Data from: Warm-loving species perform well under limiting resources: Trait combinations for future climate

Ecosystems are warming alongside shifts in other abiotic factors, leading
to interactive effects on populations and communities. This underscores
the importance of studying how organisms respond to multiple environmental
changes simultaneously. In pelagic ecosystems, as surface waters warm,
longer and stronger periods of thermal stratification lead to changes in
resource (light and nutrient) availability. We investigate the combined
effects of temperature and resource availability on the growth rates of 19
populations (comprising 17 species) of freshwater phytoplankton to examine
how temperature influences the minimum resource requirements (and Monod
parameters) for light, nitrogen, and phosphorus. We also evaluate how
resource availability affects each population's thermal traits (i.e.,
thermal performance curve -­ TPC -­ parameters). When averaged across all
populations, the requirements for light and phosphorus tended to display a
U-shaped relationship with temperature. Individual populations varied
greatly in their responses to temperature, leading to shifts in the
identity of the best competitor across the thermal gradient, particularly
for nitrogen and phosphorus. TPC responses to resource limitation were
highly variable, but thermal optima and maxima of individual populations
often decreased with resource limitation, and thermal breadths (range
where growth is 80% or more of its maximum) often increased due to a
flattening of TPCs. Across all populations and resource types, the maximum
optimum temperature across resource levels (maximum Topt) tended to be
positively correlated with the temperature at which populations had the
lowest resource requirements (minimum R). However, the temperature at
which populations were the best competitors tended to be ~5°C colder on
average than the temperature at which they grew the fastest. The
populations with the highest thermal optima also had the lowest minimum
resource requirements. Our findings reveal trait associations suggesting
that some taxa already exhibit trait combinations that would support high
performance under future warm and resource-­ limited conditions.