Stressor richness intensifies productivity loss but mitigates biodiversity loss

• Published in: Ecology and evolution Vol. 11; no. 21; pp. 14977 - 14987
• Main Authors: Holmes, Mark, Spaak, Jurg Werner, De Laender, Frederik
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.11.2021; John Wiley and Sons Inc; Wiley
• Subjects: Anthropogenic factors; Biodiversity; Biodiversity loss; community ecology; Complementarity; Ecological function; Ecosystems; Efficiency; Environmental changes; Experimental research; Hypotheses; multiple stressors; Population growth; Positive selection; theoretical ecology; traits; traits; theoretical ecology; community ecology; ecosystems; multiple stressors
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.8182

Ecosystems are subject to a multitude of anthropogenic environmental changes. Experimental research in the field of multiple stressors has typically involved varying the number of stressors, here termed stressor richness, but without controlling for total stressor intensity. Mistaking stressor intensity effects for stressor richness effects can misinform management decisions when there is a trade‐off between mitigating these two factors. We incorporate multiple stressors into three community models and show that, at a fixed total stressor intensity, increasing stressor richness aggravates joint stressor effects on ecosystem functioning, but reduces effects on species persistence and composition. In addition, stressor richness weakens the positive selection and negative complementarity effects on ecosystem function. We identify the among‐species variation of stressor effects on traits as a key determinant of the resulting community‐level stressor effects. Taken together, our results unravel the mechanisms linking multiple environmental changes to biodiversity and ecosystem function. Experimental research in the field of multiple stressors typically involves varying the number of stressors, but without controlling for total stressor intensity. We incorporate multiple stressors into community models and show that, at constant total stressor intensity, increasing stressor richness aggravates joint stressor effects on ecosystem functioning, but reduces effects on species persistence and community composition. We identify the among‐species variation of stressor effects on traits as a key determinant of the resulting community‐level stressor effects.