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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)  

Public [article]  inForest ecology and management > vol 417 (15 May 2018) . - pp 1 - 17 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 : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91148 [article]

Seed dispersal, microsites or competition : what drives gap regeneration in an old-growth forest? An application of spatial point process modelling / Georg Gratzer in Forests, vol 9 n° 5 (May 2018)  

Public [article]  inForests > vol 9 n° 5 (May 2018) Titre : Seed dispersal, microsites or competition : what drives gap regeneration in an old-growth forest? An application of spatial point process modelling Type de document : Article/Communication Auteurs : Georg Gratzer, Auteur ; Rasmus Plenge Waagepetersen, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] croissance végétale [Termes descripteurs IGN] dynamique de la végétation [Termes descripteurs IGN] forêt ancienne [Termes descripteurs IGN] modèle de croissance [Termes descripteurs IGN] modèle de simulation [Termes descripteurs IGN] processus ponctuel [Termes descripteurs IGN] régénération (sylviculture) Résumé : (Auteur) The spatial structure of trees is a template for forest dynamics and the outcome of a variety of processes in ecosystems. Identifying the contribution and magnitude of the different drivers is an age-old task in plant ecology. Recently, the modelling of a spatial point process was used to identify factors driving the spatial distribution of trees at stand scales. Processes driving the coexistence of trees, however, frequently unfold within gaps and questions on the role of resource heterogeneity within-gaps have become central issues in community ecology. We tested the applicability of a spatial point process modelling approach for quantifying the effects of seed dispersal, within gap light environment, microsite heterogeneity, and competition on the generation of within gap spatial structure of small tree seedlings in a temperate, old growth, mixed-species forest. By fitting a non-homogeneous Neyman–Scott point process model, we could disentangle the role of seed dispersal from niche partitioning for within gap tree establishment and did not detect seed densities as a factor explaining the clustering of small trees. We found only a very weak indication for partitioning of within gap light among the three species and detected a clear niche segregation of Picea abies (L.) Karst. on nurse logs. The other two dominating species, Abies alba Mill. and Fagus sylvatica L., did not show signs of within gap segregation. Numéro de notice : A2018-486 Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/f9050230 date de publication en ligne : 27/04/2018 En ligne : https://doi.org/10.3390/f9050230 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91222 [article]

Waste heaps left by historical Zn-Pb ore mining are hotspots of species diversity of beech forest understory vegetation / Marcin W. Woch in Science of the total environment, vol 599 - 600 (December 2017)  

Public [article]  inScience of the total environment > vol 599 - 600 (December 2017) . - pp 32 - 41 Titre : Waste heaps left by historical Zn-Pb ore mining are hotspots of species diversity of beech forest understory vegetation Type de document : Article/Communication Auteurs : Marcin W. Woch, Auteur ; Anna M. Stefanowicz, Auteur ; Małgorzata Stanek, Auteur Année de publication : 2017 Article en page(s) : pp 32 - 41 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] état de conservation [Termes descripteurs IGN] Fagus (genre) [Termes descripteurs IGN] forêt ancienne [Termes descripteurs IGN] hêtraie [Termes descripteurs IGN] métal lourd [Termes descripteurs IGN] mine [Termes descripteurs IGN] placette d'échantillonnage [Termes descripteurs IGN] Pologne [Termes descripteurs IGN] sous-bois Résumé : (auteur) Metalliferous mining and smelting industries are associated with very high levels of heavy metal(loid) contamination of the environment. Heavy metals have been proved to significantly influence the species diversity and composition of grassland communities, but little is known on their effects on forest understory vegetation. Therefore, the aim of this study was to investigate the effects of the presence of small heaps of waste rock left by historical Zn-Pb ore mining on understory vegetation. The heaps are scattered over vast areas of beech forests in southern Poland. Three types of study plots were established: (1) on waste heaps themselves, (2) in their vicinity (5–10 m from the foot of the heaps, with no waste rock but potentially influenced by the heaps through drainage water), and (3) at least 100 m from the foot of the heaps (pseudo-control). In all plots vegetation parameters, i.e., plant species number, cover and community composition, life forms and strategies, as well as basic soil properties were assessed. Although the heaps contained high concentrations of metals, namely Cd, Pb and Zn, they were characterised by higher cover and diversity of understory vegetation, including ancient forest and endangered species, in comparison to their surroundings. They were also characterised by the distinct species composition of their plant communities. This might have resulted from the beneficial influence of high pH and Ca content originating from waste rock composed of dolomite and calcite, as well as from increased habitat heterogeneity, e.g. soil skeleton and steeper slopes. Another important factor influencing the richness and composition of understory was tree cover, which relates to the light transmissibility of the canopy. Our study proved that the disturbance brought about by the former mining and processing of metal ores led to the formation of species-rich understory with high frequency and cover of naturally-valuable species. Numéro de notice : A2017-194 Thématique : BIODIVERSITE/FORET Nature : Article En ligne : https://doi.org/10.1016/j.scitotenv.2017.04.197 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=84836 [article]

