Author ORCID Identifier : Catherine Febria : Isabelle Barrett : Angus McIntosh : Helen Warburton

Document Type

Conference Proceeding

Publication Date


Publication Title

Proceedings of the Royal Society B




biotic interactions, colonization, priority effects, resistance and resilience


Traditionally, resistance and resilience are associated with good ecological health, often underpinning restoration goals. However, degraded ecosystems can also be highly resistant and resilient, making restoration difficult: degraded communities often become dominated by hyper-tolerant species, preventing recolonization and resulting in low biodiversity and poor eco-system function. Using streams as a model, we undertook a mesocosm experiment to test if degraded community presence hindered biological recovery. We established 12 mesocosms, simulating physically healthy streams. Degraded invertebrate communities were established in half, mimicking the post-restoration scenario of physical recovery without biological recovery. We then introduced a healthy colonist community to all mesocosms, testing if degraded community presence influenced healthy community establishment. Colonists established less readily in degraded community mesocosms, with larger decreases in abundance of sensitive taxa, likely driven by biotic interactions rather than abiotic constraints. Resource depletion by the degraded community likely increased competition, driving priority effects. Colonists left by drifting, but also by accelerating development, reducing time to emergence but sacrificing larger body size. Since degraded community presence prevented colonist establishment, our experiment suggests successful restoration must address both abiotic and biotic factors, especially those that reinforce the ‘negative’ resistance and resilience which perpetuate degraded communities and are typically overlooked



Funding Reference Number



Our work, including support for I.C.B., H.J.W. and C.M.F., was funded by New Zealand’s Ministry of Business, Innovation and Employment (through New Zealand’s Biological Heritage National Science Challenge, C09X1501, Project 3.4, ‘Reigniting Healthy Resilience’). C.M.F. and A.R.M. were also supported by a grant from the Mackenzie Charitable Foundation as part of the Canterbury Waterway Rehabilitation Experiment (CAREX).

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.