Intraguild predation (IGP) has been explained in terms of competitor-removal, food-stress and predator-removal hypotheses.
Only the first two hypotheses have been fairly well studied. To test the predator-removal hypothesis as a force determining
IGP in avian predators, we performed a field experiment to simulate the presence of an IG predator (eagle owl Bubo bubo dummy) in the surrounding of the nests of four potential IG prey (black kite Milvus migrans, red kite Milvus milvus, booted eagle Aquila pennata and common buzzard Buteo buteo). To discard the possibility that an aggressive reaction towards the eagle owl was not related to the presence of the IG
predator, we also presented a stuffed tawny owl Strix aluco, which is a potential competitor but cannot be considered an IG predator of the studied diurnal raptors considered in the
experiment. While almost always ignoring the tawny owl, raptors chiefly showed an interspecific aggressive behaviour towards
their IG predator. Our results seem to support the predator-removal hypothesis, as the IG prey may take advantage of the diurnal
inactivity of the IG predator to remove it from their territory. However, the recorded behaviour may be also considered as
a special variety of mobbing (i.e. a prey’s counter-strategy against its predator), where the mobber is sufficiently powerful
to escalate predator harassment into deliberate killing attempts. In their turn, eagle owls can respond with an IG predatory
behaviour aimed at removing IG prey species which are highly aggressive mobbers. 相似文献
Environmental Chemistry Letters - The anthraquinone dye Remazol Brilliant Blue R is largely used in the textile industry. However, its removal from wastewaters is costly and complex. Many methods... 相似文献
This paper presents a study of cement replacement by sugar cane bagasse ash (SCBA) in industrial scale aiming to reduce the CO2 emissions into the atmosphere. SCBA is a by-product of the sugar/ethanol agro-industry abundantly available in some regions of the world and has cementitious properties indicating that it can be used together with cement. Recent comprehensive research developed at the Federal University of Rio de Janeiro/Brazil has demonstrated that SCBA maintains, or even improves, the mechanical and durability properties of cement-based materials such as mortars and concretes. Brazil is the world’s largest sugar cane producer and being a developing country can claim carbon credits. A simulation was carried out to estimate the potential of CO2 emission reductions and the viability to issue certified emission reduction (CER) credits. The simulation was developed within the framework of the methodology established by the United Nations Framework Convention on Climate Change (UNFCCC) for the Clean Development Mechanism (CDM). The State of São Paulo (Brazil) was chosen for this case study because it concentrates about 60% of the national sugar cane and ash production together with an important concentration of cement factories. Since one of the key variables to estimate the CO2 emissions is the average distance between sugar cane/ethanol factories and the cement plants, a genetic algorithm was developed to solve this optimization problem. The results indicated that SCBA blended cement reduces CO2 emissions, which qualifies this product for CDM projects. 相似文献
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
This study aimed to assess the influence of excess iron on the capacity of accumulation of this heavy metal, mineral composition, and growth of Setaria parviflora and Paspalum urvillei. Seedlings were submitted to 0.009; 1; 2; 4; and 7 mM of Fe-EDTA. In both species there was an increase in the concentration of Fe, Zn, P, and Ca and a decrease in Mn, K, and Mg in the iron plaque. Both species accumulated more iron in roots. In the shoots, S. parviflora showed higher iron content, except at 7 mM. Iron altered the contents of Fe, Cu, K, and Mg in roots, and of Fe, Mn, Zn, N, P, K, Ca, and Mg in shoots. The two species tolerated high iron concentrations and accumulated high content of this element in both shoots and roots. The iron did not reduce their growth. Both species are indicated for studies aiming restoration of iron-contaminated areas. 相似文献
Social acceptance is fundamental, and directly affects the installation of wind farms. In this paper, the factors that have had the greatest influence on the development of wind energy in the Itsmo region of Tehuantepec, Mexico are identified. The data were collected face to face through a semi-structured questionnaire of 31 people: owners, municipal authorities, opposition groups, and academic members. The results of the interview highlight the social impact, the lack of application, and concerning ILO Convention 169, the abuse of community rights. As a result, people interviewed perceive that the environmental impact of the installation, and operation of wind farms has been ambivalent: positive due to the intrinsic benefits that wind energy generates compared to other energy sources, and negative in terms of affectation by the noise, and the landscape. However, the income received by the owners of land in which wind facilities are located is lower compared to other parts of the world. In general, the facts show a disintegration between the authorities (federal, state, and municipal), universities are isolated from wind projects, communities are not consulted in projects, and large companies are the main beneficiaries.
Journal of Material Cycles and Waste Management - The use of food waste (FW) for the production of biofuels and value-added compounds is growing worldwide. However, the significant chemical... 相似文献
Methods to determine nutrient release rates of coated fertilizers usually rely on chemical analyses, which often are time-consuming and/or expensive. Our goal was to develop an innovative and rapid low-cost method to evaluate nutrient release from polymer coated MAP or urea using conductometry. The release in water is determined by measuring the electric conductivity (EC) over time, with intervals dependent on release rates. In the case of soluble salt fertilizers, EC can be immediately determined and converted to a concentration using a calibration curve. In the case of urea, an additional step is needed to convert the neutral urea into ammonium. The release rates in water were assessed for a range of commercial and laboratory-coated fertilizers. A validation test demonstrated strong agreement with the release determined using analytical techniques. The EC method hence offers an easy way to quickly evaluate the time course of release of nutrients from controlled-release fertilizers. 相似文献