Assessing water ecosystem services for water resource management

AbstractEcosystem service concepts can offer a valuable approach for linking human and nature, and arguments for the conservation and restoration of natural ecosystems. Despite an increasing interest in the topic, the application of these concepts for water resource management has been hampered by the lack of practical definitions and methodologies. In this study we review and analyse the current literature and propose an approach for assessing and valuing ecosystem services in the context of water management. In particular, to study the link between multiple pressures, ecological status and delivery of ecosystem services in aquatic ecosystems under different scenarios of measures or future changes. This is of interest for the development of River Basin Management Plans under the EU Water Framework Directive. We provide a list of proxies/indicators of natural capacity, actual flow and social benefit for the biophysical assessment of the ecosystem services. We advocate the use of indicators of sustainability, combining information on capacity and flow of services. We also suggest methods for economic valuation of aquatic ecosystem for each service and spatial scale of application. We argue that biophysical assessment and economic valuation should be conducted jointly to account for the different values of ecosystem services (ecologic, social and economic) and to strengthen the recognition of human dependency on nature. The proposed approach can be used for assessing the benefits of conservation and restoration of aquatic ecosystems in the implementation of the EU water policy

A study of hydrous ethanol combustion in an optical central direct injection spark ignition engine

The aim of this experimental work was to improve understanding of the influence of hydrous ethanol on combustion in an engine demonstrating a tendency for biased flame migration towards the hotter exhaust walls as often reported for typical modern pent roof design IC engines. The work aimed to uncover the degree of residual water content that can be reasonably tolerated in terms of combustion characteristics in future ethanol SI engines (with the energy required to reduce water levels then potentially reduced). The experiments were performed in a single cylinder optical research engine equipped with a modern central direct injection combustion chamber and Bowditch type optical piston. Results were obtained under part-load engine operating conditions (selected to represent typical highway cruising conditions) with hydrous ethanol at 5%, 12% and 20% volume water. Baseline results were obtained using pure isooctane. High-speed cross-correlated particle image velocimetry was undertaken at 1500 rpm under motoring conditions with the intake plenum pressure set to 0.5 bar absolute. The horizontal imaging plane was fixed 10 mm below the combustion chamber “fire face”. Comparisons were made to CFD computations of the in-cylinder flow. Complimentary flame images were obtained via the “natural light” (chemiluminescence) technique over multiple engine cycles. The flame images revealed the tendency of an iso-octane fueled flame to migrate towards the exhaust side of the combustion chamber, with no complimentary bulk air motion apparent in this area in the horizontal imaging plane. The faster-burning ethanol offset this tendency of the flame to migrate towards the hotter exhaust walls. The fastest combustion rate occurred with pure ethanol, with higher water content (>5%) generally slowing down the flame speed rate to 10.64 m/s from 10.92 of ethanol and offsetting the flame speed/migration benefit (in good agreement with recent laminar burning velocity correlations for hydrous ethanol). When adding 20% water to ethanol the combustion rate was significantly slower (8.2 m/s) with a considerable increase in flame shape distortion as quantified by flame image shape factor values. The results demonstrate how the added water increases flame distortion and leads to higher flame centre displacement. Such flame centre displacement could potentially be offset in the future with a spark plug location biased further towards the intake side of the chamber (albeit sometimes practically constrained by the priorities given to intake valve sizing and local cooling jacket design). The results indicate that ethanol fuels offset such bias flame growth and allow residual water to be tolerated for an equivalent degree of biased flame migration. The implication is reduced fuel production energy and cost required to produce usable ethanol fuels

Cyclically resolved flame and flow imaging in an alcohol fuelled SI engine

The work was concerned with improving understanding of the interaction of the bulk in-cylinder flow with turbulent premixed flame propagation when using varied fuels including iso-octane, ethanol or butanol. The experiments were performed in a single cylinder research engine equipped with a modern central direct injection combustion chamber and Bowditch style optical piston. Results were obtained under typical part-load engine operating conditions. High speed cross-correlated particle image velocimetry was undertaken at 1500 rpm under motoring conditions with the plenum pressure set to 0.5 bar absolute, with the horizontal imaging plane fixed 10 mm below the combustion chamber “fireface”. Comparisons were made to CFD computations of the flow. Complementary flame images were then obtained via natural light (chemiluminescence) over multiple engine cycles. The flame images revealed the tendency of the flame to migrate towards the hotter exhaust side of the combustion chamber, with no complementary bulk air motion apparent in this area in the imaging plane. In terms of fuel effects, the addition of 16% butanol to iso-octane resulted in marginally faster combustion. Fastest combustion was observed with ethanol, in good agreement with laminar burning velocity correlations within the literature. The ethanol could be seen to offset the tendency of migration of the flame toward the exhaust walls under the fixed spark timing conditions. This exhaust migration phenomenon has been noted previously by others in optical pent-roofed engines but without both flow and flame imaging data being available. The results may imply that the spark plug should ideally be biased further towards the intake side of the chamber if the flame is to approach the intake and exhaust walls at similar times resulting in symmetrical flame propagation, reduced premature wall quenching and hence increase combustion stability and thermal efficiency. Such a layout is typically not preferred due to the priority given to the central fuel injector (and associated cooling jacket) location and maximizing the size of the inlet valves for improved volumetric efficiency

