Centre dedocumentation
scientifique

Relative influence of stand and site factors on aboveground live-tree carbon sequestration and mortality in managed and unmanaged forests / Christel C. Kern in Forest ecology and management, vol 493 (1st August 2021)  

Public [article]  inForest ecology and management > vol 493 (1st August 2021) . - n° 119266 Titre : Relative influence of stand and site factors on aboveground live-tree carbon sequestration and mortality in managed and unmanaged forests Type de document : Article/Communication Auteurs : Christel C. Kern, Auteur ; Laura S. Kenefic, Auteur ; Christian Kuehne, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 119266 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] arbre mort [Termes IGN] climat [Termes IGN] Etats-Unis [Termes IGN] forêt inéquienne [Termes IGN] gestion forestière [Termes IGN] puits de carbone [Termes IGN] structure d'un peuplement forestier [Termes IGN] teneur en carbone [Vedettes matières IGN] Foresterie Résumé : (auteur) We compiled data from several independent, long-term silvicultural studies on USDA Forest Service experimental forests across a latitudinal gradient in the northeastern and north-central U.S.A. to evaluate factors influencing aboveground live-tree carbon sequestration and mortality. Data represent five sites with more than 70,000 repeated tree records spanning eight decades, five ecoregions, and a range of stand conditions. We used these data to test the relative influence of factors such as climate, treatment history (uneven-aged or no management), species composition, and stand structural conditions on aboveground live-tree carbon sequestration and mortality in repeatedly measured trees. Relative to no management, we found that uneven-aged management tended to have a positive effect on carbon sequestration at low stocking levels and in areas of favorable climate (expressed as a combination of growing season precipitation and annual growing degree days > 5 °C). In addition, losses of carbon from the aboveground live-tree pool due to tree mortality were lower in managed than unmanaged stands. These findings suggest that there may be conditions at which rate of sequestration in living trees is higher in stands managed with uneven-aged silviculture than in unmanaged stands, and that this benefit is greatest where climate is favorable. Numéro de notice : A2021-458 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2021.119266 date de publication en ligne : 28/04/2021 En ligne : https://doi.org/10.1016/j.foreco.2021.119266 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97920 [article]

Analysis of plot-level volume increment models developed from machine learning methods applied to an uneven-aged mixed forest / Seyedeh Kosar Hamidi in Annals of Forest Science [en ligne], vol 78 n° 1 (March 2021)  

Public [article]  inAnnals of Forest Science [en ligne] > vol 78 n° 1 (March 2021) . - n° 4 Titre : Analysis of plot-level volume increment models developed from machine learning methods applied to an uneven-aged mixed forest Type de document : Article/Communication Auteurs : Seyedeh Kosar Hamidi, Auteur ; Eric K. Zenner, Auteur ; Mahmoud Bayat, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 4 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Acer velutinum [Termes IGN] alnus cordata [Termes IGN] analyse comparative [Termes IGN] apprentissage automatique [Termes IGN] carpinus betulus [Termes IGN] classification barycentrique [Termes IGN] classification par forêts aléatoires [Termes IGN] classification par réseau neuronal [Termes IGN] classification par séparateurs à vaste marge [Termes IGN] dynamique de la végétation [Termes IGN] écosystème forestier [Termes IGN] Fagus orientalis [Termes IGN] forêt inéquienne [Termes IGN] inventaire forestier étranger (données) [Termes IGN] Iran [Termes IGN] modèle de croissance végétale [Termes IGN] modèle de simulation [Termes IGN] peuplement mélangé [Termes IGN] régression linéaire [Termes IGN] volume en bois [Vedettes matières IGN] Sylviculture Résumé : (auteur) Key message: We modeled 10-year net stand volume growth with four machine learning (ML) methods, i.e., artificial neural networks (ANN), support vector machines (SVM), random forests (RF), and nearest neighbor analysis (NN), and with linear regression analysis. Incorporating interactions of multiple variables, the ML methods ANN and SVM predicted nonlinear system behavior and unraveled complex relations with greater accuracy than regression analysis. Context: Investigating the quantitative and qualitative characteristics of short-term forest dynamics is essential for testing whether the desired goals in forest-ecosystem conservation and restoration are achieved. Inventory data from the Jojadeh section of the Farim Forest located in the uneven-aged, mixed Hyrcanian Forest were used to model and predict 10-year net annual stand volume increment with new machine learning technologies. Aims: The main objective of this study was to predict net annual stand volume increment as the preeminent factor of forest growth and yield models. Methods: In the current study, volume increment was modeled from two consecutive inventories in 2003 and 2013 using four machine learning techniques that used physiographic data of the forest as input for model development: (i) artificial neural networks (ANN), (ii) support vector machines (SVM), (iii) random forests (RF), and (iv) nearest neighbor analysis (NN). Results from the various machine learning technologies were compared against results produced with regression analysis. Results: ANNs and SVMs with a linear kernel function that incorporated field-measurements of terrain slope and aspect as input variables were able to predict plot-level volume increment with a greater accuracy (94%) than regression analysis (87%). Conclusion: These results provide compelling evidence for the added utility of machine learning technologies for modeling plot-level volume increment in the context of forest dynamics and management. Numéro de notice : A2021-071 Affiliation des auteurs : non IGN Thématique : FORET/INFORMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-020-01011-6 date de publication en ligne : 12/01/2021 En ligne : https://doi.org/10.1007/s13595-020-01011-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96794 [article]

