A long-term analysis of the declining population of the Egyptian vulture in the Italian peninsula: Distribution, habitat preference, productivity and conservation implications

Between the beginning of the 1970s and the early 1990s the breeding population of the Egyptian vulture (Neophron percnopterus) in the Italian peninsula declined from 29 to nine breeding pairs. We analysed the main aspects of the decline of this population during the last 30 years, namely: (1) landscape structure and composition of active and extinct nesting sites; (2) changes in the land use and number of cattle within the breeding range; (3) productivity (1986-1999) of the last nine pairs breeding in the Italian peninsula. Further decline in the breeding population was probably stopped by creating artificial feeding sites and protecting the last nesting sites from direct persecution. Nearly two-thirds of the pairs laid at least one egg per year, and half of the pairs fledged at least one young per year. The mean number of fledged young was 0.99±0.66 per breeding pair, and 1.27±0.45 per successful pair. About 75% of the breeding failures occurred during incubation, and 71% were related to human activities and direct persecution. The nesting cliff occupation rate, percentage of breeding attempts that fledged at least one chick and mean number of fledged young were negatively correlated with the distance to an artificial feeding site. © 2001 Elsevier Science Ltd. All rights reserved.Peer Reviewe

Competitive Ability of Rice Cultivars in the Era of Weed Resistance

Almost all plants are negatively affected by neighboring plants, which impose some degree of competition within the population, depending mainly on the quantity and quality of natural resources available in the environment. In rice cultivation, the occurrence of a high and diverse infestation of weeds results in high competition levels among the species. In addition, the high and growing number of cases about herbicide-resistant weeds, especially the widespread distribution of Imidazolinone-resistant weedy-rice and the high infestation of weeds belonging to the Echinochloa genus, has increased the competition levels within rice cultivation due to the lack of control. Therefore, the inclusion of rice cultivars with greater competitive ability represents a promising tool for weed management, since new cases of resistance to herbicides are often reported and alternative control strategies are scarce. The use of rice cultivars with a greater ability to suppress weeds can alleviate the competitive effect of these species, giving priority to the crop for the use of environmental resources due to the faster occupation of the ecological niches. Thus, this chapter aims to explore the competitive ability of rice cultivars against troublesome weed species, accounting for the role of their morphological and physiological traits as a function of environment-friendly crop practices

On the dust temperatures of high redshift galaxies

Dust temperature is an important property of the interstellar medium (ISM) of galaxies. It is required when converting (sub)millimeter broadband flux to total infrared luminosity (L_IR), and hence star formation rate, in high-z galaxies. However, different definitions of dust temperatures have been used in the literature, leading to different physical interpretations of how ISM conditions change with, e.g., redshift and star formation rate. In this paper, we analyse the dust temperatures of massive (M* > 10^10 Msun) z=2-6 galaxies with the help of high-resolution cosmological simulations from the Feedback in Realistic Environments (FIRE) project. At z~2, our simulations successfully predict dust temperatures in good agreement with observations. We find that dust temperatures based on the peak emission wavelength increase with redshift, in line with the higher star formation activity at higher redshift, and are strongly correlated with the specific star formation rate. In contrast, the mass-weighted dust temperature does not strongly evolve with redshift over z=2-6 at fixed IR luminosity but is tightly correlated with L_IR at fixed z. The mass-weighted temperature is important for accurately estimating the total dust mass. We also analyse an 'equivalent' dust temperature for converting (sub)millimeter flux density to total IR luminosity, and provide a fitting formula as a function of redshift and dust-to-metal ratio. We find that galaxies of higher equivalent (or higher peak) dust temperature ('warmer dust') do not necessarily have higher mass-weighted temperatures. A 'two-phase' picture for interstellar dust can explain the different scaling relations of the various dust temperatures.Comment: 26 pages, 15 figures, accepted for publication in MNRA

