The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Bernard Riera - One of the best experts on this subject based on the ideXlab platform.
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The Spatiotemporal Dynamics of Forest-Heathland Communities over 60 Years in Fontainebleau, France
ISPRS International Journal of Geo-Information, 2015Co-Authors: Samira Mobaied, Nathalie Machon, Arnault Lalanne, Bernard RieraAbstract:According to the EU Habitats Directive, Heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of Heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on Heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of Heathland during 1946–2003 due to tree colonisation of abandoned Heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of Heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, Heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those Heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of Heathland.
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The Spatiotemporal Dynamics of Forest–Heathland Communities over 60 Years in Fontainebleau, France
ISPRS International Journal of Geo-Information, 2015Co-Authors: Samira Mobaied, Nathalie Machon, Arnault Lalanne, Bernard RieraAbstract:According to the EU Habitats Directive, Heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of Heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on Heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of Heathland during 1946–2003 due to tree colonisation of abandoned Heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of Heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, Heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those Heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of Heathland.
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the use of diachronic spatial approaches and predictive modelling to study the vegetation dynamics of a managed Heathland
Biodiversity and Conservation, 2011Co-Authors: Samira Mobaied, Arnault Lalanne, Bernard Riera, Michel Baguette, Nathalie MachonAbstract:According to the EU Habitats Directive, Heathlands are a semi-natural habitat type of community interest. This status aims at conserving these habitats, especially where and when they are threatened by various changes, including natural vegetation succession. We present results of a study of the dynamics of a typical dry Heathland plot located in the Fontainebleau massif (France). An exhaustive observation of vegetation changes were made on this area of four hectares between 2000 and 2008, employing a spatial approach. We recorded the expansion of Molinia caerulea (L.) Moench at the expense of Ericaceae. The potential future vegetation of the site was modelled using Markov chains coupled to a GIS programme. This model predicted a gradual change in the floristic composition of Heathland in favour of M. caerulea at the expense of Calluna vulgaris (L.) Hull and Erica tetralix L., and the expansion of Pinus sylvestris L. The study demonstrates how spatial methods can contribute to the design of reliable management methods of habitats such as the Heathlands.
Davide Ascoli - One of the best experts on this subject based on the ideXlab platform.
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prescribed burning and browsing to control tree encroachment in southern european Heathlands
Forest Ecology and Management, 2013Co-Authors: Davide Ascoli, Giovanni Bovio, Michele Lonati, Raffaella Marzano, Andrea Cavallero, Giampiero LombardiAbstract:Abstract Land abandonment and the cessation of traditional management practices is favouring scrubland and forest expansion throughout Europe, reducing the extent of many semi-natural open habitats of a high ecological value. Tree encroachment is threatening several Calluna vulgaris (L.) Hull Heathlands. The objective of this study was to analyze vegetation dynamics resulting from an experiment designed to test management options aiming at controlling the encroachment of Populus tremula (aspen) and favouring Heathland recovery. The research was conducted at Vauda Heath, North-western Italy, from 2005 till 2009. We studied prescribed burning and goat browsing, both alone or in combination, assessing their effects on structure and density of encroaching trees, as well as on Heathland main species, C. vulgaris and Molinia arundinacea. Treatments were applied to 42 experimental units (300–650 m2 each), with each treatment combination replicated from six to twelve times (including untreated controls). Prescribed burning and browsing showed complementary effects on post-fire vegetation development. Both back and head fire behaviors were effective in inducing stem mortality of aspen and rejuvenating the Heathland, but in the absence of measures to control post-fire suckering, aspen tended to recover the pre-treatment stand structure. A higher fire frequency (annual winter fire) controlled tree encroachment, but hindered Calluna recovery, whilst favouring competing grass species. Goat browsing alone was initially able to reduce tree growth and slow down woodland expansion, until aspen individuals reached an escape size of 1.5 m in height. Prescribed burning followed by yearly goat browsing effectively contained tree encroachment while maximizing post-fire Heathland regeneration. This integrated approach thus proved its efficacy also at the southern limits of Calluna distributional area.
