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Forest vegetation in western Romania in relation to climate variables: Does community composition reflect modelled tree species distribution? / S. Heinrichs in Annals of forest research, vol 59 n° 2 (July - December 2016)
[article]
Titre : Forest vegetation in western Romania in relation to climate variables: Does community composition reflect modelled tree species distribution? Type de document : Article/Communication Auteurs : S. Heinrichs, Auteur ; Helge Walentowski, Auteur ; E. Bergmeier, Auteur ; et al., Auteur Année de publication : 2016 Article en page(s) : pp 219 - 236 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] changement climatique
[Termes IGN] composition floristique
[Termes IGN] Europe centrale
[Termes IGN] Fagus sylvatica
[Termes IGN] forêt thermophile
[Termes IGN] phytosociologie
[Termes IGN] Quercus sessiliflora
[Termes IGN] Roumanie
[Termes IGN] unité phytosociologique
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) European beech (Fagus sylvatica L.) is the prevailing tree species of mesic forests in Central Europe. Increasing summer temperatures and decreasing precipitation, as climate change scenarios predict, may, however, negatively influence beech growth and induce a shift to more thermophilous forest communities. Temperatures as expected in the future for western Central Europe are currently found in parts of western Romania. In light of this climate analogy we investigated forest vegetation as an indicator for future vegetation changes in five regions of western Romania representing a climatic gradient. We related species composition to climate variables and examined if tree and understorey species composition respond similarly to the climatic gradient. We further analysed if tree species occurrences correspond with their modelled distance to the rear niche edge. We found evidence for climatic effects on vegetation composition among regions as well as within deciduous and pine forests, respectively. This underlines that vegetation composition is a useful indicator for environmental change. Tree and understorey species compositions were closely linked showing that community-based characterization of forest stands can provide additional information on tree species suitability along environmental gradients. Both, vegetation composition and a climatic marginality index demonstrate the rear niche edge occurrence of beech in the studied sites of Romania and can predict the site suitability for different tree species. While vegetation surveys indicate Quercus petraea to be associated to moderately mesic forests, the marginality index suggested an inner niche position of sessile oak along the climatic gradient. Phytosociological relevés that differentiate between subspecies (or microspecies) of sessile oak with differing habitat requirements should be considered to complement national forest inventories and species distribution maps when modelling rear distribution edges. We conclude that climate driven forest vegetation composition in western Romania is a suitable analogon and may indicate future forest development in western Central Europe. Numéro de notice : A2016--094 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.15287/afr.2016.692 En ligne : http://doi.org/10.15287/afr.2016.692 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84646
in Annals of forest research > vol 59 n° 2 (July - December 2016) . - pp 219 - 236[article]Two new montane grassland communities from the SE Alps (N Slovenia) / Igor Dakskobler in Hacquetia, vol 15 n° 1 (June 2016)
[article]
Titre : Two new montane grassland communities from the SE Alps (N Slovenia) Type de document : Article/Communication Auteurs : Igor Dakskobler, Auteur ; Andrej Seliškar, Auteur Année de publication : 2016 Article en page(s) : pp 31 - 48 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Alpes
[Termes IGN] Fagus (genre)
[Termes IGN] phytosociologie
[Termes IGN] Slovénie
[Termes IGN] unité phytosociologique
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) On very steep dolomite slopes in the western foothills of the Kamnik Alps (Ravni hrib, Javorov vrh, Zaplata, Kriška gora) and southwestern Karavanke Mountains (Dobrča) we conducted a phytosociological study into montane grasslands (former hay meadows, partly pastures) where Gladiolus palustris, a species of European conservation concern, also occasionally occurs. They were compared with similar montane grasslands (former hay meadows) on sunny slopes of the Stol ridge above Breginj in the southwestern foothills of the Julian Alps. Based on this comparison we described three new syntaxa: Centaureo julici-Laserpitietum sileris gladioletosum palustris, Festuco amethystinae-Seslerietum calcariae and Pediculari julici-Bromopsietum transsilvanicae. Both new associations are classified into the alliance Caricion austroalpinae and treated as a long-term successional stage in the belt of altimontane beech forests from the association Ranunculo platanifolii-Fagetum. Numéro de notice : A2016-942 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1515/hacq-2016-0008 En ligne : https://doi.org/10.1515/hacq-2016-0008 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=83420
