This page has only limited features, please log in for full access.
Long-term perspectives on climate- and human-induced shifts in plant communities and tree line in mountains are often inferred from fossil pollen records. However, various factors, such as complex patterns of orographic wind fields and abundant insect-pollinated plants in higher altitudes, make pollen-based reconstruction in mountain regions difficult. Over the last decade the Landscape Reconstruction Algorithm (LRA) - a model-based approach in reconstruction of vegetation – has been successfully applied in various parts of the globe. However, evaluation of its effectiveness in mountain ranges is still limited. The present study assesses the extent to which the LRA approach helps quantify the local changes in vegetation cover at Vicdessos valley in northern French Pyrenees as a case study. In the study area well-dated sediment cores are available from eight bogs and ponds, 6–113 m in radius, located above the current tree line. We first use a simple simulation experiment to evaluate the way how pollen records from “landscape islands” (mountain tops and plateaus) would represent local vegetation and to clarify important factors affecting the LRA-based reconstruction in a mountainous region. This study then uses pollen records from these sites and vegetation and land-cover data both within a 50-km radius around the Vicdessos valley and within a 2-km radius from each site for evaluation of the REVEALS- and LOVE-based reconstruction of the regional and local plant cover, respectively, in the LRA approach. The land-cover data are complied for coniferous trees, broadleaved trees and non-forested areas from the CORINE and historical maps in three time windows: 1960–1970, 1990–2000 and 2000–2013. Major findings are as follows. (1) Accuracy of the regional vegetation estimates affects the reliability of the LRA-based reconstruction of vegetation within a 2-km radius; use of the CORINE data as input to the LOVE model improves reliability of the results over the use of the REVEALS-based estimates of regional vegetation. This implies that a systematic selection of pollen data only from sites above the tree line is problematic for estimating regional vegetation, and thus the entire LRA process. (2) Selection of the dispersal models for pollen transport (i.e. the Langrangian Stochastic Model vs. Gaussian Plume Model) does not affect significantly the LRA-based estimates at both the regional and local scales in the study area. (3) The LRA approach improves the pollen-based reconstruction of local vegetation compared to pollen percentage alone in northern Pyrenees. Although further empirical and simulation studies are necessary, our results emphasize the importance of site selection for the LRA-based reconstruction of vegetation in mountain regions.
Laurent Marquer; Florence Mazier; Shinya Sugita; Didier Galop; Thomas Houet; Elodie Faure; Marie-José Gaillard; Sébastien Haunold; Nicolas de Munnik; Anaëlle Simonneau; François De Vleeschouwer; Gaël Le Roux. Pollen-based reconstruction of Holocene land-cover in mountain regions: Evaluation of the Landscape Reconstruction Algorithm in the Vicdessos valley, northern Pyrenees, France. Quaternary Science Reviews 2019, 228, 106049 .
AMA StyleLaurent Marquer, Florence Mazier, Shinya Sugita, Didier Galop, Thomas Houet, Elodie Faure, Marie-José Gaillard, Sébastien Haunold, Nicolas de Munnik, Anaëlle Simonneau, François De Vleeschouwer, Gaël Le Roux. Pollen-based reconstruction of Holocene land-cover in mountain regions: Evaluation of the Landscape Reconstruction Algorithm in the Vicdessos valley, northern Pyrenees, France. Quaternary Science Reviews. 2019; 228 ():106049.
Chicago/Turabian StyleLaurent Marquer; Florence Mazier; Shinya Sugita; Didier Galop; Thomas Houet; Elodie Faure; Marie-José Gaillard; Sébastien Haunold; Nicolas de Munnik; Anaëlle Simonneau; François De Vleeschouwer; Gaël Le Roux. 2019. "Pollen-based reconstruction of Holocene land-cover in mountain regions: Evaluation of the Landscape Reconstruction Algorithm in the Vicdessos valley, northern Pyrenees, France." Quaternary Science Reviews 228, no. : 106049.
Quantitative reconstruction of past plant abundance from fossil pollen data is still a challenging task for palynologists. During the last decades, mechanistic methods have been developed to convert pollen assemblages from peat and lake deposits into vegetation abundance at regional and local scale. Coastal areas are particularly sensitive to climate and environmental hazards. Thus, quantitative estimates of past vegetation are important to better understand their history and address potential effects of future environmental changes. However, assumptions of the mechanistic models of pollen dispersal and deposition originally designed for near-circular lakes and bogs located inland are violated when applied to coastal sites because of different basin shape and wind direction distribution. This study investigates how to adapt a model of pollen dispersal and deposition developed for lakes to coastal lagoons. A new geometry is defined, and it is demonstrated how some of the major formulas from previous models can be used without any modification in this singular context.
Julien Azuara; Florence Mazier; Vincent Lebreton; Shinya Sugita; Nicolas Viovy; Nathalie Combourieu-Nebout. Extending the applicability of the REVEALS model for pollen-based vegetation reconstructions to coastal lagoons. The Holocene 2019, 29, 1109 -1112.
AMA StyleJulien Azuara, Florence Mazier, Vincent Lebreton, Shinya Sugita, Nicolas Viovy, Nathalie Combourieu-Nebout. Extending the applicability of the REVEALS model for pollen-based vegetation reconstructions to coastal lagoons. The Holocene. 2019; 29 (7):1109-1112.
Chicago/Turabian StyleJulien Azuara; Florence Mazier; Vincent Lebreton; Shinya Sugita; Nicolas Viovy; Nathalie Combourieu-Nebout. 2019. "Extending the applicability of the REVEALS model for pollen-based vegetation reconstructions to coastal lagoons." The Holocene 29, no. 7: 1109-1112.
Andria Dawson; X Cao; M Chaput; E Hopla; F Li; M Edwards; R Fyfe; K Gajewski; Sj Goring; U Herzschuh; F Mazier; S Sugita; Jw Williams; Q Xu; M-J Gaillard. Finding the magnitude of human-induced Northern Hemisphere land-cover transformation between 6 and 0.2 ka BP. Past Global Changes Magazine 2018, 26, 34 -35.
