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Bravo-Oviedo A.,INIA CIFOR | Bravo-Oviedo A.,Sustainable Forest Management Research Institute | Pretzsch H.,TU Munich | Ammer C.,University of Gottingen | And 36 more authors.
Forest Systems | Year: 2014

Aim of study: We aim at (i) developing a reference definition of mixed forests in order to harmonize comparative research in mixed forests and (ii) briefly review the research perspectives in mixed forests. Area of study: The definition is developed in Europe but can be tested worldwide. Material and methods: Review of existent definitions of mixed forests based and literature review encompassing dynamics, management and economic valuation of mixed forests. Main results: A mixed forest is defined as a forest unit, excluding linear formations, where at least two tree species coexist at any developmental stage, sharing common resources (light, water, and/or soil nutrients). The presence of each of the component species is normally quantified as a proportion of the number of stems or of basal area, although volume, biomass or canopy cover as well as proportions by occupied stand area may be used for specific objectives. A variety of structures and patterns of mixtures can occur, and the interactions between the component species and their relative proportions may change over time. The research perspectives identified are (i) species interactions and responses to hazards, (ii) the concept of maximum density in mixed forests, (iii) conversion of monocultures to mixed-species forest and (iv) economic valuation of ecosystem services provided by mixed forests. Research highlights: The definition is considered a high-level one which encompasses previous attempts to define mixed forests. Current fields of research indicate that gradient studies, experimental design approaches, and model simulations are key topics providing new research opportunities. © 2014 Ministerio de Agricultura Pesca y Alimentacion. All rights reserved. Source


Freudenberger L.,University for Sustainable Development Eberswalde | Hobson P.,University for Sustainable Development Eberswalde | Hobson P.,Writtle College | Schluck M.,University for Sustainable Development Eberswalde | And 8 more authors.
Biodiversity and Conservation | Year: 2013

The limited resources available for the conservation of biodiversity and ecosystem services call for prioritisation schemes. For instance, in the process of systematic conservation planning site selection is partly determined by efficiency gains. In this paper we present an alternative method for global spatial priority-setting based on ecological indicators, combined with social and economic conditions that influence the effectiveness of conservation, and measures for the long-term persistence of biodiversity. In the analysis the assumption made is that nature conservation should prioritize the effective maintenance of functional ecosystems that do not only provide the most ecosystem services but are also more likely to have a high adaptive capacity towards unavoidable environmental change. Furthermore, the effectiveness and permanence of conservation projects is tied to certain socioeconomic and political conditions that, as we suggest, should be evaluated as part of the conservation priority-setting process. We propose three new priority categories: eco-functionally wise (EcoWise), socioeconomically wise (SocioWise) and proactive allocation of conservation resources considering future climate change (ClimateWise) expressed as indices based on 16 different indicators. Analysing the combined effects of these three categories (EcoSocioClimateWise), in a spatially explicit way highlights the importance of tropical, subtropical but also some temperate and boreal forest areas all of which are characterized by high values of vegetation density, tree height and carbon storage. Our recommendations for policy makers prompt a shift in conservation planning towards advocating the use of ecological and socioeconomic indicators in combination with proxies for the vulnerability to future climate change impacts. © 2013 Springer Science+Business Media Dordrecht. Source


Dolgener N.,University of Potsdam | Freudenberger L.,University for Sustainable Development Eberswalde | Schneeweiss N.,Landesamt fur Umwelt | Ibisch P.L.,University for Sustainable Development Eberswalde | Tiedemann R.,University of Potsdam
Regional Environmental Change | Year: 2014

Environmental change is likely to have a strong impact on biodiversity, and many species may shift their distribution in response. In this study, we aimed at projecting the availability of suitable habitat for an endangered amphibian species, the Fire-bellied toad Bombina bombina, in Brandenburg (north-eastern Germany). We modelled a potential habitat distribution map based on (1) a database with 10,581 presence records for Bombina from the years 1990 to 2009, (2) current estimates for ecogeographical variables (EGVs) and (3) the future projection of these EGVs according to the statistical regional model, respectively, the soil and water integrated model, applying the maximum entropy approach (Maxent). By comparing current and potential future distributions, we evaluated the projected change in distribution of suitable habitats and identified the environmental variables most associated with habitat suitability that turned out to be climatic variables related to the hydrological cycle. Under the applied scenario, our results indicate increasing habitat suitability in many areas and an extended range of suitable habitats. However, even if the environmental conditions in Brandenburg may change as predicted, it is questionable whether the Fire-bellied toad will truly benefit, as dispersal abilities of amphibian species are limited and strongly influenced by anthropogenic disturbances, that is, intensive agriculture, habitat destruction and fragmentation. Furthermore, agronomic pressure is likely to increase on productive areas with fertile soils and high water retention capacities, indeed those areas suitable for B. bombina. All these changes may affect temporary pond hydrology as well as the reproductive success and breeding phenology of toads. © 2013 Springer-Verlag Berlin Heidelberg. Source


Dolgener N.,University of Potsdam | Freudenberger L.,University for Sustainable Development Eberswalde | Schluck M.,University for Sustainable Development Eberswalde | Schneeweiss N.,Landesamt fur Umwelt | And 2 more authors.
Conservation Genetics | Year: 2014

Increasing attempts are made to understand the factors responsible for both the demographic and genetic depletion in amphibian populations. Landscape genetics aims at a spatially explicit correlation of genetic population parameters to landscape features. Using data from the endangered fire-bellied toad Bombina bombina in Brandenburg (Northeastern Germany), we performed an environmental niche factor analysis (ENFA), relating demographic (abundance) and genetic (diversity at 17 microsatellite loci and partial sequences of the mitochondrial control region in 434 individuals from 16 populations) parameters to ecological and anthropogenic variables such as temperature, precipitation, soil wetness, water runoff, vegetation density, and road/traffic impact. We found significant correlations between road disturbance and observed heterozygosity and between soil wetness and mitochondrial diversity. As the influences of the environmental variables can differ between different indicators for genetic diversity, population size and abundance data, our ENFA-based landscape genetics approach allows us to put various aspects of long- versus short term effective population size and genetic connectivity into an ecological and spatially explicit context, enabling potentially even forecast assessment under future environmental scenarios. © 2013 Springer Science+Business Media Dordrecht. Source

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