Évolution des stocks de carbone dans la biomasse des forêts belges entre 1984 et 2000

Abstract

-• Carbon sequestration in forest ecosystems is an important though still uncertain process in the global greenhouse gas balance.• We computed biomass organic carbon (BOC) stocks of spatially explicit forested landscape units (LSU) in Belgium based on data collected in the regional forest inventories of 1984 (Wallonia region only) and 2000 (Wallonia and Flanders). C stock changes between 1984 and 2000 were estimated for Wallonia.• The total BOC pool stored in Belgian forests in 2000 amounts to 57.8 Mt C in 6 222 km 2 , or 10.0 kg C m −2 in broadleaf, 9.5 kg C m −2 in coniferous and 8.7 kg C m −2 in mixed forest. Based on previous soil organic carbon (SOC) analysis for the same LSU, BOC and SOC stock per LSU appeared only weakly correlated. The total BOC sequestration between 1984 and 2000 equals 5.7 Mt C over an area of 5 107 km 2 , resulting in a flux of 0.07 kg C m −2 y −1 . The BOC content of broadleaf forest in Wallonia increased with 6%, of coniferous forest with 32% and of mixed forest with 11%.• The observed regional differences in BOC stocks and in BOC sequestration rates are explained by the forest age-class distribution and site productivity. The strength of the spatially explicit approach lies in the fact that BOC and SOC data originating from diverse sampling strategies can be combined for spatial or temporal comparison of C stocks.forest inventory / Belgium / forest biomass / soil / carbon sequestration Résumé -Évolution des stocks de carbone dans la biomasse des forêts belges entre 1984 et 2000.• La séquestration du carbone par les écosystèmes forestiers constitue un processus important dans le bilan global des gaz à effet de serre, mais il subsiste des incertitudes dans sa compréhension. inventaire forestier / Belgique / biomasse / sol / séquestration de carbone

Current status and predicted impact of climate change on forest production and biogeochemistry in the temperate oceanic European zone: review and prospects for Belgium as a case study

“…At the same time, soil organic C stock (SOC) was 94.4 Tg C (Lettens et al 2008). Average BOC stocks are about 9-10 kg C m -2 (Table 4), and are similar to values reported for neighbouring countries (e.g.…”

“…Repeated assessments of BOC and SOC stocks over the last few decades have revealed that Belgian forests as a whole are a carbon sink, storing about 1.2 Tg C year -1 (64% BOC and 36% SOC) (Lettens et al 2005(Lettens et al , 2008Vande Walle 2007). This high sequestration capacity is likely due to the high forest production (probably due to the young ages of the Belgian forests) and to an approach to forest management that is more focused on C storage (Lettens et al 2005(Lettens et al , 2008.…”

“…Total biomass organic carbon (C) stock (BOC) in Belgian forests was 57.8 Tg C in 2000 (Lettens et al 2008), of which about 78% was stored aboveground, 20% belowground and 2% in necromass (MCPFE 2007). At the same time, soil organic C stock (SOC) was 94.4 Tg C (Lettens et al 2008).…”

Description of a new procedure to estimate the carbon stocks of all forest pools and impact assessment of methodological choices on the estimates

“…Our living biomass CS estimate of 87 Mg ha -1 is 8 and 18 % smaller than estimations for the year 2000 also based on RFIW data in Lettens et al (2008) andin Vande Walle et al (2005). The Vande Walle's estimate is derived from Belgian wood volume equations (Dagnelie et al 1999) in combination with Vande Walle's 'BEF1' biomass factor.…”

“…External databases are thus needed for estimating the total carbon stock of the forest and the carbon stocks of all pools separately. Soil pool can be equal to or even greater than tree biomass (Lettens et al 2008;Liski et al 2006;Nabuurs et al 2003). …”