Understanding how biodiversity supports ecosystem stability is crucial for maintaining their functions and services. Most research has focused on the diversity-asynchrony-stability relationships within single trophic levels, particularly the effects of population asynchrony, leaving gaps in knowledge about these dynamics across multiple levels. 

Community stability can be affected by trophic community asynchrony, leading to mismatches between consumer demand and resource availability, which reduces the stability of trophic interactions. As climate change alters seasonality and disrupts stabilizing structures, it's essential to explore how population asynchrony within and between trophic levels impacts seasonal community stability.

A research group led by Prof. XIE Ping from the Institute of Hydrobiology (IHB) of the Chinese Academy of Sciences revealed that population asynchrony, both within and between trophic levels, had contrasting effects on the stability of consumer community in lake ecosystems. This study was published in Journal of Animal Ecology.

The researchers introduced the concept of “trophic community asynchrony,” quantified as the community asynchrony between resources and consumers over time. This approach was similar to the calculation method for population asynchrony among species and did not rely on phenological mismatch.

Based on monthly monitoring data from the Donghu Experimental Station of Lake Ecosystems of the Chinese Ecosystem Research Network (CERN) from 2003 to 2020, the researchers assessed how population asynchrony within and between trophic levels (i.e. zooplankton and phytoplankton) affected seasonal ecosystem stability under the increasing pressures of climate warming, fish consumption and nutrient enrichment.

The results from linear mixed-effects models (LMMs) and structural equation models (SEMs) indicated that species diversity enhanced community stability primarily by increasing population asynchrony for both phytoplankton and zooplankton. However, trophic community asynchrony harmed zooplankton stability, while phytoplankton stability remained unaffected. This finding supported the match-mismatch hypothesis that trophic mismatch had negative effects on consumer species.

Furthermore, SEMs results showed that warming and top-down effects might simultaneously alter community stability through population dynamics processes within and between trophic levels. In contrast, nutrients primarily affect community stability through processes that occur within individual trophic levels. Additionally, the researchers discovered that rising water temperatures reduced trophic community asynchrony. This finding challenges the common belief that climate warming leads to greater trophic mismatches between primary producers and consumers.

This study provides the first evidence that population and trophic community asynchrony have contrasting effects on the stability of consumer community, offering valuable insights into addressing global environmental change.