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Multi-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density / Grégoire Vincent in Remote sensing of environment, vol 286 (March 2023)  

Public [article]  inRemote sensing of environment > vol 286 (March 2023) . - n° 113442 Titre : Multi-sensor airborne lidar requires intercalibration for consistent estimation of light attenuation and plant area density Type de document : Article/Communication Auteurs : Grégoire Vincent, Auteur ; Philippe Verley, Auteur ; Benjamin Brede, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 113442 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s) [Termes IGN] canopée [Termes IGN] densité de la végétation [Termes IGN] données lidar [Termes IGN] forêt tropicale [Termes IGN] Guyane (département français) [Termes IGN] image captée par drone [Termes IGN] plan de vol [Termes IGN] rayonnement lumineux [Termes IGN] réflectance végétale [Termes IGN] semis de points [Termes IGN] zone d'intérêt Résumé : (auteur) Leaf area is a key structural characteristic of forest canopies because of the role of leaves in controlling many biological and physical processes occurring at the biosphere-atmosphere transition. High pulse density Airborne Laser Scanning (ALS) holds promise to provide spatially resolved and accurate estimates of plant area density (PAD) in forested landscapes, a key step in understanding forest functioning: phenology, carbon uptake, transpiration, radiative balance etc. Inconsistencies between different ALS sensors is a barrier to generating globally harmonised PAD estimates. The basic assumption on which PAD estimation is based is that light attenuation is proportional to vegetation area density. This study shows that the recorded extinction strongly depends on target detectability which is influenced by laser characteristics (power, sensitivity, wavelength). Three different airborne laser scanners were flown over a wet tropical forest at the Paracou research station in French Guiana. Different sensors, flight heights and transmitted power levels were compared. Light attenuation was retrieved with an open source ray-tracing code (http://amapvox.org). Direct comparison revealed marked differences (up-to 25% difference in profile-averaged light attenuation rate and 50% difference at particular heights) that could only be explained by differences in scanner characteristics. We show how bias which may occur under various acquisition conditions can generally be mitigated by a sensor intercalibration. Alignment of light weight lidar attenuation profiles to ALS reference attenuation profiles is not always satisfactory and we discuss what are the likely sources of discrepancies. Neglecting the dependency of apparent light attenuation on scanner properties may lead to biases in estimated vegetation density commensurate to those affecting light attenuation estimates. Applying intercalibration procedures supports estimation of plant area density independent of acquisition characteristics. Numéro de notice : A2023-169 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1016/j.rse.2022.113442 Date de publication en ligne : 06/01/2023 En ligne : https://doi.org/10.1016/j.rse.2022.113442 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102928 [article]

Resilience of Pyrenean forests after recurrent historical deforestations / Valenti Rull in Forests, vol 14 n° 3 (March 2023)  

Public [article]  inForests > vol 14 n° 3 (March 2023) . - n° 567 Titre : Resilience of Pyrenean forests after recurrent historical deforestations Type de document : Article/Communication Auteurs : Valenti Rull, Auteur ; Teresa Vegas-Vilarrúbia, Auteur Année de publication : 2023 Article en page(s) : n° 567 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] déboisement [Termes IGN] forêt méditerranéenne [Termes IGN] histoire [Termes IGN] historique des données [Termes IGN] régénération (sylviculture) [Termes IGN] résilience écologique [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) The long-term resilience of Pyrenean forests in the face of historical anthropogenic clearing remains largely unknown. In this paper, a high-resolution (decadal to subdecadal) paleoecological study of mid-elevation Pyrenean forests is presented that encompasses the last two millennia. This long-term record was obtained after sediment coring, dating (varve counting) and pollen analysis of annually laminated (varved) sediments from Lake Montcortès, situated at 1027 m elevation, in the transition between the Mediterranean and montane forest belts. This allowed the definition of three major deforestation/recovery cycles during the Roman, Medieval and Modern times. Each DR cycle is characterized considering three different levels: overall forest trends, forest type and individual taxa. Overall, the studied forests exhibited high resilience, as they recovered almost completely after each deforestation event (bulk resilience). The critical point of no return (tipping point) beyond which forests would have irreversibly disappeared from the region was never reached, even after deforestation magnitudes above 60%. The different forest types identified (conifer, sclerophyll and deciduous) persisted over time, showing similar heterogeneous patterns with minor spatial reorganizations (mosaic resilience). Individually, the main forest taxa underwent minor variations in their relative abundances, always within the same attraction domains (community resilience). The high levels of resilience documented in these Pyrenean forests are attributed to the action of metapopulation and metacommunity processes and mechanisms in a highly dynamic patchy environment. Conservation actions should be focused on the maintenance of these spatial patterns and the associated ecological dynamics. Numéro de notice : A2023-166 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f14030567 Date de publication en ligne : 13/03/2023 En ligne : https://doi.org/10.3390/f14030567 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102903 [article]

