19 research outputs found

    Ungulate browsing shapes climate change impacts on forest biodiversity in Hungary

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    Climate change can result in a slow disappearance of forests dominated by less drought-tolerant native European beech (Fagus sylvatica) and oak species (Quercus spp.) and further area expansion of more drought-tolerant non-native black locust (Robinia pseudoacacia) against those species in Hungary. We assumed that the shift in plant species composition was modified by selective ungulate browsing. Thus, we investigated which woody species are selected by browsing game. We have collected data on the species composition of the understory and the browsing impact on it in five different Hungarian even-aged forests between 2003 and 2005. Based on these investigations the non-native Robinia pseudoacacialiving under more favourable climatic conditions was generally preferred (Jacobs’ selectivity index: D=0.04±0.77), while the nativeFagus sylvatica and Quercus spp. (Q. petraea, Q. robur), both more vulnerable to increasing aridity, were avoided (D=-0.37±0.11;-0.79±0.56;-0.9±0.16; respectively) among target tree species. However, economically less or not relevant species, e.g. elderberry (Sambucus spp.), blackberry (Rubus spp.) or common dogwood (Cornus sanguinea) were the most preferred species (D=0.01±0.71; -0.12±0.58; -0.2±0.78, respectively). Our results imply that biodiversity conservation, i.e. maintaining or establishing a multi-species understory layer, can be a good solution to reduce the additional negative game impact on native target tree species suffering from drought. Due to preference for Robinia pseudoacaciaselective browsing can decelerate the penetration of this species into native forest habitats. We have to consider the herbivorous pressure of ungulates and their feeding preferences in planning our future multifunctional forests in the light of climate change impacts

    The mineralogical composition of calcium and calcium-magnesium carbonate pedofeatures of calcareous soils in the European prairie ecodivision in Hungary

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    Abstract There is little data on the mineralogy of carbonate pedofeatures in the calcareous soils in Hungary which belong to the European prairie ecodivision. The aim of the present study is to enrich these data. The mineralogical composition of the carbonate pedofeatures from characteristic profiles of the calcareous soils in Hungary was studied by X-ray diffractometry, thermal analysis, SEM combined with microanalysis, and stable isotope determination. Regarding carbonate minerals only aragonite, calcite (+ magnesian calcite) and dolomite (+proto-dolomite) were identified in carbonate grains, skeletons and pedofeatures. The values relating, respectively, to stable isotope compositions (C13, O18) of carbonates in chernozems and in salt-affected soils were in the same range as those for recent soils (latter data reported earlier). There were no considerable differences between the values for the carbonate nodules and tubules from the same horizons, nor were there significant variations between the values of the same pedofeatures from different horizons (BC-C) of the same profile. Thus it can be assumed that there were no considerable changes in conditions of formation. Tendencies were recognized in the changes of (i) carbonate mineral associations, (ii) the MgCO3 content of calcites, (iii) the corrected decomposition temperatures, and (iv) the activation energies of carbonate thermal decompositions among the various substance-regimes of soils. Differences were found in substance-regimes types of soils rather than in soil types

    Breaking Functional Connectivity into Components: A Novel Approach Using an Individual-Based Model, and First Outcomes

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    Landscape connectivity is a key factor determining the viability of populations in fragmented landscapes. Predicting ‘functional connectivity’, namely whether a patch or a landscape functions as connected from the perspective of a focal species, poses various challenges. First, empirical data on the movement behaviour of species is often scarce. Second, animal-landscape interactions are bound to yield complex patterns. Lastly, functional connectivity involves various components that are rarely assessed separately. We introduce the spatially explicit, individual-based model FunCon as means to distinguish between components of functional connectivity and to assess how each of them affects the sensitivity of species and communities to landscape structures. We then present the results of exploratory simulations over six landscapes of different fragmentation levels and across a range of hypothetical bird species that differ in their response to habitat edges. i) Our results demonstrate that estimations of functional connectivity depend not only on the response of species to edges (avoidance versus penetration into the matrix), the movement mode investigated (home range movements versus dispersal), and the way in which the matrix is being crossed (random walk versus gap crossing), but also on the choice of connectivity measure (in this case, the model output examined). ii) We further show a strong effect of the mortality scenario applied, indicating that movement decisions that do not fully match the mortality risks are likely to reduce connectivity and enhance sensitivity to fragmentation. iii) Despite these complexities, some consistent patterns emerged. For instance, the ranking order of landscapes in terms of functional connectivity was mostly consistent across the entire range of hypothetical species, indicating that simple landscape indices can potentially serve as valuable surrogates for functional connectivity. Yet such simplifications must be carefully evaluated in terms of the components of functional connectivity they actually predict

