluating the soil quality, which can be significantly enhanced through vegetation restoration. Moreover, vegetation restoration can significantly enhance SOC, TN and TP accumulation in both topsoil and subsoil.


Assuntos
Agricultura/métodos , Carbono/análise , Nitrogênio/análise , Fósforo/análise , Solo/química , Agricultura/tendências , Caragana/crescimento & desenvolvimento , China , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/tendências , Produtos Agrícolas/crescimento & desenvolvimento , Ecossistema , Dinâmica Populacional , Robinia/crescimento & desenvolvimento , Fatores de Tempo
9.
Proc Natl Acad Sci U S A ; 113(10): 2609-14, 2016 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-26903638

RESUMO

Phosphorus (P) is an essential nutrient for living systems with emerging sustainability challenges related to supply uncertainty and aquatic eutrophication. However, its long-term temporal dynamics and subsequent effects on freshwater ecosystems are still unclear. Here, we quantify the P pathways across China over the past four centuries with a life cycle process-balanced model and evaluate the concomitant potential for eutrophication with a spatial resolution of 5 arc-minutes in 2012. We find that P cycling in China has been artificially intensified during this period to sustain the increasing population and its demand for animal protein-based diets, with continuous accumulations in inland waters and lands. In the past decade, China's international trade of P involves net exports of P chemicals and net imports of downstream crops, specifically soybeans from the United States, Brazil, and Argentina. The contribution of crop products to per capita food P demand, namely, the P directly consumed by humans, declined from over 98% before the 1950s to 76% in 2012, even though there was little change in per capita food P demand. Anthropogenic P losses to freshwater and their eutrophication potential clustered in wealthy coastal regions with dense populations. We estimate that Chinese P reserve depletion could be postponed for over 20 y by more efficient life cycle P management. Our results highlight the importance of closing the P cycle to achieve the cobenefits of P resource conservation and eutrophication mitigation in the world's most rapidly developing economy.


Assuntos
Produtos Agrícolas/química , Ecossistema , Água Doce/química , Fósforo/análise , Algoritmos , Animais , China , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/tendências , Eutrofização , Água Doce/microbiologia , Geografia , Humanos , Modelos Teóricos , Fósforo/metabolismo
12.
J Ethnopharmacol ; 174: 308-16, 2015 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-26277489

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Bowiea volubilis Harv. ex Hook.f. (Family: Asparagaceae) is a bulbous medicinal plant widely used against numerous ailments including headache, muscular pains, infertility, cystitis and venereal diseases in southern Africa. AIM OF THE REVIEW: To provide a critical and updated review of Bowiea volubilis with regards to its abundance, medicinal importance, conservation status and potential means to sustain its availability for future generations. METHODS: A comprehensive literature search using online databases such as Web of Science, Google Scholar, Scopus and Springerlink as well as ethnobotanical literature was done in order to obtain, collate, synthesize and critically analyze available information on Bowiea volubilis. RESULTS: On the basis of its wide distribution in many Provinces in South Africa, Bowiea volubilis has a long history of applications among the different ethnic groups. These applications include its uses as purgatives and for the treatment or relief of microbial infections, skin disorders, pains and inflammation. Scientific validation of its diverse uses in traditional medicine has been demonstrated via antimicrobial, anti-inflammatory and toxicity assays. Available results indicate a general poor antimicrobial activity especially with the bulb extracts while the anti-inflammatory activity appears promising. Phytochemical screenings revealed that Bowiea volubilis contains cardiac glycosides and related compounds while reports of other classes of compounds are unavailable. In line with its usage in traditional medicine, the majority of available studies on the species have focused on the use of different solvent extracts from the bulbs. The destructive harvesting of bulbs has led to a continuous decimation of wild populations. Consequently, there are increasing conservational concerns on the sustainability of this species for continuous supply to meet escalating demands. CONCLUSIONS: Bowiea volubilis remains a widely used medicinal plant and available but limited scientific evidence indicates its anti-inflammatory potential. The abundance of cardiac glycosides in its phytochemical composition provides an indication on the therapeutic potential. More research efforts including the application of different biotechnological techniques are still required in order to guarantee its sustainable use over time.


Assuntos
Conservação dos Recursos Naturais/métodos , Etnobotânica/métodos , Liliaceae , Compostos Fitoquímicos/uso terapêutico , Raízes de Plantas , Plantas Medicinais , África Austral/etnologia , Animais , Conservação dos Recursos Naturais/tendências , Etnobotânica/tendências , Humanos , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico
13.
Zhongguo Zhong Yao Za Zhi ; 40(17): 3395-401, 2015 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-26978979

