The ecological impacts of climate change are likely to be varied and widespread, and a PLOS collection of papers on this topic, published this week, examines the dynamics and magnitude of these changes, together with the impact on individual species and entire ecosystems. Special attention has been given to understanding the vulnerability of particular species and functions within ecosystems.
But how exactly does one go about identifying which species are vulnerable to climate change, and how is that vulnerability defined? Sensitivity? Exposure? Adaptive capacity? And should we lose one of those vulnerable species, what is the effect on the rest of the ecosystem?
While the importance of species diversity on ecosystems has been relatively well studied, the roles that individual, rare species play are less certain. Mouillot et al., present a stark finding: many critical ecosystem functions are supported by relatively rare species. Rather than the quantity of biodiversity, it is the quality of that biodiversity that matters in maintaining an ecosystem, and many of the key species have highly specialised roles with little redundancy.
So, if a keystone species is lost, then there is no other species within the ecosystem that can take its place. Consequently, Mouillot and colleagues argue, rare species don’t just offer aesthetic, cultural, and taxonomic diversity; rather, many are vital to the functioning of ecosystems. As such, they suggest that conservation should move away from charismatic species to focus on those that have irreplaceable roles in the ecosystem. These findings have far reaching scientific consequences, and what we need to communicate this are artists whose practice engages in a subtle, yet powerful way.
A few months back, I was privileged to see American architect-cum-memorial maker-cum artist, Maya Lin, speak at the Tate Modern. Best known for her elegant and powerful Vietnam War Memorial, she spoke most passionately about what she calls her ‘last memorial,’ an online project called What is Missing? This project—actually a website since Lin does not think that a memorial must be static but can exist in multiple forms simultaneously and evolving—engages with the ‘sixth mass extinction’. Through both an online presence in the form of a beautiful website, and through site-specific science-based artworks, Lin aims to highlight disappearing biomes around the world.
The website presents the past in the form of videos, historical accounts and memories from contributors of species that have diminished, or disappeared from the natural world. Clicking on a dot in the mid-Atlantic, I arrive at a video about the great Bermudan humpback whale singers of the 1960’s. Apparently, they were quite something, but we’ll never get to hear them ‘live’ now.
Clicking on London, my eyes are attracted to a number of anecdotes about oysters. Yes, it turns out oysters abounded in the Thames: according to Henry Mayhew in 1851, it was estimated that 500 million oysters were sold in Billingsgate Market that year alone. Needless to say, the main oysters associated with London today are the Oyster Cards we use on the public transport system.
What is Missing? is both memorial and ‘momento mori’ for the natural world. The piece quietly acknowledges what we have lost and reminds us that we need to look after biodiversity on our planet in all its forms. The finding that some of the rarest species have critical ecosystem functions makes this message all the more poignant.