Tree species growth response to climate in mixtures of Quercus robur/Quercus petraea and Pinus sylvestris across Europe - a dynamic, sensitive equilibrium / Sonja Vospernik in Forest ecology and management, vol 530 (February-15 2023)  

Public [article]  inForest ecology and management > vol 530 (February-15 2023) . - n° 120753 Titre : Tree species growth response to climate in mixtures of Quercus robur/Quercus petraea and Pinus sylvestris across Europe - a dynamic, sensitive equilibrium Type de document : Article/Communication Auteurs : Sonja Vospernik, Auteur ; Michael Heym, Auteur ; Hans Pretzsch, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 120753 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] climat [Termes IGN] croissance des arbres [Termes IGN] diamètre à hauteur de poitrine [Termes IGN] Europe (géographie politique) [Termes IGN] évapotranspiration [Termes IGN] forêt inéquienne [Termes IGN] modèle dynamique [Termes IGN] peuplement mélangé [Termes IGN] Pinus sylvestris [Termes IGN] Quercus pedunculata [Termes IGN] Quercus sessiliflora [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) Quercus robur/Quercus petraea and Pinus sylvestris are widely distributed and economically important tree species in Europe co-occurring on mesotrophic, xeric and mesic sites. Increasing dry conditions may reduce their growth, but growth reductions may be modified by mixture, competition and site conditions. The annual diameter growth in monospecific and mixed stands along an ecological gradient with mean annual temperatures ranging from 5.5 °C to 11.5 °C was investigated in this study. On 36 triplets (108 plots), trees were cored and the year-ring series were cross-dated, resulting in year-ring series of 785 and 804 trees for Q. spp. and P. sylvestris, respectively. A generalized additive model with a logarithmic link was fit to the data with random effects for the intercept at the triplet, year and tree level and a random slope for the covariate age for each tree; the Tweedie-distribution was used. The final model explained 87 % of the total variation in diameter increment for both tree species. Significant covariates were age, climate variables (long-term mean, monthly), local competition variables, relative dbh, mixture, stand structure and interactions thereof. Tree growth declined with age and local density and increased with social position. It was positively influenced by mixture and structural diversity (Gini coefficient); mixture effects were significant for P. sylvestris only. The influence of potential evapotranspiration (PET) in spring and autumn on tree growth was positive and non-linear, whereas tree growth sharply decreased with increasing PET in June, which proved to be the most influential month on tree growth along the whole ecological gradient. Interactions of PET with tree social position (relative dbh) were significant in July and September for Q. spp. and in April for P. sylvestris. Interactions of climate with density or mixture were not significant. Climatic effects found agree well with previous results from intra-annual growth studies and indicate that the model captures the causal factors for tree growth well. Furthermore, the interaction between climate and relative dbh might indicate a longer growth duration for trees of higher social classes. Analysis of random effects across time and space showed highly dynamic patterns, with competitive advantages changing annually between species and spatial patterns showing no large-scale trends but pointing to the prevalence of local site factors. In mixed-species stands, the tree species have the same competitivity in the long-term, which is modified by climate each year. Climate warming will shift the competitive advantages, but the direction will be highly site-specific. Numéro de notice : A2023-108 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2022.120753 Date de publication en ligne : 29/12/2022 En ligne : https://doi.org/10.1016/j.foreco.2022.120753 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102443 [article]

Forest structure and fine root biomass influence soil CO2 efflux in temperate forests under drought / Antonios Apostolakis in Forests, vol 14 n° 2 (February 2023)  

Public [article]  inForests > vol 14 n° 2 (February 2023) . - n° 411 Titre : Forest structure and fine root biomass influence soil CO2 efflux in temperate forests under drought Type de document : Article/Communication Auteurs : Antonios Apostolakis, Auteur ; Ingo Schöning, Auteur ; Beate Michalzik, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 411 Langues : Anglais (eng) Descripteur : [Termes IGN] Allemagne [Termes IGN] biomasse forestière [Termes IGN] forêt tempérée [Termes IGN] puits de carbone [Termes IGN] qualité du sol [Termes IGN] sécheresse [Termes IGN] structure d'un peuplement forestier [Termes IGN] température au sol [Termes IGN] teneur en carbone [Termes IGN] teneur en eau de la végétation [Vedettes matières IGN] Végétation et changement climatique Numéro de notice : A2023-165 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f14020411 Date de publication en ligne : 17/12/2023 En ligne : https://doi.org/10.3390/f14020411 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102871 [article]

Testing the application of process-based forest growth model PREBAS to uneven-aged forests in Finland / Man Hu in Forest ecology and management, vol 529 (February-1 2023)  

