Tidal channels are essential morphological structures that mediate hydrological connectivity and maintain coastal resilience. Previous studies on vegetation-induced channel development primarily focused on the stages of initial establishment or later elaboration, characterized by slow and localized changes. However, the impact of rapid shifts in landscape vegetation on the initiation of tidal channels, such as main or tributary channels, remains poorly understood, particularly in micro-tidal system. In this study, we investigated this relationship through satellite imagery analysis and biogeomorphic modeling of a rapidly expanding micro-tidal marsh in the Yellow River Delta, China, which has experienced an invasion by Spartina alterniflora over the past decade. The satellite imagery demonstrated that Spartina alterniflora invasion has increased drainage density and reduced overland flow path length. Our modeling results showed that local flow acceleration between vegetation patches was insufficient to rapidly initiate channels under micro-tidal conditions. As the patchy marsh coalesced and expanded into a contiguously vegetated marsh, it altered landscape-scale flow patterns, diverting from homogenous platform flow to concentrated channel flow. This shift prominently promoted the initiation of tributary channels in the landward marsh zone. The simulated scenarios of vegetation removal highlighted a marked increase in flow divergence from adjacent platforms due to changes in landscape-scale vegetation configuration. This alteration in flow pattern amplified local hydrodynamics, consequently intensifying local channel incision. Our findings emphasize that the channel initiation is significantly influenced by landscape-scale vegetation configuration under micro-tidal conditions, beyond the localized interactions between plants and flow.
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RBINS Staff Publications 2025
The ubiquitous sea cucumber Holothuria (Thymiosycia) arenicola Semper, 1868, externally characterized by a double row of dark blotches of various sizes on its dorsal body wall and a cryptic behaviour, is generally assumed to have a wide tropical distribution, although it has not been reported from the Eastern tlantic. Careful morphological examination, with emphasis on the ossicle assemblage, of type and non-type H. arenicola specimens sampled in the Indian, Pacific and tlantic Ocean, its subjective synonyms and species with a similar colouration and habit, revealed that H. arenicola is often confused with other species. This paper formally separates the different species in the H. arenicola complex, one of them being a species new to science: Holothuria (Thymiosycia) kerriensis sp. nov. dditionally, we describe two other species that are often confused with H. arenicola: Holothuria (Lessonothuria) gracilis Semper, 1868 and H. (Thymiosycia) strigosa Selenka, 1867. The H. arenicola complex per se is keyed-out, with the ossicle assemblage of the musculature being recognised as an important, previously largely neglected, guide. This contribution highlights the importance of building and curating well-maintaned natural history collections to understand biodiversity through time and space.
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RBINS Staff Publications 2024
In this article, we describe the faunal remains found in a 15th-/first half-16th-century deposit from the kitchen of Park Abbey, a Norbertine abbey that owned large farms and estates since the 12th century. The bone material, combined with information from the abbey’s archives allows documenting the provisioning of animal food. Except for the marine fish, that was bought at the markets of Leuven and Mechelen, all food was obtained from the abbey itself or from the farms on its territory. Small game, i.e. hare and rabbit, captured in the warrant the abbey owned, was only occasionally served. As for poultry, chicken, goose, duck and pigeon were found among the food waste, species that, according to the historical accounts, were kept for some time in the kitchen in braided bird cages or baskets before being slaughtered there. Where the slaughtering of the traditional domestic animals (cattle, sheep and pigs) took place is not so clear and their exact origin is not known either but the abbey owned several farms where animal husbandry was practised. As might be expected at an abbey site, the proportion of fish is very high and, unlike urban or most noble contexts in Flanders, freshwater fish strongly predominated. This can be explained by the exploitation of ponds in which different species were kept, judging from the accounts in the archives. Curiously, only remains of carp were found in the kitchen and not of the other species mentioned in the accounts such as bream or other Cyprinidae described as ‘whitefish’ such as roach, rudd or bleak. Pike, described as a more expensive fish that was sometimes specially bought for the abbot, is also completely absent. However, all these species were found in Ename Abbey. Archaeozoological and historical information from French and British sites, for example, also illustrate the importance of these species. For marine fishes, there is good agreement between the relative importance of the species in the archaeozoological material, the number of times those fishes were mentioned in the accounts and the total cost spent on them. Thus, the high proportion of cod in the food waste is striking, and the importance of this group is also evident from the accounts in which stockfish, abberdaan and fresh cod account for about 80% of expenditure on marine fish. The bone material from the kitchen contains no traces of stockfish, and there is apparently also relatively little fresh cod (the smaller specimens from the southern North Sea). Most cod remains appear to be from abberdaan, the salted form that was traded whole, with head, as opposed to dried stockfish without head. Poultry was apparently not considered meat in monasteries, but the fact that quite a lot of mammalian remains were found in the food waste of Park Abbey shows that the abstinence of meat was not very strict and that Augustine’s rule was apparently interpreted quite moderately. What is noticeable, however, is that both the cattle and sheep remains contain a lot of bone material from body parts that are not very fleshy (phalanges and cannon bones, respectively) and may have served rather for cooking a soup or broth. Skeletal elements of body parts with a lot of meat on them are less common.
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RBINS Staff Publications 2025 OA
