Abstract

The use of discontinuity analysis to assess resilience and alternative regimes of ecosystems has mostly been based on animal size. We so far lack systematic comparisons of size-based and abundance-based approaches necessary for assessing the performance and suitability of the discontinuity analysis across a broader range of organism groups. We used an outdoor mesocosm setup to mimic shallow lake ecosystems with different depths (1.2 m deep, “shallow”; 2.2 m deep, “deep”) and trophic status (i.e. low and high nutrient status characteristic of mesotrophic and hypertrophic lakes, respectively). We compared resilience assessments, based on four indicators (cross-scale structure, within-scale structure, aggregation length and gap size) inferred from the size and abundance (biovolume) structure of phytoplankton communities. Our results indicate that resilience assessments based on size and biovolume were largely comparable, which is likely related to similar variability in the size and abundance of phytoplankton as a function of nutrient concentrations. Also, nutrient enrichment rather than water depth influenced resilience, manifested in decreased cross-scale structure and increased aggregation lengths and gap sizes in the high-nutrient treatment. These resilience patterns coupled with decreased phytoplankton diversity and dominance of cyanobacteria in the high nutrient treatment support the use of discontinuity analysis for testing alternative regimes theory. Concordance of size-based and abundance-based results highlights the approach as being potentially robust to infer resilience in organism groups that lack discrete size structures.

Keywords

Quantifying resilience; Phytoplankton communities; Eutrophication; Water depth; Alternative regimes; Discontinuity analysis

Published in

Science of the Total Environment
2020, Volume: 746, article number: 141110

SLU Authors

• Baho, Didier Ludovic

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Drakare, Stina

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Johnson, Richard

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Angeler, David

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1016/j.scitotenv.2020.141110

Permanent link to this page (URI)

https://res.slu.se/id/publ/107359