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91.
Biodiversity Conservation in Traditional Coffee Systems of Mexico   总被引:27,自引:1,他引:26  
In Mexico, coffee is cultivated on the coastal slopes of the central and southern parts of the country in areas where two or more types of vegetation make contact. Based on management level and vegetational and structural complexity, it is possible to distinguish five main coffee production systems in Mexico: two kinds of traditional shaded agroforests (with native trees), one commercially oriented polyspecific shaded system, and two "modern" systems (shaded and unshaded monocultures). Traditional shaded coffee is cultivated principally by small-scale, community-based growers, most of whom belong to some indigenous culture group. Through an exhaustive review of the literature, we found that traditional shaded coffee plantations are important repositories of biological richness for groups such as trees and epiphytes, mammals, birds, reptiles, amphibians, and arthropods. We evaluated the conservation role of these traditional shaded systems by estimating the percentage of the whole coffee area under traditional management, by reviewing the ecological and geographical distribution of coffee areas in Mexico, and by connecting the geographical distribution of these coffee areas with recognized centers of species richness and endemism. The assesment revealed that in Mexico, coffee fields are located in a biogeographically and ecologically strategic elevational belt that is an area of overlap between the tropical and temperate elements and of contact among the four main types of Mexican forests. We also found that between 60% and 70% of these coffee areas are under traditional management and that at least 14 of 155 priority regions selected by experts as having high numbers of species and endemics overlap with or are near traditional coffee-growing areas.  相似文献   
92.
Institutions of Higher Education have to cope with an array of challenges in the 21st century including globalization of teaching, research and outreach activities; additionally there are dramatic increases in competition for students, staff and funding sources. Meanwhile, local and regional involvement in regional sustainable development is increasing in importance as well. This latter process is driven by the mandates from many sources for academic involvement in working on the multi-faceted issues pertaining to Sustainable Development (SD). This requires concerted action not only at the global, but also at the local and regional levels. This article provides an overview of this special issue of the Journal of Cleaner Production on the Roles of Academia in Regional Sustainable Development Initiatives. The essence of the 11 articles contained in this special issue is summarized and contextualized within the rapidly evolving academic efforts on SD. Recommendations are made of ways for academia to help their regions to make more rapid progress toward SD via involvement of their faculty, students and staff in Regional SD programs and processes.  相似文献   
93.
94.
Anthropogenic impacts on biodiversity can lead to biotic homogenization (BH) and biotic differentiation (BD). BH is a process of increasing similarity in community composition (including taxonomic, functional, and phylogenetic components), whereas BD is a process of decreasing similarity over space and time. Here, we conducted a systematic review of BH and BD in plant communities in tropical and subtropical forests to identify trends and knowledge gaps. Our bibliometric search in the Web of Science returned 1989 papers, of which 151 matched our criteria and were included in the analysis. The Neotropical region had the largest number of articles, and Brazil was the most represented country with 92 studies. Regarding the type of change, homogenization was more frequent than differentiation (noted in 69.6% of publications). The taxonomic diversity component was measured more often than functional and phylogenetic diversity components. Most studies (75.6%) assessed homogenization and differentiation based on a single observation in time; as opposed to few studies that monitored plant community over multiple years. Forest fragmentation was cited as the main determinant of homogenization and differentiation processes (57.2% of articles). Our results highlight the importance of evaluating community composition over time and more than taxonomic components (i.e., functional and phylogenetic) to advance understanding of homogenization and differentiation. Both processes were scale dependent and not mutually exclusive. As such, future research should consider differentiation as a potential transition phase to homogenization and that potential differences in both processes may depend on the spatial and temporal scale adopted. Understanding the complexity and causes of homogenization and differentiation is essential for biodiversity conservation in a world increasingly affected by anthropogenic disturbances.  相似文献   
95.
In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sertão Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81% and 85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH.The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated.  相似文献   
96.
Environmental Science and Pollution Research - In Brazil, landfills are commonly used as a method for the final disposal of waste that is compliant with the legislation. This technique, however,...  相似文献   
97.
