Invasive ecosystem engineers (IEE) are potentially one of the most influential types of biological invaders. They are expected to have extensive ecological impacts by altering the physical–chemical structure of ecosystems, thereby changing the rules of existence for a broad range of resident biota. To test the generality of this expectation, we used a global systematic review and meta-analysis to examine IEE effects on the abundance of individual species and communities, biodiversity (using several indices) and ecosystem functions, focusing on marine and estuarine environments. We found that IEE had a significant effect (positive and negative) in most studies testing impacts on individual species, but the overall (cumulative) effect size was small and negative. Many individual studies showed strong IEE effects on community abundance and diversity, but the direction of effects was variable, leading to statistically non-significant overall effects in most categories. In contrast, there was a strong overall effect on most ecosystem functions we examined. IEE negatively affected metabolic functions and primary production, but positively affected nutrient flux, sedimentation and decomposition. We use the results to develop a conceptual model by highlighting pathways whereby IEE impact communities and ecosystem functions, and identify several sources of research bias in the IEE-related invasion literature. Only a few of the studies simultaneously quantified IEE effects on community/diversity and ecosystem functions. Therefore, understanding how IEE may alter biodiversity–ecosystem function relationships should be a primary focus of future studies of invasion biology. Moreover, the clear effects of IEE on ecosystem functions detected in our study suggest that scientists and environmental managers ought to examine how the effects of IEE might be manifested in the services that marine ecosystems provide to humans.
Bibliographical noteFunding Information:
EU Seventh Framework Programme for Research, Technological Development and Demonstration, Grant/Award Number: FP7/ 2007-2013; UK Natural Environment Research Council; Department for Environment, Food and Rural Affairs, Grant/ Award Number: NE/L003279/1; Estonian Ministry of Education and Research, Grant/ Award Number: SF0180005s10; Estonian Research Council, Grant/Award Number: IUT02-20
2007-2013) within the Ocean of Tomorrow call under Grant Agreement No. 266445 for the project Vectors of Change in Oceans and Seas Marine Life (VECTORS). We would like to thank the two anonymous reviewers for their constructive suggestions and comments. Many thanks for team members of the Marine Community Ecology Lab (Rilov lab) at IOLR for their help with data extraction, and to the broader VECTORS community, and especially to Melanie Austen, for insightful discussions. AMQ and PJS acknowledge support from the UK Natural Environment Research Council and Department for Environment, Food and Rural Affairs (grant number NE/L003279/1, Marine Ecosystems Research Programme). HO and JK were partly funded by the Estonian Ministry of Education and Research (grant SF0180005s10) and the Estonian Research Council (IUT02-20).
This research was funded by the EU Seventh Framework Programme
© 2017 John Wiley & Sons Ltd
- biodiversity–ecosystem functioning
- biological diversity
- ecosystem engineers
- nutrient flux
- primary production
- systematic review
ASJC Scopus subject areas
- Global and Planetary Change
- Environmental Chemistry
- Environmental Science (all)