Social preferences towards ecosystem services provided by cloud forests in the neotropics: implications for conservation strategies

Despite the importance of neotropical cloud forests as providers of ecosystem services to society, they are one of the most threatened ecosystems in the world. We analysed the importance of three cloud forest reserves in central Colombia as providers of ecosystem services, as well as the social support to conservation actions in these ecosystems through willingness to pay (WTP) and willingness to give up time (WTT) estimates. Our results highlight the high commitment of all users of the cloud forest areas towards the conservation of the ecosystem services provided by these strategic ecosystems. We found that the most important perceived ecosystem services were water supply and habitat maintenance for species. Our findings also suggest that the respondents’ ecological knowledge (measured as the awareness of the ecosystem services supplied by cloud forests) was an important factor in determining both WTP and WTT for conserving cloud forests. Moreover, our results indicate that WTT should be a viable technique to explore individual preferences of different stakeholders towards conservation activities in cloud forests. Based on our results, we propose a conservation strategy of cloud forests that considers different users’ socio-economic and environmental characteristics, in which both experimental and experiential knowledge should be incorporated in order to promote collective action.     

Characterization of a limestone in a batch fluidized bed reactor for sulfur retention under oxy-fuel operating conditions

CO₂ and SO₂ are some of the main polluting gases emitted into atmosphere in combustion processes using fossil fuel for energy production. The former is one of the major contributors to build-up the greenhouse effect implicated in global climate change and the latter produces acid rain. Oxy-fuel combustion is a technology, which consists in burning the fuel with a mix of pure O₂ and recirculated CO₂. With this technology the CO₂ concentration in the flue gas may be enriched up to 95%, becoming possible an easy CO₂ recovery. In addition, oxy-fuel combustion in fluidized beds allows in situ desulfurization of combustion gases by supplying calcium based sorbent.In this work, the effect of the principal operation variables affecting the sulfation reaction rate in fluidized bed reactors (temperature, CO₂ partial pressure, SO₂ concentration and particle size) under typical oxy-fuel combustion conditions have been analyzed in a batch fluidized bed reactor using a limestone as sorbent. It has been observed that sulfur retention can be carried out by direct sulfation of the CaCO₃ or by sulfation of the CaO (indirect sulfation) formed by CaCO₃ calcination. Direct sulfation and indirect sulfation operating conditions depended on the temperature and CO₂ partial pressure. The rate of direct sulfation rose with temperature and the rate of indirect sulfation for long reaction times decreased with temperature. An increase in the CO₂ partial pressure had a negative influence on the sulfation conversion reached by the limestone due to a higher temperature was needed to work in conditions of indirect sulfation. Thus, it is expected that the optimum temperature for sulfur retention in oxy-fuel combustion in fluidized bed reactors be about 925–950 °C. Sulfation reaction rate rose with decreasing sorbent particle size and increasing SO₂ concentration.     

Lightning protection scenarios of communication tower sites; human hazards and equipment damage

This paper provides comprehensive analysis on the lightning protection scenarios in 48 communication and broadcasting towers situated in similar isokeraunic contours in Sri Lanka at 79°–81° East and 5°–10° North. The investigation has been conducted to study the hazardous environment created on the tower and in the neighbourhood in the event of a lightning strike to the tower. The results show that a direct strike to an antenna structure in a metallic tower is rare irrespective of the presence of an air-termination or a down conductor. However, side flashing or arcing to antenna structures is highly possible once the air-termination and/or down conductor is installed and attempts are made to insulate the system from the tower. The outcome also shows that equipotential bonding of the grounding system, a distributed grounding network including a ring conductor and a suitable system of surge protective devices play a much vital role in lightning protection of equipment and safety of people compared to the effects of simply achieving a low grounding resistance. However, in the absence of such integrated, distributed and equipotentialized grounding system, a high value of ground resistance will sharply increase the possibility of accidents and damage. Considering the observations of the investigations into account we have designed a concrete embedded grounding system for tower sites at problematic locations. Finally, the scenarios for safety management at telecommunication tower sites have been discussed.     

