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What factors shape spatial distribution of biomass in riparian forests? Insights from a LiDAR survey over a large area / Leo Huylenbroeck in Forests, vol 12 n° 3 (March 2021)  

Public [article]  inForests > vol 12 n° 3 (March 2021) . - n° 371 Titre : What factors shape spatial distribution of biomass in riparian forests? Insights from a LiDAR survey over a large area Type de document : Article/Communication Auteurs : Leo Huylenbroeck, Auteur ; Nicolas Latte, Auteur ; Philippe Lejeune, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 371 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] biodiversité [Termes IGN] biomasse forestière [Termes IGN] distribution spatiale [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] forêt ripicole [Termes IGN] modèle numérique de surface de la canopée [Termes IGN] semis de points [Termes IGN] Wallonie (Belgique) Résumé : (auteur) Riparian ecosystems are home to a remarkable biodiversity, but have been degraded in many regions of the world. Vegetation biomass is central to several key functions of riparian systems. It is influenced by multiple factors, such as soil waterlogging, sediment input, flood, and human disturbance. However, knowledge is lacking on how these factors interact to shape spatial distribution of biomass in riparian forests. In this study, LiDAR data were used in an individual tree approach to map the aboveground biomass in riparian forests along 200 km of rivers in the Meuse catchment, in southern Belgium (Western Europe). Two approaches were tested, relying either on a LiDAR Canopy Height Model alone or in conjunction with a LiDAR point cloud. Cross-validated biomass relative mean square error for 0.3 ha plots were, respectively, 27% and 22% for the two approaches. Spatial distribution of biomass patterns were driven by parcel history (and particularly vegetation age), followed by land use and topographical or geomorphological variables. Overall, anthropogenic factors were dominant over natural factors. However, vegetation patches located in the lower parts of the riparian zone exhibited a lower biomass than those in higher locations at the same age, presumably due to a combination of a more intense disturbance regime and more limiting growing conditions in the lower parts of the riparian zone. Similar approaches to ours could be deployed in other regions in order to better understand how biomass distribution patterns vary according to the climatic, geological or cultural contexts. Numéro de notice : A2021-317 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.3390/f12030371 Date de publication en ligne : 20/03/2021 En ligne : https://doi.org/10.3390/f12030371 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97540 [article]

Is the seasonal variation in frost resistance and plant performance in four oak species affected by changing temperatures? / Maggie Preißer in Forests, vol 12 n° 3 (March 2021)  

Public [article]  inForests > vol 12 n° 3 (March 2021) . - n° 369 Titre : Is the seasonal variation in frost resistance and plant performance in four oak species affected by changing temperatures? Type de document : Article/Communication Auteurs : Maggie Preißer, Auteur ; Solveig Franziska Bucher, Auteur Année de publication : 2021 Article en page(s) : n° 369 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] fluorescence [Termes IGN] gelée [Termes IGN] Leaf Area Index [Termes IGN] photosynthèse [Termes IGN] Quercus (genre) [Termes IGN] Quercus ilex [Termes IGN] Quercus rubra [Termes IGN] teneur en chlorophylle des feuilles [Termes IGN] variation saisonnière [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) Research Highlights: We found seasonal variation in frost resistance (FR) and plant performance which were affected by growth temperature. This helps to better understand ecophysiological processes in the light of climate change. Background and Objectives: FR and photosynthesis are important plant characteristics that vary with the season. The aim of this study was to find out whether there is a seasonal variation in FR, photosynthetic CO2 assimilation rates and leaf functional traits associated with performance such as specific leaf area (SLA), leaf dry matter content (LDMC), chlorophyll content, stomatal characteristics and leaf thickness in two evergreen and two deciduous species, and whether this is influenced by different temperature treatments. Additionally, the trade-off between FR and photosynthetic performance, and the influence of leaf functional traits was analyzed. By understanding these processes better, predicting species behavior concerning plant performance and its changes under varying climate regimes can be improved. Materials and Methods: 40 individuals of four oak species were measured weekly over the course of ten months with one half of the trees exposed to frost in winter and the other half protected in the green house. Two of these species were evergreen (Quercus ilex L., Quercus rhysophylla Weath.), and two were deciduous (Quercus palustris L., Quercus rubra L.). We measured FR, the maximum assimilation rate at light saturation under ambient CO2 concentrations (Amax), chlorophyll fluorescence and the leaf functional traits SLA, LDMC, stomatal pore area index (SPI), chlorophyll content (Chl) and leaf thickness. Results: All parameters showed a significant species-specific seasonal variation. There was a difference in all traits investigated between evergreen and deciduous species and between the two temperature treatments. Individuals that were protected from frost in winter showed higher photosynthesis values as well as SLA and Chl, whereas individuals exposed to frost had overall higher FR, LDMC, SPI and leaf thickness. A trade-off between FR and SLA, rather than FR and photosynthetic performance was found. Numéro de notice : A2021-323 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12030369 Date de publication en ligne : 20/03/2021 En ligne : https://doi.org/10.3390/f12030369 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97542 [article]