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Height-diameter allometry for tree species in Tanzania mainland / Wilson Ancelm Mugasha in International journal of forestry research, vol 2019 ([01/03/2019])
[article]
Titre : Height-diameter allometry for tree species in Tanzania mainland Type de document : Article/Communication Auteurs : Wilson Ancelm Mugasha, Auteur ; E.W. Mauya, Auteur ; et al., Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] allométrie
[Termes IGN] diamètre des arbres
[Termes IGN] Eucalyptus (genre)
[Termes IGN] hauteur des arbres
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] modèle mathématique
[Termes IGN] Pinus (genre)
[Termes IGN] Tanzanie
[Vedettes matières IGN] Inventaire forestierRésumé : (auteur) Total tree height (H) and diameter at beast height (D) are important independent variables in predicting volume, biomass, and other forest stand attributes. However, unlike D measurement, which is easy to measure with high accuracy, H measurement is laborious. This study, therefore, developed H-D relationships for ten different forest types in Tanzania Mainland. Extents in which climate and forest stand variables explain the variation in H-D allometry were also assessed. A total of 31782 sample trees covering miombo woodlands, humid montane, lowland forests, bushlands, grasslands, mangroves, cultivated land, wetlands forests, and pines and Eucalyptus species plantations were used for model development. The H estimating model without climate and forest stand variables referred herein as “base model” was first developed followed by “generalized model” which included climate and stand variables. All the data were fitted using nonlinear mixed effect modelling approach. Results indicated that generalized H estimating models had better fit than the base models. We therefore confirm a significant contribution of climate and forest structure variables in improving H-D allometry. Among the forest structure variables, basal area (BA) was far more important explanatory variable than other variables. In addition, it was found that the mean tree H tends to increase with the increase of mean precipitation (PRA). We therefore conclude that forest specific generalized H model is to be applied when predicting H. When forest type information is not available, generalized regional model may be applied. Base model may be applied when forest stand or climate information are missing. Numéro de notice : A2019-371 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1155/2019/4832849 Date de publication en ligne : 21/04/2019 En ligne : https://doi.org/10.1155/2019/4832849 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93397
in International journal of forestry research > vol 2019 [01/03/2019][article]Integrating dendrochronology and geomatics to monitor natural hazards and landscape changes / Marco Ciolli in Applied geomatics, vol 11 n° 1 (March 2019)
[article]
Titre : Integrating dendrochronology and geomatics to monitor natural hazards and landscape changes Type de document : Article/Communication Auteurs : Marco Ciolli, Auteur ; Marco Bezzi, Auteur ; Giovanni Comunello, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp 39 - 52 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale
[Termes IGN] Albanie
[Termes IGN] analyse diachronique
[Termes IGN] avalanche
[Termes IGN] couvert forestier
[Termes IGN] dendrochronologie
[Termes IGN] forêt
[Termes IGN] GRASS
[Termes IGN] IDRISI
[Termes IGN] lit majeur
[Termes IGN] Pinus sylvestris
[Termes IGN] positionnement par GPS
[Termes IGN] QGIS
[Termes IGN] reboisement
[Termes IGN] risque naturel
[Termes IGN] TrenteRésumé : (Auteur) The monitoring of natural hazards is of extreme importance in the areas of Italy where there are high hydrogeological and avalanche risks. Despite the fact that records of past events are sometimes available, some of their data are often incomplete and show that the monitoring and mapping of these phenomena are never enough to avoid damage. We present the results of different studies where an integrated approach has been used by combining geomatics and dendrochronology techniques. In particular, we refer to case studies concerning avalanches, debris flows, natural reforestation in Italy and riverbed path changes in Albania. The position of all the plants sampled for dendrochronology was taken by GPS (Global Positioning System). The cartographic information used in these studies was provided by official sources from public organisations or processed by extracting them from aerial photographs or satellite imagery. With the Geographic Information System, it was possible to spatialise and analyse the information from dendrochronological sampling through the creation of multi-temporal morphological and potential risk maps showing the effects of the phenomena on forest cover. The GIS software used in these studies are GRASS, QGIS and IDRISI. The results showed that avalanches, debris flow, riverbed and landscape change can be studied effectively by integrating geomatics and dendrochronological techniques. This integration enabled spatial and temporal modelling, including the reconstruction of paths and volumes of past phenomena. The analysis of growth disturbances over time also enabled the reconstruction of the frequency of avalanches and debris flow activity over the last 50 years and, in some areas, over the last century. A detailed analysis of one of the avalanche tracks provided interesting results regarding the reconstruction of avalanche dynamics. Analysis of