An agent-based approach to explore the effect of voluntary mechanisms on land use change: A case in rural Queensland,Australia

In rural regions, land use changes (LUC) are often the result of the decision-making of individual farmers. To influence this decision-making, compulsory and voluntary mechanisms are implemented. However, farmers’ decision-making is a heterogeneous process that depends on their ability and willingness to take certain decisions. Discrepancies between farmers’ ability and willingness and the design of voluntary mechanisms occur frequently. This makes it necessary to understand how farmers’ participation in these mechanisms can affect LUC. The aim of this paper was to demonstrate an agent-based approach to analyse and explore how voluntary mechanisms can influence LUC processes in rural regions. This approach was applied to a rural region in Australia, where clearing of native vegetation has occurred for agricultural development. Historical land cover data and semi-structured interviews were used to parameterise an agent-based model. Factors that influence farmers’ ability and willingness to participate in these mechanisms were identified. Three scenarios were simulated with the model to explore how the implementation of different voluntary mechanisms can affect the landscape structure of the region. This paper identifies how the diversity of farmers’ decision-making can influence the landscape structure in the region. The advantages and limitations of an agent-based approach in relation to LUC research and policy are discussed.     

Land clearance not dieback continues to drive tree loss in a Tasmanian rural landscape

Tree cover has declined markedly since European settlement in the agricultural areas of Australia due to land clearing and natural and stress-induced senescence of remnant trees combined with widespread regeneration failure. These decreases in tree cover have seldom been quantified on a landscape scale, but are important in understanding losses in carbon storage and biodiversity across large areas of the continent. We used historical aerial photography and satellite imagery to study changes in tree canopy cover in the southern Tasmanian Midlands, one of the oldest agricultural regions in Australia. Tree cover at 1,000 random sites was assessed from imagery captured on four occasions between 1947 and 2010. Tree cover was stable between 1947 and the 1970s, but decreased from 33 % in the 1970s to 21 % in 2010. The decrease appeared driven by transition from some cover to no cover, rather than from more cover to less cover, because sites with tree cover in 2010 showed little net change during the study period. Statistical modelling showed soils derived from igneous rocks lost more cover than did the less fertile sedimentary soils, and contrary to the expectations, if drought was the cause of cover loss, sun-exposed north-facing sites did not lose more cover than south-facing ones. We argue that these temporal and spatial patterns of tree cover change are consistent with tree clearing rather than loss of remnant isolated trees due to drought-induced dieback.     

Growth conditions,elemental accumulation and induced physiological changes in Chinese cabbage

Soils contaminated with low levels of heavy metals and other trace elements are now frequently used for vegetable growing. In this situation, heavy metals and trace elements from these polluted soils may accumulate in the agricultural plants being grown in them and thereby enter the human food chain. The objectives of this study are to elucidate the effects of growth conditions, manipulated by the crop covers, on the phytoaccumulation of elements, and to investigate the conceivable influences of these conditions on the plant biochemistry. In three consecutive years of field experiments, open air (T(0)), and floating rowcover treatments (T(1): perforated polyethylene 50 micrometers; T(2): polypropylene 17 gm(-2)) were used to produce different environmental conditions for the growth of Chinese cabbage [Brassica rapa L. (Pekinensis group) cv. 'Nagaoka 50']. Five samplings (whole tops) were carried out from transplanting to harvest and measurements of B, Al, Ag, Si and Ca concentration as well as phenolics (orto-diphenols, total phenols and anthocyanins), pectic fractions, amino acids (histidine, phenylalanine and tyrosine) and polyphenol oxidase activity, were carried out in samples. The T(1) (perforated polyethylene sheet) gave greater B, Al, Ag and Si concentration and phytoextraction (in weight units) than the open-air control. These findings can help to develop new cost-effective techniques for phytoremediation as the application of plastic covers in the field. The build-up of heavy metals in those crops would make the product less suitable for human consumption.     

Relations between innovation management and organisational sustainability: a case study in a Brazilian higher education institution

Environment, Development and Sustainability - The objective of this work was to analyse the relations between innovation management and organisational sustainability in a Brazilian higher education...     

