Efeito de armadilha das passagens em grelha sobre os anfíbios

As passagens em grelha são infra-estruturas largamente utilizadas para impedir a deslocação do gado, mas que permitem a circulação de viaturas. Porém, também resultam numa armadilha de fosso onde pequenos animais terrestres podem cair inadvertidamente. O principal objectivo deste estudo foi verificar o efeito que as passagens em grelha têm sobre as populações de anfíbios, aquando das suas deslocações sazonais. Estudaram-se 18 passagens em grelha localizadas em duas zonas de amostragem - Elvas e Alandroal - no Alto Alentejo (Portugal). Esta investigação revelou que a principal espécie encarcerada nestas infra-estruturas é o sapo-de-unha-negra (Pelobates cultripes). Em termos gerais, os anfíbios mais terrestres são significativamente (teste do x2) mais afectados do que os anfíbios marcadamente aquáticos. O teste de Mantel mostrou que não existe correlação entre o tipo de passagem em grelha e os anfíbios encontrados nessas infra-estruturas. Para mitigar o aprisionamento de anfíbios nas passagens em grelha, são propostas cinco medidas. ABSTRACT; Cattle grids are infrastructures widely used to avoid the movement of cattle along a road, though allowing the circulation of vehicles. However, they also result in a pit trap where small terrestrial animals may inadvertently fall. The main objective of this study was to check the effect that cattle grids have on amphibian populations, during their seasonal migrations. 18 cattle grids, located in two sampling zones - Elvas and Alandroal- in Alto Alentejo (Portugal), were studied. This investigation showed that the main species imprisoned in these devices is the iberian spadefoot toad (Pelobates cultripes). Generally, the more terrestrial amphibians are significantly (x2 test) more affected than markedly aquatic amphibians. Mantel test showed that there is no correlation between different kinds of cattle grids and the amphibians found in these infrastructures. To mitigate the imprisonment of amphibians in cattle grids, five measures are proposed.

Caracterização da qualidade da água para rega nas captações do sistema Alqueva-Pedrogão

O Empreendimento de Fins Múltiplos de Alqueva (EFMA) é um projecto estruturante centrado na barragem do Alqueva, que pretende garantir o recurso Água na região e com isso viabilizar uma série de infra-estruturas que contribuirão para o desenvolvimento, em termos económicos e sociais, de uma das regiões mais desfavorecidas da Europa. O EFMA é constituído pelo "Reservatório Mãe" e por um conjunto de outras albufeiras de menor dimensão, interligados por uma rede com cerca de dois mil quilómetros de canais e condutas e mais de meia centena de estações de bombagem, contemplando os seguintes usos da água: - Abastecimento público. - Fornecimento de água para o desenvolvimento de actividades agrícolas e agro-industriais; - Produção de energia; Este trabalho tem por objectivo avaliar a adequabilidade da qualidade da água para o uso rega na origem e produzir informação adequada de suporte à decisão. Os resultados obtidos permitem afirmar que de um modo geral a qualidade da água captada no sistema Alqueva- Pedrógão é adequada para o uso rega, apesar de se verificar uma persistente contaminação de coliformes fecais. ABSTRACT; The Multipurpose Alqueva Project (EFMA- Empreendimento de Fins Múltiplos de Alqueva) is a groundwork project centred in Alqueva dam and its reservoir, which intends to guarantee a strategic water reserve in the region, and therefore making possible a series of associated infrastructures, contributing for the potential development of the region, in economic and social terms, in one of the most poorest regions of Europe. The EFMA includes a "Main Reservoir" and set of other dams with lesser dimension, connected by a several canals and pipelines about two thousand kilometers long (including Primary and Secondary Network), and about 50 pumping stations, with the goal of attaining the following main objectives: - Water supply for the development of agricultural and agro-industrial activities; - Production of energy; - Public Water Supply. This study intends to evaluate the suitability of water quality in the origin for irrigation use and to achieve adequate information for support decision. The results have revealed that the quality of water abstracted in the Alqueva - Pedrógão System is suitable for irrigation, although the persistent contamination of fecal coliforms.

O impacto da rede viária no uso do espaço da geneta (Genetta genetta L., 1758)

O presente estudo foi realizado numa área com 156,5 Km/ localizada nos municípios de Évora e Montemor-o-Novo, a Sul de Portugal. Cinco genetas foram seguidas via telemetria durante seis meses visando o estudo do uso do espaço e comportamento relativamente às estradas. Estas, parecem funcionar como limites das áreas vitais da geneta actuando como barreira física e/ou social aos seus movimentos. Contudo, as genetas cruzaram diferentes tipos de estrada embora com frequência reduzida. Por outro lado, as genetas adoptaram uma distância de segurança média das estradas, de 1km, onde se verifica uma aproximação durante a noite e um distanciamento durante o dia. Todos os animais evidenciaram ter uma distribuição não aleatória relativamente às estradas concentrando-se maioritariamente apenas num dos lados da estradão que indica o efeito destas infra-estruturas como barreiras parciais ao movimento. A presença de galerias ripicolas parece promover o uso das bermas e durante o estudo todos os indivíduos seleccionaram positivamente estes habitats. ABSTRACT: The present study, was conducted in a 156,5 Km 2 area, located in the Évora and Montemor-o-Novo counties, southern Portugal. Five genets were radio-tracked for six months with the purpose of studying their space use and behavior towards roads. ln this study, roads seem to be artificial boundaries to genets' home ranges acting as physical and social barrier to their movements. However, genets have crossed different types of roads, although in lower frequencies. They adopted, in average, a security distance of 1km from roads being further during the day and closer at night. Ali animals showed a not random distribution on their activity concerning roads presence and their localizations tend to concentrate on one side of the road which confirms that these infrastructures pose a significant barrier to genets' movements. The existence of riparian galleries seems to promote roadside usage and during the study genets have selected positively these habitats.