AMA StyleAndria Dawson, X Cao, M Chaput, E Hopla, F Li, M Edwards, R Fyfe, K Gajewski, Sj Goring, U Herzschuh, F Mazier, S Sugita, Jw Williams, Q Xu, M-J Gaillard. Finding the magnitude of human-induced Northern Hemisphere land-cover transformation between 6 and 0.2 ka BP. Past Global Changes Magazine. 2018; 26 (1):34-35.
Chicago/Turabian StyleAndria Dawson; X Cao; M Chaput; E Hopla; F Li; M Edwards; R Fyfe; K Gajewski; Sj Goring; U Herzschuh; F Mazier; S Sugita; Jw Williams; Q Xu; M-J Gaillard. 2018. "Finding the magnitude of human-induced Northern Hemisphere land-cover transformation between 6 and 0.2 ka BP." Past Global Changes Magazine 26, no. 1: 34-35.
Jessie Woodbridge; Rm Fyfe; Cn Roberts; Ak Trondman; F Mazier; B Davis. European forest cover since the start of Neolithic agriculture: a critical comparison of pollen-based reconstructions. Past Global Changes Magazine 2018, 26, 10 -11.
AMA StyleJessie Woodbridge, Rm Fyfe, Cn Roberts, Ak Trondman, F Mazier, B Davis. European forest cover since the start of Neolithic agriculture: a critical comparison of pollen-based reconstructions. Past Global Changes Magazine. 2018; 26 (1):10-11.
Chicago/Turabian StyleJessie Woodbridge; Rm Fyfe; Cn Roberts; Ak Trondman; F Mazier; B Davis. 2018. "European forest cover since the start of Neolithic agriculture: a critical comparison of pollen-based reconstructions." Past Global Changes Magazine 26, no. 1: 10-11.
Wild bees are declining in intensively farmed regions worldwide, threatening pollination services to flowering crops and wild plants. To halt bee declines, it is essential that conservation actions are based on a mechanistic understanding of how bee species utilize landscapes. We aimed at teasing apart how foraging resources in the landscape through the nesting season affected nesting and reproduction of a solitary bee in a farmland region. We investigated how availability of floral resources and potentially resource-rich habitats surrounding nests affected nest provisioning and reproduction in the solitary polylectic bee Osmia bicornis. The study was performed in 18 landscape sectors dominated by agriculture, but varying in agricultural intensity in terms of proportion of organic crop fields and seminatural permanent pastures. Pasture-rich sectors contained more oak (Quercus robur), which pollen analysis showed to be favored forage in early season. More oaks ≤100 m from nests led to higher proportions of oak pollen in nest provisions and increased speed of nest construction in early season, but this effect tapered off as flowering decreased. Late-season pollen foraging was dominated by buttercup (Ranunculus spp.), common in various noncrop habitats. Foraging trips were longer with more oaks and increased further through the season. The opposite was found for buttercup. Oak and buttercup interacted to explain the number of offspring; buttercup had a positive effect only when the number of oaks was above the mean for the studied sectors. The results show that quality of complex and pasture-rich landscapes for O. bicornis depends on preserving existing and generating new oak trees. Lignose plants are key early-season forage resources in agricultural landscapes. Increasing habitat heterogeneity with trees and shrubs and promoting suitable late-flowering forbs can benefit O. bicornis and other wild bees active in spring and early summer, something which existing agri-environment schemes seldom target.
Anna S. Persson; Florence Mazier; Henrik G. Smith. When beggars are choosers-How nesting of a solitary bee is affected by temporal dynamics of pollen plants in the landscape. Ecology and Evolution 2018, 8, 5777 -5791.
AMA StyleAnna S. Persson, Florence Mazier, Henrik G. Smith. When beggars are choosers-How nesting of a solitary bee is affected by temporal dynamics of pollen plants in the landscape. Ecology and Evolution. 2018; 8 (11):5777-5791.
Chicago/Turabian StyleAnna S. Persson; Florence Mazier; Henrik G. Smith. 2018. "When beggars are choosers-How nesting of a solitary bee is affected by temporal dynamics of pollen plants in the landscape." Ecology and Evolution 8, no. 11: 5777-5791.
Questions As the dominant tree in many European forests, Fagus sylvatica functions as an ecosystem engineer, yet its history remains little understood. Here we ask: Are there indications for its presence in south‐eastern France during the last Glacial period? What was the timing of the expansion and decline of F. sylvatica dominated forests? Which factors influenced their dynamics and in particular to what extent did past precipitation changes impact upon them? Finally, at which altitudes did these beech forests occur within the region?. Location The Languedoc, within the French Mediterranean area. Method This article presents a well dated and high‐resolution pollen sequence covering the last 7800 years from the Palavas Lagoon in the Languedoc together with a review of Fagus charcoal occurrences in the Languedoc and the lower Rhône Valley, and a review of pollen data from a compilation of 69 sites in south‐eastern France. Results The Palavas pollen sequence provides a regional summary of F. sylvatica abundance changes near the Mediterranean coast. Around 6000 yrs cal BP, an abrupt transition from small beech populations to well‐developed forests is recorded. The maximum development of beech forests occurred between 4000 and 3000 yrs cal BP, while F. sylvatica started to regress after 3000 yrs cal BP. Conclusion Scattered F. sylvatica populations probably survived throughout southern France during the last Glacial period. F. sylvatica started to spread around 8000 yrs cal BP while beech forests never expanded before 6000 yrs cal BP. The complex patterns of F. sylvatica expansion in southern France after 6000 yrs cal BP suggests that a combination of global (climate change) and local (human impact) factors were responsible for this major change. Recurrent abrupt climate changes, the aridity trend and human deforestation caused beech forests to decline after 3000 yrs cal BP. This article is protected by copyright. All rights reserved.
Julien Azuara; Vincent Lebreton; Odile Peyron; Florence Mazier; Nathalie Combourieu-Nebout. The Holocene history of low altitude Mediterranean Fagus sylvatica forests in southern France. Journal of Vegetation Science 2018, 29, 438 -449.
AMA StyleJulien Azuara, Vincent Lebreton, Odile Peyron, Florence Mazier, Nathalie Combourieu-Nebout. The Holocene history of low altitude Mediterranean Fagus sylvatica forests in southern France. Journal of Vegetation Science. 2018; 29 (3):438-449.