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Tree encroachment dynamics in Heathlands of north-west Italy: the fire regime hypothesis
iForest - Biogeosciences and Forestry, 2010Co-Authors: Davide Ascoli, Giovanni BovioAbstract:Abstract: Tree encroachment is one of the primary conservation issues in Calluna-Heathlands, a priority habitat in Europe. Improving understanding of the ecological factors that trigger transitions to woodlands is key to developing strategies for Heathlands management. The irrational use of fire has been recognized as one of the key factors that drives the loss of Heathlands of north-west Italy. The effect of high frequency pastoral burning on the replacement of Heathlands by grasslands has been documented by several studies. The relationship between fire and tree encroachment is less clear. The paper examines the effect of the fire regime on the encroachment of Populus tremula L. and Betula pendula Roth. in the Heathland. The study was carried out at the Managed Nature Reserve of Vauda (7° 41’ E, 45° 13’ N), which includes one of the most valuable Heathlands of north-western Italy. The experimental design consisted of analysing the age structure, dendrometric variables and the species composition of three aspen and birch stands, circular-shaped and isolated within the Heathland matrix. From 1986 to 2009 all stands experienced the same fire regime due to pastoral burning. Wildfires of similar behaviour occurred in 1998, 2003 and 2008 and determined the stand structure observed in 2009. The results evidenced that fire acts as a catalyst not only for seedlings establishment, as previously documented, but also for woodland expansion in the Heathland. After initial establishment, stands showed a concentric encroachment dynamic, mainly due to aspen root suckering after post-fire stem mortality, whose steps of expansion coincided with the return interval of wildfires. Moreover, aspen determined the loss of Heathland characteristic species, whose relative abundances were inversely correlated to aspen density along a gradient from the stands centre to the surrounding Heathland. The regulation of current burning practices by prescribed burning, integrated with rational grazing, presents the next research questions to be addressed.
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developing an adaptive management approach to prescribed burning a long term Heathland conservation experiment in north west italy
International Journal of Wildland Fire, 2009Co-Authors: Davide Ascoli, Giovanni Bovio, Rachele Beghin, Riccardo Ceccato, Alessandra Gorlier, Giampiero Lombardi, Michele Lonati, Raffaella Marzano, Andrea CavalleroAbstract:Calluna vulgaris-dominated Heathlands are globally important habitats and extremely scarce outside of north- west Europe. Rotational fire, grazing and cutting by local farmers were dominant features of past Heathland management throughout Europe but have been abandoned, altering the historical fire regime and habitat structure. We briefly review research on Calluna Heathland conservation management and provide the background and methodology for a long-term research project that will be used to define prescribed fire regimes in combination with grazing and cutting, for management of Calluna Heathlands in north-west Italy. We outline the ecological and research issues that drive the fire experiment, making explicit the experimental design and the hypotheses that will be tested. We demonstrate how Adaptive Management can be used to inform decisions about the nature of fire prescriptions where little formal knowledge exists. Experimental plots ranging from 600 to 2500 m 2 are treated according to one of eight alternative treatments (various combinations of fire, grazing and cutting), each replicated four times. To date, all treatments have been applied for 4 years, from 2005 to 2008, and a continuation is planned. Detailed measurement of fire characteristics is made to help interpret ecological responses at a microplot scale. The results of the experiment will be fed back into the experimental design and used to inform Heathland management practice in north-west Italy.
Nathalie Machon - One of the best experts on this subject based on the ideXlab platform.
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The Spatiotemporal Dynamics of Forest-Heathland Communities over 60 Years in Fontainebleau, France
ISPRS International Journal of Geo-Information, 2015Co-Authors: Samira Mobaied, Nathalie Machon, Arnault Lalanne, Bernard RieraAbstract:According to the EU Habitats Directive, Heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of Heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on Heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of Heathland during 1946–2003 due to tree colonisation of abandoned Heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of Heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, Heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those Heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of Heathland.
