Temperature and nutrients drive eco-phenotypic dynamics in a microbial food web

Abstract

Anthropogenic increases in temperature and nutrient loads will likely impact food web structure and stability. Although their independent effects have been reasonably well studied, their joint effects—particularly on coupled ecological and phenotypic dynamics—remain poorly understood. Here we experimentally manipulated temperature and nutrient levels in microbial food webs and used time-series analysis to quantify the strength of reciprocal effects between ecological and phenotypic dynamics across trophic levels. We found that (1) joint—often interactive—effects of temperature and nutrients on ecological dynamics are more common at higher trophic levels, (2) temperature and nutrients interact to shift the relative strength of top-down versus bottom-up control, and (3) rapid phenotypic change mediates observed ecological responses to changes in temperature and nutrients. Our results uncover how feedback between ecological and phenotypic dynamics mediate food web responses to environmental change. This suggests important but previously unknown ways that temperature and nutrients might jointly control the rapid eco-phenotypic feedback that determine food web dynamics in a changing world.

Climate Change Factors Interactively Shift Peatland Functional Microbial Composition in a Whole-Ecosystem Warming Experiment

“…S10). We find strong support for a super-linear scaling relationship between body size and volume that indicates protist populations might undergo density-dependent (population) and density-independent (individual phenotypic) responses to climate change (41, 61, 87, 98, 99). Our results indicate a significant relationship between proportional change of traits and size—larger protists’ size (Fig.…”

Temperature and CO2 interactively drive shifts in the compositional and functional structure of peatland protist communities

“…We found that overall, the trend reversals reported here (biomass, abundance, traits) were size-dependent (Figure S14). We find strong support for a super-linear scaling relationship between body size and volume that indicates protist populations might undergo density-dependent (population) and density-independent (individual phenotypic) responses to climate change (Gibert et al, 2022(Gibert et al, , 2023Han et al, 2023;Wieczynski et al, 2021;Yoshida et al, 2003).…”

Mixotrophic microbes create carbon tipping points under warming

“…There is growing recognition that temperature and nutrients interact to impact the structure and dynamics of ecological communities (Binzer et al, 2012(Binzer et al, , 2016Gilbert et al, 2014;Han et al, 2023;Sentis et al, 2014). Discovering conditions under which temperature-nutrient interactions occur and which properties of ecological systems are affected (e.g.…”