Chicago/Turabian StyleJulien Azuara; Vincent Lebreton; Odile Peyron; Florence Mazier; Nathalie Combourieu-Nebout. 2018. "The Holocene history of low altitude Mediterranean Fagus sylvatica forests in southern France." Journal of Vegetation Science 29, no. 3: 438-449.
8000 years ago, prior to Neolithic agriculture, Europe was mostly a wooded continent. Since then, its forest cover has been progressively fragmented, so that today it covers less than half of Europe’s land area, in many cases having been cleared to make way for fields and pasture-land. Establishing the origin of Europe’s current, more open land-cover mosaic requires a long-term perspective, for which pollen analysis offers a key tool. In this study we utilise and compare three numerical approaches to transforming pollen data into past forest cover, drawing on >1000 14C-dated site records. All reconstructions highlight the different histories of the mixed temperate and the northern boreal forests, with the former declining progressively since ~6000 years ago, linked to forest clearance for agriculture in later prehistory (especially in northwest Europe) and early historic times (e.g. in north central Europe). In contrast, extensive human impact on the needle-leaf forests of northern Europe only becomes detectable in the last two millennia and has left a larger area of forest in place. Forest loss has been a dominant feature of Europe’s landscape ecology in the second half of the current interglacial, with consequences for carbon cycling, ecosystem functioning and biodiversity.
N. Roberts; R. M. Fyfe; J. Woodbridge; M.-J. Gaillard; B. A. S. Davis; J. O. Kaplan; Laurent Marquer; Florence Mazier; A. B. Nielsen; S. Sugita; A.-K. Trondman; M. Leydet. Europe’s lost forests: a pollen-based synthesis for the last 11,000 years. Scientific Reports 2018, 8, 1 -8.
AMA StyleN. Roberts, R. M. Fyfe, J. Woodbridge, M.-J. Gaillard, B. A. S. Davis, J. O. Kaplan, Laurent Marquer, Florence Mazier, A. B. Nielsen, S. Sugita, A.-K. Trondman, M. Leydet. Europe’s lost forests: a pollen-based synthesis for the last 11,000 years. Scientific Reports. 2018; 8 (1):1-8.
Chicago/Turabian StyleN. Roberts; R. M. Fyfe; J. Woodbridge; M.-J. Gaillard; B. A. S. Davis; J. O. Kaplan; Laurent Marquer; Florence Mazier; A. B. Nielsen; S. Sugita; A.-K. Trondman; M. Leydet. 2018. "Europe’s lost forests: a pollen-based synthesis for the last 11,000 years." Scientific Reports 8, no. 1: 1-8.
Anthropogenic land cover change (ALCC) is the most important transformation of the Earth system that occurred in the preindustrial Holocene, with implications for carbon, water and sediment cycles, biodiversity and the provision of ecosystem services and regional and global climate. For example, anthropogenic deforestation in preindustrial Eurasia may have led to feedbacks to the climate system: both biogeophysical, regionally amplifying winter cold and summer warm temperatures, and biogeochemical, stabilizing atmospheric CO2 concentrations and thus influencing global climate. Quantification of these effects is difficult, however, because scenarios of anthropogenic land cover change over the Holocene vary widely, with increasing disagreement back in time. Because land cover change had such widespread ramifications for the Earth system, it is essential to assess current ALCC scenarios in light of observations and provide guidance on which models are most realistic. Here, we perform a systematic evaluation of two widely-used ALCC scenarios (KK10 and HYDE3.1) in northern and part of central Europe using an independent, pollen-based reconstruction of Holocene land cover (REVEALS). Considering that ALCC in Europe primarily resulted in deforestation, we compare modeled land use with the cover of non-forest vegetation inferred from the pollen data. Though neither land cover change scenario matches the pollen-based reconstructions precisely, KK10 correlates well with REVEALS at the country scale, while HYDE systematically underestimates land use with increasing magnitude with time in the past. Discrepancies between modeled and reconstructed land use are caused by a number of factors, including assumptions of per-capita land use and socio-cultural factors that cannot be predicted on the basis of the characteristics of the physical environment, including dietary preferences, long-distance trade, the location of urban areas and social organization.
Jed O. Kaplan; Kristen M. Krumhardt; Marie-José Gaillard; Shinya Sugita; Anna-Kari Trondman; Ralph Fyfe; Laurent Marquer; Florence Mazier; Anne Birgitte Nielsen. Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions. Land 2017, 6, 91 .
AMA StyleJed O. Kaplan, Kristen M. Krumhardt, Marie-José Gaillard, Shinya Sugita, Anna-Kari Trondman, Ralph Fyfe, Laurent Marquer, Florence Mazier, Anne Birgitte Nielsen. Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions. Land. 2017; 6 (4):91.
Chicago/Turabian StyleJed O. Kaplan; Kristen M. Krumhardt; Marie-José Gaillard; Shinya Sugita; Anna-Kari Trondman; Ralph Fyfe; Laurent Marquer; Florence Mazier; Anne Birgitte Nielsen. 2017. "Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions." Land 6, no. 4: 91.
In this study we estimate relative pollen productivity (RPP) for plant taxa characteristic of human-induced vegetation in ancient cultural landscapes of the low mountain ranges of Shandong province in eastern temperate China. RPP estimates are required to achieve pollen-based reconstructions of Holocene plant cover using modelling approaches based on Prentice’s and Sugita’s theoretical background and models (REVEALS and LOVE). Pollen counts in moss samples and vegetation data from 36 sites were used in the Extended R-Value (ERV) model to estimate the relevant source area of pollen (RSAP) of moss polsters and RPP of major plant taxa. The best results were obtained with the ERV sub-model 3 and Prentice’s taxon-specific method (using a Gaussian Plume dispersal model) to distance weight vegetation data. RSAP was estimated to 145 m using the maximum likelihood method. RPP was obtained for 18 taxa of which two taxa had unreliable RPP (Amaranthaceae/Chenopodiaceae and Vitex negundo). RPPs for Castanea, Cupressaceae, Robinia/Sophora, Aster/Anthemis-type, Cannabis/Humulus, Caryophyllaceae, Brassicaceae and Galium-type are the first ones for China. Trees, except Robinia/Sophora (RPP = 0.78 ± 0.03) have larger RPPs than herbs other than Artemisia (RPP = 24.7 ± 0.36). The RPPs for Quercus, Pinus and Artemisia are comparable with other RPPs obtained in China, the RPPs for Pinus, Quercus, Ulmus, Cyperaceae and Galium-type with the mean RPPs obtained in Europe, and RPP for Cupressaceae with that for Juniperus in Europe. The values for Aster/Anthemis-type, Caryophyllaceae, Asteraceae SF Cichorioideae and Juglans differ from the few RPPs available in China and/or Europe.