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The Spatiotemporal Dynamics of Forest–Heathland Communities over 60 Years in Fontainebleau, France
ISPRS International Journal of Geo-Information, 2015Co-Authors: Samira Mobaied, Nathalie Machon, Arnault Lalanne, Bernard RieraAbstract:According to the EU Habitats Directive, Heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of Heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on Heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of Heathland during 1946–2003 due to tree colonisation of abandoned Heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of Heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, Heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those Heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of Heathland.
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the use of diachronic spatial approaches and predictive modelling to study the vegetation dynamics of a managed Heathland
Biodiversity and Conservation, 2011Co-Authors: Samira Mobaied, Arnault Lalanne, Bernard Riera, Michel Baguette, Nathalie MachonAbstract:According to the EU Habitats Directive, Heathlands are a semi-natural habitat type of community interest. This status aims at conserving these habitats, especially where and when they are threatened by various changes, including natural vegetation succession. We present results of a study of the dynamics of a typical dry Heathland plot located in the Fontainebleau massif (France). An exhaustive observation of vegetation changes were made on this area of four hectares between 2000 and 2008, employing a spatial approach. We recorded the expansion of Molinia caerulea (L.) Moench at the expense of Ericaceae. The potential future vegetation of the site was modelled using Markov chains coupled to a GIS programme. This model predicted a gradual change in the floristic composition of Heathland in favour of M. caerulea at the expense of Calluna vulgaris (L.) Hull and Erica tetralix L., and the expansion of Pinus sylvestris L. The study demonstrates how spatial methods can contribute to the design of reliable management methods of habitats such as the Heathlands.
Samira Mobaied - One of the best experts on this subject based on the ideXlab platform.
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The Spatiotemporal Dynamics of Forest-Heathland Communities over 60 Years in Fontainebleau, France
ISPRS International Journal of Geo-Information, 2015Co-Authors: Samira Mobaied, Nathalie Machon, Arnault Lalanne, Bernard RieraAbstract:According to the EU Habitats Directive, Heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of Heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on Heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of Heathland during 1946–2003 due to tree colonisation of abandoned Heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of Heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, Heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those Heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of Heathland.
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The Spatiotemporal Dynamics of Forest–Heathland Communities over 60 Years in Fontainebleau, France
ISPRS International Journal of Geo-Information, 2015Co-Authors: Samira Mobaied, Nathalie Machon, Arnault Lalanne, Bernard RieraAbstract:According to the EU Habitats Directive, Heathlands are “natural habitats of community interest”. Heathland management aims at conserving these habitats threatened by various changes, including successional processes leading to forest vegetation. We investigate the dynamics of woody species to the detriment of Heathland over a period of 60 years in the Fontainebleau forest and we examine the effects of soil types, soil depth and topography parameters on Heathland stability. We assess changes in forest cover between 1946 and 2003 by comparing vegetation maps derived from aerial photographs coupled to GIS analyses. The results show the loss of more than 75% of Heathland during 1946–2003 due to tree colonisation of abandoned Heathland. We detected differences in the dynamics of colonisation between coniferous and deciduous trees. The colonisation of Heathland by coniferous species was faster over the last 20 years of our study period. Tree encroachment was faster in north-facing areas and in areas of acidic luvisols. While this dynamic was very slow in acid sandstone soils, Heathland stability was more important in shallow soils on flat and south facing areas. Our study has the potential to assist land managers in selecting those Heathland areas that will be easier to conserve and/or to restore by focusing on areas and spatial conditions that prevent forest colonisation and hence favour the long-term stability of Heathland.
