Détail de l'auteur
Auteur Sonja Vospernik
Documents disponibles écrits par cet auteur (2)
Ajouter le résultat dans votre panier Visionner les documents numériques Affiner la recherche Interroger des sources externes
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)
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
in Forest ecology and management > vol 530 (February-15 2023) . - n° 120753[article]Do competition-density rule and self-thinning rule agree? / Sonja Vospernik in Annals of Forest Science, vol 72 n° 3 (May 2015)
Titre : Do competition-density rule and self-thinning rule agree? Type de document : Article/Communication Auteurs : Sonja Vospernik, Auteur ; Hubert Sterba, Auteur Année de publication : 2015 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies (genre)
[Termes IGN] auto-éclaircie
[Termes IGN] Autriche
[Termes IGN] croissance des arbres
[Termes IGN] densité de la végétation
[Termes IGN] inventaire forestier étranger (données)
[Termes IGN] Larix decidua
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] Picea abies
[Termes IGN] Pinus nigra
[Termes IGN] Pinus pinea
[Termes IGN] Pinus sylvestris
[Vedettes matières IGN] Foresterie
Résumé : (auteur) Context : The competition-density principle, which can mathematically be described by the competition-density rule, is an important principle in plant ecology. The border line relationship is the self-thinning rule. Despite the importance of both rules for forest management, they have been fit for few species.
Aims : The aim of this study is to compare competition-density rule and self-thinning rule in particular with respect to potential density for 15 species from the Austrian National Forest Inventory (ANFI).
Methods : The self-thinning line was estimated using quantile regression. The competition-density rule was fit as four- and as three-parameter model, where the fourth parameter was substituted (a) with a specific slope from the self-thinning line estimated from the ANFI and (b) Reineke’s slope (−1.605).
Results : Potential density was highest for Austrian pine and Norway spruce, followed by silver fir and Scots pine; it was considerably lower for European larch, stone pine and broadleaf species. Species-specific slopes of the self-thinning line ranged between −1.5 and −2.0 and were significantly different from Reineke’s slope for Norway spruce, European larch and European beech.
Conclusions : Using robust estimation techniques, both competition-density rule and self-thinning line can also be fit for minor species, providing an important guide for practical forest management.
Numéro de notice : A2015-456 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-014-0433-x Date de publication en ligne : 30/10/2014 En ligne : https://doi.org/10.1007/s13595-014-0433-x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=77120
in Annals of Forest Science > vol 72 n° 3 (May 2015)[article]