Functional Diversity and Traits Assembly Patterns of Benthic Macrofaunal Communities in the Southern North Sea - Towards an Interdisciplinary Approach in Earth System Science - page 178

Maire et al. 2012 ) affect the distribution of trait values within assemblages
(Cornwell et al. 2006 ). Within a local community, competition aims to ecological
differentiation of coexisting species, whereas abiotic

filtering reduces the spread of

trait values, re fl ecting common ecological tolerances (de Bello 2012 ; Kang et al.

2014 ).
The results also revealed that not only functional composition but also functional
diversity differed signi cantly among sampling sites (Fig. 3 ). Spatial differences in

functional diversity of benthic assemblages may emerge as a result of the envi-
ronmental variation as well as distinct behaviors, processes and functions that are
known to prevail in each ecosystem type (Dimitriadis et al. 2012 ; Levin et al. 2001 ).
In conclusion, two important results can be deduced from our results: First, changes
in benthic assemblages (e.g. homogenization of benthic assemblages in this study)
are not necessarily linked with changes in ecological functions played by organ-
isms. Second, biological traits analysis (BTA) is sensitive method in identifying
differences among benthic assemblages and, thus, can provide additional infor-
mation of community distribution patterns (Alves et al. 2014 ). For example, this
method has proven to be a very useful approach for determining changes in benthic
assemblages exposed to different disturbances such as bottom trawling (Tillin et al.
2006 ), marine aggregate dredging (Newell et al. 2004 ; Robinson et al. 2005 ) and
eutrophication (Paganelli et al. 2012 ).

Acknowledgments We are deeply indebted to all the persons who contributed in the sampling,
sample sorting and taxonomic identi cation. We thank the crew of all research vessels especially
“ FS Heincke ” and “ FS Uth ö rn ” for their help with sampling throughout the years. The authors are
also grateful for the very valuable comments of three anonymous reviewers. MSh is funded by the
Iranian Ministry of Sciences, Research and Technology. We gratefully acknowledge partial sup-
port through Earth System Sciences Research School (ESSReS).

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