|Revealing species assembly rules in nematode communities|
Merckx, B.; Steyaert, M.; Ferrero, T.; McEvoy, A.; Gheskiere, T.; Schratzberger, M.; Lambshead, J.; Vanreusel, A.; Vincx, M.; Vanaverbeke, J. (2011). Revealing species assembly rules in nematode communities, in: Merckx, B. Habitat suitability and community modelling of marine benthos = Modeleren van habitatgeschiktheid en gemeenschapsstructuren van marien benthos. pp. 25-43
In: Merckx, B. (2011). Habitat suitability and community modelling of marine benthos = Modeleren van habitatgeschiktheid en gemeenschapsstructuren van marien benthos. PhD Thesis. Ghent University: Gent. ISBN 978-90-77713-87-7. 309 pp., more
Patchiness; Nematoda [WoRMS]; Marine
Null models; Nematoda; species assembly rules; aggregated pattern; patchiness
|Authors|| || Top |
- Merckx, B., more
- Steyaert, M., more
- Ferrero, T.
- McEvoy, A., more
- Gheskiere, T., more
- Schratzberger, M., more
- Lambshead, J.
- Vanreusel, A., more
- Vincx, M., more
- Vanaverbeke, J., more
Species assemblages are not randomly assembled from a local species pool; they often show segregated or aggregated distribution patterns. These patterns may be attributed to both biotic and abiotic factors. On a large scale abiotic factors may be important, while on a smaller scale other factors such as species interactions may become essential. Here we will focus on small-scale patterns in nematode communities. Species patterns are generally revealed by null models based on presence/absence data. Since there is an increasing chance of falsely rejecting the null hypothesis of a random assembled community with increasing matrix size, we used an algorithm generating independent null matrices and applied a large number of swap attempts to build a null matrix. Moreover, we applied an additional test to reveal the susceptibility of the analyses of checker and the C-, T- and Vscore to a Type I error for randomised data. To minimise the influence of the abiotic environment, we restricted the swapping algorithm of the null model to the replicate samples of one sampling event. Since stronger species interactions are expected for species of the same functional type, the nematode data was split according to the four feeding types defined by Wieser (1953). Our data indicate that species tend to aggregate and co-occur more often in some replicate samples than would be expected from a random species distribution of the local species pool. This is in accordance with the patchy distribution patterns known for nematode species. These aggregated patterns are also found for the different feeding types. The factors causing these aggregated patterns cannot be established since they are not included in the data, but the data do indicate that competitive exclusion is unlikely at the scale of a sample core.