RESUMO

The objects of research on the resources chemistry of Chinese medicinal materials (RCCMM) are promotion of efficient production, rational utilization and improving quality of CMM and natural products. The development of TCM cause depends on the efficient utilization and sustainable development of CMM, hinges on the technologies and methods for using and discovering medicinal biological resources, stand or fall on the extension of industy chains, detailed utilizaion of resource chemical components by multi-way, multi-level. All of these may help to the recycling utilization and sound development of RCMM. In this article, five respects were discussed to the RCCMM researches and resources recycling utilization ways and goals and tasks. First, based on the principle of resource scarcity, discovering or replacing CMM resources, protecting the rare or endangered species or resources. Second, based on the multifunctionality of CMM, realizing the value-added and value compensation, and promoting the utilization efficiency through systermatic and detailed exploitation and utilization. Third, based on the resource conservation and environment-friendly, reducing raw material consumption, lowering cost, promoting recycling utilization and elevating utilization efficiency. Fourth, based on the stratege of turning harm into good, using the invasive alien biological resources by multi-ways and enriching the medicial resources. Fifth, based on the method of structure modification of chemical components, exploring and enhancing the utility value of resouces chemical substances. These data should provide references and attention for improving the utilization efficiency, promoting the development of recycling economy, and changing the mode of economic growth of agriculture and industry of CMM fundamentally.


Assuntos
Medicamentos de Ervas Chinesas/química , Materia Medica/química , Plantas Medicinais/química , Agricultura/economia , Agricultura/tendências , China , Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/tendências , Medicamentos de Ervas Chinesas/economia , Materia Medica/economia , Medicina Tradicional Chinesa/economia , Medicina Tradicional Chinesa/tendências , Plantas Medicinais/crescimento & desenvolvimento
14.
Sci Prog ; 98(Pt 4): 379-90, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26790176

RESUMO

Population growth makes food production increase necessary; economic growth increases demand for animal products and livestock feed. As further increase of the cropland area is ecologically undesirable, it is necessary to increase crop yields; this requires, inter alia, more nitrogen and phosphorus fertiliser despite the environmental problems which this will exacerbate. It is probable that a satisfactory food supply and an environmentally benign agriculture worldwide cannot be achieved without reducing population to approximately three billion. The reduction could be achieved by 2200 if the total fertility rate--currently 2.5--declined to 1.5 as a world average by 2050, and remained at that level until 2200, but the probability of such a global fertility trajectory is close to zero. It will also be necessary to replace fossil energy by nuclear and renewable energy in order to stabilise atmospheric carbon dioxide concentration, but the phase-out cannot be completed until the 22nd century, when the atmospheric concentration will be approximately 50% above the 2015 level of 400 ppm.


Assuntos
Conservação dos Recursos Naturais/tendências , Produtos Agrícolas/provisão & distribuição , Fertilizantes/provisão & distribuição , Abastecimento de Alimentos , Controle da População/tendências , Crescimento Demográfico , Animais , Pegada de Carbono , Produtos Agrícolas/crescimento & desenvolvimento , Humanos , Nitrogênio/provisão & distribuição , Fósforo/provisão & distribuição
15.
Environ Manage ; 54(1): 84-97, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24794194

RESUMO

Indonesia is subject to rapid land use change. One of the main causes for the conversion of land is the rapid expansion of the oil palm sector. Land use change involves a progressive loss of forest cover, with major impacts on biodiversity and global CO2 emissions. Ecosystem services have been proposed as a concept that would facilitate the identification of sustainable land management options, however, the scale of land conversion and its spatial diversity pose particular challenges in Indonesia. The objective of this paper is to analyze how ecosystem services can be mapped at the provincial scale, focusing on Central Kalimantan, and to examine how ecosystem services maps can be used for a land use planning. Central Kalimantan is subject to rapid deforestation including the loss of peatland forests and the provincial still lacks a comprehensive land use plan. We examine how seven key ecosystem services can be mapped and modeled at the provincial scale, using a variety of models, and how large scale ecosystem services maps can support the identification of options for sustainable expansion of palm oil production.


Assuntos
Agricultura/métodos , Biodiversidade , Conservação dos Recursos Naturais/estatística & dados numéricos , Ecossistema , Mapeamento Geográfico , Modelos Biológicos , Agricultura/estatística & dados numéricos , Animais , Conservação dos Recursos Naturais/tendências , Indonésia , Óleo de Palmeira , Óleos de Plantas , Pongo pygmaeus/fisiologia
17.
Sci Prog ; 96(Pt 2): 109-52, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23901632

RESUMO

The peak in the world production of phosphorus has been predicted to occur in 2033, based on world reserves of rock phosphate (URR) reckoned at around 24,000 million tonnes (Mt), with around 18,000 Mt remaining. This figure was reckoned-up to 71,000 Mt, by the USGS, in 2012, but a production maximum during the present century is still highly probable. There are complex issues over what the demand will be for phosphorus in the future, as measured against a rising population (from 7 billion to over 9 billion in 2050), and a greater per capita demand for fertiliser to grow more grain, in part to feed animals and meet a rising demand for meat by a human species that is not merely more populous but more affluent. As a counterweight to this, we may expect that greater efficiencies in the use of phosphorus - including recycling from farms and of human and animal waste - will reduce the per capita demand for phosphate rock. The unseen game changer is peak oil, since phosphate is mined and recovered using machinery powered by liquid fuels refined from crude oil. Hence, peak oil and peak phosphorus might appear as conjoined twins. There is no unequivocal case that we can afford to ignore the likelihood of a supply-demand gap for phosphorus occurring sometime this century, and it would be perilous to do so.