scars on buried stems of Pinus sylvestris also provided interesting results in terms of debris volume estimation. The dendrochronological reconstruction of the patterns of natural reforestation led to the determination of forest expansion rates that were used for modelling future scenarios and refining the changes of river morphology. Dendrochronology strongly improved the results of GIS satellite imagery analysis. These reconstructions are particularly important for the areas that are more exposed to the direct risk of avalanches, debris flows and floods in order to prevent the consequences of such phenomena in a changing climate. Numéro de notice : A2019-160 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s12518-018-0236-0 Date de publication en ligne : 21/08/2018 En ligne : https://doi.org/10.1007/s12518-018-0236-0 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92521
in Applied geomatics > vol 11 n° 1 (March 2019) . - pp 39 - 52[article]Non-stationary response of tree growth to climate trends along the Arctic margin / Annika Hofgaard in Ecosystems, vol 22 n° 2 (March 2019)
[article]
Titre : Non-stationary response of tree growth to climate trends along the Arctic margin Type de document : Article/Communication Auteurs : Annika Hofgaard, Auteur ; Clémentine Ols , Auteur ; Igor Drobyshev, Auteur ; Andreas Kirchhefer, Auteur ; Staffen Sandberg, Auteur ; Lars Söderström, Auteur Année de publication : 2019 Projets : PPS Arctic / Hofgaard, Annika Article en page(s) : pp 434 - 451 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Arctique
[Termes IGN] croissance des arbres
[Termes IGN] écosystème forestier
[Termes IGN] Pinus sylvestris
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Climate change modulates cold-marginal forest ecosystems through changing growth constraints. Understanding spatiotemporal variations in climate–growth relationships is essential to project forest ecosystem dynamics, and climate–environmental feedbacks. We explored variations in growth and climate–growth relationships, along the Arctic margin in north-western Europe, using Scots pine radial growth chronologies, climate data and links between the geographical origin of dominant air masses and growth-controlling variables. Analyses covered nineteenth century to early twenty-first century, with emphasis on two separate warming periods (early twentieth century, and late twentieth to early twenty-first century) and the intervening cooling period. The analyses revealed spatiotemporally unstable growth responses to climate along the Arctic margin. Spatial growth patterns were most similar during the cooling period. However, climate trends (warming, cooling) were weak drivers of growth-limiting climate variables. Instead, a transition in growth-limiting variables occurred throughout the analysed period. A wide range of growing season and non-growing season climate variables limited growth during the early twentieth century. Thereafter the number of growth-limiting variables progressively decreased. This change was accompanied by a contraction in the spatial correspondence between growth and climate, and by a shift in the geographical origin of dominant air masses. This was particularly emphasized close to the Atlantic during recent warming period. The weak association between growth-limiting variables and climate trends question projections of future ecosystem dynamics based on climate variables identified during specific periods (for example, recent warming period). Such projections may be misleading as the diversity of climate conditions constraining cold-marginal forests will be underestimated. Numéro de notice : A2019-620 Affiliation des auteurs : LIF+Ext (2012-2019) Autre URL associée : vers HAL Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10021-018-0279-4 Date de publication en ligne : 31/07/2018 En ligne : https://doi.org/10.1007/s10021-018-0279-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95349
in Ecosystems > vol 22 n° 2 (March 2019) . - pp 434 - 451[article]Single-image photogrammetry for deriving tree architectural traits in mature forest stands: a comparison with terrestrial laser scanning / Kamil Kędra in Annals of Forest Science, vol 76 n° 1 (March 2019)
[article]
Titre : Single-image photogrammetry for deriving tree architectural traits in mature forest stands: a comparison with terrestrial laser scanning Type de document : Article/Communication Auteurs : Kamil Kędra, Auteur ; Ignacio Barbeito, Auteur ; Mathieu Dassot , Auteur ; Patrick Vallet, Auteur ; Anna Gazda, Auteur Année de publication : 2019 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications photogrammétriques
[Termes IGN] allométrie
[Termes IGN] analyse comparative
[Termes IGN] coefficient de corrélation
[Termes IGN] détection d'arbres
[Termes IGN] diamètre à hauteur de poitrine
[Termes IGN] diamètre des arbres
[Termes IGN] forêt tempérée
[Termes IGN] hauteur des arbres
[Termes IGN] houppier
[Termes IGN] image isolée
[Termes IGN] Orléans, forêt domaniale d' (Loiret)
[Termes IGN] peuplement forestier
[Termes IGN] peuplement mélangé
[Termes IGN] Pinus sylvestris
[Termes IGN] Quercus (genre)
[Termes IGN] télémétrie laser terrestreRésumé : (auteur) Key message : We compared two methods for detailed individual tree measurements: single image photogrammetry (SIP), a simplified, low-cost method, and the state-of-the-art terrestrial laser scanning (TLS). Our results provide evidence that SIP can be successfully applied to obtain accurate tree architectural traits in mature forests.
