Centre de documentation
scientifique

Desiccation does not increase frost resistance of pedunculate oak (Quercus robur L.) seeds / Paweł Chmielarz in Annals of Forest Science, vol 79 n° 1 (2022)  

Public [article]  inAnnals of Forest Science > vol 79 n° 1 (2022) . - n° 3 Titre : Desiccation does not increase frost resistance of pedunculate oak (Quercus robur L.) seeds Type de document : Article/Communication Auteurs : Paweł Chmielarz, Auteur ; Jan Suszka, Auteur ; Mikołaj Krzysztof Wawrzyniak, Auteur Année de publication : 2022 Article en page(s) : n° 3 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] croissance des arbres [Termes IGN] gelée [Termes IGN] germination [Termes IGN] Quercus pedunculata [Termes IGN] semence [Termes IGN] stockage [Termes IGN] teneur en eau de la végétation [Vedettes matières IGN] Botanique Résumé : (Auteur) Key message: Decreasing acorns moisture content does not significantly increase the frost resistance of pedunculate oak seeds. Slight reduction in acorn moisture content below the relatively high, optimal level decreased seed survival at temperatures below − 5 °C. The limiting temperature for pedunculate oak’s acorns below which they lose their ability to germinate is about − 10 °C. Context: Seed moisture content plays an important role in successful seed storage of many species, as desiccation increases frost resistance; however, oak seeds tolerate desiccation only to a very small extent. Aims: In our study, we examined the impact of decreasing moisture content in acorns of pedunculate oak (Quercus robur L.) on their frost resistance (below − 3 °C) and the growth of seedling derived from frozen seeds. Methods: Germination and seedling emergence of individual seeds, as well as the dry mass of their 3-month-old seedlings, were measured after acorn desiccation (24–40%, fresh weight basis) and desiccation followed by freezing at temperatures from − 3 °C to − 18 °C for 2 weeks. Results: Decreasing acorns moisture content did not significantly increase the frost resistance of pedunculate oak seeds. The lowest temperature at which at least half seeds remain viable was − 10 °C. Slight acorns desiccation had only a small positive effect on seeds frozen below − 11 °C (down to − 13 °C), but in this case (acorn moisture content of 33%), low germinability after freezing made storage uneconomic because of the high mortality of seeds. Germinated seeds after desiccation and freezing showed no significant difference in later growth. Conclusion: Fresh pedunculate oak seed can survive freezing temperature down to − 10 °C and produce good quality seedlings. Temperatures around − 11° to − 13 °C are near lethal to acorns and significantly reduce their viability. Overall, desiccation does not increase their frost resistance; therefore, in practice, it is important to keep acorns during a cold storage in the highly hydrated state. Numéro de notice : A2022-069 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1186/s13595-022-01121-3 Date de publication en ligne : 24/02/2022 En ligne : https://doi.org/10.1186/s13595-022-01121-3 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=100014 [article]

Improved progressive TIN densification filtering algorithm for airborne LiDAR data in forested areas / Xiaoqian Zhao in ISPRS Journal of photogrammetry and remote sensing, vol 117 (July 2016)  

Public [article]  inISPRS Journal of photogrammetry and remote sensing > vol 117 (July 2016) . - pp 79 – 91 Titre : Improved progressive TIN densification filtering algorithm for airborne LiDAR data in forested areas Type de document : Article/Communication Auteurs : Xiaoqian Zhao, Auteur ; Qinghua Guo, Auteur ; Yanjun Su, Auteur ; Baolin Xue, Auteur Année de publication : 2016 Article en page(s) : pp 79 – 91 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] analyse comparative [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] filtrage numérique d'image [Termes IGN] forêt [Termes IGN] semence [Termes IGN] test de performance [Termes IGN] Triangulated Irregular Network Résumé : (auteur) Filtering of light detection and ranging (LiDAR) data into the ground and non-ground points is a fundamental step in processing raw airborne LiDAR data. This paper proposes an improved progressive triangulated irregular network (TIN) densification (IPTD) filtering algorithm that can cope with a variety of forested landscapes, particularly both topographically and environmentally complex regions. The IPTD filtering algorithm consists of three steps: (1) acquiring potential ground seed points using the morphological method; (2) obtaining accurate ground seed points; and (3) building a TIN-based model and iteratively densifying TIN. The IPTD filtering algorithm was tested in 15 forested sites with various terrains (i.e., elevation and slope) and vegetation conditions (i.e., canopy cover and tree height), and was compared with seven other commonly used filtering algorithms (including morphology-based, slope-based, and interpolation-based filtering algorithms). Results show that the IPTD achieves the highest filtering accuracy for nine of the 15 sites. In general, it outperforms the other filtering algorithms, yielding the lowest average total error of 3.15% and the highest average kappa coefficient of 89.53%. Numéro de notice : A2016-582 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2016.03.016 En ligne : https://doi.org/10.1016/j.isprsjprs.2016.03.016 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81723 [article]