Investigation of Early and Late Intake Valve Closure Strategies for Load Control in a Spark Ignition Ethanol Engine

The more strict CO2 emission legislation for internal combustion engines demands higher spark ignition (SI)engine efficiencies. The use of renewable fuels, such as bioethanol, may play a vital role to reduce not only CO2 emissions but also petroleum dependency. An option to increase SI four stroke engine efficiency is to use the so called over-expanded cycle concepts by variation of the valve events. The use of an early or late intake valve closure reduces pumping losses (the main cause of the low part load efficiency in SI engines) but decreases the effective compression ratio. The higher expansion to compression ratio leads to better use of the produced work and also increases engine efficiency. This paper investigates the effects of early and late intake valve closure strategies in the gas exchange process, combustion, emissions and engine efficiency at unthrottled stoichiometric operation. A four-valve four-stroke single cylinder camless engine running with port fuel injection of anhydrous ethanol was employed. Early and late intake valve closure (EIVC and LIVC) strategies with a fixed maximum valve lift were compared to a conventional throttled SI valve event strategy for loads from 2.0 to 9.0 bar IMEP at 1500 rpm. The consequences and benefits to implement the unthrottled operation with each strategy were discussed. To better understand the effect of the maximum valve lift at a specific load, the valve lift was varied from 1.5 to 5.0 mm and its effects were discussed for EIVC strategy. Comparatively, the EIVC strategy presented better overall performance than the LIVC. Both unthrottled strategies provided higher engine efficiency than the conventional throttled SI strategy

Sistema agrossilvipastoril como alternativa para agricultura familiar: Um Estudo de Caso em Três Passos/RS

No estado do Rio Grande do Sul há uma busca incessante para desenvolver tecnologias com finalidade de inovar no campo das produções agrícola, pecuária e florestal. Dentre essas tecnologias está o sistema de integração entre lavoura, pecuária, e floresta, também conhecido como sistema agrosilvipastoril (SASP). O objetivo deste Estudo de Caso foi Elaborar um Plano de Ações de Desenvolvimento Sustentável, através de um SASP, para uma pequena propriedade rural do município de Três Passos. O presente trabalho constou inicialmente de uma pesquisa bibliográfica sobre os sistemas integrados de produção. Em seguida, foi selecionada uma propriedade rural, onde foi realizado um diagnóstico da sua situação atual. Posteriormente, após realização de entrevista com os proprietários da área, foi apresentada uma proposta de implantação de um SASP. Observou-se que muitos dos problemas encontrados na propriedade pesquisada, eram passíveis de solução através de técnicas adequadas de manejo e conservação do solo e de tratos culturais ou culturas adaptadas à situação. Buscou-se através do SASP, propor alternativas para o gerenciamento das atividades através de tecnologias conservacionistas, que trazem inúmeros benefícios ao produtor. O Estudo de Caso abordou os principais ganhos e mudanças que a propriedade teria com a implantação do SASP, considerando as perspectivas econômicas e sustentáveis da produção agropecuária. Concluiu-se que este sistema de integração pode ser uma opção viável e próspera para o desenvolvimento da propriedade do casal de agricultores, desde que utilizado de forma correta, trabalhando práticas conservacionistas, sendo capaz de assim, mudar para melhor o atual cenário social, econômico e ambiental

Vermicompostagem de Resíduos Orgânicos e Hortas Domésticas em Instituições Assistencialistas de Três Passos – RS

A elevada produção de resíduos orgânicos é um problema atualmente. Uma maneira alternativa para a correta destinação desses resíduos é a compostagem e a vermicompostagem, cujo sistema inclui minhocas à técnica de compostagem, para transformar o material orgânico fresco em adubo orgânico maturado. O objetivo deste trabalho foi avaliar a vermicompostagem como alternativa para a produção de adubo e chorume biofertilizante, aproveitando os resíduos orgânicos gerados pelas cozinhas, diminuindo a produção de resíduos destinados aos aterros sanitários. Foram instaladas duas composteiras feitas com caixa d’agua de fibra e tubulações em PVC em duas instituições assistencialistas de Três Passos – RS (Associação de Pais e Amigos de Excepcionais – APAE; e Asilo Lar dos Idosos). Nas composteiras foram aportadas 300 gramas de minhocas da espécie Eisenia foetida, juntamente com os resíduos orgânicos gerados pelas cozinhas de cada instituição. Após 60 dias da primeira adição, o total de resíduos orgânicos colocados em cada local foi de 112 kg na APAE e 633 kg no Asilo. Desde a última adição de resíduos e após sua decomposição, obteve-se um produto maturado e com elevado teor de nutrientes, bem como a diminuição de massa, pela ação dos microrganismos durante a vermicompostagem. Com a implantação das composteiras, nas duas instituições, estimou-se que anualmente foram destinados corretamente 4,5 toneladas de resíduos orgânicos, diminuindo, assim, valores com transporte e manejo destes em aterros sanitários, além de obter-se um produto com potencial agronômico para fertilização de solo e plantas, os quais foram utilizados nas hortas localizadas em cada instituição

