Exactly How Vulnerable are Species to Climate Change?

According to Williams et al (2008), responding to the threat of climate change will require a “a concerted, multi-disciplinary, multi-scale, multi-taxon research effort that improves our predictive capacity to identify and prioritise vulnerable species in order to inform governments of the seriousness of the threat and to facilitate conservation adaptation and management”. As well as an international reduction in greenhouse gas emissions, we need to prioritise conservation efforts by identifying which species are most vulnerable in the face of our changing climate. The diagram in Figure 1 displays a conceptual framework proposed by Williams et al (2008) for assessing species’ vulnerability to climate change.

Source: Williams et al (2008)

The two things I want to draw attention to (because of their relation to the refugial hypothesis) are the panels on the diagram labelled ‘resilience’ and ‘adaptive capacity’. Clues to both resilience – the ability of a species to survive and recover from a disturbance (Williams et al 2008) – and adaptive capacity – a combination of ecological responses and evolutionary changes – can be found in studies of species’ past distribution and genetic histories. So, the point I am making here is that palaeoecological studies can (potentially) be used to identify species that are likely to be the most vulnerable to climate change.

For example, species with wide distributions and vast ranges would usually be considered to be less vulnerable to climate change than endemic species. However, by examining species responses to past climatic change, we can see that large ranges may actually be a disadvantage because it reduces the chance of certain species being able to maintain viable populations in small refugia (Williams et al 2008). When it comes to adaptive response, studies have shown how species have used ‘pre-existing flexibility’ to respond to climate change, one of these being their contraction to, and persistence and even adaptation in refugia.

 

If frameworks similar to this are used to assess vulnerability and therefore determine where conservation resources should be focused, perhaps this is a way in which palaeo-studies can realistically have an impact on wildlife conservation policies?