Ehnes, Roswitha
- Technische Universität Darmstadt (TU Darmstadt)
Abstract
Warming could strongly stabilize or destabilize populations and food webs by changing the interaction strengths between predators and their prey. Predicting the consequences of warming requires understanding how temperature affects ingestion (energy gain) and metabolism (energy loss). Here, we studied the temperature dependence of metabolism and ingestion in laboratory experiments with terrestrial arthropods (beetles and spiders). From this data, we calculated ingestion efficiencies (ingestion/metabolism) and per capita interaction strengths in the short and long term. Additionally, we investigated if and how body mass changes these temperature dependencies. For both predator groups, warming increased metabolic rates substantially, whereas temperature effects on ingestion rates were weak. Accordingly, the ingestion efficiency (the ratio of ingestion to metabolism) decreased in all treatments. This result has two possible consequences: on the one hand, it suggests that warming of natural ecosystems could increase intrinsic population stability, meaning less fluctuations in population density; on the other hand, decreasing ingestion efficiencies may also lead to higher extinction risks because of starvation. Additionally, predicted long-term per capita interaction strengths decreased with warming, which suggests an increase in perturbation stability of populations, i.e., a higher probability of returning to the same equilibrium density after a small perturbation. Together, these results suggest that warming has complex and potentially profound effects on predator-prey interactions and food-web stability.
Keywords
food webs; global warming; ingestion efficiency; ingestion rates; metabolic theory; predation theory; predator-prey dynamics
Published in
Global Change Biology
2010, volume: 16, number: 8, pages: 2145-2157
SLU Authors
UKÄ Subject classification
Zoology
Ecology
Publication identifier
- DOI: https://doi.org/10.1111/j.1365-2486.2009.02124.x
Permanent link to this page (URI)
https://res.slu.se/id/publ/84567