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The Impact of ash dieback on veteran trees in Southwestern Sweden / Vikki Bengtsson in Baltic forestry, vol 27 n° 1 (2021)  

Public [article]  inBaltic forestry > vol 27 n° 1 (2021) . - pp 2 - 9 Titre : The Impact of ash dieback on veteran trees in Southwestern Sweden Type de document : Article/Communication Auteurs : Vikki Bengtsson, Auteur ; Anna Stenström, Auteur ; C. Philip Wheater, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 2 - 9 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Chalara fraxinea [Termes IGN] coupe (sylviculture) [Termes IGN] dépérissement [Termes IGN] Fraxinus excelsior [Termes IGN] maladie phytosanitaire [Termes IGN] mortalité [Termes IGN] ombre [Termes IGN] Suède [Vedettes matières IGN] Sylviculture Résumé : (auteur) Ash dieback (Hymenoscyphus fraxineus) is a fungal disease which affects ash throughout Sweden. Monitoring to study of the impact of ash dieback on veteran trees was undertaken in southwest Sweden in 2009, 2011, 2013, 2015, and 2020. The study found that 94.5% of the ash trees observed were affected by ash dieback disease in 2020 compared with 62% in 2009. 70 of the studied ash trees have died (21%) since the monitoring began. In 2009 there was no relationship between girth and ash dieback, but in 2020 the correlation between girth and the impact of ash dieback was statistically significant. In 2020, also for the first time during monitoring, the ash trees in the shade were significantly more affected by ash dieback, compared with trees standing in the open. This difference was not detected in 2013 or 2015. The effect of ash dieback on pollarded trees has varied between the years studied, but in 2020 there is no longer any significant difference between the pollarded and the non-pollarded ash trees. There was however a significant difference in the mortality rates between the groups of trees, with ash trees pollarded in more recent times having the highest mortality. Therefore, the recommendation in relation to veteran trees with ash dieback is that all pruning on veteran ash trees should be avoided. Pollarding should only be done on ash pollards that are in a regular cutting cycle and are not showing any symptoms of ash dieback. If possible, clear around old ash trees if they are in shaded conditions. Given that there are relatively few studies on the impact of ash dieback on veteran ash trees, the results of this study should also be relevant outside of Sweden and for the management of ash trees in non-woodland situations. Numéro de notice : A2021-824 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.46490/BF558 Date de publication en ligne : 02/06/2021 En ligne : https://doi.org/10.46490/BF558 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98942 [article]

The influence of fencing on seedling establishment during reforestation of oak stands: a comparison of artificial and natural regeneration techniques including costs / Magnus Löf in European Journal of Forest Research, vol 140 n° 4 (August 2021)  

Public [article]  inEuropean Journal of Forest Research > vol 140 n° 4 (August 2021) . - pp 807 - 817 Titre : The influence of fencing on seedling establishment during reforestation of oak stands: a comparison of artificial and natural regeneration techniques including costs Type de document : Article/Communication Auteurs : Magnus Löf, Auteur ; Julien Barrere, Auteur ; Mattias Engman, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : pp 807 - 817 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] croissance végétale [Termes IGN] Quercus pedunculata [Termes IGN] reboisement [Termes IGN] régénération (sylviculture) [Termes IGN] semis (sylviculture) [Termes IGN] Suède [Vedettes matières IGN] Sylviculture Résumé : (auteur) In temperate Europe, oak-dominated forests are widespread, supporting high biodiversity and providing important ecosystem services. Insufficient natural regeneration has, however, been a concern for over a century. The objective of this study was to gain insights into differences in regeneration success using artificial and natural regeneration techniques for reforestation of oak (Quercus robur L.) stands. We monitored seedlings following planting, direct seeding and natural regeneration over five years in a randomized block experiment in southern Sweden with fenced and non-fenced plots. Fencing had a strong positive effect on height growth, especially for planted seedlings that were taller than the other seedlings and more frequently browsed in non-fenced plots. In contrast, there was little effect of fencing on survival, establishment rate and recruitment rate of seedlings. Due to aboveground damage on seedlings from voles, protection of acorns did not improve establishment rate following direct seeding. Under current circumstances at the site with a sparse shelterwood of old oaks, we conclude that natural regeneration was the most cost-efficient regeneration method. It resulted in the most seedlings at the lowest cost. However, regeneration success was heavily influenced by interference from herbaceous vegetation. With a small additional investment in vegetation control, the results might have been improved for planting and direct seeding. Numéro de notice : A2021-716 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10342-021-01369-w Date de publication en ligne : 01/03/2021 En ligne : https://doi.org/10.1007/s10342-021-01369-w Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98627 [article]

