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Variation in downed deadwood density, biomass, and moisture during decomposition in a natural temperate forest / Tomas Přívětivý in Forests, vol 12 n° 10 (October 2021)  

Public [article]  inForests > vol 12 n° 10 (October 2021) Titre : Variation in downed deadwood density, biomass, and moisture during decomposition in a natural temperate forest Type de document : Article/Communication Auteurs : Tomas Přívětivý, Auteur ; Pavel Šamonil, Auteur Année de publication : 2021 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies alba [Termes IGN] biodiversité végétale [Termes IGN] biomasse forestière [Termes IGN] bois mort [Termes IGN] Europe centrale [Termes IGN] Fagus sylvatica [Termes IGN] forêt ancienne [Termes IGN] forêt tempérée [Termes IGN] montagne [Termes IGN] Picea abies [Termes IGN] teneur en eau de la végétation [Vedettes matières IGN] Foresterie Résumé : (auteur) Deadwood is a resource of water, nutrients, and carbon, as well as an important driving factor of spatial pedocomplexity and hillslope processes in forested landscapes. The applicability of existing relevant studies in mountain forests in Central Europe is limited by the low number of data, absence of precise dating, and short time periods studied. Here, we aimed to assess the decomposition pathway in terms of changes and variability in the physical characteristics of deadwood (wood density, biomass, and moisture) during the decomposition process, and to describe differences in decomposition rate. The research was carried out in the Žofínský Primeval Forest, one of the oldest forest reserves in Europe. Samples were taken from sapwood of downed logs of the three main tree species: Fagus sylvatica L., Abies alba Mill., and Picea abies (L.) Karst. The time since the death of each downed log was obtained using tree censuses repeated since 1975 and dendrochronology. The maximal time since the death of a log was species-specific, and ranged from 61–76 years. The rate of change (slope) of moisture content along the time since death in a linear regression model was the highest for F. sylvatica (b = 3.94) compared to A. alba (b = 2.21) and P. abies (b = 1.93). An exponential model showing the dependence of biomass loss on time since death revealed that F. sylvatica stems with a diameter of 50–90 cm had the shortest decomposition rate—51 years—followed by P. abies (71 years) and A. alba (72 years). Our findings can be used in geochemical models of element cycles in temperate old-growth forests, the prediction of deadwood dynamics and changes in related biodiversity, and in refining management recommendations. Numéro de notice : A2021-619 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12101352 En ligne : https://doi.org/10.3390/f12101352 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98629 [article]

The effects of combining the variables in allometric biomass models on biomass estimates over large forest areas: A european beech case study / Erick O. Osewe in Forests, vol 12 n° 10 (October 2021)  

Public [article]  inForests > vol 12 n° 10 (October 2021) . - n° 1428 Titre : The effects of combining the variables in allometric biomass models on biomass estimates over large forest areas: A european beech case study Type de document : Article/Communication Auteurs : Erick O. Osewe, Auteur ; Ioan Dutca, Auteur Année de publication : 2021 Article en page(s) : n° 1428 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse aérienne [Termes IGN] biomasse forestière [Termes IGN] diamètre à hauteur de poitrine [Termes IGN] données allométriques [Termes IGN] Fagus sylvatica [Termes IGN] hauteur des arbres [Termes IGN] inventaire forestier étranger (données) [Termes IGN] modèle de croissance végétale [Termes IGN] modélisation de la forêt [Termes IGN] Roumanie [Vedettes matières IGN] Végétation et changement climatique Résumé : (auteur) Effective initiatives for forest-based mitigation of climate change rely on continuous efforts to improve the estimation of forest biomass. Allometric biomass models, which are nonlinear models that predict aboveground biomass (AGB) as a function of diameter at breast height (D) and tree height (H), are typically used in forest biomass estimations. A combined variable D2H may be used instead of two separate predictors. The Q-ratio (i.e., the ratio between the parameter estimates of D and parameter estimates of H, in a separate variable model) was proposed recently as a measure to guide the decision on whether D and H can be safely combined into D2H, being shown that the two model forms are similar when Q = 2.0. Here, using five European beech (Fagus sylvatica L.) biomass datasets (of different Q-ratios ranging from 1.50 to 5.05) and an inventory dataset for the same species, we investigated the effects of combining the variables in allometric models on biomass estimation over large forest areas. The results showed that using a combined variable model instead of a separate variable model to predict biomass of European beech trees resulted in overestimation of mean AGB per hectare for Q > 2.0 (i.e., by 6.3% for Q = 5.05), underestimation for Q Numéro de notice : A2021-864 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12101428 Date de publication en ligne : 19/10/2021 En ligne : https://doi.org/10.3390/f12101428 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99080 [article]

The impact of air pollution on the growth of scots pine stands in poland on the basis of dendrochronological analyses / Longina Chojnacka-Ożga in Forests, vol 12 n° 10 (October 2021)  

Public [article]  inForests > vol 12 n° 10 (October 2021) . - n° 1421 Titre : The impact of air pollution on the growth of scots pine stands in poland on the basis of dendrochronological analyses Type de document : Article/Communication Auteurs : Longina Chojnacka-Ożga, Auteur ; Wojciech Ożga, Auteur Année de publication : 2021 Article en page(s) : n° 1421 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] cerne [Termes IGN] changement climatique [Termes IGN] croissance des arbres [Termes IGN] dégradation de la flore [Termes IGN] dendrochronologie [Termes IGN] écosystème forestier [Termes IGN] Pinus sylvestris [Termes IGN] polluant [Termes IGN] pollution atmosphérique [Termes IGN] Pologne [Vedettes matières IGN] Foresterie Résumé : (auteur) The aim of this study was to evaluate Scots pine stand degradation caused by the pollutants emitted from Zakłądy Azotowe Puławy, one of the biggest polluters of the environment in Poland for over 25 years (1966–1990). To assess the pollution stress in trees, we chose the dendrochronological analysis We outlined three directions for our research: (i) the spatio-temporal distribution of the growth response of trees to the stress associated with air pollution; (ii) the direct and indirect effects of air pollution which may have influenced the growth response of trees; and (iii) the role of local factors, both environmental and technological, in shaping the growth response of trees. Eight Scots pine stands were selected for study, seven plots located in different damage zones and a reference plot in an undamaged stand. We found that pollutant emission caused disturbances of incremental dynamics and long-term strong reduction of growth. A significant decrease in growth was observed for the majority of investigated trees (75%) from 1966 (start of factory) to the end of the 1990s. The zone of destruction extended primarily in easterly and southern directions, from the pollution source, associated with the prevailing winds of the region. At the end of the 1990s, the decreasing trend stopped and the wider tree-rings could be observed. This situation was related to a radical reduction in ammonia emissions and an improvement in environmental conditions. However, the growth of damaged trees due to the weakened health condition is lower than the growth of Scots pine on the reference plot and trees are more sensitive to stressful climatic conditions, especially to drought. Numéro de notice : A2021-865 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.3390/f12101421 Date de publication en ligne : 18/10/2021 En ligne : https://doi.org/10.3390/f12101421 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99082 [article]