Microtopography and ecology of pit-mound structures in second-growth versus old-growth forests / Audrey Barker Plotkin in Forest ecology and management, vol 404 (15 November 2017)  

Public [article]  inForest ecology and management > vol 404 (15 November 2017) . - pp 14 - 23 Titre : Microtopography and ecology of pit-mound structures in second-growth versus old-growth forests Type de document : Article/Communication Auteurs : Audrey Barker Plotkin, Auteur ; Peter Schoonmaker, Auteur ; Bennet Leon, Auteur ; David Foster, Auteur Année de publication : 2017 Article en page(s) : pp 14 - 23 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] analyse comparative [Termes descripteurs IGN] Betula (genre) [Termes descripteurs IGN] forêt ancienne [Termes descripteurs IGN] forêt de seconde venue [Termes descripteurs IGN] microtopographie [Termes descripteurs IGN] richesse floristique [Termes descripteurs IGN] structure d'un peuplement forestier [Termes descripteurs IGN] tempête Résumé : (auteur) Pit and mound microtopography is an important structural component of most forests, influencing soil processes and habitat diversity. These features have diminished greatly in northeastern U.S. forests since European settlement, as a result of the history of repeated logging, land-clearance followed by reforestation, and the smaller size of trees (and therefore windthrow features) comprising the prevailing second-growth forests. Despite the potential importance of this region-wide shift in forest microtopography on ecosystem structure and function, the differences in pit and mound size, distribution, and longevity between second-growth and old-growth forests are unexplored. Likewise, although many studies demonstrate that mounds and/or pits are hotspots for tree regeneration there is scant information about whether location on a mound or pit affects tree survival and growth beyond the seedling stage, or whether microtopographic regeneration patterns differ in old-growth and second-growth forests. We compare a simulated hurricane experiment initiated in 1990 in second-growth forest (the pulldown) and an old-growth forest that was blown down by a hurricane in 1938 (Pisgah) to examine differences in pit-mound microtopography and ecology between second-growth and old-growth forest. At Pisgah, fewer, larger mounds comprised a similar areal coverage as at the pulldown. Repeated measurements of individual pit-mound structures in the pulldown revealed that pit infill proceeded more rapidly than mound erosion. Mound area increased but height decreased over time as soil from the mound tops eroded and spread around the mound base. Although 40% of mounds in the pulldown were >1 m tall immediately after the manipulation (maximum of 2.9 m), after 25 years, maximum mound height was 0.9 m. In contrast, 11% of mounds at Pisgah remained >1 m tall in 1989, 50 years after blowdown. At both sites, trees, especially Betula spp., were disproportionately found on mounds. Fewer trees than expected grew in pits at Pisgah. Tree mortality was somewhat higher on mounds and pits than on other substrates. As a mechanism to increase stand-level tree diversity, windthrow may be more critical in old-growth forests, in which niches for early-mid successional species are few, than in second-growth forest, in which early-mid successional species already comprise the majority of the trees. Pit-mound structures are a diminished component of second-growth forest, and silvicultural techniques designed to restore old-growth characteristics could include measures to preserve and enhance pit-mound features, and to cultivate large-diameter trees that will eventually create the large, long-lasting pit-mounds of the future. Numéro de notice : A2017-806 Thématique : FORET Nature : Article DOI : 10.1016/j.foreco.2017.08.012 En ligne : https://doi.org/10.1016/j.foreco.2017.08.012 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=89243 [article]