Furong Li; Marie-José Gaillard; Shinya Sugita; Florence Mazier; Qinghai Xu; Zhongze Zhou; Yuyun Zhang; Yuecong Li; Dominique Laffly. Relative pollen productivity estimates for major plant taxa of cultural landscapes in central eastern China. Vegetation History and Archaeobotany 2017, 26, 587 -605.
AMA StyleFurong Li, Marie-José Gaillard, Shinya Sugita, Florence Mazier, Qinghai Xu, Zhongze Zhou, Yuyun Zhang, Yuecong Li, Dominique Laffly. Relative pollen productivity estimates for major plant taxa of cultural landscapes in central eastern China. Vegetation History and Archaeobotany. 2017; 26 (6):587-605.
Chicago/Turabian StyleFurong Li; Marie-José Gaillard; Shinya Sugita; Florence Mazier; Qinghai Xu; Zhongze Zhou; Yuyun Zhang; Yuecong Li; Dominique Laffly. 2017. "Relative pollen productivity estimates for major plant taxa of cultural landscapes in central eastern China." Vegetation History and Archaeobotany 26, no. 6: 587-605.
Publisher: Elsevier articletitle: Quantifying the effects of land use and climate on Holocene vegetation in Europe journaltitle: Quaternary Science Reviews articlelink: http://dx.doi.org/10.1016/j.quascirev.2017.07.001 content_type: article copyright: © 2017 Elsevier Ltd. All rights reserved
Laurent Marquer; Marie-José Gaillard; Shinya Sugita; Anneli Poska; Anna-Kari Trondman; Florence Mazier; Anne Birgitte Nielsen; Ralph M. Fyfe; Anna Maria Jönsson; Benjamin Smith; Jed O. Kaplan; Teija Alenius; H. John B. Birks; Anne E. Bjune; Jörg Christiansen; John Dodson; Kevin J. Edwards; Thomas Giesecke; Ulrike Herzschuh; Mihkel Kangur; Tiiu Koff; Małgorzata Latałowa; Jutta Lechterbeck; Jörgen Olofsson; Heikki Seppä. Quantifying the effects of land use and climate on Holocene vegetation in Europe. Quaternary Science Reviews 2017, 171, 20 -37.
AMA StyleLaurent Marquer, Marie-José Gaillard, Shinya Sugita, Anneli Poska, Anna-Kari Trondman, Florence Mazier, Anne Birgitte Nielsen, Ralph M. Fyfe, Anna Maria Jönsson, Benjamin Smith, Jed O. Kaplan, Teija Alenius, H. John B. Birks, Anne E. Bjune, Jörg Christiansen, John Dodson, Kevin J. Edwards, Thomas Giesecke, Ulrike Herzschuh, Mihkel Kangur, Tiiu Koff, Małgorzata Latałowa, Jutta Lechterbeck, Jörgen Olofsson, Heikki Seppä. Quantifying the effects of land use and climate on Holocene vegetation in Europe. Quaternary Science Reviews. 2017; 171 ():20-37.
Chicago/Turabian StyleLaurent Marquer; Marie-José Gaillard; Shinya Sugita; Anneli Poska; Anna-Kari Trondman; Florence Mazier; Anne Birgitte Nielsen; Ralph M. Fyfe; Anna Maria Jönsson; Benjamin Smith; Jed O. Kaplan; Teija Alenius; H. John B. Birks; Anne E. Bjune; Jörg Christiansen; John Dodson; Kevin J. Edwards; Thomas Giesecke; Ulrike Herzschuh; Mihkel Kangur; Tiiu Koff; Małgorzata Latałowa; Jutta Lechterbeck; Jörgen Olofsson; Heikki Seppä. 2017. "Quantifying the effects of land use and climate on Holocene vegetation in Europe." Quaternary Science Reviews 171, no. : 20-37.
Sophia V. Hansson; Adrien Claustres; Anne Probst; François De Vleeschouwer; Sandrine Baron; Didier Galop; Florence Mazier; Gael Le Roux. Atmospheric and terrigenous metal accumulation over 3000 years in a French mountain catchment: Local vs distal influences. Anthropocene 2017, 19, 45 -54.
AMA StyleSophia V. Hansson, Adrien Claustres, Anne Probst, François De Vleeschouwer, Sandrine Baron, Didier Galop, Florence Mazier, Gael Le Roux. Atmospheric and terrigenous metal accumulation over 3000 years in a French mountain catchment: Local vs distal influences. Anthropocene. 2017; 19 ():45-54.
Chicago/Turabian StyleSophia V. Hansson; Adrien Claustres; Anne Probst; François De Vleeschouwer; Sandrine Baron; Didier Galop; Florence Mazier; Gael Le Roux. 2017. "Atmospheric and terrigenous metal accumulation over 3000 years in a French mountain catchment: Local vs distal influences." Anthropocene 19, no. : 45-54.
