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The use of tree allometric equations into national forest inventories : French case study [diaporama] / Antoine Colin (2015)  

Public Titre : The use of tree allometric equations into national forest inventories : French case study [diaporama] Type de document : Article/Communication Auteurs : Antoine Colin , Auteur ; Jean-Christophe Hervé (1961-2017) , Auteur ; Laurent Saint André, Auteur Editeur : Saint-Mandé : Institut national de l'information géographique et forestière - IGN (2012-) Année de publication : 2015 Conférence : UN-REDD 2015, Regional Technical Workshop Minding the gap: Scaling biomass allometric equations for National Forest Inventories in South and Central America 13/01/2015 15/01/2015 Turrialba Costa Rica OA Abstracts only Langues : Anglais (eng) Résumé : (auteur) Introduction : The forest land cover area is 29.7% of the country; of those, 75% belongs to private owners and 25% is public. The total volume of wood in forests is 2.5 billion m3 (4th European country after Russia, Germany and Sweden), where 12 tree species contribute to 80% of that volume. Yearly, the Institute (IFN) in charge of the national forest inventory does an assessment of forest inventory. The results provided by administrative departments and by Sylvo Ecological Regions show 91 SER (Sylvo Ecological Region) that are determinants of forest growth conditions and habitats, and 12 GRECO (Ecological regions), each one regrouping several SER. Methods : Three compartments were considered for the model: stem, bark, branches, twigs to make the equation: Where, Vtot is the total volume; Htot, the total height. The actual forest inventory included 8 volume equations, targeting around 7 specific species (for the main tree species in France). Results : Carbon stock in woody biomass in 2010 is consistent with regional patterns (higher stocks in mountains area and lower stocks in the Mediterranean zone). Between 1980 and 2010, forest areas increased due to recolonisation of abandoned agricultural lands + afforestation with coniferous species. This caused an increase in carbon stocks for broadleaves species (higher wood density and higher branch proportion, less market opportunities). The growing stock in the French forest increased between 1980 and 2013: 810 m3 (570 broadleaved + 240 coniferous), of those 710 m3 was in private lands and 100 m3 in public lands. 19 Conclusions : Although it comprised over 4000 trees, the sample used to build the total volume allometric equations (Vallet et al. 2006) was probably not fully representative of the entire French forests because many species are absent especially for broadleaves species, trees mainly collected in the northern part of France, data are old (1920-1955) while several factors may have modified the shape of the trees (sylvicultural changes, genetic improvement, environmental changes, etc.), data have mainly been collected in high forest (half of the forest structure). The NFI field campaigns were taken advantage of to take additional in situ measurements (ex: standing stem volume, wood density cores, etc.). Random sampling is of utmost importance to ensure the largest coverage of the forest resource. The same variables should be used for building the models and their application to prevent methodological biases (ex. if DBH is used in the equation, DBH should be measured on the field, not the circumference). The methods for estimating biomass through allometric equations in wood production oriented forests (like in France and in most of European countries) are probably not the same for natural forests. Numéro de notice : C2015-039 Affiliation des auteurs : LIF+Ext (2012-2019) Thématique : FORET Nature : Communication nature-HAL : ComSansActesPubliés-Unpublished DOI : sans En ligne : https://hal.science/hal-02792826/document Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99979