Context : Tree crown variables are necessary in forest modelling; however, they are time consuming to measure directly, and they are measured in many different ways. We compare two methods to obtain crown variables: laser-based and image-based. TLS is an advanced technology for three-dimensional data acquisition; SIP is a simplified, low-cost method.
Aims : To elucidate differences between the methods, and validate SIP accuracy and usefulness for forest research, we investigated if (1) SIP and TLS measurements are in agreement in terms of the most widely used tree characteristics; (2) differences between the SIP traits and their TLS counterparts are constant throughout tree density and species composition; (3) tree architectural traits obtained with SIP explain differences in laser-based crown projection area (CPA), under different forest densities and stand compositions; and (4) CPA modelled with SIP variables is more accurate than CPA obtained with stem diameter-based allometric models. We also examined the correspondence between local tree densities extracted from images and from field measurements.
Methods : We compared TLS and SIP in a temperate pure sessile oak and mixed with Scots pine stands, in the Orléans Forest, France. Standard major axis regression was used to establish relations between laser-based and image-based tree height and diameter at breast height. Four SIP-derived traits were compared between the levels of stand density and species composition with a t test, in terms of deviations and biases to their TLS counterparts. We created a set of linear and linear mixed models (LMMs) of CPATLS, with SIP variables. Both laser-based and image-based stem diameters were used to estimate CPA with the published allometric equations; the results were then compared with the best predictive LMM, in terms of similarity with CPATLS measurement. Local tree density extracted from images was compared with field measurements in terms of basic statistics and correlation.
Results : Tree height and diameter at breast height were reliably represented by SIP (Pearson correlation coefficients r = 0.92 and 0.97, respectively). SIP measurements were affected by the stand composition factor; tree height attained higher mean absolute deviation (1.09 m) in mixed stands, compared to TLS, than in pure stands (0.66 m); crown width was more negatively biased in mixed stands (− 0.79 m), than in pure stands (− 0.05 m); and diameter at breast height and crown asymmetry were found unaffected. Crown width and mean branch angle were key SIP explanatory variables to predict CPATLS. The model was approximately 2-fold more accurate than the CPA allometric estimations with both laser-based and image-based stem diameters. SIP-derived local tree density was similar to the field-measured density in terms of mean and standard deviation (9.6 (3.5) and 9.4 (3.6) trees per plot, respectively); the correlation between both density measures was significantly positive (r = 0.76).
Conclusion : SIP-derived variables, such as crown width, mean branch angle, branch thickness, and crown asymmetry, were useful to explain tree architectural differences under different densities and stand compositions and may be implemented in many forest research applications. SIP may also provide a coarse measure of local competition, in terms of number of neighbouring trees. Our study provides the first test in mature forest stands, for SIP compared with TLS.Numéro de notice : A2019-044 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-018-0783-x Date de publication en ligne : 07/01/2019 En ligne : https://doi.org/10.1007/s13595-018-0783-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92050
in Annals of Forest Science > vol 76 n° 1 (March 2019)[article]How do tree mortality models from combined tree-ring and inventory data affect projections of forest succession? / Marco Vanoni in Forest ecology and management, vol 433 (15 February 2019)
[article]
Titre : How do tree mortality models from combined tree-ring and inventory data affect projections of forest succession? Type de document : Article/Communication Auteurs : Marco Vanoni, Auteur ; Maxime Cailleret, Auteur ; Lisa Hülsmann, Auteur ; et al., Auteur Année de publication : 2019 Article en page(s) : pp 606 - 617 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes IGN] Abies alba
[Termes IGN] arbre (flore)
[Termes IGN] arbre mort
[Termes IGN] croissance des arbres
[Termes IGN] diamètre des arbres
[Termes IGN] données dendrométriques
[Termes IGN] dynamique de la végétation
[Termes IGN] Europe centrale
[Termes IGN] Fagus sylvatica
[Termes IGN] forêt
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Larix decidua
[Termes IGN] modèle de croissance végétale
[Termes IGN] modèle de simulation
[Termes IGN] mortalité
