Studie van de invloed van voedselkwaliteit op de meiofaunale rekolonisatie in een natuurlijk mangrovebos (Kenia). Study of the influence of food quality on the meiofaunal recolonisation in a natural mangrove forest (Kenya)
De Busschere, C. (2007). Studie van de invloed van voedselkwaliteit op de meiofaunale rekolonisatie in een natuurlijk mangrovebos (Kenia). Study of the influence of food quality on the meiofaunal recolonisation in a natural mangrove forest (Kenya).. MSc Thesis. Universiteit Gent. Faculteit Wetenschappen: Ghent. 128 pp. |
| Keywords | Aquatic communities > Benthos > Meiobenthos
Isotopes > Carbon isotopes > Carbon 13
Mangroves
Nematoda [WoRMS]
ISW, Kenya, Coast, Gazi Bay [Marine Regions]
Marine/Coastal |
| Abstract | This study fits within a broader study on the rehabilitation of benthic mangrove ecosystems after degradation and reforestation. Especially the study aims to identify the factors that are important for the recovery of the habitat of meiobenthic organims by means of a colonisation experiment. In this study the effect of different species of primary producers at a different stage of degradation (decomposition), on the densities and composition of the colonizing meiobenthic community in a natural R. mucronata forest, is tested. In addition the uptake ofdiatoms was for the first time tested by means of a 13C enrichment experiment. Therefore halfopen experimentel units were filled with inorganic defaunated sediment from a natural mangrove site enriched with on the one side different plant material (seagrass or mangroveleaves) at a different stage of decomposition (0 or 4 days decomposed) and at the other side labelled diatoms. The units with different combinations of plant material and stage ofdecomposition were planted in the sediment of a natural R. mucronata forest and followed up during a time span of maximal two months. In this way the colonization of and changes and in meiobenthic comminities was studied in relation to type of plant material and the decomposition stage of the plant material. Finally CN analyses were carried out to reveal changes in the plantmaterial in respect to decomposition and food quality during the incubation period.A pronounced colonisation mainly by nematodes of all the experimental units was observed 24 hours after starting the experiment in all the units largely by lateral interstitial migration but also partly through the watercolum as a respons to the availability of new space. Especially the units filled with mangrove leaves were capable to attract high numbers of nematodes with even higher densities than in the natural environment. The observed gradual changes in the communitystructure of nematodes in time in this units was linked to changes in the decompostion stage of the plant material and/or the biofilm associated with the decomposing mangrove leaves. Colonisation was characterized by a succession of dominant genera from who the deposit feeders and especially the microvores, reached the highest densities.Colonisation and establishment of deposit feeders was associated with the decomposition process of the mangrove leaves in the experimental units and was linked to the leaching out of tannine. The achievement of densities higher than in the natural environment could be a consequence of the experimental design (burying fragmented leaves and exclusion of crabs). After two months the composition of communities in the units resembled the natural composition due to the disappearing of the experimental conditions in the units. Units with diatoms and sea grasses were despite their higher nutritional value not capable to attract numerous densities of nematodes and it is suggested that these units were repeatedlycolonized by nematodes from the neighbouring environment. The 13C enrichment revealed no uptake of the labelled diatoms by the colonizing nematodes.The reason(s) why mangrove leaves in contrast to seagrass and diatoms are so attractive to the meiofauna remains unanswered. The fact that mangrove leaves are more autochtone than the seagrass and diatoms is a possible explanation although with little evidence sofar. |
| Dataset | - De Busschere, C. (2007). Study of the influence of food quality on meiofaunal recolonisation in a natural mangrove forest (Kenya). Ghent University., more
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