Tree mortality in the dynamics and management of uneven-aged Norway spruce stands in southern Finland / Sauli Valkonen in European Journal of Forest Research, vol 139 n° 6 (December 2020)  

Public [article]  inEuropean Journal of Forest Research > vol 139 n° 6 (December 2020) . - pp 989 – 998 Titre : Tree mortality in the dynamics and management of uneven-aged Norway spruce stands in southern Finland Type de document : Article/Communication Auteurs : Sauli Valkonen, Auteur ; Lucie Aulus Giacosa, Auteur ; Juha Heikkinen, Auteur Année de publication : 2020 Article en page(s) : pp 989 – 998 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] analyse diachronique [Termes IGN] diamètre des arbres [Termes IGN] Finlande [Termes IGN] forêt inéquienne [Termes IGN] mortalité [Termes IGN] neige [Termes IGN] Picea abies [Termes IGN] vent [Vedettes matières IGN] Sylviculture Résumé : (auteur) This study focused on tree mortality in spruce-dominated stands managed using the single-tree selection method in southern Finland. Together with regeneration and tree growth, mortality is one of the basic elements of the stand structure and dynamics in selection stands. The study was based on data acquired from a set of 20 permanent experimental plots monitored with repeated measurements for 20 years. The average mortality in the number of stems (N) was 4.45 trees ha−1a−1, in basal area (G) 0.07 m2 ha−1a−1, and in stemwood volume (V) 0.56 m3 ha−1a−1. In relative terms it was 0.50% of N, 0.30% of G and 0.27% of V, respectively. Wind and snow were the most common causes of mortality, while deaths by biotic causes (mammals, insects, pathogens) were extremely rare. Some 6–10% of the total loss in the number of stems and volume was attributable to the loss or removal of trees that sustained serious damage in harvesting. Most of the mortality occurred in the smallest diameter classes of up to 20 cm. Such a high mortality among small trees can have an adverse influence on the sustainability of selection structures if not successfully checked in harvesting and management. Numéro de notice : A2020-746 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10342-020-01301-8 date de publication en ligne : 30/06/2020 En ligne : https://doi.org/10.1007/s10342-020-01301-8 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96394 [article]

Economics of harvesting uneven-aged forest stands in Fennoscandia / Janne Rämo in Scandinavian journal of forest research, vol 29 n° 8 (October 2014)  

