Plant functional traits from an early successional grassland community at KBS LTER

Identifying the factors mediating the resilience and invariability of
plant communities and their associated ecosystem functions is critical to
understand the ecological impacts of climate change. Prior work has
explored how classic “community properties” (characterizing a community by
species composition) regulate the resilience and invariability of
ecosystem functioning. Mechanistically, community properties influence
resilience and invariability via species’ traits, and as a result,
“functional properties” (characterizing a community via functional traits)
might better predict these qualities. For example, functional traits
associated with conservative resource-use strategies (e.g., short stature,
low specific leaf area (SLA), high leaf dry matter content (LDMC)) are
expected to promote both resistance to periods of stress or resource
limitation and long-term invariability. While there is a strong conceptual
basis linking functional traits and functional diversity to resilience and
invariability, empirical evidence is thus far mixed, and sourcing accurate
functional trait data may be challenging. Therefore, it is important to
know if community properties are sufficient for evaluating the resilience
and invariability of ecosystem functioning, or if functional properties
provide necessary insights. Capitalizing on a decades-long study, we
tested the effects of plant functional and community properties on the
resistance of ecosystem functioning (a component of resilience) to drought
or long-term invariability. Including functional properties did not
improve our ability to explain primary productivity resistance to droughts
but considerably improved our explanatory power for productivity
invariability. Our results supported expectations that conservative trait
strategies promote ecosystem functioning resistance to perturbations and
temporal invariability. These findings highlight that the utility of
functional properties in explaining the resilience and invariability of
ecosystem functioning may depend on the attribute under consideration and
that functional properties may primarily be useful for identifying the
traits promoting resilience and invariability.