The b-32 ribosome inactivating protein from maize influences fumonisin accumulation in in-vitro bioassays

Fungi of the genus Fusarium are common plant pathogens mainly associated with cereal crops. In particular, Fusarium verticillioides Sacc. is the most common toxigenic fungus in maize worldwide, causing root, stalk, and ear rot. Fusarium spp. can produce a wide range of secondary metabolites, some of which can unfavourably affect human and animal health. Owing to the potential risks of fumonisins F. verticillioides secondary metabolites, new regulations for the allowable mycotoxin limit in food and feed have been put in place by most agencies worldwide. Plants act on the attack of pathogenic fungi through a complex network of active responses such as the production of proteins toxic or inhibitory to pathogens such as RIP (Ribosome-Inactivating-Protein). The RIP present in maize endosperm (termed b-32) has been widely investigated. Similarly to other RIPs, is accumulated in the seed as an inactive pro-RIP precursor, which is converted into an active form by proteolytic processing. To understand the relationships between structure and substrate specificity of the maize b-32 RIP protein, a series of recombinant b-32 sequences, by selective deleting of different domains (RIP b-32, RIP ∆N, RIP ∆C and RIP-∆C (Ala), were prepared. Recombinant sequences were expressed in Escherichia coli to obtain high levels of recombinant proteins, which were subsequently tested for their potential ability to reduce both the colonization of F. verticillioides and fumonisin accumulation

Characterization of the maize b-32 ribosome inactivating protein and its interaction with fungal pathogen development

Plants respond to attack by pathogenic fungi with a complex network of responses, including the production and accumulation of proteins, such as the Ribosome Inactivating Proteins (RIPs) that are toxic or inhibitory to pathogens. In maize endosperm, a cytosolic albumin termed b-32 (RIP1) is synthesized in temporal and quantita¬tive coordination with the deposition of storage proteins. Research has shown that b-32 is able to i) enzymati¬cally inactive ribosomes modifying rRNA inhibiting protein synthesis in vitro, ii) inhibit the growth of Rhizoctonia solani mycelia in an in vitro and in planta assays, iii) reduce Fusarium culmorum head blight in wheat transgenic plants expressing b-32, and iv) diminish Fusarium verticillioides attack symptoms in leaf tissues assays of maize transgenic expressing ectopically b-32 protein. Similarly to other RIPs, maize b-32 is accumulated in the seed as an inactive precursor, which is converted into an active form by proteolytic processing which removes peptide segments from the N (residues 1-16 of pro-RIP) and C (residues 295-301) termini and also from the center (linker domain) of the polypeptide. In this review we will summarize evidence and advances related to the ability of the b-32 protein in contrasting pathogen attacks by considering and describing i) in vivo b-32 antifungal activity and ii) in vitro fungal development inhibition. These data provide information for assessing b-32 in developing plants with a higher capacity to contrast damages induced by pathogens

Spectroscopic Kernel Quality From A Symbiotic Corn Production

The management of the inoculation of a plant's roots, by means of biofertilizers (BF) containing arbuscular mycorrhizal (AM) fungi, is aimed at inducing modifications of the quality of the seeds. It is here shown that a seed-soil treatment can be elicited in the fingerprints of a symbiotic treatment using Near Infra Red (NIR)-SCiO NIR-SCiO spectra collections of single kernels: overall, a sensitivity of 73% and a specificity of 73% have been achieved, thus suggesting that it may be possible to assign the symbiotic origin of corn from just twenty kernels, provided that the dataset is adequately representative of the cultivar and AM. A global correlation study has shown a positive general trend (R2 0.45) of quality vs. quantity, in the sense that an increase in yield corresponded to an increase in the spectral differences between the symbiotic spectra and the control ones, but the inverse was also true, as a result of the parasitic behaviour of the BF treatments. The efficacy of the symbiosis can be back predicted from the NIR spectra; in fact, around 90% of the positive yield outcome results were discriminated from the negative ones. A reduction in the foliar pH (R2 0.37) and an increase in the foliar protein (R2 0.43) were observed as immediate phenotypic signs of a productive symbiosis. The commercial raw composition of the kernels appeared to only be affected slightly by the BF treatments; thus, till now uncharted secondary compounds of the maize kernels are involved, as supported by animal performances