This study aims to evaluate three classes of methods to discriminate between 13 peatland vegetation types using reflectance data. These vegetation types were empirically defined according to their composition, strata and biodiversity richness. On one hand, it is assumed that the same vegetation type spectral signatures have similarities. Consequently, they can be compared to a reference spectral database. To catch those similarities, several similarities criteria (related to distances (Euclidean distance, Manhattan distance, Canberra distance) or spectral shapes (Spectral Angle Mapper) or probabilistic behaviour (Spectral Information Divergence)) and several mathematical transformations of spectral signatures enhancing absorption features (such as the first derivative or the second derivative, the normalized spectral signature, the continuum removal, the continuum removal derivative reflectance, the log transformation) were investigated. Furthermore, those similarity measures were applied on spectral ranges which characterize specific biophysical properties. On the other hand, we suppose that specific biophysical properties/components may help to discriminate between vegetation types applying supervised classification such as Random Forest (RF), Support Vector Machines (SVM), Regularized Logistic Regression (RLR), Partial Least Squares-Discriminant Analysis (PLS-DA). Biophysical components can be used in a local way considering vegetation spectral indices or in a global way considering spectral ranges and transformed spectral signatures, as explained above. RLR classifier applied on spectral vegetation indices (training size = 25%) was able to achieve 77.21% overall accuracy in discriminating peatland vegetation types. It was also able to discriminate between 83.95% vegetation types considering specific spectral range [[range-phrase = –]3501350 nm], first derivative of spectral signatures and training size = 25%. Conversely, similarity criterion was able to achieve 81.70% overall accuracy using the Canberra distance computed on the full spectral range [[range-phrase = –]3502500 nm]. The results of this study suggest that RLR classifier and similarity criteria are promising to map the different vegetation types with high ecological values despite vegetation heterogeneity and mixture.
Thierry Erudel; Sophie Fabre; Thomas Houet; Florence Mazier; Xavier Briottet. Criteria Comparison for Classifying Peatland Vegetation Types Using In Situ Hyperspectral Measurements. Remote Sensing 2017, 9, 748 .
AMA StyleThierry Erudel, Sophie Fabre, Thomas Houet, Florence Mazier, Xavier Briottet. Criteria Comparison for Classifying Peatland Vegetation Types Using In Situ Hyperspectral Measurements. Remote Sensing. 2017; 9 (7):748.
Chicago/Turabian StyleThierry Erudel; Sophie Fabre; Thomas Houet; Florence Mazier; Xavier Briottet. 2017. "Criteria Comparison for Classifying Peatland Vegetation Types Using In Situ Hyperspectral Measurements." Remote Sensing 9, no. 7: 748.
The relationship between land-use and floristic diversity in the landscape, for the last millennia, is analysed from two small lakes in southern Sweden. Pollen analysis and the Local Vegetation Estimates (LOVE) model are used to quantify land-cover at local scales with 100-year time windows. Floristic richness is estimated using palynological richness, and we introduce LOVE-based evenness as a proxy for floristic evenness on a local scale based on the LOVE output. The results reveal a dynamic land-use pattern, with agricultural expansion during the 13th century, a partly abandoned landscape around AD 1400, re-establishment during the 15th–17th centuries and a transition from traditional to modern land-use during the 20th century. We suggest that the more heterogeneous landscape and the more dynamic land-use during the 13th–19th centuries were of substantial importance for achieving the high floristic diversity that characterises the traditional landscape. Pollen-based studies of this type are helpful in identifying landscape characteristics and land-use practices that are important for floristic diversity and may therefore guide the development of ecosystem management strategies aiming at mitigating the on-going loss of species seen in the landscape of southern Sweden and many other regions worldwide.
Daniel Fredh; Florence Mazier; Petra Bragée; Per Lagerås; Mats Rundgren; Dan Hammarlund; Anna Broström. The effect of local land-use changes on floristic diversity during the past 1000 years in southern Sweden. The Holocene 2016, 27, 694 -711.
AMA StyleDaniel Fredh, Florence Mazier, Petra Bragée, Per Lagerås, Mats Rundgren, Dan Hammarlund, Anna Broström. The effect of local land-use changes on floristic diversity during the past 1000 years in southern Sweden. The Holocene. 2016; 27 (5):694-711.
Chicago/Turabian StyleDaniel Fredh; Florence Mazier; Petra Bragée; Per Lagerås; Mats Rundgren; Dan Hammarlund; Anna Broström. 2016. "The effect of local land-use changes on floristic diversity during the past 1000 years in southern Sweden." The Holocene 27, no. 5: 694-711.
In this paper we test the performance of the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model using pollen records from multiple small sites. We use Holocene pollen records from large and small sites in southern Sweden to identify what is/are the most significant variable(s) affecting the REVEALS-based reconstructions, i.e. type of site (lakes and/or bogs), number of sites, site size, site location in relation to vegetation zones, and/or distance between small sites and large sites. To achieve this objective we grouped the small sites according to (i) the two major modern vegetation zones of the study region, and (ii) the distance between the small sites and large lakes, i.e. small sites within 50, 100, 150, or 200 km of the large lakes. The REVEALS-based reconstructions were performed using 24 pollen taxa. Redundancy analysis was performed on the results from all REVEALS-model runs using the groups within (i) and (ii) separately, and on the results from all runs using the groups within (ii) together. The explanatory power and significance of the variables were identified using forward selection and Monte Carlo permutation tests. The results show that (a) although the REVEALS model was designed for pollen data from large lakes, it also performs well with pollen data from multiple small sites in reconstructing the percentage cover of groups of plant taxa (e.g. open land taxa, summer-green trees, evergreen trees) or individual plant taxa; however, in the case of this study area, the reconstruction of the percentage cover of Calluna vulgaris, Cyperaceae, and Betula may be problematic when using small bogs; (b) standard errors of multiple small-site REVEALS estimates will generally be larger than those obtained using pollen records from large lakes, and they will decrease with increasing size of pollen counts and increasing number of small sites; (c) small lakes are better to use than small bogs if the total number of small sites is low; and (d) the size of small sites and the distance between them do not play a major role, but the distance between the small sites and landscape/vegetation boundaries is a determinant factor for the accuracy of the vegetation reconstructions.
Anna-Kari Trondman; Marie-José Gaillard; Shinya Sugita; Leif Björkman; Annica Greisman; Tove Hultberg; Per Lagerås; Matts Lindbladh; Florence Mazier. Are pollen records from small sites appropriate for REVEALS model-based quantitative reconstructions of past regional vegetation? An empirical test in southern Sweden. Vegetation History and Archaeobotany 2015, 25, 131 -151.
AMA StyleAnna-Kari Trondman, Marie-José Gaillard, Shinya Sugita, Leif Björkman, Annica Greisman, Tove Hultberg, Per Lagerås, Matts Lindbladh, Florence Mazier. Are pollen records from small sites appropriate for REVEALS model-based quantitative reconstructions of past regional vegetation? An empirical test in southern Sweden. Vegetation History and Archaeobotany. 2015; 25 (2):131-151.
