Preserving the evolutionary potential of floras in biodiversity hotspots

Abstract

One of the biggest challenges for conservation biology is to provide conservation planners with ways to prioritize effort. Much attention has been focused on biodiversity hotspots. However, the conservation of evolutionary process is now also acknowledged as a priority in the face of global change. Phylogenetic diversity (PD) is a biodiversity index that measures the length of evolutionary pathways that connect a given set of taxa. PD therefore identifies sets of taxa that maximize the accumulation of 'feature diversity'. Recent studies, however, concluded that taxon richness is a good surrogate for PD. Here we show taxon richness to be decoupled from PD, using a biome-wide phylogenetic analysis of the flora of an undisputed biodiversity hotspot--the Cape of South Africa. We demonstrate that this decoupling has real-world importance for conservation planning. Finally, using a database of medicinal and economic plant use, we demonstrate that PD protection is the best strategy for preserving feature diversity in the Cape. We should be able to use PD to identify those key regions that maximize future options, both for the continuing evolution of life on Earth and for the benefit of society.

Representing Hotspots of Evolutionary History in Systematic Conservation Planning for European Mammals

“…This implies that targeting species alone does not necessarily succeed in protection of hotspots of evolutionary history. Past research has found mixed evidence of such surrogacy relationships between protecting species and phylogenetic diversity (Polasky et al 2001;Rodrigues and Gaston 2002;Sechrest et al 2002;Forest et al 2007;Spathelf and Waite 2007;Rodrigues et al 2011). Our findings show that it makes a difference in what regions such comparisons are made: we found little difference between priorities around the Mediterranean, but much more e.g.…”

“…However, in practice different types of conservation actions could be necessary to address the different objectives, and therefore the conflicts may be more apparent than real. For instance, regions with particularly low phylogenetic diversity may also be of conservation concern as they can represent areas of active diversification (Forest et al 2007), but they might require different type of conservation from "museum" areas with relict species, as these areas and species in them might be threatened by very different processes.…”

“…Arponen et al (2005) used species weights based on species originality in conservation prioritization for plants in Finnish herb-rich forests. There are also some examples of considering assemblagelevel phylogenetic diversity across a network of sites: The "Phylogenetic Diversity" of Faith (1992) has been used for conservation prioritization with birds (Rodrigues and Gaston 2002) and plants (Forest et al 2007) in South Africa, as well as in a global analysis for mammals (Rodrigues et al 2011). Instead of spatial prioritization of areas for protection, evolutionary history has been considered much more commonly in other kinds of conservation contexts (reviewed in Arponen 2012), such as creating priority lists of species for conservation.…”

“…The use of alpha-level phylogenetic diversity is based on the assumption that it would correlate with ecological processes better than species richness of the community (Forest et al 2007), and therefore work as an indicator for functional diversity when species traits data are missing. This is based on the idea that phylogenetically distinct species are likely to be functionally different (Cadotte et al 2008), although this assumption has also been challenged (Mouquet et al 2012).…”

Using Phylogenetic Dissimilarities Among Sites for Biodiversity Assessments and Conservation

“…Feature diversity represents biodiversity "option values" -the term we use to refer to all those potential future benefits for humans -and so is well-justified as a target for biodiversity conservation. Forest et al (2007) provide a good exemplar study, illustrating how PD links to feature diversity and to food, medicine, and other benefits to humans. Faith (2002) summarised the link between evolutionary history, PD, and features as follows: "representation of "evolutionary history" (Faith 1994) encompassing processes of cladogenesis and anagenesis is assumed to provide representation of the feature diversity of organisms.…”