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ENFORCE: Expertiserapport ref. exp-572 (plaat 1A-639543503) & exp-573 (plaat 2A-639543891) - 18/9/2024 & addendum 14/10/2024
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The Cambro-Ordovician Gondwana Superfan in Central Africa: insights from the Paleozoic sandstones of Inkisi Group, Congo
No full textThe Paleozoic arkoses of the Inkisi Group in both the Republic and the Democratic Republic of the Congo has been investigated in order to examine whether they can represent an alluvial fan originating from the Gondwana supermountains in Northern and East Africa. This study focuses on outcrops description, lithofacies, bounding surfaces, architectural and sequential organization of sedimentary bodies and paleocurrents. The aim is to determine the nature of the Inkisi sandstones, the provenance of its sediments and the depositional setting, in order to test whether the East African orogen was also the sediments source for the formation of sedimentary fan in the western part of Central Africa. The study shows that the Inkisi Group consists of various sandstone lithofacies, amalgamated by conglom erates. The sediments are immature composed of quartz and feldspars associate with lithic fragments and micas. The sediments originated from the erosion of the West-Congolian belt and the Congo Craton, and were trans ported by braided fluvial system under mainly upper flow regime and secondarily lower flow regime. Sediments were deposited in the Inkisi basin, which was extensional and affected by burial. The Inkisi sediments setting up in a proximal to medial distributary zone of an alluvial megafan. The flows were directed southward, as opposed to paleofans originating from the Gondwana supermountain in Northern and East Africa. Thus, the Inkisi sandstone constitutes a new alluvial megafan distinguished from the Gondwana superfan derived from the Gondwana supermountain. It originated from the Pan-African belt of Mayombe and the Congo Craton. We name this megafan the Cambro-Ordovician alluvial megafan of Central Africa
Wood identification techniques for combatting illegal logging: Applications on macroscopic wood anatomical assessment using digital classification keys and AI
No full textWood identification is a key step in the enforcement of laws and regulations aiming at combatting illegal timber trade. It is a major concern especially for countries with species-rich forest resources. The most used, cheapest and most generally applicable method for wood identification is the anatomical assessment by trained experts. Such assessment includes the observation of features on tissues and cells on the transversal, tangential and radial plane and aims at scoring diagnostic features to characterize the botanical taxon. Traditionally, this process requires a laboratory setting to prepare microscopic thin sections, and large collections of reference material to identify a wood specimen unto species level. Some features do not require the use of laboratory equipment to observe them as they are visible with the unaided eye or a handheld macro-lens. Those macroscopic features can be used to indicate the genus or species of the specimen, and thereby provide a cheap way to identify wood. Nowadays, modern technology can provide simplified ways in order to aid macroscopic wood identification such as digital identification keys. These are essentially decision trees, using large databases of textual descriptions on anatomical features or other distinguishing characteristics. They are consulted by giving the observed features as input and result in a list of possible genera or species. The main advantages of classification keys are their speed and flexibility, although they still require training of the user in recognition of macroscopic features. AI is another example of modern technology that can simplify identification, as learning to use a picture snapping app or device is easy in comparison to the long and difficult training on wood anatomy. Machine learning and specifically deep learning can be used to identify the botanical taxon of specimens by taking images of the wood surface and using Convolutional Neural networks to classify the
Natural emissions of VOC and NOx over Africa constrained by TROPOMI HCHO and NO2 data using the MAGRITTEv1.1 model
