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Auteur Tomas Vrska
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Very large trees in a lowland old-growth beech (Fagus sylvatica L.) forest : Density, size, growth and spatial patterns in comparison to reference sites in Europe / Kris Vandekerkhove in Forest ecology and management, vol 417 (15 May 2018)
Titre : Very large trees in a lowland old-growth beech (Fagus sylvatica L.) forest : Density, size, growth and spatial patterns in comparison to reference sites in Europe Type de document : Article/Communication Auteurs : Kris Vandekerkhove, Auteur ; Margot Vanhellemont, Auteur ; Tomas Vrska, Auteur ; Peter Meyer, Auteur ; et al., Auteur Année de publication : 2018 Article en page(s) : pp 1 - 17 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes descripteurs IGN] distribution spatiale
[Termes descripteurs IGN] données dendrométriques
[Termes descripteurs IGN] Europe du nord
[Termes descripteurs IGN] Fagus sylvatica
[Termes descripteurs IGN] forêt ancienne
[Termes descripteurs IGN] forêt secondaire
Résumé : (Auteur) The frequent occurrence of very large trees (diameter at breast height DBH ≥ 80 cm) is a typical element of both primary and secondary old-growth forests. We analyzed the characteristics of very large trees in one of the few stands of lowland old-growth beech forest in Northwestern Europe, regenerated around 1775 and left unmanaged since 1986. We examined their density, diameter range, increment, mortality rate and spatial distribution, based on repeated full dendrometric surveys. In order to evaluate the results, we compared them to original datasets from primary and secondary old-growth beech forests in Europe, and an extensive reference table, compiled from inventories and literature.
In our study site, the density of very large trees increased from 31.5 to 34.3 trees ha−1 over the last 25 years, reaching a median DBH of 97 cm (mean 98.9), with the largest tree attaining a DBH of 159 cm. Although the trees were over 240 years old, they still showed an average DBH increment of 4.75 mm year−1 and a low mortality rate (0.89% year−1), indicating that they were still vital. These figures are remarkably high compared to other old-growth beech forest reference sites, where the density of very large trees generally varies between 5 and 20 trees ha−1 (median value 13.1), with a median diameter of 85–90 cm and maximum DBH for beech trees rarely exceeding 100–130 cm.
The regular spatial distribution pattern of the very large trees in the studied stand clearly differed from a typical old-growth stand, in which very large trees are randomly distributed. Over the last 25 years though, because of random mortality and ingrowth, the spatial distribution gradually became more random.
The extraordinary densities and sizes of the very large trees in our study site can be explained by the favorable climate and site conditions that promote high increments, in combination with the former management interventions of tending and thinning that resulted in continuous non-suppressed growth. Although derived from a very specific case with particular conditions, our observations may be relevant to other beech forests, as they tend to reset certain baseline assumptions for tree size and longevity potential of beech in Northwestern Europe.
Numéro de notice : A2018-468 Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.foreco.2018.02.033 date de publication en ligne : 02/03/2018 En ligne : https://doi.org/10.1016/j.foreco.2018.02.033 Format de la ressource électronique : URL article Permalink :
in Forest ecology and management > vol 417 (15 May 2018) . - pp 1 - 17[article]Comparing close-to-nature silviculture with processes in pristine forests: lessons from Central Europe / Jean-Philippe Schütz in Annals of Forest Science [en ligne], vol 73 n° 4 (December 2016)
Titre : Comparing close-to-nature silviculture with processes in pristine forests: lessons from Central Europe Type de document : Article/Communication Auteurs : Jean-Philippe Schütz, Auteur ; Milan Saniga, Auteur ; Jurij Diaci, Auteur ; Tomas Vrska, Auteur Année de publication : 2016 Article en page(s) : pp 911 - 921 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation
[Termes descripteurs IGN] dynamique de la végétation
[Termes descripteurs IGN] Europe centrale
[Termes descripteurs IGN] processus naturel
[Termes descripteurs IGN] sylviculture
Résumé : (auteur) [introduction] The term close-to-nature silviculture already contains some ambiguity since (silvi) culture implies the act of forest use. This notion was coined a long time ago by well-known silviculturists (Gayer 1885; Engler 1905; Leibundgut 1943 and more) to characterise a new form of forest management that differs from plantation forestry and the clear-cut system. The aim was a paradigmatic alternative to create multi-storeyed and rich mixed forest stands, with forest management emulating natural processes and seamless replacement of generations. Which of these processes should be selected and the degree to which natural forest dynamics should be imitated have not yet been specifically defined because the term was conceived in a general and conceptual sense and, furthermore, the aim has never been to let nature work alone. We can here quote Leibundgut (1943, p. 152) [transl. from German] “The main task of silviculture is to maximise and maintain the value produced by the forest”. Such a formulation is still quite relevant today, when the term “value” is understood in a broader sense. Actually, it would be more appropriate to use the term “utility” (original term “utilité”) in the sense of Biolley (1901). Numéro de notice : A2016--167 Thématique : FORET Nature : Article DOI : 10.1007/s13595-016-057 En ligne : https://doi.org/10.1007/s13595-016-0579-9 Format de la ressource électronique : URL article Permalink :
in Annals of Forest Science [en ligne] > vol 73 n° 4 (December 2016) . - pp 911 - 921[article]