Forest floor bryophyte and lichen diversity in Scots pine and Norway spruce production forests / Lisa Petersson in Forest ecology and management, vol 493 (1 August 2021)  

Public [article]  inForest ecology and management > vol 493 (1 August 2021) . - n° 119210 Titre : Forest floor bryophyte and lichen diversity in Scots pine and Norway spruce production forests Type de document : Article/Communication Auteurs : Lisa Petersson, Auteur ; Staffan Nilsson, Auteur ; Emma Hölmstrom, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 119210 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Bryophyte [Termes IGN] écosystème forestier [Termes IGN] lichen [Termes IGN] phytosociologie [Termes IGN] Picea abies [Termes IGN] Pinophyta [Termes IGN] Pinus sylvestris [Termes IGN] sol forestier [Termes IGN] Suède [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) Bryophytes and lichens are two main components of the forest floor vegetation. They provide essential ecosystem services, including nutrient recycling and water regulation. Here, we contrast the species richness, cover and community composition of forest floor bryophytes and lichens in Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) dominated production forests. The study sites were located in the hemiboreal zone of southern Sweden, and represented early-, mid- and late rotation stands. Our aim was to examine the potential consequences for forest floor biodiversity from the decreasing use of Scots pine production forests in this region. Whereas Scots pine and Norway spruce stands did not differ in bryophyte cover, we found a higher cover of lichens in Scots pine stands, and highest in the intermediate aged stands. Also the species richness of lichens was higher in the Scots pine stands, while bryophyte species richness was higher in the Norway spruce stands. Differences in canopy cover and associated light transmittance to the forest floor appears to be important drivers for distinctive different forest floor communities in the Scots pine and Norway spruce stands, as revealed by Non-Metric Multidimensional Scaling (NMDS). Mean Ellenberg indicator values for bryophytes and lichens showed that species associated with Scots pine stands were characterized by their tolerance of brighter conditions, higher insolation, and better adaptation to a continental climate. Norway spruce stands instead had a comparably larger proportion of species tolerating lower light, but also indicators of higher available nutrient levels, humidity, and pH. The outcome of the Ellenberg indicator species analysis, as well as the larger cover of lichens,and adaptations to drought found among some mosses, revealed that forest floor communities are shaped by different environmental factors in Scots pine and Norway spruce production stands. These environmental differences, and the quantified shifts in forest floor communities identified in this study, indicate the large shifts in understory bryophyte and lichen species composition and abundance that is likely to occur if Scots pine stands are converted to Norway spruce. Numéro de notice : A2021-459 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1016/j.foreco.2021.119210 Date de publication en ligne : 03/05/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119210 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97922 [article]

Towards generating network of bikeways from Mapillary data / Xuan Ding in Computers, Environment and Urban Systems, vol 88 (July 2021)  

Public [article]  inComputers, Environment and Urban Systems > vol 88 (July 2021) . - n° 101632 Titre : Towards generating network of bikeways from Mapillary data Type de document : Article/Communication Auteurs : Xuan Ding, Auteur ; Hongchao Fan, Auteur ; Jianya Gong, Auteur Année de publication : 2021 Article en page(s) : n° 101632 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géomatique web [Termes IGN] approche participative [Termes IGN] cycliste [Termes IGN] données localisées des bénévoles [Termes IGN] gestion des itinéraires [Termes IGN] Mapillary [Termes IGN] OpenStreetMap [Termes IGN] Suède [Termes IGN] système d'information géographique Résumé : (auteur) Nowadays, biking is flourishing in many Western cities. While many roads are used for both cars and bicycles, buffered bike lanes are marked for the safety of cyclists. In many cities, segregated paths are built up to have physical separation from motor vehicles. These types of biking ways are regarded as attributes in geographic information system (GIS) data. This information is required and important in the service of route planning, as cyclists may prefer certain types of bikeways. This paper presents a framework for generating networks of bikeways with attribute information from the data collected on the collaborative street view data platform Mapillary. The framework consists of two layers: The first layer focuses on constructing a bikeway road network using Global Positioning System (GPS) information of Mapillary images. Mapillary sequences are classified into walking, cycling, driving (ordinary road), and driving (motorway) trajectories based on the transportation mode with a trained XGBoost classifier. The bikeway road network is then extracted from cycling and driving (ordinary road) trajectories using a raster-based method. The second layer focuses on extracting attribute information from Mapillary images. Cycling-specific information (i.e., bicycle signs/markings) is extracted using a two-stage detection and classification model. A series of quantitative evaluations based on a case study demonstrated the ability and potential of the framework for extracting bikeway road information to enrich the existing OSM cycling road data. Numéro de notice : A2021-432 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1016/j.compenvurbsys.2021.101632 Date de publication en ligne : 17/04/2021 En ligne : https://doi.org/10.1016/j.compenvurbsys.2021.101632 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97798 [article]