Mapping spatial distribution of forest age in China / Yuan Zhang in Earth and space science, vol 4 n° 3 (March 2017)  

Public [article]  inEarth and space science > vol 4 n° 3 (March 2017) . - pp 108 - 116 Titre : Mapping spatial distribution of forest age in China Type de document : Article/Communication Auteurs : Yuan Zhang, Auteur ; Yitong Yao, Auteur ; Xuhui Wang, Auteur ; Yongwen Liu, Auteur ; Shilong Piao, Auteur Année de publication : 2017 Article en page(s) : pp 108 - 116 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes descripteurs IGN] carte forestière [Termes descripteurs IGN] Chine [Termes descripteurs IGN] Cupressaceae [Termes descripteurs IGN] distribution spatiale [Termes descripteurs IGN] données lidar [Termes descripteurs IGN] données localisées 3D [Termes descripteurs IGN] forêt ancienne [Termes descripteurs IGN] hauteur des arbres [Termes descripteurs IGN] incertitude des données [Termes descripteurs IGN] inventaire forestier (techniques et méthodes) [Termes descripteurs IGN] inventaire forestier étranger (données) [Termes descripteurs IGN] peuplement forestier [Termes descripteurs IGN] pinophyta [Termes descripteurs IGN] Pinus massoniana [Termes descripteurs IGN] puits de carbone Résumé : (auteur) Forest stand age is a meaningful metric, which reflects the past disturbance legacy, provides guidelines for forest management practices, and is an important factor in qualifying forest carbon cycles and carbon sequestration potential. Reliable large-scale forest stand age information with high spatial resolutions, however, is difficult to obtain. In this study, we developed a top-down method to downscale the provincial statistics of national forest inventory data into 1 km stand age map using climate data and light detection and ranging-derived forest height. We find that the distribution of forest stand age in China is highly heterogeneous across the country, with a mean value of ~42.6 years old. The relatively young stand age for Chinese forests is mostly due to the large proportion of newly planted forests (0–40 years old), which are more prevailing in south China. Older forests (stand age > 60 years old) are more frequently found in east Qinghai-Tibetan Plateau and the central mountain areas of west and northeast China, where human activities are less intensive. Among the 15 forest types, forests dominated by species of , with the exception of Cunninghamia lanceolata stands, have the oldest mean stand age (136 years), whereas Pinus massoniana forests are the youngest (18 years). We further identified uncertainties associated with our forest age map, which are high in west and northeast China. Our work documents the distribution of forest stand age in China at a high resolution which is useful for carbon cycle modeling and the sustainable use of China's forest resources. Numéro de notice : A2107-277 Thématique : FORET Nature : Article En ligne : https://doi.org/10.1002/2016EA000177 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=85298 [article]

L’écocomplexe de Païolive en Ardèche méridionale (France) : un pic de biodiversité du hotspot méditerranéen / Patrick Blandin in Ecologia mediterranea, vol 42 n° 2 (2016) 

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Modélisation de la structure en diamètre des reboisements et des peuplements naturels de Cèdre de l’Atlas (Cedrus atlantica Manetti) du Djurdjura (Algérie) / Khellaf Rabhi in Revue forestière française [en ligne], vol 68 n° 1 (janvier 2016)  

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Les approches intégratives en tant qu‘opportunités de conservation de la biodiversité forestière / Daniel Kraus (2013) 

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