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Effects of a large-scale late spring frost on a beech (Fagus sylvatica L.) dominated Mediterranean mountain forest derived from the spatio-temporal variations of NDVI / Angelo Nolè in Annals of Forest Science, vol 75 n° 3 (September 2018)  

Public [article]  inAnnals of Forest Science > vol 75 n° 3 (September 2018) Titre : Effects of a large-scale late spring frost on a beech (Fagus sylvatica L.) dominated Mediterranean mountain forest derived from the spatio-temporal variations of NDVI Type de document : Article/Communication Auteurs : Angelo Nolè, Auteur ; Angelo Rita, Auteur ; Agostino Maria Silvio Ferrara, Auteur ; Marco Borghetti, Auteur Année de publication : 2018 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse diachronique [Termes IGN] canopée [Termes IGN] Fagus sylvatica [Termes IGN] forêt alpestre [Termes IGN] forêt méditerranéenne [Termes IGN] gelée [Termes IGN] image Landsat-8 [Termes IGN] image Landsat-OLI [Termes IGN] image Landsat-TIRS [Termes IGN] Italie [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] variation temporelle Résumé : (Auteur) Key message: A remote sensing-based approach was implemented to detect the effect of a late spring frost on beech forests in the Mediterranean mountain region. The analysis of spatio-temporal variability of frost effects on normalised difference vegetation index (NDVI) highlighted the distribution of the canopy damage across the forest according to geomorphic factors such as slope, aspect, and altitude. Context: Increased intensity and frequency of extreme temperatures such as late spring frosts and heat waves represent the main drivers affecting forest ecosystem structure and composition in the Mediterranean region. Aims: The main objective of this study was to evaluate the effects of a late spring frost disturbance, which occurred during spring 2016 in southern Italy, through the assessment of the spatial pattern of the damage to the beech forest canopy associated with the peak decrease in normalised difference vegetation index (NDVI), and the analysis of the NDVI temporal recovery after this frost disturbance. Methods: The forest areas affected by frost were detected through the NDVI differencing technique based on Landsat 8 (OLI/TIRS) imagery time series. The influence of local geomorphic factors (i.e., aspect, elevation, and slope) on forest NDVI patterns was assessed by means of a generalized additive model (GAM). Results: A rather counterintuitive NDVI patterns emerged according to the forest exposition, with NDVI significantly higher on the north facing areas than the southerly ones. The main canopy damage occurred at about 1250 m and reached up to 1500 m asl, representing the altitudinal range affected by the frost disturbance. Finally, the full canopy recovery occurred within 3 months of the frost event. Conclusion: The analysis of seasonal Landsat 8 image time series related to local geomorphic factors, such as aspect, slope, and altitude, and plant phenology on a frost event date, contributed to highlight the NDVI spatio-temporal variation and canopy recovery of a Mediterranean mountain beech forest. Numéro de notice : A2018-328 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-018-0763-1 Date de publication en ligne : 16/08/2018 En ligne : https://doi.org/10.1007/s13595-018-0763-1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90472 [article]

Future management options for cembran pine forests close to the alpine timberline / Nathalia Jandl in Annals of Forest Science, vol 75 n° 3 (September 2018)  