Chicago/Turabian StyleAnna-Kari Trondman; Marie-José Gaillard; Shinya Sugita; Leif Björkman; Annica Greisman; Tove Hultberg; Per Lagerås; Matts Lindbladh; Florence Mazier. 2015. "Are pollen records from small sites appropriate for REVEALS model-based quantitative reconstructions of past regional vegetation? An empirical test in southern Sweden." Vegetation History and Archaeobotany 25, no. 2: 131-151.
Understanding social-ecological system dynamics is a major research priority for sustainable management of landscapes, ecosystems and resources. But the lack of multi-decadal records represents an important gap in information that hinders the development of the research agenda. Without improved information on the long-term and complex interactions between causal factors and responses, it will be difficult to answer key questions about trends, rates of change, tipping points, safe operating spaces and pre-impact conditions. Where available long-term monitored records are too short or lacking, palaeoenvironmental sciences may provide continuous multi-decadal records for an array of ecosystem states, processes and services. Combining these records with conventional sources of historical information from instrumental monitoring records, official statistics and enumerations, remote sensing, archival documents, cartography and archaeology produces an evolutionary framework for reconstructing integrated regional histories. We demonstrate the integrated approach with published case studies from Australia, China, Europe and North America.
John Dearing; B Acma; S Bub; Fm Chambers; X Chen; J Cooper; D Crook; Xh Dong; M Dotterweich; Me Edwards; Th Foster; M.J. Gaillard; Didier Galop; Peter Gell; A Gil; Elizabeth Jeffers; Rt Jones; K Anupama; Peter Langdon; R Marchant; Florence Mazier; Ce McLean; Lh Nunes; R Sukumar; I Suryaprakash; M Umer; Xd Yang; R Wang; K Zhang. Social-ecological systems in the Anthropocene: The need for integrating social and biophysical records at regional scales. The Anthropocene Review 2015, 2, 220 -246.
AMA StyleJohn Dearing, B Acma, S Bub, Fm Chambers, X Chen, J Cooper, D Crook, Xh Dong, M Dotterweich, Me Edwards, Th Foster, M.J. Gaillard, Didier Galop, Peter Gell, A Gil, Elizabeth Jeffers, Rt Jones, K Anupama, Peter Langdon, R Marchant, Florence Mazier, Ce McLean, Lh Nunes, R Sukumar, I Suryaprakash, M Umer, Xd Yang, R Wang, K Zhang. Social-ecological systems in the Anthropocene: The need for integrating social and biophysical records at regional scales. The Anthropocene Review. 2015; 2 (3):220-246.
Chicago/Turabian StyleJohn Dearing; B Acma; S Bub; Fm Chambers; X Chen; J Cooper; D Crook; Xh Dong; M Dotterweich; Me Edwards; Th Foster; M.J. Gaillard; Didier Galop; Peter Gell; A Gil; Elizabeth Jeffers; Rt Jones; K Anupama; Peter Langdon; R Marchant; Florence Mazier; Ce McLean; Lh Nunes; R Sukumar; I Suryaprakash; M Umer; Xd Yang; R Wang; K Zhang. 2015. "Social-ecological systems in the Anthropocene: The need for integrating social and biophysical records at regional scales." The Anthropocene Review 2, no. 3: 220-246.
Long-term records of environmental history at decadal to millennial time-scales enable an assessment of ecosystem variability and responses to past anthropogenic disturbances and are fundamental for the development of environmental management strategies. This study examines the local variability of land-use history in the South Swedish Uplands over the last 200 years based on pollen records from three lake-sediment successions. Temporal changes in the proportional cover of 14 plant taxa were quantified as percentages using the landscape reconstruction algorithm (LRA). The LRA-based estimates of the extent of four land-use categories (cropland, meadows/grassland, wetland, outland/woodland) were compared to corresponding estimates based on historical maps and aerial photographs from ad 1769–1823, 1837–1895, 1946 and 2005. Although the LRA approach tends to overestimate grassland cover by 10–30 % for the two earliest time periods, the reconstructed vegetation composition is generally in good agreement with estimates based on the historical records. Subsequently, the LRA approach was used to reconstruct the 200-year history of local land-use dynamics at 20-year intervals around two small lakes. The qualitative assessment of difference approach, which requires fewer assumptions and parameters than LRA for objective evaluation of between-site differences in plant abundances, provides consistent results in general. Significant differences exist in the land-use history between the sites. Local catchment characteristics, such as soil conditions and wetland cover, appear important for the development of human impact on the landscape. Quantifications of past vegetation dynamics provide information on the amplitude, frequency and duration of the land-use changes and their effects on terrestrial and aquatic ecosystems, and should be taken into account when nature conservation strategies are developed.
Florence Mazier; Anna Broström; Pétra Bragée; Daniel Fredh; Li Stenberg; Geraldine Thiere; Shinya Sugita; Dan Hammarlund. Two hundred years of land-use change in the South Swedish Uplands: comparison of historical map-based estimates with a pollen-based reconstruction using the landscape reconstruction algorithm. Vegetation History and Archaeobotany 2015, 24, 555 -570.
AMA StyleFlorence Mazier, Anna Broström, Pétra Bragée, Daniel Fredh, Li Stenberg, Geraldine Thiere, Shinya Sugita, Dan Hammarlund. Two hundred years of land-use change in the South Swedish Uplands: comparison of historical map-based estimates with a pollen-based reconstruction using the landscape reconstruction algorithm. Vegetation History and Archaeobotany. 2015; 24 (5):555-570.
Chicago/Turabian StyleFlorence Mazier; Anna Broström; Pétra Bragée; Daniel Fredh; Li Stenberg; Geraldine Thiere; Shinya Sugita; Dan Hammarlund. 2015. "Two hundred years of land-use change in the South Swedish Uplands: comparison of historical map-based estimates with a pollen-based reconstruction using the landscape reconstruction algorithm." Vegetation History and Archaeobotany 24, no. 5: 555-570.