Análise da estrutura e dos critérios na elaboração do índice de Sustentabilidade

The sustainability of human-environmental systems currently represents the best choice for its continuity.Sustainability index can be used for possibly identifying the direction of sustainability, althoughregarded as complex and subjective. Therefore, this study aims to analyze the process of constructinga sustainability index, by identifying main definitions, structure and methods. The used methodology included qualitative research, with data collection from literature review and interpretation analysis. Theresults illustrate that the structure of a sustainability index is developed by identifying the aims and thehuman-environmental system, by the selection, normalization, ponderation and aggregation of indices,thus generating the index. We conclude that there is no single model for the process of elaboratingsustainability index, so different processes can be used, differing in their quality of measurement ofsustainability. Additionally, the choice for a process is related to the available information on themeasured subsystem. In this context, it is recommended great attention, once the generated indexcould present unsatisfactory and unrealistic results.A sustentabilidade do sistema ambiental-humano representa, na atualidade, a melhor opção para a sua continuidade. A identificação da direção da sustentabilidade pode ser realizada utilizando-se um índice de sustentabilidade, porém, este é considerado complexo e subjetivo. Portanto, este estudo objetiva analisar o processo de elaboração do índice de sustentabilidade, identificando as principais definições, a estrutura e os métodos. A metodologia utilizada quanto ao tipo de pesquisa é qualitativa e a coleta dos dados realizou-se com base em uma revisão bibliográfica, e sua análise ocorreu por meio do processo de interpretação. Os resultados revelam que a estrutura de um índice de sustentabilidade ocorre diante da identificação do objetivo e do sistema ambiental-humano, da seleção dos indicadores, normalização, ponderação, agregação, assim gerando o índice. Conclui-se que o processo de elaboração do índice de sustentabilidade não tem um modelo único, assim, os diferentes processos podem ser utilizados, mas diferenciam-se diante da qualidade da mensuração do nível de sustentabilidade. Além disso, a escolha de um processo está relacionada com as informações que estão disponíveis no subsistema a ser mensurado. Nesse sentido, recomenda-se muita cautela, pois o índice gerado pode apresentar resultados insatisfatórios e irreais

Rice Crop Rotation: A Solution for Weed Management

The challenges for weed management have increased in rice cultivation due to the high number of cases of herbicide-resistant weeds, especially the widespread distribution of imidazolinone-resistant weedy rice. Therefore, there has been particular interest in preventive, physical, and cultural methods in recent decades. In this context, the adoption of the rice-soybean rotation is reported to be one of the most important factors for weed management in rice fields. Additionally, the use of a diversified crop rotation enables the implementation of a broader herbicide program, which is an important feature influencing weed population dynamics. Rice-soybean rotation has been adopted by farmers to control problematic weed species, reduce seed bank of troublesome weed species, and prevent rice grain yield and quality losses caused by its interference. This crop rotation scheme has brought several benefits when it comes to weed management; however, there are also some drawbacks when adopting this strategy such as the limited productivity of soybean and new weed species becoming problematic, such as Conyza species. Thus, this chapter explores the advantages and disadvantages of adopting crop rotation in Brazilian lowlands, and proposes a set of strategies to successfully implement crop rotation in lowland soils as a tool for weed management

Aspectos ecofisiológicos da germinação de sementes em biótipos de Sagittaria montevidensis resistentes e suscetível a herbicidas

