Phylogenetic measures of diversity contain information on evolutionary divergences amongst species, thus representing the diversity of phylogenetically conserved traits related to resource use, acquisition and storage. Thereby, distantly related species are expected to respond differently to changing environmental conditions. These functional traits can be general traits related to the fast–slow growth rate spectrum, such as specific leaf area and wood density, and also physiological traits triggering plant responses to climatic fluctuations, such as flowering and leafing phenologies. [Mazzochini 2019: 1431].
This study shows that (phylogenetic) plant diversity helps to stabilize ecosystem productivity – even at the landscape scale. Previous experiments have shown that plant diversity increases the stability of ecosystem productivity in small patches of vegetation where plant interaction boosts overall productivity, as does difference in response to environmental fluctuations among different species. The present study increases the scale of observation to the landscape level, and finds that biodiversity increases ecosystem stability due to varied or “asynchronous responses of distantly related species during environmental fluctuations” [Mazzochini 2019: 1431].
Our results expand by several orders of magnitude the spatial scale of evidence that high biodiversity strengthens the resistance of key ecosystem features to climatic fluctuations. Specifically, we show that the positive relationship between phylogenetic diversity and stability reported in local experiments can also be observed at larger spatial extents and grain sizes using available biodiversity databases and modelling techniques. As we expected, in the analyses at the landscape resolution, phylogenetic diversity correlates with vegetation productivity stability mainly due to a reduction in productivity variability across the years, and not by increasing average productivity, which was mostly driven by climatic variables [Mazzochini 2019: 1435].
Mazzochini, Guilherme G., et al., 2019, Plant phylogenetic diversity stabilizes large‐scale ecosystem productivity, Global Ecology and Biogeography 28, https://onlinelibrary.wiley.com/doi/abs/10.1111/geb.12963.