Forest height estimation from a robust TomoSAR method in the case of small tomographic aperture with airborne dataset at L-band / Xing Peng in Remote sensing, vol 13 n° 11 (June-1 2021)  

Public [article]  inRemote sensing > vol 13 n° 11 (June-1 2021) . - n° 2147 Titre : Forest height estimation from a robust TomoSAR method in the case of small tomographic aperture with airborne dataset at L-band Type de document : Article/Communication Auteurs : Xing Peng, Auteur ; Xinwu Li, Auteur ; Yanan Du, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 2147 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] bande L [Termes IGN] données localisées 3D [Termes IGN] forêt boréale [Termes IGN] hauteur des arbres [Termes IGN] image 3D [Termes IGN] image radar moirée [Termes IGN] inventaire forestier (techniques et méthodes) [Termes IGN] itération [Termes IGN] matrice de covariance [Termes IGN] modèle numérique de surface de la canopée [Termes IGN] semis de points [Termes IGN] Suède [Termes IGN] tomographie radar Résumé : (auteur) Forest height is an essential input parameter for forest biomass estimation, ecological modeling, and the carbon cycle. Tomographic synthetic aperture radar (TomoSAR), as a three-dimensional imaging technique, has already been successfully used in forest areas to retrieve the forest height. The nonparametric iterative adaptive approach (IAA) has been recently introduced in TomoSAR, achieving a good compromise between high resolution and computing efficiency. However, the performance of the IAA algorithm is significantly degraded in the case of a small tomographic aperture. To overcome this shortcoming, this paper proposes the robust IAA (RIAA) algorithm for SAR tomography. The proposed approach follows the framework of the IAA algorithm, but also considers the noise term in the covariance matrix estimation. By doing so, the condition number of the covariance matrix can be prevented from being too large, improving the robustness of the forest height estimation with the IAA algorithm. A set of simulated experiments was carried out, and the results validated the superiority of the RIAA estimator in the case of a small tomographic aperture. Moreover, a number of fully polarimetric L-band airborne tomographic SAR images acquired from the ESA BioSAR 2008 campaign over the Krycklan Catchment, Northern Sweden, were collected for test purposes. The results showed that the RIAA algorithm performed better in reconstructing the vertical structure of the forest than the IAA algorithm in areas with a small tomographic aperture. Finally, the forest height was estimated by both the RIAA and IAA TomoSAR methods, and the estimation accuracy of the RIAA algorithm was 2.01 m, which is more accurate than the IAA algorithm with 3.25 m. Numéro de notice : A2021-441 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.3390/rs13112147 Date de publication en ligne : 29/05/2021 En ligne : https://doi.org/10.3390/rs13112147 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97828 [article]

Updating of forest stand data by using recent digital photogrammetry in combination with older airborne laser scanning data / Niels Lindgren in Scandinavian journal of forest research, vol 36 n° 5 ([01/06/2021])  

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Canopy openness and exclusion of wild ungulates act synergistically to improve oak natural regeneration / Julien Barrere in Forest ecology and management, Vol 487 ([01/05/2021])  

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Evaluating P-Band TomoSAR for biomass retrieval in boreal forest / Erik Blomberg in IEEE Transactions on geoscience and remote sensing, vol 59 n° 5 (May 2021)  

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Assessing forest phenology: A multi-scale comparison of near-surface (UAV, spectral reflectance sensor, PhenoCam) and satellite (MODIS, Sentinel-2) remote sensing / Shangharsha Thapa in Remote sensing, vol 13 n° 8 (April-2 2021)  

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Forest fragmentation assessment using field-based sampling data from forest inventories / Habib Ramezani in Scandinavian journal of forest research, vol 36 n° 4 ([01/04/2021])  

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The impact of drought stress on the height growth of young norway spruce full-sib and half-sib clonal trials in Sweden and Finland / Haleh Hayatgheibi in Forests, vol 12 n° 4 (April 2021)  

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Early detection of forest stress from European spruce bark beetle attack, and a new vegetation index: Normalized distance red & SWIR (NDRS) / Langning Huo in Remote sensing of environment, Vol 255 (March 2021)  

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Keeping mixtures of Norway spruce and birch in production forests: insights from survey data / Emma Hölmstrom in Scandinavian journal of forest research, vol 36 n° 2-3 ([01/03/2021])  

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Effects of thinning practice, high pruning and slash management on crop tree and stand growth in young even-aged stands of planted silver birch (Betula pendula Roth) / Jens Peter Skovsgaard in Forests, vol 12 n° 2 (February 2021)  

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Range-wide demographic patterns in European forests along climatic marginality gradients : An approach using national forest inventories / Alexandre Changenet (2021)  

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