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Comparison of spatially and nonspatially explicit nonlinear mixed effects models for Norway spruce individual tree growth under single-tree selection / Simone Bianchi in Forests, vol 11 n° 12 (December 2020)  

Public [article]  inForests > vol 11 n° 12 (December 2020) . - n° 1338 Titre : Comparison of spatially and nonspatially explicit nonlinear mixed effects models for Norway spruce individual tree growth under single-tree selection Type de document : Article/Communication Auteurs : Simone Bianchi, Auteur ; Mari Myllymäki, Auteur ; Jouni Siipilehto, Auteur ; Hannu Salminen, Auteur ; et al., Auteur Année de publication : 2020 Article en page(s) : n° 1338 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] arbre (flore) [Termes IGN] croissance des arbres [Termes IGN] forêt boréale [Termes IGN] modèle de croissance végétale [Termes IGN] modèle non linéaire [Termes IGN] Picea abies [Vedettes matières IGN] Sylviculture Résumé : (auteur) Background and Objectives: Continuous cover forestry is of increasing importance, but operational forest growth models are still lacking. The debate is especially open if more complex spatial approaches would provide a worthwhile increase in accuracy. Our objective was to compare a nonspatial versus a spatial approach for individual Norway spruce tree growth models under single-tree selection cutting. Materials and Methods: We calibrated nonlinear mixed models using data from a long-term experiment in Finland (20 stands with 3538 individual trees for 10,238 growth measurements). We compared the use of nonspatial versus spatial predictors to describe the competitive pressure and its release after cutting. The models were compared in terms of Akaike Information Criteria (AIC), root mean square error (RMSE), and mean absolute bias (MAB), both with the training data and after cross-validation with a leave-one-out method at stand level. Results: Even though the spatial model had a lower AIC than the nonspatial model, RMSE and MAB of the two models were similar. Both models tended to underpredict growth for the highest observed values when the tree-level random effects were not used. After cross-validation, the aggregated predictions at stand level well represented the observations in both models. For most of the predictors, the use of values based on trees’ height rather than trees’ diameter improved the fit. After single-tree selection cutting, trees had a growth boost both in the first and second five-year period after cutting, however, with different predicted intensity in the two models. Conclusions: Under the research framework here considered, the spatial modeling approach was not more accurate than the nonspatial one. Regarding the single-tree selection cutting, an intervention regime spaced no more than 15 years apart seems necessary to sustain the individual tree growth. However, the model’s fixed effect parts were not able to capture the high growth of the few fastest-growing trees, and a proper estimation of site potential is needed for uneven-aged stands. Numéro de notice : A2020-578 Affiliation des auteurs : non IGN Thématique : FORET/MATHEMATIQUE Nature : Article DOI : 10.3390/f11121338 Date de publication en ligne : 16/12/2020 En ligne : https://doi.org/10.3390/f11121338 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97034 [article]

Models 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)  

Public [article]  inSilva fennica > vol 52 n° 5 (November 2018) Titre : Models for diameter and height growth of Scots pine, Norway spruce and pubescent birch in drained peatland sites in Finland Type de document : Article/Communication Auteurs : Jaakko Repola, Auteur ; Hannu Hökkä, Auteur ; Hannu Salminen, Auteur Année de publication : 2018 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] betula pubescens [Termes IGN] croissance des arbres [Termes IGN] diamètre des arbres [Termes IGN] Finlande [Termes IGN] hauteur des arbres [Termes IGN] inventaire forestier étranger (données) [Termes IGN] modèle de croissance végétale [Termes IGN] modèle linéaire [Termes IGN] Picea abies [Termes IGN] Pinus sylvestris [Termes IGN] tourbière [Vedettes matières IGN] Economie forestière Résumé : (auteur) The aim of this study was to develop individual-tree diameter and height growth models for Scots pine, Norway spruce, and pubescent birch growing in drained peatlands in Finland. Trees growing in peatland sites have growth patterns that deviate from that of trees growing in mineral soil sites. Five-year growth was explained by tree diameter, different tree and stand level competition measures, management operations and site characteristics. The drainage status of the site was influencing growth directly or in interaction with other variables. Site quality had a direct impact but was also commonly related to current site drainage status (need for ditch maintenance). Recent thinning increased growth of all species and former PK fertilization increased growth of pine and birch. Temperature sum was a significant predictor in all models and altitude for spruce and birch. The data were a subsample of the 7th National Forest Inventory (NFI) sample plots representing northern and southern Finland and followed by repeated measurements for 15–20 yrs. Growth levels predicted by the models were calibrated using NFI11 data to remove bias originating from the sample of the modelling data. The mixed linear models technique was used in model estimation. The models will be incorporated into the MOTTI stand simulator to replace the current peatlands growth models. Numéro de notice : A2018-651 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.14214/sf.10055 Date de publication en ligne : 13/12/2018 En ligne : https://doi.org/10.14214/sf.10055 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=93441 [article]

Summer temperature affects the ratio of radial and height growth of Scots pine in northern Finland / Hannu Salminen in Annals of Forest Science, Vol 66 n° 8 (December 2009)  

Public [article]  inAnnals of Forest Science > Vol 66 n° 8 (December 2009) . - n° 810 Titre : Summer temperature affects the ratio of radial and height growth of Scots pine in northern Finland Titre original : Les températures estivales influent sur le rapport croissance en hauteur et croissance radiale chez le pin sylvestre dans le nord de la Finlande Type de document : Article/Communication Auteurs : Hannu Salminen, Auteur ; Risto Jalkanen, Auteur ; Markus Lindholm, Auteur Année de publication : 2009 Article en page(s) : n° 810 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] croissance des arbres [Termes IGN] dendrochronologie [Termes IGN] Finlande [Termes IGN] limite bioclimatique [Termes IGN] Pinus sylvestris [Termes IGN] température [Vedettes matières IGN] Sylviculture Résumé : (Auteur) Radial and height growth chronologies from 150-year-old and 50-year old Scots pine stands, both located near to the northern timberline in Laanila, Finland (68° 30′ N, 27° 28′ E), were cross-correlated with each other and with mean temperatures of various temperature periods defined as months, days or growing-degree-days. The height-growth chronology correlates significantly with radial growth at lags 1 and 2, and radial growth with height growth at lag 2 when the effect of temperature is omitted. On average, low and high growth years represent cool and warm average growing seasons. The summer temperatures (June, July and August) affect most on growth, but height and radial growth do have a different set of effective temperature periods. Furthermore, July temperature variation affects stronger height than radial growth. Those years with low height/radial-growth ratio, i.e. relatively higher current year’s radial than next year’s height growth, do have lower growth and cooler-than-average July temperature whereas those years with high height/radial-growth ratio do have clearly warmer mid-summer temperatures. Note de contenu : DOI: 10.1051/forest/2009074. Résumé en anglais et français. Bibliogr. Numéro de notice : A2009-616 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1051/forest/2009074 Date de publication en ligne : 25/11/2009 En ligne : https://www.afs-journal.org/articles/forest/full_html/2009/08/f09077/f09077.html Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=72899 [article]

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Code-barres	Cote	Support	Localisation	Section	Disponibilité
IFN-001-P000694	PER	Revue	Nogent-sur-Vernisson	Salle périodiques	Exclu du prêt