Détail de l'auteur
Auteur Lars Söderström |
Documents disponibles écrits par cet auteur (2)
Ajouter le résultat dans votre panier Affiner la recherche Interroger des sources externesSpatiotemporal variation in the relationship between boreal forest productivity proxies and climate data / Clémentine Ols in Dendrochronologia, vol 58 (December 2019)
Titre : Spatiotemporal variation in the relationship between boreal forest productivity proxies and climate data Type de document : Article/Communication Auteurs : Clémentine Ols Année de publication : 2019 Projets : PREREAL / Ali, Ahmed Adam Article en page(s) : n° 125648 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] croissance des arbres
[Termes IGN] données météorologiques
[Termes IGN] données spatiotemporelles
[Termes IGN] écosystème forestier
[Termes IGN] forêt boréale
[Termes IGN] hauteur des arbres
[Termes IGN] Normalized Difference Vegetation Index
[Termes IGN] Norvège
[Termes IGN] Pinus sylvestris
[Termes IGN] productivité
[Termes IGN] puits de carbone
[Termes IGN] série temporelle
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) The impacts of climate change on high-latitude forest ecosystems are still uncertain. Divergent forest productivity trends have recently been reported both at the local and regional level challenging the projections of boreal tree growth dynamics. The present study investigated (i) the responses of different forest productivity proxies to monthly climate (temperature and precipitation) through space and time; and (ii) the local coherency between these proxies through time at four high-latitude boreal Scots pine sites (coastal and inland) in Norway. Forest productivity proxies consisted of two proxies representing stem growth dynamics (radial and height growth) and one proxy representing canopy dynamics (cumulative May-to-September Normalized Difference Vegetation Index (NDVI)). Between-proxy and climate-proxy correlations were computed over the 1982–2011 period and over two 15-yr sub-periods. Over the entire period, radial growth significantly correlated with current year July temperature, and height growth and cumulative NDVI significantly correlated with previous and current growing season temperatures. Significant climate responses were quite similar across sites, despite some higher sensitivity to non-growing season climate at inland sites. Significant climate-proxy correlations identified over the entire period were temporarily unstable. Local coherency between proxies was generally insignificant. The spatiotemporal instability in climate-proxy correlations observed for all proxies underlines evolving responses to climate and challenges the modelling of forest productivity. The general lack of local coherency between proxies at our four study sites suggests that forest productivity estimations based on a single proxy should be considered with great caution. The combined use of different forest growth metrics may help circumvent uncertainties in capturing responses of forest productivity to climate variability and improve estimations of carbon sequestration by forest ecosystems. Numéro de notice : A2019-618 Affiliation des auteurs : LIF+Ext (2012-2019) Autre URL associée : vers HAL Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.dendro.2019.125648 Date de publication en ligne : 06/11/2019 En ligne : https://doi.org/10.1016/j.dendro.2019.125648 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95346
in Dendrochronologia > vol 58 (December 2019) . - n° 125648[article]
Titre : Non-stationary response of tree growth to climate trends along the Arctic margin Type de document : Article/Communication Auteurs : Annika Hofgaard, Auteur ; Clémentine Ols Année de publication : 2019 Projets : PPS Arctic / Hofgaard, Annika Article en page(s) : pp 434 - 451 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Arctique
[Termes IGN] croissance des arbres
[Termes IGN] écosystème forestier
[Termes IGN] Pinus sylvestris
[Vedettes matières IGN] Végétation et changement climatiqueRésumé : (auteur) Climate change modulates cold-marginal forest ecosystems through changing growth constraints. Understanding spatiotemporal variations in climate–growth relationships is essential to project forest ecosystem dynamics, and climate–environmental feedbacks. We explored variations in growth and climate–growth relationships, along the Arctic margin in north-western Europe, using Scots pine radial growth chronologies, climate data and links between the geographical origin of dominant air masses and growth-controlling variables. Analyses covered nineteenth century to early twenty-first century, with emphasis on two separate warming periods (early twentieth century, and late twentieth to early twenty-first century) and the intervening cooling period. The analyses revealed spatiotemporally unstable growth responses to climate along the Arctic margin. Spatial growth patterns were most similar during the cooling period. However, climate trends (warming, cooling) were weak drivers of growth-limiting climate variables. Instead, a transition in growth-limiting variables occurred throughout the analysed period. A wide range of growing season and non-growing season climate variables limited growth during the early twentieth century. Thereafter the number of growth-limiting variables progressively decreased. This change was accompanied by a contraction in the spatial correspondence between growth and climate, and by a shift in the geographical origin of dominant air masses. This was particularly emphasized close to the Atlantic during recent warming period. The weak association between growth-limiting variables and climate trends question projections of future ecosystem dynamics based on climate variables identified during specific periods (for example, recent warming period). Such projections may be misleading as the diversity of climate conditions constraining cold-marginal forests will be underestimated. Numéro de notice : A2019-620 Affiliation des auteurs : LIF+Ext (2012-2019) Autre URL associée : vers HAL Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s10021-018-0279-4 Date de publication en ligne : 31/07/2018 En ligne : https://doi.org/10.1007/s10021-018-0279-4 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=95349
in Ecosystems > vol 22 n° 2 (March 2019) . - pp 434 - 451[article]
