Issue 5 has now been published online. Associate Editor Sedonia Sipes has written a commentary about our current Editor’s Choice by Greve et al. For even more information about this paper watch Scott’s interview with Michelle Greve right here on the blog!
Editor’s Choice 100:5
It is always exciting to read a study that exemplifies the ways that evolution and ecology are inextricably linked. Communities that we observe today are outcomes of selective pressures on species from both biotic and abiotic interactions, but these are assumed to operate at different spatial scales. In this study, Michelle Greve, of Aarhus University, Denmark, and fourteen of her colleagues, examine biodiversity patterns at the continental scale, and question a major tenet of community ecology: that large-scale determinants of plant communities are generally considered to be climate and other abiotic factors, rather than biotic factors, such as species interactions.
They compiled distributions for 92 species of African acacias by geo-referencing thousands of localities from herbarium records, field observations, and other sources, and used these distributions to produce maps of acacia diversity throughout Africa. They then explored, via modeling, what factors best explained the resulting biodiversity patterns. Surprisingly, they found that mammalian browser diversity explained these large-scale patterns significantly better than climate, habitat heterogeneity, or climate change velocity did. Moreover, their analyses of residual variation (that portion not explained by browsers, climate, or habitat variables) revealed an intriguing phylogenetic pattern: the two clades of acacias included in the study each influenced the other’s distributional patterns. The authors suggest that this finding might indicate that additional biological interactions (for example, with shared pollinators, mutualist ants, or seed dispersers) or climatic factors not considered, such as fire, are influencing both acacia clades in similar ways.
On a final note, this study exemplifies another important point, that well-curated herbaria and other biological collections represent an immense source of ecological data, one that is all too often left to languish when budgets get tight. Loosing these resources affects a much larger field of science than just systematics.
Associate Editor, Journal of Ecology