Parmi les derniers développements en matière de palynologie, un nombre croissant de travaux s’intéresse notamment à la reconstitution quantitative du couvert végétal. En effet, la relation non-linéaire observée entre les comptages polliniques et la végétation, principalement liée à des différences interspécifiques de production pollinique et de dispersion du pollen, peut être corrigée via l’utilisation de modèles mathématiques comme le Landscape Reconstruction Algorithm, avec ses deux sous-modèles REVEALS et LOVE .L’application du modèle REVEALS aux données holocènes du Bassin parisien a permis d’obtenir une estimation des proportions relatives des principaux taxons présents dans le paysage, au niveau régional. Ces résultats modifient significativement la hiérarchie des différentes essences floristiques. Par exemple, la part accentuée des taxons herbacés dans les quantifications conduit à une importante réévaluation de l’étendue des milieux ouverts durant toute la période postglaciaire. De même, on perçoit plus fortement l’impact sur le paysage des pratiques agro-pastorales au travers de proportions accrues des taxons marqueurs d’anthropisation.
Rémi David; Chantal Leroyer; Florence Mazier. Les modélisations du couvert végétal en palynologie. Les Nouvelles de l'archéologie 2015, 44 -49.
AMA StyleRémi David, Chantal Leroyer, Florence Mazier. Les modélisations du couvert végétal en palynologie. Les Nouvelles de l'archéologie. 2015; (138):44-49.
Chicago/Turabian StyleRémi David; Chantal Leroyer; Florence Mazier. 2015. "Les modélisations du couvert végétal en palynologie." Les Nouvelles de l'archéologie , no. 138: 44-49.
Decadal-scale variations in total organic carbon (TOC) concentration in lake water since AD 1200 in two small lakes in southern Sweden were reconstructed based on visible–near-infrared spectroscopy (VNIRS) of their recent sediment successions. In order to assess the impacts of local land-use changes, regional variations in sulfur, and nitrogen deposition and climate variations on the inferred changes in TOC concentration, the same sediment records were subjected to multi-proxy palaeolimnological analyses. Changes in lake-water pH were inferred from diatom analysis, whereas pollen-based land-use reconstructions (Landscape Reconstruction Algorithm) together with geochemical records provided information on catchment-scale environmental changes, and comparisons were made with available records of climate and population density. Our long-term reconstructions reveal that inferred lake-water TOC concentrations were generally high prior to AD 1900, with additional variability coupled mainly to changes in forest cover and agricultural land-use intensity. The last century showed significant changes, and unusually low TOC concentrations were inferred at AD 1930–1990, followed by a recent increase, largely consistent with monitoring data. Variations in sulfur emissions, with an increase in the early 1900s to a peak around AD 1980 and a subsequent decrease, were identified as an important driver of these dynamics at both sites, while processes related to the introduction of modern forestry and recent increases in precipitation and temperature may have contributed, but the effects differed between the sites. The increase in lake-water TOC concentration from around AD 1980 may therefore reflect a recovery process. Given that the effects of sulfur deposition now subside and that the recovery of lake-water TOC concentrations has reached pre-industrial levels, other forcing mechanisms related to land management and climate change may become the main drivers of TOC concentration changes in boreal lake waters in the future.
P. Bragée; F. Mazier; A. B. Nielsen; P. Rosén; D. Fredh; A. Broström; W. Granéli; D. Hammarlund. Historical TOC concentration minima during peak sulfur deposition in two Swedish lakes. Biogeosciences 2015, 12, 307 -322.
AMA StyleP. Bragée, F. Mazier, A. B. Nielsen, P. Rosén, D. Fredh, A. Broström, W. Granéli, D. Hammarlund. Historical TOC concentration minima during peak sulfur deposition in two Swedish lakes. Biogeosciences. 2015; 12 (2):307-322.
Chicago/Turabian StyleP. Bragée; F. Mazier; A. B. Nielsen; P. Rosén; D. Fredh; A. Broström; W. Granéli; D. Hammarlund. 2015. "Historical TOC concentration minima during peak sulfur deposition in two Swedish lakes." Biogeosciences 12, no. 2: 307-322.
Reliable estimates of past land cover are critical for assessing potential effects of anthropogenic land-cover changes on past earth surface-climate feedbacks and landscape complexity. Fossil pollen records from lakes and bogs have provided important information on past natural and human-induced vegetation cover. However, those records provide only point estimates of past land cover, and not the spatially continuous maps at regional and sub-continental scales needed for climate modelling. We propose a set of statistical models that create spatially continuous maps of past land cover by combining two data sets: 1) pollen-based point estimates of past land cover (from the REVEALS model) and 2) spatially continuous estimates of past land cover, obtained by combining simulated potential vegetation (from LPJ-GUESS) with an anthropogenic land-cover change scenario (KK10). The proposed models rely on statistical methodology for compositional data and use Gaussian Markov Random Fields to model spatial dependencies in the data. Land-cover reconstructions are presented for three time windows in Europe: 0.05, 0.2, and 6 ka years before present (BP). The models are evaluated through cross-validation, deviance information criteria and by comparing the reconstruction of the 0.05 ka time window to the present-day land-cover data compiled by the European Forest Institute (EFI). For 0.05 ka, the proposed models provide reconstructions that are closer to the EFI data than either the REVEALS- or LPJ-GUESS/KK10-based estimates; thus the statistical combination of the two estimates improves the reconstruction. The reconstruction by the proposed models for 0.2 ka is also good. For 6 ka, however, the large differences between the REVEALS- and LPJ-GUESS/KK10-based estimates reduce the reliability of the proposed models. Possible reasons for the increased differences between REVEALS and LPJ-GUESS/KK10 for older time periods and further improvement of the proposed models are discussed.
Behnaz Pirzamanbein; Johan Lindström; Anneli Poska; Shinya Sugita; Anna-Kari Trondman; Ralph Fyfe; Florence Mazier; Anne B. Nielsen; Jed O. Kaplan; Anne Elisabeth Bjune; H. John B. Birks; Thomas Giesecke; Mikhel Kangur; Małgorzata Latałowa; Laurent Marquer; Benjamin Smith; Marie-José Gaillard. Creating spatially continuous maps of past land cover from point estimates: A new statistical approach applied to pollen data. Ecological Complexity 2014, 20, 127 -141.
