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Preliminary study on the assessment of deadwood volume by the French national forest inventory / Rémi Teissier du Cros in Annals of Forest Science, Vol 66 n° 3 (April - May 2009)  

Public [article]  inAnnals of Forest Science > Vol 66 n° 3 (April - May 2009) . - n° 302 Titre : Preliminary study on the assessment of deadwood volume by the French national forest inventory Titre original : Étude préliminaire de l'évaluation du volume de bois mort à l'Inventaire forestier national français Type de document : Article/Communication Auteurs : Rémi Teissier du Cros, Auteur ; Sandra Lopez, Auteur Année de publication : 2009 Article en page(s) : n° 302 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] bois mort [Termes IGN] échantillonnage (statistique) [Termes IGN] étude préliminaire [Termes IGN] Inventaire Forestier National (organisme France) [Termes IGN] placette d'échantillonnage [Vedettes matières IGN] Inventaire forestier Résumé : (auteur) As the French national forest inventory does not currently monitor the lying compartment of the forest deadwood, the figures obtained on this topic are therefore partial. This study provides cost estimates and guidelines for assessing stumps, and standing and lying deadwood. Comparisons were made between a fixed-area sampling method and a line-intersect one. LIS was judged more time-efficient, especially in dense understorey. Computer simulations were performed in order to estimate the gain in precision with increasing transect lengths. The results showed a continuous improvement in precision associated with increases in transect length. The longest transect tested (50 m) still had a large coefficient of variation, suggesting that improvement in precision at the plot level could still be gained with longer transects. Therefore, from a practical standpoint in terms of fieldwork, we suggest that on a national scale lying deadwood should be measured by line-intersect sampling, whereas stumps, standing dead trees and snags can be monitored using standard fixed-area plots. To meet needs at the national level, we consider that local imprecision could be compensated for by the large number of plots measured each year. Numéro de notice : A2009-705 Affiliation des auteurs : IFN (1958-2011) Thématique : FORET Nature : Article DOI : 10.1051/forest/2009007 Date de publication en ligne : 07/04/2009 En ligne : https://www.afs-journal.org/articles/forest/full_html/2009/03/f07196/f07196.html Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=72057 [article]

Using cover measurements to estimate aboveground understorey biomass in Maritime pine stands / Annabel J. Porté in Annals of Forest Science, Vol 66 n° 3 (April - May 2009)  

Public [article]  inAnnals of Forest Science > Vol 66 n° 3 (April - May 2009) . - n° 307 Titre : Using cover measurements to estimate aboveground understorey biomass in Maritime pine stands Titre original : Estimation de la biomasse aérienne du sous-bois de peuplements de pin maritime à l'aide de mesures de recouvrement Type de document : Article/Communication Auteurs : Annabel J. Porté, Auteur ; Jean-Charles Samalens, Auteur ; Raphaël Dulhoste, Auteur ; Rémi Teissier du Cros, Auteur ; Alexandre Bosc, Auteur ; Céline Meredieu, Auteur Année de publication : 2009 Article en page(s) : n° 307 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes IGN] biomasse forestière [Termes IGN] mise à l'échelle [Termes IGN] modèle de croissance végétale [Termes IGN] Pinus pinaster [Termes IGN] sous-bois Résumé : (auteur) Understorey plays a major role in forest fluxes and stocks balances, however this compartment is generally poorly quantified. Our objectives were to establish models to estimate understorey biomass using vegetation cover measurements and to investigate upscaling methodologies from stand to regional level. Understorey aboveground biomass measurements were undertaken in Maritime pine stands of mesohygric, mesic and dry moorlands in South West France. Average biomass stock in this compartment was estimated to 3.50 t DM ha-1. The more abundant species groups varied with moorland types, with a higher relative contribution of herbaceous species (23.3%), bracken (59.2%) and mosses (31.6%) for mesohygric, mesic and dry moorlands, respectively. For each species group, we established significant relationships to estimate biomass using a volumetric index, based on cover and height measurements. No relationship between stand characteristics and understorey biomass was founded. We investigated the upscaling of these estimations to a several thousands hectare area using understorey cover measurements done along a regular spatial grid. The only significant correlation linked one satellite vegetation index to understorey biomass. We successfully developed empirical relationships to estimate the understorey biomass at the stand level. Further investigations could focus on the analysis of understorey variability over a finer space grid and the potential use of satellite vegetation indexes. Numéro de notice : A2009-710 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1051/forest/2009005 Date de publication en ligne : 10/03/2009 En ligne : https://www.afs-journal.org/articles/forest/full_html/2009/03/f08135/f08135.html Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=72062 [article]