145 research outputs found
Combining the conservation of biodiversity with the provision of ecosystem services in urban green infrastructure planning. Critical features arising from a case study in the metropolitan area of Rome
A large number of green infrastructure (GI) projects have recently been proposed, planned and implemented in European cities following the adoption of the GI strategy by the EU Commission in 2013. Although this policy tool is closely related to biodiversity conservation targets, some doubts have arisen as regards the ability of current urban GI to provide beneficial effects not only for human societies but also for the ecological systems that host them. The aim of this work is to review the features that should be considered critical when searching for solutions that simultaneously support biodiversity and guarantee the provision of ecosystem services (ES) in urban areas. Starting from a case study in the metropolitan area of Rome, we highlight the role of urban trees and forests as proxies for overall biodiversity and as main ecosystem service providers. We look beyond the individual functional features of plant species and vegetation communities to promote the biogeographic representativity, ecological coherence and landscape connectivity of new or restored GI elements
Qualitative Uncertainty Orderings Revised
AbstractIn recent decades, qualitative approaches to probabilistic uncertainty have been receiving wider and wider attention. We propose a new characterization of some of the most adopted partial preference orders by providing an uniform axiomatic treatment of a variety of qualitative uncertainty notions. We prove a representation result that connects qualitative notions of partial uncertainty to their numerical counterparts. We also describe an executable specification, in the declarative framework of Answer Set Programming, that constitutes the core engine for the qualitative management of uncertainty. Some basic reasoning tasks are also identified
Mapping and assessment of ecosystems and their services. Urban ecosystems
Action 5 of the EU Biodiversity Strategy to 2020 requires member states to Map and Assess the state of Ecosystems and their Services (MAES). This report provides guidance for mapping and assessment
of urban ecosystems. The MAES urban pilot is a collaboration between the European Commission, the European Environment Agency, volunteering Member States and cities, and stakeholders. Its ultimate
goal is to deliver a knowledge base for policy and management of urban ecosystems by analysing urban green infrastructure, condition of urban ecosystems and ecosystem services. This report presents guidance for mapping urban ecosystems and includes an indicator framework to assess the condition of urban ecosystems and urban ecosystem services. The scientific framework of mapping and assessment is designed to support in particular urban planning policy and policy on green infrastructure at urban, metropolitan and regional scales. The results are based on the following different sources of information: a literature survey of 54 scientific articles, an online-survey (on urban ecosystems, related policies and planning instruments and with participation of 42 cities), ten case studies (Portugal: Cascais, Oeiras, Lisbon; Italy: Padua, Trento, Rome; The Netherlands: Utrecht; Poland: Poznań; Spain: Barcelona; Norway: Oslo), and a two-day expert workshop. The case studies constituted the core of the MAES urban pilot. They provided real examples and applications of how mapping and assessment can be organized to support policy; on top, they provided the necessary expertise to select a set of final indicators for condition and ecosystem services. Urban ecosystems or cities are defined here as socio-ecological systems which are composed of green infrastructure and built infrastructure. Urban green infrastructure (GI) is understood in this report as the multi-functional network of urban green spaces situated within the boundary of the urban ecosystem. Urban green spaces are the structural components of urban GI.
This study has shown that there is a large scope for urban ecosystem assessments. Firstly, urban policies increasingly use urban green infrastructure and nature-based solutions in their planning process. Secondly, an increasing amount of data at multiple spatial scales is becoming available to support these policies, to provide a baseline, and to compare or benchmark cities with respect to the extent and management of the urban ecosystem. Concrete examples are given on how to delineate urban ecosystems, how to choose an appropriate spatial scale, and how to map urban ecosystems based on a combination of national or European datasets (including Urban Atlas) and locally collected information (e.g., location of trees). Also examples of typologies for urban green spaces are presented.
This report presents an indicator framework which is composed of indicators to assess for urban ecosystem condition and for urban ecosystem services. These are the result of a rigorous selection
process and ensure consistent mapping and assessment across Europe. The MAES urban pilot will continue with work on the interface between research and policy. The framework presented in this report needs to be tested and validated across Europe, e.g. on its applicability at city scale, on how far the methodology for measuring ecosystem condition and ecosystem service delivery in urban areas can be used to assess urban green infrastructure and nature-based solutions
Effects of cadmium and phenanthrene mixtures on aquatic fungi and microbially mediated leaf litter decomposition
This version does not correspond to the published one. To access the final version go to: http://www.springerlink.com/content/t8t302617003m078/Urbanization and industrial activities have contributed to widespread contamination by metals and polycyclic aromatic hydrocarbons, but the combined effects of these toxics on aquatic biota and processes are poorly understood. We examined the effects of cadmium (Cd) and phenanthrene on the activity and diversity of fungi associated with decomposing leaf litter in streams. Leaves of Alnus glutinosa were immersed for 10 days in an unpolluted low-order stream in northwest Portugal to allow microbial colonization. Leaves were then exposed in microcosms for 14 days to Cd (0.06–4.5 mg L−1) and phenanthrene (0.2 mg L−1) either alone or in mixture. A total of 19 aquatic hyphomycete species were found sporulating on leaves during the whole study. The dominant species was Articulospora tetracladia, followed by Alatospora pulchella, Clavatospora longibrachiata, and Tetrachaetum elegans. Exposure to Cd and phenanthrene decreased the contribution of A. tetracladia to the total conidial production, whereas it increased that of A. pulchella. Fungal diversity, assessed as denaturing gradient gel electrophoresis fingerprinting or conidial morphology, was decreased by the exposure to Cd and/or phenanthrene. Moreover, increased Cd concentrations decreased leaf decomposition and fungal reproduction but did not inhibit fungal biomass production. Exposure to phenanthrene potentiated the negative effects of Cd on fungal diversity and activity, suggesting that the co-occurrence of these stressors may pose additional risk to aquatic biodiversity and stream ecosystem functioning.The Portuguese Foundation for the Science and Technology supported this work (POCI/MAR/56964/2004) and S. Duarte (SFRH/BPD/47574/2008
Standard and Nonstandard Representability of Positive Uncertainty Orderings. Preprint (accepted for the publication in Kybernetika)
Axioms are given for positive comparative probabilities and plausibilities dened either on Boolean algebras or on arbitrary sets of events. These axioms allow to characterize binary relations representable by either standard or nonstandard measures (i.e. taking values either on the reals or on a hyperreal eld). We also study relations between conditional events induced
by preferences on conditional acts
Non Additive Ordinal Relations Representable by Lower and Upper Probabilities
We characterize (in terms of necessary and sufficient conditions) binary relations representable
by a lower probability. Such relations can be non-additive (as the relations
representable by a probability) and also not "partially monotone" (as the relations representable
by a belief function).
Moreover we characterize relations representable by upper probabilities and those representable
by plausibility. In fact the conditions characterizing these relations are not
immedi~tely deducible by means of "dual" conditions given on the contrary events, like in
the numerical case
- …