Data from: The functional diversity–productivity relationship of woody plants is climatically sensitive

Plot-scale experiments indicate that functional diversity (FD) plays a
pivotal role in sustaining ecosystem functions such as net primary
productivity (NPP). However, the relationships between functional
diversity and NPP across larger scale under varying climatic conditions is
sparsely studied, despite its significance for understanding
forest–atmosphere interactions and informing policy development. Hence, we
examine the relationships of community-weighted mean (CWM) and functional
dispersion (FDis) of woody plant traits on NPP across China and if such
relationships are modulated by climatic conditions at the national scale.
Using comprehensive datasets of distribution, functional traits and
productivity for 9,120 Chinese woody plant species, we evaluated the
distribution pattern of community-weighted mean and functional dispersion
(including three orthogonal trait indicators: plant size, leaf morphology
and flower duration) and its relationships with NPP. Finally, we tested
the effects of climatic conditions on community-weighted mean/functional
dispersion–NPP relationships. We firstly found overall functional
diversity–NPP relationships, but also that the magnitude of these
relationships was sensitive to climate, with plant size community-weighted
mean promoting NPP in warm regions and plant size functional dispersion
promoting NPP in wet regions. Secondly, warm and wet conditions indirectly
increased NPP by its positive effects on community-weighted mean or
functional dispersion, particularly through mean plant size and leaf
morphology. Our study provides comprehensive evidence for the
relationships between functional diversity and NPP under varying climates
at the large scale. Importantly, our results indicate a broadening
significance of multidimensional plant functional traits for woody
vegetation NPP in response to rising temperatures and wetter climates.
Restoration, reforestation actions and natural capital accounting need to
carefully consider not only community-weighted mean and functional
dispersion, but also their interactions with climate, to predict how
functional diversity may promote ecosystem functioning under future
climatic conditions.