Hot and hungry: A mechanistic approach to the direct and indirect
effects of marine heatwaves on plankton communities
Abstract
Marine heatwaves, increasingly frequent, impact marine ecosystems and
services. Still, understanding how temperature affects observed
responses remains limited due to complex interactions among temperature,
abiotic and biotic factors, and community dynamics. Here we try to fill
this gap by exposing simulated plankton communities to seasonal
heatwaves of 4°C with a trait- and size-structured model that accounts
for protists and the life cycle of copepods. Despite the short lifespans
and fast growth rates of plankton, results show that heatwaves affect
communities differently and for an extended period up to six years after
their appearance. Temperature affects species physiology and ecosystem
dynamics, directly and indirectly, shaping structure and biomass.
Species traits, interactions, and functional diversity under changing
temperatures emerge as pivotal. Our study advances mechanistic insights
into marine heatwave impacts, highlighting the complex connections
between temperature, species traits, and ecological interactions.