The world’s biodiversity is in crisis. Species are declining at an alarming rate. And this is happening at just the time we are really beginning to understand this diversity through an unprecedented cataloging and compiling of information. Data repositories are filled with hundreds of thousands of entries about species, where they live, how they live, and who they are related to. And this is only the beginning. New DNA-based surveys are exploding onto the scene and our ideas and understanding of biodiversity are improving everyday.
So when and how do we use this burgeoning knowledge of biodiversity in biodiversity conservation?
We take a stab at this question in our recent paper out in Nature by analysing the world’s bird and mammal diversity from a conservation perspective. We ask how much of the world’s bird and mammal diversity is currently protected and how much better we could do if protected areas were to be expanded. We consider diversity to be not only species, but also phylogenetic and functional diversity. The use of these types of diversity means we have a better chance of meeting big policy goals of preserving biodiversity that benefits humans and ecosystems than with a sole focus on species. Continue reading Where in the world is the unprotected diversity? New paper out in Nature
Artists: r-inla, Matt Talluto, and merge
We have a new paper out in Nature Climate Change that combines Species Distribution Models (SDMs), climate change and phylogenetic diversity metrics. This is very exciting as it is the first paper from our PD working group.
-We explore the effect of climate change on various PD metrics (including endemism-based metrics) for all eucalypts across Australia. Eucalypts are stand dominants in many forests across the continent and are also of course inherently awesome.
-We present the first complete phylogenetic tree for eucalypts (657 species)
-We include SDMs for dispersal and no-dispersal scenarios for all species for the present and future projections (more on the models soon..)
-The results? Overall, there is a loss of PD within cells as well as between cells- so an increasingly homogenous PD landscape. Rare, ancient lineages are the most impacted, and some areas, such as the Kimberley Region will likely be increasingly important refugia for PD. The southern coastline is an important reservoir of both ‘old’ and ‘young’ lineages. This distinction is important as we might value old and young lineages for different reasons from a conservation perspective.
After a long road, that began with a comment, ‘Of course related eucalypts don’t coexist, most of them are distributed allopatrically, and if they do re-mix, they will hybridise anyway’.. followed by many years of field-work, lab work, running models, revisions, more revisions, even more revisions.. we came to the conclusion, that indeed, evolutionary history probably explains why closely related species don’t co-occur.
Ecology is also important. Species in plots tend to have similar trait values (especially specific leaf area). One cool thing about a model-based approach is that we can estimate how much different factors influence co-occurrence and we can detect interactions- e.g. similar species co-occur unless they hybridise. The negative effect of reproductive compatibility was nearly as strong as the positive effect of having similar traits.
See more here
When using phylogenies in spatial conservation prioritisation, we need to link the phylogeny with distribution data. Increasingly, distribution data is used to predict where species occur across the landscape using a species distribution model (SDM). SDMs are currently underused in conservation, but have great potential for a variety of applications from threatened species management to conservation planning. Our recent paper shows how to use SDMs with a phylogeny in spatial conservation planning (this method could also be used for a variety of applications linking phylogenies and SDMs).
An SDM models the response of a species to a set of predictor variables (usually environmental variables). The model can be extended across a landscape with a probability of occurrence of species in grid cells**. The external branches (tips) of the phylogeny correspond to a particular taxon (let’s assume we have a species-level tree). Therefore, each external branch can simply be the probability of that species occurring in each cell (a,b,c,e,f in figure above). Now, for the internal branches. Continue reading Linking species distribution models (SDM) and phylogenies