Practices of energy use management and sustainable performance in Brazilian mineral industries

Energy is an essential asset for the existence of industrial activities, however, the absence of energy use management may lead to numerous environmental, economic, and social impacts. Thus, industries, which are major consumers of energy, play an essential role in seeking to preserve the energy system. This study aimed at analyzing the practices of energy use management and their relation to sustainable performance in the industries within the Brazilian mineral sector. The practices of energy use management were measured using the model proposed by Liu et al. (2012, Journal of Cleaner Production, 26, 79–89). After that, evidence of sustainable performance was identified based on performance indicators developed by the Global Reporting Initiative (2006, 2010, 2014). The study is characterized as quantitative, and it was conducted through a survey of industries linked to the Brazilian Mining Association. Through our results, we verified that the practices related to energy use management existent in the companies that we studied are subjected to periodic verification of the impacts caused by company activities on the environment, and that attention to energy use provides an incentive to daily practices of energy saving. On the other hand, the practices of energy use management are still little disseminated among these companies, as is certification to the International Organisation for Standardization's (ISO) Energy Management Systems framework, ISO 50001. In general, through the analyses that we performed, we can verify the existence of positive associations between the factors related to the practices of energy use management and to corporate sustainable performance.     

Deferoxamine pretreatment inhibits metal neurotoxicity in Caenorhabditis elegans

Neurodegenerative diseases are increasingly common in humans. Alzheimer's disease (AD) is a neurodegenerative disease characterized by the presence of extracellular plaques containing β‐amyloid peptides and neurofibrillary tangles in the brains. Researchers have focused on the elucidation of a correlation between high concentrations of aluminum or iron (in the organism with observed neuropathology). The objective of this study was to evaluate the effects of aluminum and iron on the behavioral parameters (pharyngeal pumping and defecation cycle) of the nematode Caenorhabditis elegans pretreated with deferoxamine (DFX). Acetylcholinesterase (AChE) activity was evaluated as well. DFX is a chelant that is widely used for the treatment of metal toxicity, and it has a high affinity for aluminum and iron. The worms were pretreated with DFX, and then exposed to aluminum and iron. In the absence of DFX, aluminum exposure decreased pharyngeal pumping compared with that in the control group. The defecation cycle of the control was significantly different from that of the worms exposed to aluminum. In contrast, an increased defecation cycle was observed in worms exposed to iron without DFX pretreatment. AChE activity increased in aluminum‐exposed groups that received DFX pretreatment compared with those that did not receive pretreatment. These results suggest that pretreatment with DFX is effective in reducing metal toxicity, particularly with reference to AChE activity, which did not decrease in groups that did not receive DFX pretreatment.     

Effects of elevated yolk testosterone levels on survival, growth and immunity of male and female yellow-legged gull chicks

Androgen hormones of maternal origin contained in the eggs of avian species are considered to have positive effects on offspring characteristics and performance. However, negative consequences have also been reported, suggesting that mothers may experience a trade-off between beneficial and detrimental effects of egg androgens to offspring fitness. We studied the effects of elevated yolk testosterone (T) concentration on survival, development and phenotype of male and female yellow-legged gull (Larus michahellis) chicks by injecting egg yolks with physiological doses of the hormone. Elevated yolk T resulted in a male-biased post-hatching sex ratio, T-treated clutches producing a greater proportion of males compared to control ones at day 4 post-hatching, likely resulting from a reduction of female embryonic survival, whereas no effect of hormone treatment on hatching success or short-term chick survival was observed. In addition, T depressed post-hatching body mass in both sexes but had no effects on the intensity of the cell-mediated immune response or skeletal growth. No sex differences in egg characteristics or chick phenotype were detected. Time to hatching was not affected by T, but females originating from first laid eggs hatched earlier than males of the same laying order, independently of hormone treatment. However, the implications of sex differences in hatching times are unclear in the study species. Taken together, our results suggest that female yellow-legged gulls may be constrained in transferring androgens to their eggs by negative consequences on the viability of female offspring and growth of chicks of the two sexes.