Full text linkNatural emissions (vegetation, soil, and lightning) are the dominant sources of non-methane biogenic volatile organic compounds (BVOCs) and nitrogen oxides (NOx≡ NO + NO2) released into the atmosphere over Africa. BVOCs and NOx interact with each other and strongly impact their own chemical lifetimes and degradation pathways, in particular through their influence on hydroxyl radical levels. To account for this intricate interplay between NOx and VOCs, we design and apply a novel inversion setup aiming at simultaneous optimization of monthly VOC and NOx emissions in 2019 in a regional chemistry-transport model, based on Tropospheric Ozone Monitoring Instrument (TROPOMI) HCHO and NO2 satellite observations. The TROPOMI-based inversions suggest substantial underestimations of natural NOx and VOC emissions used as a priori in the model. The annual flux over Africa increases from 125 to 165 Tg yr−1 for isoprene, from 1.9 to 2.4 TgN yr−1 for soil NO emissions, and from 0.5 to 2.0 TgN yr−1 for lightning NO emissions. Despite the NOx emission increase, evaluation against in situ NO2 measurements at seven rural sites in western Africa displays significant model underestimations after optimization. The large increases in lightning emissions are supported by comparisons with TROPOMI cloud-sliced upper-tropospheric NO2 volume mixing ratios, which remain underestimated by the model even after optimization. Our study strongly supports the application of a bias correction to the TROPOMI HCHO data and the use of a two-species constraint (vs. single-species inversion), based on comparisons with isoprene columns retrieved from the Cross-track Infrared Sensor (CrIS)
Technical Expertise Report ref. exp-67, 23/1/2015 - Applicant: Veldeman Structure Solution, Industrieterrein Vostert 1220, 3960 Bree, 31/10/2014
No full textHidden species diversity in the <i>Enteromius</i> Cope, 1867 (Teleostei: Cyprinidae) from the Aruwimi basin (Middle Congo) in the Okapi Wildlife Reserve (Democratic Republic of the Congo)
No full textTwo new African minnow species, Enteromius cerinus sp. nov. and Enteromius ruforum sp. nov., are described for science from the Angadiko River, a left-bank sub-affluent of first order of the Nepoko River, draining the north-eastern part of the Okapi Wildlife Reserve (OWR). Both new species belong to the group of Enteromius for which the last unbranched dorsal-fin ray is flexible and underrated. Within this morphological group, both are most similar to Enteromius kamolondoensis, especially in life colour pattern characteristics. However, Enteromius cerinus sp. nov. differs from E. kamolondoensis by its low number of circumpeduncular scales, 10 11 (vs. 12), low maximum body depth, 22.8% 25.7% standard length (Ls) (vs. 26.1% 30.0%), and long anterior and posterior barbel lengths, 32.6% 35.3% head length (LH) (vs. 23.6% 27.2%) and 41.6% 43.9% LH (vs. 30.3% 34.9%), respectively. Further, E. ruforum sp. nov. is also easily distinguished from E. kamolondoensis by its high maximum body depth, 30.6% 33.3% Ls (vs. 26.1% 30.0%), and small, isometric, eye diameter, 26.2% 28.0% LH (vs. 29.1% 31.9%). A barcoding study (mtDNA, cytochrome oxidase subunit I [COI]) revealed that specimens of both new species form lineages well differentiated from those of other available species. As such, (i) E. cerinus sp. nov. diverges from E. kamolondoensis by a K2P genetic distance (GD) of 10.3% and (ii) E. ruforum sp. nov. by a K2P GD of 11.2%. To the present day, the fish fauna of the left-bank sub-affluents of the Nepoko River, in general, remains poorly known or undocumented. Unfortunately, at the same time, multiple anthropogenic impacts are affecting this fauna, such as (i) the destruction of habitats along the river banks for agriculture and fishing and (ii) the use of illegal fishing practices, such as fishing with plant-based ichthyotoxins during ecopage, which is combined with dam building. As a result of the demographic growth, this ecopage results in overfishing and thus is threatening both new species in particular, but all other co-occurring fish species as well. Both new species, E. cerinus sp. nov. and E. ruforum sp. nov., should thus be considered Vulnerable (VU) according to IUCN criterion D2. It is therefore hoped that their discovery highlights the urgent need for a better protection and further in situ exploration of the reserve's freshwater (fish) biodiversity, in general, and that of those small sub-affluents, in particular