Public [article]  inScandinavian journal of forest research > vol 29 n° 8 (October 2014) . - pp 777 - 792 Titre : Economics of harvesting uneven-aged forest stands in Fennoscandia Type de document : Article/Communication Auteurs : Janne Rämo, Auteur ; Olli Tahvonen, Auteur Année de publication : 2014 Article en page(s) : pp 777 - 792 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Economie [Termes IGN] Betula (genre) [Termes IGN] Fennoscandie [Termes IGN] forêt inéquienne [Termes IGN] peuplement forestier [Termes IGN] Picea abies [Termes IGN] Pinus sylvestris [Termes IGN] rendement Résumé : (auteur) This study analyzes the optimal harvesting of uneven-aged Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.), and birch (Betula pendula Roth. and B. pubescens Ehrh.) stands. The analysis is based on an economic description of uneven-aged forestry using a size-structured transition matrix model and a single-tree model. The optimization problem is solved in its general dynamic form using gradient-based interior point methods. Increasing the harvesting interval decreases the annual volume yield. Assuming natural regeneration, this suggests that volume yield is maximized by uneven-aged rather than even-aged management. The present value of stumpage revenues is maximized after saw timber and pulpwood prices, interest rate, and a 15-year harvesting interval are included. The economically optimal solution with a 3% interest rate produces an annual yield of 1.9, 6.2, and 3.1 cubic meters for Scots pine, Norway spruce, and birch, respectively. Both the optimal volume yield and net present value maximization solutions converge to unique species- and site-type-specific steady states with constant harvests. The transition matrix model typically used in optimization studies is computationally less demanding than the single-tree model, but the differences in optimal solutions are more remarkable than earlier studies suggest. Numéro de notice : A2014-783 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1080/02827581.2014.982166 date de publication en ligne : 31/10/2014 En ligne : http://dx.doi.org/10.1080/02827581.2014.982166 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79380 [article]

Basic features of a group selection system modification aimed to sustain regular-uneven-aged stand structure / Roman Efremov in Annals of forest research, vol 52 n° 1 (January 2009)    

Public [article]  inAnnals of forest research > vol 52 n° 1 (January 2009) . - p. 143-150 Titre : Basic features of a group selection system modification aimed to sustain regular-uneven-aged stand structure Type de document : Article/Communication Auteurs : Roman Efremov, Auteur Année de publication : 2009 Article en page(s) : p. 143-150 Note générale : Bibliogr. Langues : Anglais (eng) Descripteur : [Termes IGN] Fagus sylvatica [Termes IGN] forêt inéquienne [Termes IGN] structure d'un peuplement forestier [Vedettes matières IGN] Botanique Résumé : (Auteur) "Proposed modification of group selection system is aimed to successfully combine its elements with biological peculiarities (such as sympodial growth, distinct heliotropism and crown growth plasticity, heavy seeds and difficult dissemination, etc.) of shade-intolerant and mid-tolerant tree species, stands of which may be managed under the same system. Principles, on which the modification is based, are: (i) application of well founded extended rotations in order to increase the proportion of tree groups above 90-100 years age in the stand, where upon the height increment and crown side spread by most of the main tree species in Bulgary drop to considerably lower level, and (ii) optimum systematic spatial positioning of openings in the stand canopy (and tree groups respectively) over the stand area, so that new gaps created by consecutive selection cuttings adjoin to a minimum number of middle aged (40-80 y. age) tree groups. Such clumps of vigorous trees with high growth rates, heliotropism and plasticity carry certain risks of spoiling the target regular-unevenaged stand structure. Factors of significance are discussed by determining the rotation age, size of gaps opened in the stand canopy, selection cutting cycle, a regularuneven- aged stand structure design and the minimum area that enables realisation of full selection system cycle. Definitions and determination of selection system elements in their mutual connections are presented in consecutive steps when designing a particular application of group selection system for exemplary pure stand of common beech (Fagus sylvatica L.). By the proposed group selection system modification the amount of combinations of various factors having impact upon processes in the tree groups are diminished compared to that by random spatial arrangement of the gaps over the stand area. Silvicultural activities aimed to maintain a stable unevenaged stand structures are thus getting more predictable, easier to schedule and efficient." Numéro de notice : IFN_5803 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article En ligne : http://www.editurasilvica.ro/afr/52/1/14_Efremov.pdf Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=73515 [article]

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
IFN-001-P000915	PER	Revue	Nogent-sur-Vernisson	Archives périodiques	Exclu du prêt

Documents numériques

en open access Basic features of a group selection system modification... Adobe Acrobat PDF

Modélisation de la dynamique forestière : recherche de configurations spatiales / J.P. Pascal (1997)

Permalink