caa a22 4500 44538364X CHVBK 20180317143025.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10021-011-9468-0 doi (NATIONALLICENCE)springer-10.1007/s10021-011-9468-0 Context-Specific Bioturbation Mediates Changes to Ecosystem Functioning [Elektronische Daten] [Hazel Needham, Conrad Pilditch, Andrew Lohrer, Simon Thrush] Species are often grouped according to their biological or functional traits to better understand their contribution to ecosystem functioning. However, it is becoming clear that a single species can perform different roles in different habitats. Austrohelice crassa, a burrow-building mud crab shifts its primary bioturbational role to that of a vertical mixer in non-cohesive sediments as frequent burrow collapse greatly enhances sediment reworking. We conducted in situ crab density manipulations in two sediment environments (a non-cohesive sand and a cohesive muddy-sand) to examine if the context-specific functional roles were linked to changes in solute fluxes across the sediment-water interface. Across both habitats, we show that A. crassa regulated nutrient cycling, creating strong density driven effects on solute exchanges. Increasing crab density increased sediment O2 demand and the flux of NH4 + from the sediment, indicating much of the response was physiologically driven. Clear interactions between A. crassa and microphytobenthos were also detected in both habitats. Despite lowering microphyte standing stock through deposit feeding, A. crassa increased benthic primary production per unit of chlorophyll a. Our experiment also revealed important context-specific differences, most notably for NH4 + fluxes, which were higher where burrows and their associated microbial communities were most stable (muddy-sand). This study highlights the need to integrate interactions between organism behavior and habitat type into functional group studies to broaden conceptual frameworks and avoid oversimplification of highly complex organism-sediment interactions. Springer Science+Business Media, LLC, 2011 benthic-pelagic coupling nationallicence Austrohelice crassa nationallicence crab nationallicence intertidal nationallicence density nationallicence solute flux nationallicence ecosystem processes nationallicence Needham Hazel Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton, New Zealand aut Pilditch Conrad Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton, New Zealand aut Lohrer Andrew National Institute of Water and Atmospheric Research, P.O. Box 11-115, Hamilton, New Zealand aut Thrush Simon National Institute of Water and Atmospheric Research, P.O. Box 11-115, Hamilton, New Zealand aut Ecosystems Springer-Verlag 14/7(2011-11-01), 1096-1109 1432-9840 14:7<1096 2011 14 10021 https://doi.org/10.1007/s10021-011-9468-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-011-9468-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Needham Hazel Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton, New Zealand aut NATIONALLICENCE 700 1- Pilditch Conrad Department of Biological Sciences, University of Waikato, Private Bag 3105, Hamilton, New Zealand aut NATIONALLICENCE 700 1- Lohrer Andrew National Institute of Water and Atmospheric Research, P.O. Box 11-115, Hamilton, New Zealand aut NATIONALLICENCE 700 1- Thrush Simon National Institute of Water and Atmospheric Research, P.O. Box 11-115, Hamilton, New Zealand aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag 14/7(2011-11-01), 1096-1109 1432-9840 14:7<1096 2011 14 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer