Data from: No evidence for larger leaf trait plasticity in ecological generalists compared to specialists

Aim: Phenotypic plasticity is hypothesized to contribute to a species’
capacity to occupy broader ranges of conditions and to optimally exploit
resource-rich environments. Although this is supported by case studies of
individual species, we do not know whether larger plasticity in functional
traits is generally associated with ecological characteristics of species
such as their niche breadth or niche position. Here, we test whether there
is such a relationship for plasticity in leaf functional traits. Location:
Central Europe. Methods: We surveyed 110–132 grassland plant species for
plasticity in five leaf traits [leaf thickness, leaf greenness, specific
leaf area, leaf dry matter content (LDMC) and plant height] and for
biomass changes in response to experimental fertilization, shading and
waterlogging. Trait plasticity and changes in biomass were compared with
species niche characteristics along three environmental axes (light,
nutrient and soil moisture) derived from a vegetation-plot database.
Results: Although response of several traits to experimental treatments
correlated with niche position and breadth (change in leaf thickness,
greenness and biomass in response to fertilization; change in LDMC due to
shading; and change in plant height and biomass due to waterlogging), we
did not find evidence that species with broader niches or species from
resource-rich environments are more plastic. Ecological generalists even
turned out to be less plastic in some traits, including leaf thickness
after fertilization and waterlogging. Generalists also displayed smaller
plastic response averaged across all five traits (‘composite plasticity’),
though the relationship was not statistically significant. This composite
plasticity was positively related to absolute change in biomass in all
experimental treatments. Main conclusions: Our results suggest that larger
species-level plasticity in leaf traits is not necessarily associated with
a capacity to occupy a broader range of environments or with growth in
resource-rich habitats; rather, it may indicate species’ sensitivity to
environmental changes.