in Hacquetia > vol 15 n° 1 (June 2016) . - pp 31 - 48[article]Assessment of forest canopy vertical structure with multi - scale remote sensing : from the plot to the large area / Phil Wilkes (2016)
Titre : Assessment of forest canopy vertical structure with multi - scale remote sensing : from the plot to the large area Type de document : Thèse/HDR Auteurs : Phil Wilkes, Auteur Editeur : Enschede [Pays Bas] : University of Twente Année de publication : 2016 Collection : ITC Dissertation num. 280 Importance : 180 p. ISBN/ISSN/EAN : 978-90-365-4038-4 Note générale : bibliographie
Dissertation to obtain the Double-Badged Degree of Doctor at the University of Twente, Enschede, The Netherlands; and RMIT University, Melbourne, AustraliaLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] allométrie
[Termes IGN] canopée
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] hauteur des arbres
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] ombre
[Termes IGN] placette d'échantillonnage
[Termes IGN] régression
[Termes IGN] semis de points
[Termes IGN] strate végétale
[Termes IGN] structure d'un peuplement forestier
[Termes IGN] Victoria (Australie)Index. décimale : 33.80 Lasergrammétrie Résumé : (auteur) The attribution of forest structure forms an integral part of international monitoring and reporting obligations with regard to sustainable forest management. Furthermore, detailed information about forest structure allows land managers and forest scientists to determine a forests ability to provide ecosystems services. Currently, forest attribution is achieved using a network of forest inventory plots that are revisited periodically. This approach comprises a sparse sample, both temporally and spatially, that may not capture variance in forest structure. This is particularly true in dynamic native forests where variability in forest structure can be high. In recent years the capability of remote sensing techniques has been realised for sustainable forest management applications. Advantages of a remote sensing approach include synoptic and high temporal coverage as well as reduced costs to the end - user. Furthermore, recent advancement in active sensors, such as Light Detection and Ranging Instruments (LiDAR) have allowed for detailed three - dimensional forest measurement of structure across large areas.
This thesis presents new metrics, techniques and acquisition specifications for the attribution of forest canopy over large areas (e.g. comprising two or more forest types where forest structure maybe unknown a priori) using active and passive remote sensing. In particular, the focus is on attributes that quantify the vertical structure of forests; canopy height and canopy vertical structure. Canopy height is a commonly measured multipurpose attribute that is utilised, for example, to estimate biomass. Attribution of the canopy height profile, although less common, is important for mapping habitat suitability, biomass and fire susceptibility. Current techniques to attribute forests tend to be tailored to a particular forest type or location and therefore application of these models across large areas is unreliable. Here the aim is to develop metrics and techniques that are transferable between different forest types and applicable to forests where there is no prior knowledge of forest structure.
Here a multi - scale remote sensing approach was taken, where plot scale measurements were upscaled to attribute large areas. Initially, existing LiDAR derived metrics applicable at the plot scale were tested at three 5 km x 5 km study areas in Victoria, Australia where forests cover a broad range of structural types. Results indicate existing metrics of canopy height were applicable across the range of forest types, for example the 95 th percentile of LiDAR derived height estimated inventory measured canopy height with a RMSE of 12% (~5 m). An existing mixture modelling technique to attribute the canopy height profile was found unsuitable when applied across heterogeneously forested landscape. This was due to the inability to parameterise the model correctly without a priori knowledge of forest structure e.g. presence or absence of shade tolerant layers. For this reason a new technique was developed utilising a nonparametric regression of LiDAR derived gap probability that generalised the canopy profile. Taking the second derivative of the regression curve identified locations within the canopy that correspond with canopy strata, this therefore allowed a dynamic attribution of canopy vertical structure. Model output was validated with a crown volume modelling approach at 24 plots, where crown models were parameterised with inventory data and allometry. Results indicate this technique can estimate the number of canopy strata with a RMSE of 0. 41 strata. Furthermore, the new technique met the transferability criteria , as a universal regression coefficient was transferable between forest types with different structural attributes.
