14-18 l’art dans la tourmente

Conference, Andenne (Belgium), 6-7.10.2015

Seasonality of tree growth and carbon uptake through assessments of the cambial phenology in the Biosphere Reserve of Yangambi in the Democratic Republic of the Congo

Tropical forests play a significant role in the global carbon cycle. The carbon is taken up through the xylogenesis, a key mechanism resulting from the division, differentiation, and lignification of tree cells in the cambial zone. This periodic process depends on environmental and genetic drivers that influence wood structure and anatomy. Yet patterns of seasonal cambial growth remain poorly understood for tropical forests, especially for those experiencing low seasonality. However, detailed information on the xylogenesis complements assessments of radial growth, measured through on-the-ground inventories, and the quantification of ecosystem carbon sinks and sources, assessed by eddy-covariance sensors. This is gaining relevance in the context of Congo Basin forests, because of the operationalization of the first flux tower (Congoflux) in semi-deciduous African forests and the increasing number of classic, intensive, and large-scale permanent inventory plots. Cambial phenology monitoring is therefore mandatory to link effective tree growth and permanent carbon sequestration. To meet this goal, we first need to better understand the tree growth cycles. For this purpose, we monitored the cambial phenology of six representative species of Yangambi forests (Democratic Republic of Congo) over the seasonal transition for which we suppose the onset of cambial activity. We characterized the cambial phenology among and within species through a study of the cells and tissues in the cambial zone over time. The description of xylogenesis phases over climatic variations is required to grasp how environmental changes affect ecosystem dynamics and their ability to provide ecosystem services. Studying the cambial phenology is therefore essential for a better understanding of the carbon cycle in a forest ecosystem

Een zilveren kelk van de abdis van Herkenrode in de kerk van Jesseren

Jeroen Reyniers en Katrien Houbey, ‘Een zilveren kelk van de abdis van Herkenrode in de kerk van Jesseren’, Tijdschrift voor Interieurgeschiedenis en Design, 46, 2024 (2025), p. 1-9. An art historical study of a silver chalice; identification of the silver marks, the depicted coat of arms and a context analysis in the archives focussing on the provenance and the link between Herkenrode Abbey and the church of Jesseren.A silver chalice belonging to the abbess of Herkenrode in Jesseren church In the Holy Cross church in Jesseren near Borgloon, a thorough inventory campaign in 2018 led to the discovery of a silver chalice that had not previously been subjected to study. Stylistically, the chalice can be dated back to the seventeenth century, and bears a coat of arms with the motto “Pie et Provide”. In previous inventories, the chalice had only been described briefly, and it had apparently been impossible to identify the hallmark or the coat of arms with the accompanying motto. The hallmark, although difficult to read, can be linked to silversmith Peter II Massart from Sint-Truiden, who produced the chalice between 1661 and 1663. Since her coat of arms appears on the foot of the chalice, the object must have been commissioned by Anna Catharina de Lamboy (1609-1675), abbess of the Cistercian abbey of Herkenrode, near Hasselt. In the Jesseren church archives, the oldest archival source mentioning the chalice dates from 1883. Whether the chalice was made for the Herkenrode abbey or specifically for the church in Jesseren is debatable. There is insufficient source material to rule out extensive use within the abbey walls. For centuries, the Herkenrode abbey held the patronage rights of the church of Jesseren. It appointed the parish priest and was responsible for the maintenance of the building and the cult. A visitation report from 1666 states that a new silver chalice has been put into use in this church. It is very likely a reference to the chalice that is the subject of this study