A Natural History of the Future

Why are biodiversity—ecosystem functioning relationships so elusive? Trophic interactions may amplify ecosystem function variability 

Wu et al., 2022.

1. The relationship between biodiversity and ecosystem functions (BEFs) has attracted great interest. Studies on BEF have so far focused on the average trend of ecosystem function as species diversity increases. A tantalizing but rarely addressed question is why large variations in ecosystem functions are often observed across systems with similar species diversity, likely obscuring observed BEFs.
2. Here we use a multi-trophic food web model in combination with empirical data to examine the relationships between species richness and the variation in ecosystem functions (VEFs) including biomass, metabolism, decomposition, and primary and secondary production. We then probe the mechanisms underlying these relationships, focusing on the role of trophic interactions.
3. While our results reinforce the previously documented positive BEF relationships, we found that ecosystem functions exhibit significant variation within each level of species richness and the magnitude of this variation displays a hump-shaped relationship with species richness. Our analyses demonstrate that VEFs is reduced when consumer diversity increases through elevated nonlinearity in trophic interactions, and/or when the diversity of basal species such as producers and decomposers decreases. This explanation is supported by a 34-year empirical food web time series from the Gulf of Riga ecosystem.
4. Our work suggests that biodiversity loss may not only result in ecosystem function decline, but also reduce the predictability of functions by generating greater function variability among ecosystems. It thus helps to reconcile the debate on the generality of positive BEF relationships and to disentangle the drivers of ecosystem stability. The role of trophic interactions and the variation in their strengths mediated by functional responses in shaping ecosystem function variation warrants further investigations and better incorporation into biodiversity—ecosystem functioning research.

https://bit.ly/3BQ6WJq

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Living systems are cognitive systems, and living as a process is a process of cognition. This statement is valid for all organisms, with or without a nervous system.

Humberto Maturana and Francisco Varela

(Santiago theory of cognition)

 

“I don’t like either the word or the thing. People ought to saunter in the mountains - not hike! Do you know the origin of that word ‘saunter?’ It’s a beautiful word. Away back in the Middle Ages people used to go on pilgrimages to the Holy Land, and when people in the villages through which they passed asked where they were going, they would reply, ‘A la sainte terre,’ ‘To the Holy Land.’ And so they became known as sainte-terre-ers or saunterers. Now these mountains are our Holy Land, and we ought to saunter through them reverently, not ‘hike’ through them.”

John Muir