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Nadal-Romero E.,CSIC - Pyrenean Institute of Ecology | Nadal-Romero E.,Physical and Regional Geography Research Group | Regues D.,CSIC - Pyrenean Institute of Ecology | Serrano-Muela P.,CSIC - Pyrenean Institute of Ecology
Pirineos | Year: 2010

The Inner Depression (Central Pyrenees) presents a great heterogeneity of land uses and vegetation covers. In this context, a hundred of badlands areas are distributed along the ranges of the Depression. This morphologies occurrence has been associated to the combination of different factors: bedrock, climate, deforestation, slope terracing and field crop abandonment. In this way, most of the hydrological basins show a mosaic of contrasted environments: badlands, meadows, meadows with shrubs and reforested slopes. This study presents the analyses of the hydrological response on the Araguás catchment, which is monitored for recording discharges from the most extreme environments: badlands and reforested slopes. The results show great differences on discharge generation, both by runoff generation processes and by its frequency and water volume. Reforested environments decreases flooding and erosion risks, but also generate a big reduction of water resources disposability. Source

Lasanta T.,CSIC - Pyrenean Institute of Ecology | Nadal-Romero E.,CSIC - Pyrenean Institute of Ecology | Nadal-Romero E.,Physical and Regional Geography Research Group | Serrano-Muela P.,CSIC - Pyrenean Institute of Ecology | And 2 more authors.
Pirineos | Year: 2010

The main landscape feature in the Pyrenean middle mountain is the presence of hillslopes occupies by old cultivated fields already abandoned, affected by different stages of plant colonization. By means of experimental plots, this paper studies runoff generation and sediment yield in two types of abandoned fields: (i) sloping fields previously cultivated with cereal and frequently fertilized; and (ii) fields corresponding to shifting agriculture, with scarce conservation measures. The results obtained were compared to a dense shrub cover plot. The abandoned plots yield much more water and sediment than the dense shrub cover, which shows a lower variability in the hydromorphological response. The progressive plant colonization of the two abandoned plots favoured the occurrence of a negative trend in runoff and erosion. This paper also demonstrated that the shifting agriculture fields yield more water and erosion than sloping fields, because of difficulties for plant succession. Source

Lana-Renault N.,CSIC - Pyrenean Institute of Ecology | Lana-Renault N.,University Utrecht | Regues D.,CSIC - Pyrenean Institute of Ecology | Nadal-Romero E.,CSIC - Pyrenean Institute of Ecology | And 3 more authors.
Pirineos | Year: 2010

A small catchment affected by agricultural practices in the past, then progressively abandoned and naturally re-vegetated was monitored in the central Spanish Pyrenees. The results obtained over a 9-year period revealed the complexity of its hydrological and geomorphological behaviour. Several runoff generation processes can occur at the same time and in different parts of the catchment, depending on the water reserves conditions and rainfall characteristics. Sediment response is mainly controlled by the spatial and temporal dynamics of water and sediment contributing areas within the catchment. The sediment output illustrates the complexity of the geomorphic response of mountain environments modified by past farmland activities. Source

Serrano-Muela M.P.,CSIC - Pyrenean Institute of Ecology | Regues D.,CSIC - Pyrenean Institute of Ecology | Estela Nadal-Romero E.,Physical and Regional Geography Research Group
Cuaternario y Geomorfologia | Year: 2012

Throughfall and stemflow have been studied in a forest-covered catchment in the Central Spanish Pyrenees. The San Salvador catchment (0,92 km2) is located in the Aísa Valley, in which trends in plant cover evolution show an increase of the presence of open and dense forests, after the abandonment of agricultural activities since the middle of the 20th Century. San Salvador catchment shows a dense forest in all area (more than 90%). Pinus sylvestris, Fagus sylvatica and Quercus gr. faginea, forest patches alternate in the catchment according to altitude and shape of the slopes (concave, convex). Three open plots have been selected in the San Salvador catchment, corresponding to the three types of forest cover. The results (April 2006-April 2008) has demonstrated that the percentages of throughfall are associated with type of forest cover, due to differences in the morphology of the leaves and the foliage density. Thus, the species that causes a major interception is Fagus sylvatica, while Quercus gr. faginea and Pinus sylvestris has shown a similar enough seasonal behaviour, the last one more homogenous due to the invariable coverage. Source

Ashebir D.,Mekelle University | Ashebir D.,University of Natural Resources and Life Sciences, Vienna | Deckers T.,PCFruit Vzw Proefcentrum Fruitteelt | Nyssen J.,Ghent University | And 9 more authors.
Experimental Agriculture | Year: 2010

Lack of effective chilling during the dormant season is one of the major problems when apples are growing under a tropical climate. We evaluated the response of different apple cultivars (Golden Delicious, Gala, Fuji, Granny Smith and Jonagold) grown on M9 rootstock with different dormancy-management practices. The trials were carried out between 2004 and 2006 in a tropical mountain area (Tigray, Ethiopia), where chilling conditions are poor with the aim of improving and synchronizing the bud break and the blossoming period of these apple cultivars. Two-year-old well-feathered trees were planted in two experimental trial sites in a randomized complete block design. Trees were subjected to the following treatments in two sets of experiments: one defoliation per year only; two defoliations per year, one defoliation followed by 1% hydrogen cyanamide (Dormex) treatment; one defoliation followed by 2% Dormex treatment; one defoliation followed by 4% winter oil; one defoliation followed by 0.5% Dormex and 2% winter oil; and a control with no defoliation or dormancy breaking treatments. The results show positive effects of the dormancy breaking agents on the productivity of the trees after defoliation, with comparable results for the effectiveness of both Dormex and winter oil. There were no statistically significant differences between the Dormex doses. The defoliation treatment alone was not sufficient to break dormancy for the cultivars Golden Delicious, Granny Smith or Gala but showed promising results with dormancy breaking on Jonagold. Yields increased as a result of better flowering time synchronization within a tree but even with the dormancy treatments the length of the flowering period was still spread over five weeks, where under a more temperate climate it lasted two to three weeks. The average fruit weight of Jonagold and Granny Smith can be considered as a good fruit quality while the fruit of other diploid cultivars like Golden, Gala and Fuji were rather small, which indicates that fruit thinning by hand will be a necessity for these cultivars. Red colouration of the apples on the cultivars Gala and Jonagold was excellent and meets the standards necessary for commercialization of these fruits. The sugar concentration of the fruits and the fruit firmness at harvest was high. The results of these first trials indicate that it is possible to develop new apple production in the mountain region of Tigray, Ethiopia. Copyright © Cambridge University Press 2009. Source

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