Public [article]  inForest ecology and management > vol 529 (February-1 2023) . - n° 120702 Titre : Testing the application of process-based forest growth model PREBAS to uneven-aged forests in Finland Type de document : Article/Communication Auteurs : Man Hu, Auteur ; Francesco Minunno, Auteur ; Mikko Peltoniemi, Auteur ; et al., Auteur Année de publication : 2023 Article en page(s) : n° 120702 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse forestière [Termes IGN] croissance des arbres [Termes IGN] diamètre à hauteur de poitrine [Termes IGN] Finlande [Termes IGN] forêt boréale [Termes IGN] forêt inéquienne [Termes IGN] hauteur des arbres [Termes IGN] modèle de croissance végétale [Termes IGN] modèle de simulation [Termes IGN] modélisation de la forêt [Termes IGN] mortalité [Termes IGN] peuplement mélangé [Termes IGN] photosynthèse [Termes IGN] Picea abies [Termes IGN] structure d'un peuplement forestier [Vedettes matières IGN] Foresterie Résumé : (auteur) The challenges of applying process-based models to uneven-aged forests are the difficulties in simulating the interactions between trees and resource allocation between size classes. In this study, we focused on a process-based forest growth model PREBAS which is a mean tree model with Reineke self-thinning mortality and was originally developed for even-aged forests. The primary aim was to test the application of PREBAS model to uneven-aged forests by introducing different diameter at breast height (DBH) size classes to better represent the forest structure. Additionally, we introduced a new mortality model to PREBAS which is developed for uneven-aged stands and compared with the current PREBAS version in which a modification Reineke rule is used. The tests were conducted in 26 old Norway spruce dominated stands in southern and central Finland with three consecutive measurements (on average a 25-year study period). To evaluate the model performance, we compared the estimations of stand averaged diameter at breast height (D), stand averaged tree height (H), stand averaged crown base height (), stand basal area (B) and density (N) with measurements. Moreover, biomass estimations of each tree component (foliage, branch and stem) were compared to estimations from empirical models. Results showed that introducing size distributions can represent better stand structure and improve the model predictions compared with data. Moreover, the new mortality model showed promise with qualitatively more realistic results especially among the largest tree size classes. However, model bias still existed in the simulation although the predictions were improved. It revealed that further calibration of the PREBAS model with size classes should be done to better extend the model applicability to uneven-aged forests. Numéro de notice : A2023-022 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2022.120702 Date de publication en ligne : 05/12/2022 En ligne : https://doi.org/10.1016/j.foreco.2022.120702 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102228 [article]

Tree growth, wood anatomy and carbon and oxygen isotopes responses to drought in Mediterranean riparian forests / J. Julio Camarero in Forest ecology and management, vol 529 (February-1 2023)  

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GIS-based planning of buffer zones for protection of boreal streams and their riparian forests / Heikki Mykrä in Forest ecology and management, vol 528 (January-15 2023)  

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Estimating mangrove above-ground biomass at Maowei Sea, Beibu Gulf of China using machine learning algorithm with Sentinel-1 and Sentinel-2 data / Zhuomei Huang in Geocarto international, vol 38 n° inconnu ([01/01/2023])  

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Improving generalized models of forest structure in complex forest types using area- and voxel-based approaches from lidar / Andrew W. Whelan in Remote sensing of environment, vol 284 (January 2023)  

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Improving methods to predict aboveground biomass of Pinus sylvestris in urban forest using UFB model, LiDAR and digital hemispherical photography / Ihor Kozak in Urban Forestry & Urban Greening, vol 79 (January 2023)  

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Mitigating the risk of wind damage at the forest landscape level by using stand neighbourhood and terrain elevation information in forest planning / Roope Ruotsalainen in Forestry, an international journal of forest research, vol 96 n° 1 (January 2023)  

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Prescribed fire after thinning increased resistance of sub-Mediterranean pine forests to drought events and wildfires / Lena Vilà-Vilardell in Forest ecology and management, vol 527 (January-1 2023)  

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A simple approach to enhance the TROPOMI solar-induced chlorophyll fluorescence product by combining with canopy reflected radiation at near-infrared band / Xinjie Liu in Remote sensing of environment, vol 284 (January 2023)  

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Tree diversity and identity modulate the growth response of thermophilous deciduous forests to climate warming / Giovanni Jacopetti in Oikos, vol 2023 n° inconnu (2023)  

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Using Google Earth Engine to classify unique forest and agroforest classes using a mix of Sentinel 2a spectral data and topographical features: a Sri Lanka case study / W.D.K.V. Nandasena in Geocarto international, vol 38 n° inconnu ([01/01/2023])  

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