As LiDAR acquisition that cover large areas will inevitably encounter a range of forest types, parameters for attributing canopy structure that were transferable between forest types were investigated; in particular sampling frequency. To effectively assess a range of pulse densities would require repeat capture over a study area at a range of flying heights , which would be prohibitively expensive. For this reason a new technique was developed that systematically thinned point clouds. This technique differs from previous approaches by allowing simulation of multi - return instruments as well as repeat capture of the same plot. Six sites from around Australia were utilised which covered a broad range of forest types, from open savanna to tropical rainforest. For a suite of metrics, the ability of progressively less dense point clouds ( 4 – 0. 05 pl m - 2 ) to estimate canopy structure was estimated by comparison with higher density data (10 pl m - 2 ). Results indicate that canopy structure can be adequately attributed with data captured at 0.5 pl m - 2 . When pulse densities are Techniques derived at the plot scale were then applied to estimate canopy height across 2.9 million hectares of heterogeneous forest. Canopy height in the study area ranged from 0 – 70 m and comprised forest types from open woodland to tall closed canopy rainforest. LiDAR derived canopy height was used to t rain ensemble regression tree s (random forest) , where predictor datasets included synoptic passive optical imagery and other ancillary spatial datasets , such as Landsat TM and MODIS. Results suggest canopy height can be estimated with a RMSE of 30% (5.5 m) when validated with an independent inventory dataset. This is a similar error to that reported in previous studies for less complex forests and is within the European Space Agency target for canopy height estimation. However, model output did show a systematic error, where the height of short and tall forests were over and underestimated respectively. This was corrected by subtracting a model led estimate of error from the random forest output. Production of a canopy height map over a large area allowed for a consistent product that covered a broad range of forest types, derivation at a 30 m resolution allowed the identification of landscape features such as logging coupes. The presented technique utilised an open source computing framework as well as freely available predictor datasets to facilitate uptake of by land management agencies and forest scientists.Note de contenu : Chapter 1 : Introduction
1.1. General introduction
1.2. Problem statement
1.3. Research questions
1.4. Thesis structure
Chapter 2 : Metrics of canopy vertical structure suitable for large area forest attribution
2.1. Introduction
2.1.1. Canopy height
2.1.2. Canopy vertical structure
2.1.3. Aims and objectives
2.2. Materials and methods
2.2.1. Study area
2.2.2. Forest inventory data
2.2.3. Airborne laser scanning data
2.3. Data processing
2.3.1. Canopy height
2.3.2. Canopy vertical structure
2.4. Results
2.4.1. Canopy height
2.4.2. Canopy height profiles
2.5. Discussion
2.6. Conclusion
Chapter 3 : Using discrete-return ALS to quantify number of canopy strata across diverse forest types
3.1. Introduction
3.2. Attributing canopy vertical structure
3.3. Application across a diverse forested landscape
3.3.1. ALS acquisition and preprocessing
3.3.2. Pgap from ALS
3.3.3. Derivation of smoothing coefficient (α)
3.3.4. Bootstrapping simulated point clouds
3.3.5. Validation with field inventory
3.4. Results and Discussion
3.4.1. Methodology evaluation
3.4.2. Validation results
3.4.3. Canopy vertical structure as an independent metric
3.5. Conclusion
Chapter 4 : Understanding the effects of ALS pulse density for metric retrieval across diverse forest types
4.1. Introduction
4.2. Method
4.2.1. Study area and data capture
4.2.2. Data processing
4.2.3. Metrics
4.3. Results
4.3.1. Canopy height
4.3.2. Canopy cover
4.3.3. Canopy vertical structure
4.3.4. Characteristics of thinned point clouds
4.4. Discussion
4.5. Conclusion
Chapter 5 : Mapping forest canopy height across large areas by upscaling ALS estimates with freely available satellite data
5.1. Introduction
5.2. Materials and methods
5.3. Results
5.3.1. Canopy height estimation
5.3.2. Validation with inventory data
5.3.3. Training and validation of random forest using smaller geographic areas
5.3.4. Simulating disparate ALS capture for training a random forest
5.4. Discussion
5.5. Conclusions
Chapter 6 : Summary and synthesis
6.1. Summary of results
6.2. Identifying trends in large area forest structure
6.3. Remote sensing in sustainable forest management: a future perspectiveNuméro de notice : 17249 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Thèse étrangère Note de thèse : PhD thesis : Remote sensing : Twente : 2016 Organisme de stage : RMIT DOI : sans En ligne : http://www.itc.nl/library/papers_2016/phd/wilkes.pdf Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81928 The species pool concept as a framework for studying patterns of plant diversity / Martin Zobel in Journal of vegetation science, vol 27 n° 1 (January 2016)
[article]
Titre : The species pool concept as a framework for studying patterns of plant diversity Type de document : Article/Communication Auteurs : Martin Zobel, Auteur Année de publication : 2016 Article en page(s) : pp 8 - 18 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] habitat (nature)
[Termes IGN] unité phytosociologique
