Prioritizing areas for conservation with phylogenetic diversity

Why is evolutionary history rarely considered in actual conservation planning? Well, there are many reasons. Conservation practitioners might not be aware that evolutionary diversity can be used in conservation. If they are aware, maybe it doesn’t compete with the vast number of other conservation concerns. Or maybe they do value it, and would like to use it, but are not sure how.

We have a new paper out in PhilTransRocSocB that addresses this last problem. We show how to use phylogenetic diversity in spatial prioritisation software. The advantage of using this software is that diversity can be considered alongside other concerns–extinction risk, connectivity, cost etc.

What do you need to do this?

1-distribution data (occurrence in grids or a species distribution model-SDM)

2-a phylogeny

How does it work?  The spatial prioritisation is based on branches of the phylogeny rather than on species, which are typically used. We used Zonation software to set priority areas for eucalypts in Victoria, Australia (about 100 species that dominate forests across the state). We tried different scenarios: an optimal scenario, a hypothetical protected area expansion, and a recent change in protected area status.

An optimal solution for protecting eucalypt phylogenetic diversity (dashed line) and a solution including protected areas (solid line). As the landscape is removed during the spatial prioritisation (x-axis), PD is lost (y-axis). In the protected area scenario (solid line), the unprotected areas are removed followed by the protected areas (green block). The dark red represents the amount of PD that could be gained by expanding the protected areas by 5%. These expansion areas are shown on the map above.
An optimal solution for protecting eucalypt phylogenetic diversity (dashed line) one including protected areas (solid line). As the landscape is removed during the spatial prioritisation (x-axis), PD is lost (y-axis). In the protected area scenario (solid line), the unprotected areas are removed followed by the protected areas (green block).

An interesting result is that if we increased protected areas by 5% (which is <1% of the state area), we could increase phylogenetic diversity of eucalypts by 33% (see the dark red blocks in the figure).

This figure also shows some other useful numbers. There is a large difference between what is actually protected and what could be protected (the y-axis difference between the dashed and dotted lines).

PollockFig3Nab
If we expanded protected areas by 5% or 20%, where would we look to include the most eucalypt phylogenetic diversity?

Where are the locations that correspond to large PD gains? The map shows the best places to expand the protected area system to capture the most eucalypt phylogenetic diversity.

The other way we can visualise this is on the phylogeny itself.

PollockFigN5PhyloTourismBelow5

Some parts of the phylogeny are much more vulnerable to a change in the National Park System than others. Particularly the Red Gum group.

For more, see the paper:

Pollock LJ, Rosauer DF, Thornhill AH, Kujala H, Crisp MD, Miller JT, McCarthy MA. 2015. Phylogenetic diversity meets conservation policy: small areas are key to preserving eucalypt lineages. Phil. Trans. R. Soc. B 20140007. http://dx.doi.org/10.1098/rstb.2014.0007

And some other work that similarly use branches rather than species in a spatial prioritisation:

Using Zonation to prioritise fish species in southwestern USA..

Angela L. Strecker, Julian D. Olden, Joanna B. Whittier, and Craig P. Paukert 2011. Defining conservation priorities for freshwater fishes according to taxonomic, functional, and phylogenetic diversity. Ecological Applications 21:3002–3013. http://dx.doi.org/10.1890/11-0599.1

And, very recently, using Marxan for stygofauna in aquifers. A great example on why using phylogenetic branches might be the best solution for those cases when many taxa are unknown.

Asmyhr MG, Linke S, Hose G, Nipperess DA (2014). Systematic Conservation Planning for Groundwater Ecosystems Using Phylogenetic Diversity. PLoS ONE 9(12): e115132. doi:10.1371/journal.pone.0115132 

Another approach in spatial prioritisation is to weight species by their evolutionary distinctiveness (ED), which gives the evolutionary contribution of each species. Mathematically, this is different than prioritising for PD. See Faith 2008 for a good explanation.

Faith DP. 2008 Threatened species and the potential loss of phylogenetic diversity: conservation scenarios based on estimated extinction probabilities and phylogenetic risk analysis. Conserv. Biol. 22,1461–1470. (doi:10.1111/j.1523-1739.2008.01068.x)

However, in practice, weighting species by ED and range-based ED captured much of the PD for global birds (Jetz et al. 2014).

 

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