Public [article]  inAnnals of Forest Science > vol 75 n° 3 (September 2018) Titre : Future management options for cembran pine forests close to the alpine timberline Type de document : Article/Communication Auteurs : Nathalia Jandl, Auteur ; Robert Jandl, Auteur ; Andreas Schindlbacher, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biomasse forestière [Termes IGN] changement climatique [Termes IGN] économie forestière [Termes IGN] forêt alpestre [Termes IGN] gestion forestière [Termes IGN] grume [Termes IGN] Larix decidua [Termes IGN] marché du bois [Termes IGN] Pinus cembra [Termes IGN] prévention des risques [Termes IGN] puits de carbone [Termes IGN] service écosystémique [Termes IGN] simulation [Termes IGN] Tyrol (Autriche) [Vedettes matières IGN] Sylviculture Résumé : (auteur) Key message: High-elevation forests in the Alps protect infrastructure and human lives against natural hazards such as rockfall, flooding, and avalanches. Routinely performed silvicultural interventions maintain the required stand structure but are not commercially viable in remote forests due to high operational costs. Financial subsidies for the management of high-elevation protection forests are an efficient strategy to ensure sustainable forest cover. Context:Presently, many high-elevation forests in the Alps are managed in order to ensure the provision of ecosystem services with emphasis on the minimization of natural hazards. Aims: We studied the possible economic performance of a high-elevation protection forest from an owner’s perspective. We investigated whether the increase in productivity due to climate change and a favorable market for the dominating cembran pine (Pinus cembra L.) are sufficient for profitable timber production in protection forests. Methods: We simulated the standing timber stock and the soil carbon pool for a 100-year period with climate-sensitive models and compared harvesting costs with expected revenues. Our scenarios included different climates, intensities of timber extractions, parameters of the timber market, and the availability of government subsidies. Results: Overall, the productivity of forests increases by approximately 15% until the end of the century. In a zero-management scenario, the forest accumulates carbon both in the aboveground biomass and the soil. In the case of an extensive management with moderate timber extractions every 50 years, the carbon stocks decline both in biomass and soil. A more intensive management scenario with extractions every 30 years leads to substantial losses of the soil and biomass carbon pools. In addition, the stand structure changes and the protective function of the forest is not sustainably ensured. Timber production can be economically successful only with high selling prices of cembran pine timber and the availability of governmental subsidies for forest management. The admixed European larch (Larix decidua Mill.) contributes only marginally to the economic success. The main challenge are harvesting costs. The costs of timber extraction by a long-distance cableway logging system exceed the value of the harvested timber. Conclusion: The intensification of forest management cannot be recommended from the perspective of timber production, sustainable forest management, and protection against natural hazards. Our simulation experiment shows that the extraction of timber at decadal intervals depletes the carbon stock that is insufficiently replenished from aboveground and belowground litterfall. Leaving the forest unmanaged does not impose a particular threat to stand stability and is under the encountered situation, a justified strategy. Numéro de notice : A2018-332 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-018-0760-4 Date de publication en ligne : 15/08/2018 En ligne : https://doi.org/10.1007/s13595-018-0760-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90483 [article]

Managing tree species diversity and ecosystem functions through coexistence mechanisms / Thomas Cordonnier in Annals of Forest Science, vol 75 n° 3 (September 2018)  

Public [article]  inAnnals of Forest Science > vol 75 n° 3 (September 2018) Titre : Managing tree species diversity and ecosystem functions through coexistence mechanisms Type de document : Article/Communication Auteurs : Thomas Cordonnier, Auteur ; Georges Kunstler, Auteur ; Benoît Courbaud, Auteur ; Xavier Morin, Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] biodiversité végétale [Termes IGN] écosystème forestier [Termes IGN] gestion forestière [Termes IGN] gestion forestière durable [Termes IGN] indice de diversité [Termes IGN] peuplement végétal [Termes IGN] service écosystémique [Termes IGN] surveillance forestière [Vedettes matières IGN] Sylviculture Résumé : (auteur) Key message: A better transfer to managers of studies examining the functional role of tree species diversity would be achieved by explicitly addressing two missing links: the effect of management interventions on coexistence mechanisms and the relationships between coexistence mechanisms and ecosystem functions. Context: Plant species diversity has been shown to promote a wide array of ecosystem functions and ecosystem services. However, scientific results concerning relationships between species diversity or species mixing and ecosystem functions have not been well transferred to management practices so far. Part of the problem lies in the difficulty of assessing whether interesting species mixtures can persist over the long term and how management influences ecosystem functions. Aims: We argue that a better transfer of knowledge to managers would be achieved by addressing two missing links: (i) the effect of management interventions on coexistence mechanisms and (ii) the relationships between coexistence mechanisms and ecosystem functions. Methods: To do so, we first provide a brief overview of the recent scientific results on relations between tree diversity (or two-species mixing) and ecosystem functions, focusing on studies dealing with productivity and stability in forests. We further introduce the key question of whether mixed stands are transient or permanent. We then briefly present key elements of modern coexistence theory and illustrate them with three examples in forest ecosystems. We finish by discussing how management interventions in forests can affect coexistence mechanisms and by addressing some methodological perspectives. Results: We provide examples of management actions (e.g. gap-based silviculture, preferential selection of the most frequent species, preferential selection of the most competitive species, planting weakly competitive species) that may increase the strength of coexistence mechanisms. Conclusion: Analysing long-term management impacts on species coexistence and ecosystem functions with a combination of long-term monitoring of large permanent plots and mechanistic dynamic model simulations will be useful to develop relevant practices favouring mixed forests in the long term. Numéro de notice : A2018-333 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s13595-018-0750-6 Date de publication en ligne : 26/06/2018 En ligne : https://doi.org/10.1007/s13595-018-0750-6 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=90493 [article]