Assuntos
Conservação dos Recursos Naturais/estatística & dados numéricos , Conservação dos Recursos Naturais/tendências , Abastecimento de Alimentos/estatística & dados numéricos , Mineração/estatística & dados numéricos , Mineração/tendências , Fósforo , Previsões
18.
Philos Trans R Soc Lond B Biol Sci ; 368(1625): 20120406, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23878342

RESUMO

We review the literature and find 16 studies from across Africa's savannas and woodlands where woody encroachment dominates. These small-scale studies are supplemented by an analysis of long-term continent-wide satellite data, specifically the Normalized Difference Vegetation Index (NDVI) time series from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset. Using dry-season data to separate the tree and grass signals, we find 4.0% of non-rainforest woody vegetation in sub-Saharan Africa (excluding West Africa) significantly increased in NDVI from 1982 to 2006, whereas 3.52% decreased. The increases in NDVI were found predominantly to the north of the Congo Basin, with decreases concentrated in the Miombo woodland belt. We hypothesize that areas of increasing dry-season NDVI are undergoing woody encroachment, but the coarse resolution of the study and uncertain relationship between NDVI and woody cover mean that the results should be interpreted with caution; certainly, these results do not contradict studies finding widespread deforestation throughout the continent. However, woody encroachment could be widespread, and warrants further investigation as it has important consequences for the global carbon cycle and land-climate interactions.


Assuntos
Conservação dos Recursos Naturais/história , Árvores , Clima Tropical , África Subsaariana , Ciclo do Carbono , Mudança Climática , Conservação dos Recursos Naturais/estatística & dados numéricos , Conservação dos Recursos Naturais/tendências , Monitorização de Parâmetros Ecológicos , Ecossistema , História do Século XX , História do Século XXI , Chuva , Árvores/metabolismo
19.
J Hazard Mater ; 260: 534-42, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23811631

RESUMO

Copper-indium-gallium-selenium-sulfide (CIGS) thin film photovoltaics are increasingly penetrating the market supply for consumer solar panels. Although CIGS is attractive for producing less greenhouse gas emissions than fossil-fuel based energy sources, CIGS manufacturing processes and solar cell devices use hazardous materials that should be carefully considered in evaluating and comparing net environmental benefits of energy products. Through this research, we present a case study on the toxicity hazards associated with alternative materials selection for CIGS manufacturing. We applied two numeric models, The Green Screen for Safer Chemicals and the Toxic Potential Indicator. To improve the sensitivity of the model outputs, we developed a novel, life cycle thinking based hazard assessment method that facilitates the projection of hazards throughout material life cycles. Our results show that the least hazardous CIGS solar cell device and manufacturing protocol consist of a titanium substrate, molybdenum metal back electrode, CuInS2 p-type absorber deposited by spray pyrolysis, ZnS buffer deposited by spray ion layer gas reduction, ZnO:Ga transparent conducting oxide (TCO) deposited by sputtering, and the encapsulant polydimethylsiloxane.


Assuntos
Conservação de Recursos Energéticos/tendências , Molibdênio/química , Fotoquímica/instrumentação , Titânio/química , Conservação dos Recursos Naturais/tendências , Cobre/química , Dimetilpolisiloxanos/química , Fontes de Energia Elétrica , Eletrodos , Desenho de Equipamento , Gálio/química , Índio/química , Indústrias , Óxidos/química , Fotoquímica/métodos , Selênio/química , Energia Solar , Sulfetos/química , Compostos de Zinco/química
20.
Sci Total Environ ; 461-462: 792-8, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23683936

RESUMO

Historic data from many countries demonstrate that on average no more than 50-70% of the uranium in a deposit could be mined. An analysis of more recent data from Canada and Australia leads to a mining model with an average deposit extraction lifetime of 10±2 years. This simple model provides an accurate description of the extractable amount of uranium for the recent mining operations. Using this model for all larger existing and planned uranium mines up to 2030, a global uranium mining peak of at most 58±4 ktons around the year 2015 is obtained. Thereafter we predict that uranium mine production will decline to at most 54±5 ktons by 2025 and, with the decline steepening, to at most 41±5 ktons around 2030. This amount will not be sufficient to fuel the existing and planned nuclear power plants during the next 10-20 years. In fact, we find that it will be difficult to avoid supply shortages even under a slow 1%/year worldwide nuclear energy phase-out scenario up to 2025. We thus suggest that a worldwide nuclear energy phase-out is in order. If such a slow global phase-out is not voluntarily effected, the end of the present cheap uranium supply situation will be unavoidable. The result will be that some countries will simply be unable to afford sufficient uranium fuel at that point, which implies involuntary and perhaps chaotic nuclear phase-outs in those countries involving brownouts, blackouts, and worse.


Assuntos
Conservação dos Recursos Naturais/métodos , Mineração/métodos , Mineração/tendências , Modelos Econômicos , Urânio/economia , Urânio/provisão & distribuição , Conservação dos Recursos Naturais/tendências , História do Século XX , História do Século XXI , Mineração/história , Mineração/estatística & dados numéricos
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