5 resultados para Invasive Species Prevention, Management and Control
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Background: Biological invasions are one of the major causes of biodiversity loss, yet remain rather understudied in tropical environments. The Australian palm tree Archontophoenix cunninghamiana was introduced into Brazil for ornamental purposes, but has become an invasive species in urban and suburban forest patches. The substitution of A. cunninghamiana by the native palm Euterpe edulis has been proposed as a management action. Aims: We aimed to evaluate the regeneration potential of these two palm species in an Atlantic forest remnant in south-eastern Brazil where both species occur. Methods: We compared seedling establishment and seed longevity of both species through seed sowing, and also measured the contribution of A. cunninghamiana to the local seed rain and seed bank. Results: Nearly half of the non-anemochoric diaspores collected from the seed rain belonged to A. cunninghamiana, which represented a high propagule pressure in the community. The distribution of the alien palm seeds in the seed rain correlated with the distribution of nearby young and adult individuals inside the forest. Neither A. cunninghamiana nor E. edulis appeared to have a persistent seed bank in a burial experiment; seedling survival experiments suggested a much better performance for A. cunninghamiana, which had a survival rate of ca. 30% compared with a rate of only 3.5% for E. edulis. Conclusions: The results suggest a higher regeneration capacity for the alien palm over the native species when co-occurring in a forest fragment. Management actions are thus proposed to reduce a potential biological invasion process.
Resumo:
This paper presents a survey of the insects that feed on fruits of Psittacanthus Martius (Santalales: Loranthaceae), a hemiparasitic mistletoe genus that infects trees in Brazil and other neotropical countries. The aim of the study was to identify candidate insects for biological control of Psittacanthus mistletoes. Unripe and mature fruits were collected in several localities of Cerrado, bordering South Pantanal, Southwestern Brazil, from 29 Apr 1998 to 30 Jul 2000. A total of 24,710 fruits (54 samples) of Psittacanthus acinarius infecting 15 species from 10 plant families were evaluated. Psittacanthus acinarius (Mart.) was the most abundant and frequent species of mistletoe parasitizing trees in the ecotonal Cerrado-Pantanal. From 24,710 fruits of Psittacanthus acinarius were obtained 1,812 insect larvae including 1,806 Neosilba McAlpine (Diptera: Lonchaeidae) species and 6 Thepytus echelta (Hewitson) (Lepidoptera: Lycaenidae). From these emerged 1,550 Neosilba spp. adults and 6 T. echelta. Neosilba pantanense Strikis was described from this research. Larvae of T. echelta occurred in fruits of P. acinarius parasitizing Cecropia pachystachya Trecul (Urticaceae) and Anadenanthera colubrina (Vellozo) Brenan (Fabaceae). Larvae of Neosilba caused no adverse effects on the germination of infected fruits of Psittacanthus, because they do not eat the embryo or viscin tissues. This differs from the larvae of T. echelta that interrupted the germination of seeds by feeding on those tissues. Thepytus echelta may be a promising insect for the biological control of P. acinarius in the ecotonal Cerrado-Pantanal, although its abundance and frequency were low throughout the sampling period.
Resumo:
Based on the concepts of sustainability and knowledge management, this article seeks to identify points of contact between the two themes through an exploratory study of existing literature. The first objective is to find, in international literature, the largest number of papers jointly related to the theme of knowledge management and sustainability. In these documents, the authors looked at the kind of relationship existing between the two themes and what the benefits introduced in organizations are. Based on an ergonomic point of view, the second objective of this article is to analyze the role of the worker (whether at the strategic or operational level) and his importance in this context. The results demonstrate that there is very little literature that addresses the two themes together. The few papers found, however, can be said to show the many advantages of introducing sustainability policies supported by adequate knowledge management. Very little has been studied with regards to the role of workers, which could be interpreted as meaning that little importance is given to the proactive role they may play. On the other hand, there is a high potential for future research in these areas, based on the high level of consideration of workers in knowledge management and sustainability literature, as well as in literature in the areas of ergonomics and sociology.
Resumo:
Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of 'Comprehensive control of Dengue fever under changing climatic conditions'. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named 'DengueTools' to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change. The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change. In this paper, we report on the rationale and specific study objectives of 'DengueTools'. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools.
Resumo:
Contrafreeloading occurs when animals spend time and effort to obtain food in the presence of freely available food. There are several interpretations for such an apparent contradiction to optimal foraging models, with an emphasis either on the need to gather and update information about the environment or on the value of performing species-typical responses. Evidence suggests that both gathering information about the environment and the expression of species-typical behaviour are important for the welfare of captive animals. The aim of the present study was to assess the existence of contrafreeloading in maned wolves (Chrysocyon brachyurus), in a situation where animals could get food directly from a "free" source and/or search and handle hidden food items, an alternative that requires more effort and is probably more similar to natural foraging conditions. Eight captive, pair-housed maned wolves were given weekly choice tests in which they could obtain food either by approaching the usual food tray in one section of the enclosure (Tray), and/or by searching for food at variable sites amongst the vegetation in the other section of the enclosure (Scattered). Results indicate that maned wolves spent more time in the Scattered than in the Tray section of the enclosure (P = 0.02) and that they obtained about half of the food from that section (48.54% +/- SE 0.69). Our results, the first to demonstrate contrafreeloading in maned wolves, have implications for the husbandry and welfare of this endangered species. (C) 2012 Elsevier B.V. All rights reserved.