Algunas citas recientes de especies del género Phoma Sacc. en Catalunya

Se citan 14 táxones del género Phoma (Ph. cava, Ph. epicoccinu, Ph. exigua, Ph.exigua var. foveata, Ph. glomerata, Ph. hedericola, Ph. herbarum, Ph. jolyana, Ph. leveillei, Ph. lycopersici, Ph. macrostoma, Ph. medicaginis var. pinodella, Ph. pomorum y Ph.tracheiphila). Para cada uno de los táxones se indica la fecha de recolección y la especie vegetal sobre la cual se desarrollaba.On cite 14 taxons du genre Phoma (Ph. cava, Ph. epicoccina, Ph. exigua, Ph.exigua var. foveata, Ph. glomerata, Ph. hedericola, Ph. herbarum, Ph. jolyana, Ph. leveillei, Ph. lycopersici, Ph. macrostroma, Ph. medicaginis var. pinodella, Ph. pomorum et Ph.tracheiphila). Pour chacun des taxons on signale le date de racolte et l'espéce végétal sur laquelle il se develope

Distribución de Diplodia mutila Fr. apud Mont. en Catalunya

Se ha recolectado Diplodia mutila en 62 localidades de las comarcas catalanas sobre 32 táxones de hospedantes, varios de los cuales no aparecen citados en la bibliografía; se indica también la fecha de recolección de cada muestra (día, mes y año).On récolte Diplodia mutila dans 62 localités des provinces catalanes sur 32 hótes differents, dont plusieurs n'ont pas été cités dans la bibliographic; on signale aussi la date de récolte de chaque echantillon (jour, mois et an)

Assessing desertification risk using system stability condition analysis

This paper describes a procedure for evaluating the desertification risk in threatened areas. The procedure is based on an eight-equation dynamic model of a generic human–resource system that can be applied to different desertification syndromes. For each application, interest focuses on finding all the possible long-term final states of the system and on defining the conditions that mark out sustainability and long-term desertification by means of unambiguous specific parameter relations. The procedure is applied to three typified cases in Spain: (A) rainfed crops in areas with high soil erosion risk; (B) irrigated intensive agricultural systems; and (C) commercial rangelands. Results show that, in case A, high profit scenarios are responsible for the final extension of desertification but do not determine the specific threshold between sustainability and desertification. They do, however, in cases B and C

Assessing desertification risk using system stability condition analysis

This paper describes a procedure for evaluating the desertification risk in threatened areas. The procedure is based on an eight-equation dynamic model of a generic human–resource system that can be applied to different desertification syndromes. For each application, interest focuses on finding all the possible long-term final states of the system and on defining the conditions that mark out sustainability and long-term desertification by means of unambiguous specific parameter relations. The procedure is applied to three typified cases in Spain: (A) rainfed crops in areas with high soil erosion risk; (B) irrigated intensive agricultural systems; and (C) commercial rangelands. Results show that, in case A, high profit scenarios are responsible for the final extension of desertification but do not determine the specific threshold between sustainability and desertification. They do, however, in cases B and C

Distribución de Diplodia mutila Fr. apud Mont. en Catalunya

Se ha recolectado Diplodia mutila en 62 localidades de las comarcas catalanas sobre 32 táxones de hospedantes, varios de los cuales no aparecen citados en la bibliografía; se indica también la fecha de recolección de cada muestra (día, mes y año).On récolte Diplodia mutila dans 62 localités des provinces catalanes sur 32 hótes differents, dont plusieurs n'ont pas été cités dans la bibliographic; on signale aussi la date de récolte de chaque echantillon (jour, mois et an)

Algunas citas recientes de especies del género Phoma Sacc. en Catalunya

On cite 14 taxons du genre Phoma (Ph. cava, Ph. epicoccina, Ph. exigua, Ph. exigua var. foveata, Ph. glomerata, Ph. hedericola, Ph. herbarum, Ph. jolyana, Ph. leveillei, Ph. lycopersici, Ph. macrostroma, Ph. medicaginis var. pinodella, Ph. pomorum et Ph. tracheiphila). Pour chacun des taxons on signale le date de racolte et l'espéce végétal sur laquelle il se develope.Se citan 14 táxones del género Phoma (Ph. cava, Ph. epicoccinu, Ph. exigua, Ph. exigua var. foveata, Ph. glomerata, Ph. hedericola, Ph. herbarum, Ph. jolyana, Ph. leveillei, Ph. lycopersici, Ph. macrostoma, Ph. medicaginis var. pinodella, Ph. pomorum y Ph. tracheiphila). Para cada uno de los táxones se indica la fecha de recolección y la especie vegetal sobre la cual se desarrollaba

Assessing overexploitation in Mediterranean aquifers using system stability condition analysis

This paper analyses competitive groundwater exploitation for irrigation by means of a special case of a dynamic predator–prey or human-resource theoretical model. On the human side, the model considers both farmers’ rational behaviour and a set of economic parameters. Then the model explicitly links these issues to the dynamics of the natural resource. Equilibrium states are evaluated, and the drivers and conditions for final states leading to groundwater overexploitation are assessed. The theoretical model finally serves to discuss the long-term sustainability of the processes of transformation from traditional to highly intensive pumping-based agricultural systems. These are processes now taking place in aquifers of southern Spain and Maghreb oases

The importance of surface controls on overland flow connectivity in semi-arid environments: results from a numerical experimental approach

In semi-arid environments, the characteristics of the land surface determine how rainfall is transformed into surface runoff and influences how this runoff moves from the hillslopes into river channels. Whether or not water reaches the river channel is determined by the hydrological connectivity. This paper uses a numerical experiment-based approach to systematically assess the effects of slope length, gradient, flow path convergence, infiltration rates and vegetation patterns on the generation and connectivity of runoff. The experiments were performed with the Connectivity of Runoff Model, 2D version distributed, physically based, hydrological model. The experiments presented are set within a semi-arid environment, characteristic of south-eastern Spain, which is subject to low frequency high rainfall intensity storm events. As a result, the dominant hydrological processes are infiltration excess runoff generation and surface flow dynamics. The results from the modelling experiments demonstrate that three surface factors are important in determining the form of the discharge hydrograph: the slope length, the slope gradient and the infiltration characteristics at the hillslope-channel connection. These factors are all related to the time required for generated runoff to reach an efficient flow channel, because once in this channel, the transmission losses significantly decrease. Because these factors are distributed across the landscape, they have a fundamental role in controlling the landscape hydrological response to storm events