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the use of diachronic spatial approaches and predictive modelling to study the vegetation dynamics of a managed Heathland
Biodiversity and Conservation, 2011Co-Authors: Samira Mobaied, Arnault Lalanne, Bernard Riera, Michel Baguette, Nathalie MachonAbstract:According to the EU Habitats Directive, Heathlands are a semi-natural habitat type of community interest. This status aims at conserving these habitats, especially where and when they are threatened by various changes, including natural vegetation succession. We present results of a study of the dynamics of a typical dry Heathland plot located in the Fontainebleau massif (France). An exhaustive observation of vegetation changes were made on this area of four hectares between 2000 and 2008, employing a spatial approach. We recorded the expansion of Molinia caerulea (L.) Moench at the expense of Ericaceae. The potential future vegetation of the site was modelled using Markov chains coupled to a GIS programme. This model predicted a gradual change in the floristic composition of Heathland in favour of M. caerulea at the expense of Calluna vulgaris (L.) Hull and Erica tetralix L., and the expansion of Pinus sylvestris L. The study demonstrates how spatial methods can contribute to the design of reliable management methods of habitats such as the Heathlands.
N. R. Webb - One of the best experts on this subject based on the ideXlab platform.
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The traditional management of European Heathlands
Journal of Applied Ecology, 2008Co-Authors: N. R. WebbAbstract:SUMMARY Throughout western Europe Heathlands dominated by ericaceous subshrubs occur on poor soils. Mostly, these heaths have developed and have been maintained by human activities. Traditional management has perpetuated ecosystems of a low nutrient status in which plant succession is arrested. Traditional management has involved a complex interaction between grazing, arable cultivation and the use of turf and plant material from the heaths. This basic system occurs throughout the European Heathlands but with local variants. This paper reviews and compares the various systems of Heathland use and management with the aim of developing new methods to maintain these cultural landscapes.
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The application of geographic information systems and remotely sensed data to the conservation of Heathland fragments
Biological Conservation, 1995Co-Authors: N. Veitch, N. R. Webb, B.k. WyattAbstract:Abstract The integration of data from field observations and remote sensing within geographic information systems (GIS) offers the potential for rapid, cost-effective surveying and assessment of biotopes of high conservation value. A case study of the Dorset Heathlands in southern England illustrates the application of this approach. Information on the historical extent of the Heathlands was combined with Landsat Thematic Mapper (TM) data to assess the current extent of the Heathlands together with the potential for adjacent other lands (formerly Heathland) to be converted to Heathland again. The results of this work showed that the current extent of the Dorset Heathlands is about 44·3 km2. Heathland that had been converted to grassland since 1960 was considered to be the category of land use most suitable for the restoration of Heathland. It was found that 27·5% of this type of land falls within 100 m of existing Heathland and, under changed management, could significantly improve the natural resource of the region. This work draws upon an existing understanding of Heathland ecology and demonstrates the application of geographical information systems to the solution of ecological and conservation problems.
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Responses to severe fires in Heathland mosaics in Southern England
Biological Conservation, 1995Co-Authors: J.m. Bullock, N. R. WebbAbstract:We investigated the effects of uncontrolled fires in 1976 on 11 large heaths in Dorset, England, which were unmanaged over the period of study. These heaths consisted of mosaics of Heathland and associated semi-natural vegetation which we categorised into a number of vegetation types. We compared the cover values and species compositions of these types in burnt and unburnt zones in 1978 shortly after the fires and again in 1987. The vegetation in the unburnt zones was stable between the two surveys except for a loss of some dry Heathland to scrub and woodland invasion. The dry, humid and wet Heathlands and peatland showed few responses to the fires and all effects were transitory. Some of the scrub, woodland and carr vegetation was burnt out and the latter two vegetation types had not recovered by 1987. The scrub recolonised rapidly in the burnt zones but with a changed species composition. Bracken showed slight increases after burning. The uncontrolled fires did not seem to have the devastating effects on the Heathland vegetation that might be expected. We discuss the reasons for this.