Spatial, environmental and human influences on the distribution of otter (Lutra lutra) in the Spanish provinces

In a previous survey of otters ( Lutra lutra L. 1758) in Spain, different causes were invoked to explain the frequency of the species in each province. To find common causes of the distribution of the otter in Spain, we recorded a number of spatial, environmental and human variables in each Spanish province. We then performed a stepwise linear multiple regression of the proportion of positive sites of otter in the Spanish provinces separately on each of the three groups of variables. Geographic longitude, January air humidity, soil permeability and highway density were the variables selected. A linear regression of the proportion of otter presence on these variables explained 62.4% of the variance. We then used the selected variables in a partial regression analysis to specify which proportions of the variation are explained exclusively by spatial, environmental and human factors, and which proportions are attributable to interactions between these components. Pure environmental effects accounted for only 5.5% of the variation, while pure spatial and pure human effects explained 18% and 9.7%, respectively. Shared variation among the components totalled 29.2%, of which 10.9% was explained by the interaction between environmental and spatial factors. Human factors explained globally less variance than spatial and environmental ones, but the pure human influence was higher than the pure environmental one. We concluded that most of the variation in the proportion of occurrences of otter in Spanish provinces is spatially structured, and that environmental factors have more influence on otter presence than human ones; however, the human influence on otter distribution is less structured in space, and thus can be more disruptive. This effect of large infrastructures on wild populations must be taken into account when planning large-scale conservation policies

From Landscape to Garden-with Wildflowers Meadows

Since the middle age wildflower meadows are used to bring the flowers from the natural and rural areas into urban landscapes. Wildflowers meadows can improve the quality of Green Infrastructures as they increase biodiversity. However, after a few centuries of given flowers a principal part, lawns started to be used in every kind of places leading to a green obsession. Nowadays, urban lawns are cover more than 70% of urban green spaces all over the world. Frequently design options aren’t environmental or economical friendly, and lawns are this example. Lawns are green deserts with low biodiversity, and unsustainable. Wildflower meadows are an alternative to lawns, more sustainable, less resources consumer and much more biodiverse. In the regions with a Mediterranean climate water is a limit factor, especial in summer.

Ravines in Angola. Causes and restraint methods

The Earth we know today was not always so. Over millions of years have undergone significant ch an g e s brought about by numerous geological phenomena aimed at your balance, some internal order, creating new geological formations and other external order smoothing formations previously created. From t h e tectonic standpoint, Angola is located in a relatively stable area which gives it a certain p ri v i l e g e w h e n compared with some Asian countries or even Americans where quite often occur earthquakes and volcanic eruptions. However, the same cannot be said in relation to the occurrence of an external geodynamics phenomena, such as the ravines, which in recent years has taken shape in many provinces, especially due to anthropogenic activity, giving rise to geological hazards, increasing the risk of damage in buildings and others infrastructures, losses direct or indirect in economic activities and loss of human lives. We understand that the reducing of these risks starts, in particular, by their identification, for later take preventive measures. This work is the result of some research work carried out by the authors through erosion courses of s o i l and stabilization of soils subject to erosion phenomena, carried out by Engineering Laboratory of Angola (LEA). For the realization of this work, we resorted to cartographic data query, literature, listening to s o m e o f the provincial representatives and local residents, as well as the observation in lo co o f s o m e af f e ct ed areas. The results allow us to infer that the main provinces affected by ravine phenomenon are located in Central and Northern highlands, as well as in the eastern region, and more recently in Cuando-Cub an go province. Not ruling out, however, other regions, such as in Luanda and Cabinda [1]. Relatively the causes, we can say that the ravines in Angola are primarily due to the combination of three natural factors: climate, topography and type of soil [2]. When we add the anthropogenic activit y , namely the execution of construction works, the drainage system obstructio n, exploration of m i n e ral s, agriculture and fires, it is verified an increasing of the phenomenon, often requiring immedi at e act i o n . These interventions can be done through structural or engineering measures and by the stabilization measures on the degraded soil cover [3]. We present an example of stabilization measures throu g h t h e deployment of a local vegetation called Pennisetum purpureum. It is expected that the results may contribute to a better understanding of the causes of the ravine phenomenon in Angola and that the adopted stabilization method can be adapted in other affected provinces in order to prevent and making the contention of the ravines.