AMA StyleBehnaz Pirzamanbein, Johan Lindström, Anneli Poska, Shinya Sugita, Anna-Kari Trondman, Ralph Fyfe, Florence Mazier, Anne B. Nielsen, Jed O. Kaplan, Anne Elisabeth Bjune, H. John B. Birks, Thomas Giesecke, Mikhel Kangur, Małgorzata Latałowa, Laurent Marquer, Benjamin Smith, Marie-José Gaillard. Creating spatially continuous maps of past land cover from point estimates: A new statistical approach applied to pollen data. Ecological Complexity. 2014; 20 ():127-141.
Chicago/Turabian StyleBehnaz Pirzamanbein; Johan Lindström; Anneli Poska; Shinya Sugita; Anna-Kari Trondman; Ralph Fyfe; Florence Mazier; Anne B. Nielsen; Jed O. Kaplan; Anne Elisabeth Bjune; H. John B. Birks; Thomas Giesecke; Mikhel Kangur; Małgorzata Latałowa; Laurent Marquer; Benjamin Smith; Marie-José Gaillard. 2014. "Creating spatially continuous maps of past land cover from point estimates: A new statistical approach applied to pollen data." Ecological Complexity 20, no. : 127-141.
We present quantitative reconstructions of regional vegetation cover in north‐western Europe, western Europe north of the Alps, and eastern Europe for five time windows in the Holocene [around 6k, 3k, 0.5k, 0.2k, and 0.05k calendar years before present (bp)] at a 1° × 1° spatial scale with the objective of producing vegetation descriptions suitable for climate modelling. The REVEALS model was applied on 636 pollen records from lakes and bogs to reconstruct the past cover of 25 plant taxa grouped into 10 plant‐functional types and three land‐cover types [evergreen trees, summer‐green (deciduous) trees, and open land]. The model corrects for some of the biases in pollen percentages by using pollen productivity estimates and fall speeds of pollen, and by applying simple but robust models of pollen dispersal and deposition. The emerging patterns of tree migration and deforestation between 6k bp and modern time in the REVEALS estimates agree with our general understanding of the vegetation history of Europe based on pollen percentages. However, the degree of anthropogenic deforestation (i.e. cover of cultivated and grazing land) at 3k, 0.5k, and 0.2k bp is significantly higher than deduced from pollen percentages. This is also the case at 6k in some parts of Europe, in particular Britain and Ireland. Furthermore, the relationship between summer‐green and evergreen trees, and between individual tree taxa, differs significantly when expressed as pollen percentages or as REVEALS estimates of tree cover. For instance, when Pinus is dominant over Picea as pollen percentages, Picea is dominant over Pinus as REVEALS estimates. These differences play a major role in the reconstruction of European landscapes and for the study of land cover–climate interactions, biodiversity and human resources.
Anna-Kari Trondman; M.‐J. Gaillard; Florence Mazier; S. Sugita; Ralph Fyfe; Anne Birgitte Nielsen; C. Twiddle; Philip Barratt; H. John B. Birks; Anne Elisabeth Bjune; L. Björkman; Anna Broström; C. Caseldine; R. David; J. Dodson; W. Dörfler; E. Fischer; B. Van Geel; Thomas Giesecke; T. Hultberg; L. Kalnina; M. Kangur; P. Van Der Knaap; T. Koff; Petr Kuneš; P. Lagerås; Malgorzata Latalowa; J. Lechterbeck; C. Leroyer; M. Leydet; M. Lindbladh; Laurent Marquer; Fraser Mitchell; B. V. Odgaard; S. M. Peglar; T. Persson; Anneli Poska; M. Rösch; Heikki Seppä; Siim Veski; L. Wick. Pollen‐based quantitative reconstructions of Holocene regional vegetation cover (plant‐functional types and land‐cover types) in Europe suitable for climate modelling. Global Change Biology 2014, 21, 676 -697.
AMA StyleAnna-Kari Trondman, M.‐J. Gaillard, Florence Mazier, S. Sugita, Ralph Fyfe, Anne Birgitte Nielsen, C. Twiddle, Philip Barratt, H. John B. Birks, Anne Elisabeth Bjune, L. Björkman, Anna Broström, C. Caseldine, R. David, J. Dodson, W. Dörfler, E. Fischer, B. Van Geel, Thomas Giesecke, T. Hultberg, L. Kalnina, M. Kangur, P. Van Der Knaap, T. Koff, Petr Kuneš, P. Lagerås, Malgorzata Latalowa, J. Lechterbeck, C. Leroyer, M. Leydet, M. Lindbladh, Laurent Marquer, Fraser Mitchell, B. V. Odgaard, S. M. Peglar, T. Persson, Anneli Poska, M. Rösch, Heikki Seppä, Siim Veski, L. Wick. Pollen‐based quantitative reconstructions of Holocene regional vegetation cover (plant‐functional types and land‐cover types) in Europe suitable for climate modelling. Global Change Biology. 2014; 21 (2):676-697.
Chicago/Turabian StyleAnna-Kari Trondman; M.‐J. Gaillard; Florence Mazier; S. Sugita; Ralph Fyfe; Anne Birgitte Nielsen; C. Twiddle; Philip Barratt; H. John B. Birks; Anne Elisabeth Bjune; L. Björkman; Anna Broström; C. Caseldine; R. David; J. Dodson; W. Dörfler; E. Fischer; B. Van Geel; Thomas Giesecke; T. Hultberg; L. Kalnina; M. Kangur; P. Van Der Knaap; T. Koff; Petr Kuneš; P. Lagerås; Malgorzata Latalowa; J. Lechterbeck; C. Leroyer; M. Leydet; M. Lindbladh; Laurent Marquer; Fraser Mitchell; B. V. Odgaard; S. M. Peglar; T. Persson; Anneli Poska; M. Rösch; Heikki Seppä; Siim Veski; L. Wick. 2014. "Pollen‐based quantitative reconstructions of Holocene regional vegetation cover (plant‐functional types and land‐cover types) in Europe suitable for climate modelling." Global Change Biology 21, no. 2: 676-697.