In the lower Guadalquivir river basin, a system stressed by a wide variety of anthropogenic activities, eight pesticides (four triazines, two chloroacetanilide herbicides, one organochlorine, and one organophosphorus insecticide); and four emerging pollutants (two personal care products, one organophosphorous flame retardant, and one xanthine alkaloid) were analyzed in river water during a 2-year monitoring program, and after rain episodes. Samples were extracted using the solid phase extraction (SPE) technique prior to determination of compounds using gas chromatograph coupled to a mass spectrometer detector. Except for caffeine, recoveries were mostly above 80 %, while limits of detection and quantification were in the low nanograms per liter level (except for dimethoate). Terbuthylazine, simazine (triazine herbicides), and dimethoate (organophosphorus insecticide), present in agrochemicals, were predominant in the river water, although concentrations were below the quality standards established by the EU Water-Framework-Directive. A general trend to increase concentration was observed after rain events, in particular for pesticides, possibly as a consequence of surface runoff.  相似文献   
98.
This research aimed at assessing the properties of guinea pig manure digestate from low-cost tubular digesters for crops fertilization in rural Andean communities. To this end, field trials were carried out to evaluate the effect of the digestate on two common Andean crops: potato (Solanum tuberosum) and forage (Lolium multiflorum and Trifolium pratense L.). The potato yield (20-25 tha(-1)) increased by 27.5% with digestate, by 15.1% with pre-compost and by 10.3% with the mixture, compared to the control. The forage yield (20-21 tha(-1)) increased by 1.4% with digestate - 50% dose, and by 8.8% with digestate - 100% dose and digestate - 150% dose, compared to the control. The results suggest that the digestate is an appropriate substitute of manure pre-compost for potato fertilization. The results with forage indicate that it can be applied in a range of doses, according to the amount produced by the digester. Currently, manure is either used for cooking or as fertilizer. With low-cost tubular digesters implementation, it could be used to feed the digester, using the digestate for crops fertilization and biogas for cooking; improving household living conditions and protecting the environment. Since soil properties in rural Andean communities differ from experimental layouts, the effect of fertilizers should be re-evaluated in-situ in future research studies.  相似文献   
99.
Abstract

Sugarcane vinasse is a by-product obtained during ethanol production in sugar-ethanol plants. For each 1?L of ethanol produced approximately 11?L of vinasse are generated. As this residue is obtained in high amounts, it is used as fertilizer in sugarcane crops. However, despite being rich in nutrients, sugarcane vinasse is approximately one hundred times more polluting than domestic sewage, making it an environmental problem. Thus, the aim of the present study was to propose a treatment sequence for sugarcane vinasse and evaluate the possibility of energetic use of the generated sludge in the coagulation/flocculation stage. pH, conductivity, turbidity and decreases in UV/Vis absorption spectra were determined for each treatment step. In addition, the upper calorific value of the generated sludge was also determined, while ash (adsorption treatment) and catalyst (heterogeneous photocatalysis) characterizations were also carried out. At the end of the treatment, initial vinasse turbidity was reduced by 100% and pH and conductivity values were stabilized. The sludge presented a higher calorific value of approximately 3,000?kcal kg?1 and the ash and catalyst displayed favorable characteristics to be applied to the sugarcane vinasse treatment stages.  相似文献   
100.
Sequestration of carbon dioxide (CO2) in deep saline aquifers has emerged as an option for reducing greenhouse gas emissions to the atmosphere. The large amounts of supercritical CO2 that need to be injected into deep saline aquifers may cause large fluid pressure increases. The resulting overpressure may promote reactivation of sealed fractures or the creation of new ones in the caprock seal. This could lead to escape routes for CO2. In order to assess the probability of such an event, we model an axisymmetric horizontal aquifer–caprock system, including hydromechanical coupling. We study the failure mechanisms, using a viscoplastic approach. Simulations illustrate that, depending on boundary conditions, the least favorable moment takes place at the beginning of injection. Initially, fluid pressure rises sharply because of a reduction in permeability due to desaturation. Once CO2 fills the pores in the vicinity of the injection well and a capillary fringe is fully developed, the less viscous CO2 displaces the brine and the capillary fringe laterally. The overpressure caused by the permeability reduction within the capillary fringe due to desaturation decreases with distance from the injection well. This results in a drop in fluid pressure buildup with time, which leads to a safer situation. Nevertheless, in the presence of low-permeability boundaries, fluid pressure continues to rise in the whole aquifer. This occurs when the radius of influence of the injection reaches the outer boundary. Thus, caprock integrity might be compromised in the long term.  相似文献   
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