References of "Van den Bulcke, Jan"
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See detailDensity variations and their influence on carbon stocks: case-study on two Biosphere Reserves in the Democratic Republic of Congo
De Ridder, Maaike; de Haulleville, Thalès ULg; Kearsley, Elizabeth et al

Poster (2014, April 28)

It is commonly acknowledged that allometric equations for aboveground biomass and carbon stock estimates are improved significantly if density is included as a variable. However, not much attention is ... [more ▼]

It is commonly acknowledged that allometric equations for aboveground biomass and carbon stock estimates are improved significantly if density is included as a variable. However, not much attention is given to this variable in terms of exact, measured values and density profiles from pith to bark. Most published case-studies obtain density values from literature sources or databases, this way using large ranges of density values and possible causing significant errors in carbon stock estimates. The use of one single fixed value for density is also not recommended if carbon stock increments are estimated. Therefore, our objective is to measure and analyze a large number of tree species occurring in two Biosphere Reserves (Luki and Yangambi). Nevertheless, the diversity of tree species in these tropical forests is too high to perform this kind of detailed analysis on all tree species (> 200/ha). Therefore, we focus on the most frequently encountered tree species with high abundance (trees/ha) and dominance (basal area/ha) for this study. Increment cores were scanned with a helical X-ray protocol to obtain density profiles from pith to bark. This way, we aim at dividing the tree species with a distinct type of density profile into separate groups. If, e.g., slopes in density values from pith to bark remain stable over larger samples of one tree species, this slope could also be used to correct for errors in carbon (increment) estimates, caused by density values from simplified density measurements or density values from literature. In summary, this is most likely the first study in the Congo Basin that focuses on density patterns in order to check their influence on carbon stocks and differences in carbon stocking based on species composition (density profiles ∼ temperament of tree species). [less ▲]

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See detailExploring ancient charcoal archives in Central Africa
Hubau, Wannes; Morin-Rivat, Julie ULg; Van den Bulcke, Jan et al

Conference (2012, July)

Fossil pollen and charcoal fragments are preserved in lake sediments, in forest soils and in ancient human settlements, were they can be accompanied by artifacts. As such, vegetation history is remarkably ... [more ▼]

Fossil pollen and charcoal fragments are preserved in lake sediments, in forest soils and in ancient human settlements, were they can be accompanied by artifacts. As such, vegetation history is remarkably well archived and sometimes closely linked to cultural history. Direct evidence for Central African vegetation history has been mainly derived from pollen analysis, while the charcoal archive remains hardly explored. However, analysis of charred wood remains has proven worthwhile for palaeovegetation reconstructions in temperate and arid regions. One of the main challenges for charcoal identification in tropical regions is species diversity. Therefore we developed and present a transparent charcoal identification protocol within an umbrella database of species names and metadata, compiled from the on-line database of wood-anatomical descriptions (InsideWood), the database of the world’s largest reference collection of Central African wood specimens (RMCA, Tervuren, Belgium) and inventory and indicator species lists. We applied the protocol on radiocarbon dated charcoal collections sampled in the Mayumbe forest (Bas-Congo, DRCongo), in human settlements along the Aruwimi and Lomami rivers (Province Orientale, DRCongo), along the Sangha river (Sangha department, Republic of the Congo) and in Pallisco logging concessions (East Province of Cameroon). First charcoal identification results are promising and sometimes seem to be taxonomically more precise than pollen identification. However, next to opportunities, we also present some pitfalls when exploring ancient charcoal archives. [less ▲]

Detailed reference viewed: 117 (26 ULg)