[Termes IGN] Picea abies
[Termes IGN] Pinus cembra
[Termes IGN] prévision
[Termes IGN] Quercus (genre)
[Termes IGN] SuisseRésumé : (auteur) Tree mortality is caused by complex interactions between multiple biotic and abiotic factors. Processes of tree mortality that are not induced by natural disturbances are often reflected in distinct radial growth patterns of trees, which typically serve as reliable indicators of impending tree mortality. However, it remains unclear whether empirical mortality models that are based on tree size and growth result in more realistic projections of forest succession in dynamic vegetation models (DVMs). We used a combination of tree-ring and inventory data from unmanaged Swiss natural forest reserves to derive species-specific survival models for six Central European tree species (Abies alba, Fagus sylvatica, Larix decidua, Picea abies, Pinus cembra and Quercus spp.). We jointly used 528 tree-ring samples and inventory data from eight forest reserves. We implemented the estimated parameters of the survival models into the DVM ForClim and performed simulations of forest succession that were validated using the inventory data of the forest reserves. Size- and growth-dependent variables (i.e., diameter at breast height and mean ring width) over the last few years prior to tree death were reliable predictors to distinguish between dying and living trees. Very low mean ring widths over several preceding years as well as small and large trees, respectively, reflected low survival probabilities. However, the small sample sizes of small and large trees resulted in considerable uncertainty of the survival probabilities. The implementation of these survival models in ForClim yielded plausible projections in short-term simulations and for some sites improved the predictions compared to the current ForClim version. Stand basal area, however, tended to be overestimated. Long-term simulations of ForClim based on the empirical survival models resulted in realistic predictions only if the uncertainty of the predicted survival probabilities was considered. We conclude that the combination of different data sources in combination with the consideration of intra-specific trait variability yields robust predictions of tree survival probabilities, thus paving the way towards better tree mortality models and more reliable projections of future forest dynamics. Numéro de notice : A2019-009 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2018.11.042 Date de publication en ligne : 29/11/2018 En ligne : https://doi.org/10.1016/j.foreco.2018.11.042 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91603
in Forest ecology and management > vol 433 (15 February 2019) . - pp 606 - 617[article]A modeling-based approach for soil frost detection in the northern boreal forest region with C-Band SAR / Juval Cohen in IEEE Transactions on geoscience and remote sensing, vol 57 n° 2 (February 2019)PermalinkTesting the generality of below-ground biomass allometry across plant functional types / Keryn I. Paul in Forest ecology and management, vol 432 (15 January 2019)PermalinkAdaptation de la sylviculture du pin laricio en France dans le contexte de la maladie des bandes rouges : Quels sont les déterminants de la vulnérabilité du pin laricio à la maladie des bandes rouges ? / Sandrine Perret (2019)PermalinkIs field-measured tree height as reliable as believed – A comparison study of tree height estimates from field measurement, airborne laser scanning and terrestrial laser scanning in a boreal forest / Yunsheng Wang in ISPRS Journal of photogrammetry and remote sensing, vol 147 (January 2019)PermalinkModels for diameter and height growth of Scots pine, Norway spruce and pubescent birch in drained peatland sites in Finland / Jaakko Repola in Silva fennica, vol 52 n° 5 (November 2018)PermalinkPredicting tree diameter distributions from airborne laser scanning, SPOT 5 satellite, and field sample data in the perm region, Russia / Jussi Peuhkurinen in Forests, vol 9 n° 10 (October 2018)PermalinkAnnual net nitrogen mineralization and litter flux in well-drained downy birch, Norway spruce and Scots pine forest ecosystems / Hardo Becker in Silva fennica, vol 52 n° 4 (September 2018)PermalinkEstimation and uncertainty of the mixing effects on Scots pine—European beech productivity from national forest inventories data / Sonia Condés in Forests, vol 9 n° 9 (September 2018)PermalinkFuture management options for cembran pine forests close to the alpine timberline / Nathalia Jandl in Annals of Forest Science, vol 75 n° 3 (September 2018)PermalinkComparison of high-density LiDAR and satellite photogrammetry for forest inventory / Grant D. Pearse in ISPRS Journal of photogrammetry and remote sensing, vol 142 (August 2018)Permalink