    A northbound interface for power management in next generation network devices

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    Recently, a number of approaches based on dynamic power management techniques have been proposed to reduce the energy consumption of telecommunication networks and devices. They are able to optimize the tradeoff between network performance and energy requirements. It is possible to execute and extend these techniques to the whole network, by using local control policies together with energy-aware routing and traffic engineering. However, the lack of a standardized representation of the energy-aware capabilities of heterogeneous networking equipment makes their deployment confusing and impractical. To this aim, we have proposed a novel framework, the Green Abstraction Layer (GAL), whose purpose is to define a multi-layered abstraction interface for the hardware and physical resources, where energy management actions are directly performed. Therefore, the GAL syntax can be exposed to the platform-independent logical representation commonly used in network control protocols. Given the internal architectural complexity and heterogeneity of many network devices, the GAL approach is based on a hierarchical decomposition, where each level provides an abstract and aggregated representation of internal components

    Design of Analysis Modules

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    This public deliverable describes the design and specification of a first set of basic analysis modules for addressing the use cases identified in WP1. The document focuses on the required algorithms, which use as input the measurements and analysis provided by the lower layers (WP2 and WP3) of the mPlane architecture to provide more advanced analysis and answers towards the resolution of the problem addressed by the use case. These analysis modules include both stream and batch processing algorithms and address issues such as classifications, estimations, predictions, detections, correlations and diagnosis.mPlane – an Intelligent Measurement Plane for Future Network and Application Managemen

    Exposing energy-aware capabilities in next generation network devices

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    Dynamic power management techniques have been proposed in a number of recent approaches to reduce the energy consumption of telecommunication networks and devices. The goal of these techniques has been to find an optimal trade off between network performance and energy requirements. Control policies using energy-aware routing and traffic engineering can be used in order to extend these techniques to the whole network. However, the deployment of the energy-aware capabilities of heterogeneous networking is still unsystematic and impractical, as a standardized representation is still missing. To overcome such an issue, we introduce a novel framework, the Green Abstraction Layer (GAL), whose goal is to define a multi-layered abstraction interface for the hardware and physical resources. Within the GAL, energy management actions are directly performed. The GAL can be thus exposed to the platform-independent logical representation commonly used in network control protocols. Given the internal architectural complexity and heterogeneity of many network devices, the GAL approach is based on a hierarchical decomposition, where each level provides an abstract and aggregated representation of internal components. The general GAL architecture is currently under consideration for standardization in ETSI

    The Green Abstraction Layer: A standard power management interface for next-generation network devices

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    In telecommunication networks, distributed power management across heterogeneous hardware requires a standardized representation of each system\u2019s capabilities to decouple distributed high-level algorithms from hardware specifics. The Green Abstraction Layer (GAL) provides this interface between high-level algorithms and a lower level representing the hardware and physical resources that directly exert energy management and actions in a network

    A northbound interface for power management in next generation network devices

    No full text
    Recently, a number of approaches based on dynamic power management techniques have been proposed to reduce the energy consumption of telecommunication networks and devices. They are able to optimize the trade-off between network performance and energy requirements. It is possible to execute and extend these techniques to the whole network, by using local control policies together with energy-aware routing and traffic engineering. However, the lack of a standardized representation of the energy-aware capabilities of heterogeneous networking equipment makes their deployment confusing and impractical. To this aim, we have proposed a novel framework, the green abstraction layer (GAL), whose purpose is to define a multi-layered abstraction interface for the hardware and physical resources, where energy management actions are directly performed. Therefore, the GAL syntax can be exposed to the platform-independent logical representation commonly used in network control protocols. Given the internal architectural complexity and heterogeneity of many network devices, the GAL approach is based on a hierarchical decomposition, where each level provides an abstract and aggregated representation of internal components
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