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) Co-existence theories fail to adequately explain observed community patterns (diversity and composition) because they mainly address local extinctions. For a more complete understanding, the regional processes responsible for species formation and geographic dispersal should also be considered. The species pool concept holds that local variation in community patterns is dependent primarily on the availability of species, which is driven by historical diversification and dispersal at continental and landscape scales. However, empirical evidence of historical effects is limited. This slow progress can be attributed to methodological difficulties in determining the characteristics of historical species pools and how they contributed to diversity patterns in contemporary landscapes. A role of landscape-scale dispersal limitation in determining local community patterns has been demonstrated by numerous seed addition experiments. However, disentangling general patterns of dispersal limitation in communities still requires attention. Distinguishing habitat-specific species pools can help to meet both applied and theoretical challenges. In conservation biology, the use of absolute richness may be uninformative because the size of species pools varies between habitats. For characterizing the dynamic state of individual communities, biodiversity relative to species pools provides a balanced way of assessing communities in different habitats. Information about species pools may also be useful when studying community assembly rules, because it enables a possible mechanism of trait convergence (habitat filtering) to be explicitly assessed. Empirical study of the role of historic effects and dispersal on local community patterns has often been restricted due to methodological difficulties in determining habitat-specific species pools. However, accumulating distributional, ecological and phylogenetic information, as well as use of appropriate model systems (e.g. archipelagos with known biogeographic histories) will allow the species pool concept to be applied effectively in future research. Numéro de notice : A2016-360 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1111/jvs.12333 En ligne : http://dx.doi.org/10.1111/jvs.12333 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81095
in Journal of vegetation science > vol 27 n° 1 (January 2016) . - pp 8 - 18[article]How much do we know about the endangered Atlantic Forest? Reviewing nearly 70 years of information on tree community surveys / Renato A.F. de Lima in Biodiversity & Conservation, vol 24 n° 9 (September 2015)
[article]
Titre : How much do we know about the endangered Atlantic Forest? Reviewing nearly 70 years of information on tree community surveys Type de document : Article/Communication Auteurs : Renato A.F. de Lima, Auteur ; Danilo P. Mori, Auteur ; Gregory Pitta, Auteur ; Melina O. Melito, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 2135 - 2148 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Brésil
[Termes IGN] échantillonnage
[Termes IGN] forêt tropicale
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Paraguay
[Termes IGN] phytosociologie
[Vedettes matières IGN] Inventaire forestierRésumé : (auteur) The structure of the Atlantic Forest (AF) has been studied for almost 70 years. However, the related existing knowledge is spread over hundreds of documents, many of them unpublished and/or difficult to access. Synthesis initiatives are available, but they are restricted to only a few parts or types of the AF or are focused on species occurrence. Here, we conducted an extensive review to compile quantitative tree community surveys on all types of the AF until 2013 and to study where and how these surveys were conducted. We found 1157 relevant references, containing 2441 forest surveys published since 1945. These surveys corresponded to 2.24 million trees and 1817 ha of forests sampled. This total sampled area represents only 0.01 % of the AF remnants, showing how limited our knowledge is on AF structure. For Paraguay and the Brazilian states of Bahia and Mato Grosso do Sul this proportion was much smaller. The same was true for evergreen rainforests, Brejos de altitude and deciduous forests and most probably for the rare cloud, swamp, Caxetal and Mussununga forests for which no accurate remnant estimates were found. Since the 1980s, the amount of AF area sampled each year has increased continuously, but approximately 100 years will be necessary to sample at least 1 % of the AF. Thus, we urgently need an enormous amount of high-quality quantitative data to overcome our limited knowledge of the AF and to support conservation programs aiming to safeguard this threatened biodiversity hotspot. Numéro de notice : A2015--032 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1007/s10531-015-0953-1 Date de publication en ligne : 19/06/2015 En ligne : https://doi.org/10.1007/s10531-015-0953-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81110
in Biodiversity & Conservation > vol 24 n° 9 (September 2015) . - pp 2135 - 2148[article]Les séries de végétation de la vallée d’Ascu (Corse) : typologie et cartographie au 1:25 000 / Pauline Delbosc in Ecologia mediterranea, vol 41 n° 1 (2015)PermalinkEnvironmental, spatial and temporal drivers of plant community composition in British forest habitat / Adam Robert Kimberley (2015)PermalinkEtude expérimentale en cartographie de la végétation par télédétection / Vanessa Sellin in Cybergeo, European journal of geography, n° 2015 ([01/01/2015])PermalinkPermalinkPermalinkDistribution, données floristiques et architecture des boisements du delta du Rhône (sud-est de la France) / Annik Schnitzler in Ecologia mediterranea, vol 40 n° 2 (2014)PermalinkPlant communities of Italy: The Vegetation Prodrome / Edoardo Biondi in Plant Biosystems, vol 148 n° 4 (2014)PermalinkApproche syntaxonomique et écologique des formations à Genévrier thurifère (Juniperus thurifera L.) dans les Alpes françaises / Luc Garraud in Ecologia mediterranea, vol 40 n° 1 (2014)PermalinkConnaissance de la biodiversité végétale / Jan-Bernard Bouzillé (2014)PermalinkEtude des habitats naturels du Parc National du Mercantour (Alpes-Maritimes et Alpes de Haute-Provence), Partie 1. Rapport technique / Jérémie Van Es (2014)Permalink