Measuring landscape-scale homogenisation and diversity with the Ecological Fractal Network

Background/Question/Methods

One of the greatest threats to the ecosystems we rely upon is not just a reduction in biodiversity, but also its homogenisation. Vast swathes of diverse, yet identical, fields are vulnerable to pathogen outbreaks or environmental disturbances. As governments plan to restore habitats under schemes such as the UK’s ‘Northern Forest’, there is a pressing need to quantify landscape-scale diversity and homogenisation. Here I outline preliminary results from the the Ecological Fractal Network, a global network of >40 researchers gathering data to quantify such homogenisation across space. I also describe planned future work and ways to get involved with the network. I focus on the initial plant community data collected in 2021, using variance composition analysis to find the spatial scale across which homogenisation is clearest.

Results/Conclusions

To begin, I outline statistical results that show how the network's sampling scheme is able to accurately and efficiently sample ecological diversity across space. I then demonstrate this empirically, showing how in more densely-sampled sites (e.g., Silwood Park in the UK, and Right-Hand Fork in the US), we detect the same responses to environmental gradients even when the sparser sampling scheme is used. I then conclude by using the data to argue that there is not one spatial scale across which biodiversity is homogenised and, in particular, that phylogenetic diversity (e.g., SESmntd) shows finer-scaled heterogeneity than metrics of species richness.