The objective of this work was to evaluate the ecophysiological aspects of seed germination in California arrowhead (Sagittaria montevidensis) biotypes resistant and susceptible to herbicides. The experimental design was completely randomized. In paddy rice fields, seeds were collected from two biotypes that are resistant (SAGMO 10 and SAGMO 32) and from one that is susceptible (SAGMO 35) to acetolactate synthase and photosystem II inhibiting herbicides. Seed dormancy release was performed with 2.0% potassium nitrate, chemical (1.0% H2SO4 for 30 s) and mechanical (sandpaper) scarification, 10 ppm gibberellic acid, water imbibition for 24 hours, water bath at 60°C, and a control. Germination was evaluated at temperatures from 10 to 40°C and seedling emergence at 0.0, 0.5, 1.0, 2.0, 4.0, and 5.0 cm burial depths. All biotypes showed a germination higher than 70% after mechanical scarification. The highest germination rate occurs at 25.9°C for SAGMO 35, the susceptible biotype, and at 26.2 and 26.5°C, respectively, for SAGMO 10 and SAGMO 32, the resistant biotypes. For all biotypes, the highest seedling emergence occurs in seeds positioned at the 0.5 and 1.0 cm burial depths.O objetivo deste trabalho foi avaliar aspectos ecofisiológicos da germinação de sementes em biótipos de sagitária (Sagittaria montevidensis) resistentes e suscetível a herbicidas. O delineamento experimental foi o inteiramente casualizado. Em campos de arroz, foram colhidas sementes de dois biótipos resistentes (SAGMO 10 e SAGMO 32) e de um suscetível (SAGMO 35) aos herbicidas inibidores da acetolactato sintase e do fotossistema II. A liberação da dormência foi realizada com 2,0% de nitrato de potássio, escarificação química (1,0% de H2SO4 por 30 s) e mecânica (lixa), 10 ppm de ácido giberélico, embebição em água por 24 horas, banho-maria a 60oC e um controle. Avaliaram-se a germinação às temperaturas de 10 a 40°C e a emergência de plântulas aos 0,0, 0,5, 1,0, 2,0, 4,0 e 5,0 cm de profundidade de enterrio. Todos os biótipos apresentaram germinação superior a 70% após escarificação mecânica. A maior taxa de germinação ocorre a 25,9°C para SAGMO 35, o biótipo suscetível, e a 26,2 e 26,5°C, respectivamente, para SAGMO 10 e SAGMO 32, biótipos resistentes. Para todos os biótipos, a maior emergência de plântulas ocorre em sementes posicionadas a 0,5 e 1,0 cm de profundidade de enterrio

A Complexidade do Sistema Ambiental e Humano e sua Relação com a Sustentabilidade

It is a consensus that the function and structure of the human and environmental systems are complex when analyzed in an isolated and/or integrated way. This subject is part of a current debate about sustainability. In this sense, this research has the goal of offering a literature review about the complexity of the integration between the human and environmental systems, and its relation with the concept of sustainability. This is a qualitative study with an exploratory descriptive design as to the method, and a bibliographical review As to the technical procedures. The results reveal that the idea of sustainability is only feasible when the functioning of the human and environmental systems are observed, because the process of co-evolution, or panarchy, must be considered when identifying the elements or subsystems which should be preserved or kept. Comprehending the complexity of the interactions of the human and environmental systems is essential when defining the idea of sustainability, because they evidence the essence of its purpose.É consenso que a função e a estrutura do sistema ambiental e humano são complexas quando analisadas de forma isolada e/ou integrada, e esse assunto é tema de debate atual para a compreensão da sustentabilidade. Nesse sentido, esta pesquisa objetiva realizar uma revisão de literatura sobre as complexidades das interações entre os sistemas ambientais e humanos, e a sua relação com o conceito de sustentabilidade. A metodologia utilizada, quanto à abordagem, é qualitativa de caráter exploratório-descritivo e, quanto aos procedimentos técnicos, é uma revisão bibliográfica. Os resultados revelam que a ideia de sustentabilidade apenas é factível quando observados o funcionamento e a estrutura do sistema ambiental e humano, pois os processos de coevolução e/ou panarchy devem ser considerados na identificação dos elementos ou subsistemas a serem preservados ou mantidos. A compreensão da complexidade e das interações dos sistemas ambientais e humanos é essencial na definição da ideia de sustentabilidade, pois estes evidenciam a essência de seu propósito