A chat about springtails, biodiversity, and conservation
By Camellia Williams
At Vizzuality we’re getting ready for Half-Earth Day. One of the information sources we’re using is the book, Half-Earth: Our Planet’s Fight for Life, by E. O. Wilson. As I read it, a story about springtails caught my attention.
“These tiny and very elusive creatures possess a lever beneath their bodies, free at one end and attached at the other, allowing it to be opened and closed like a jackknife. When the collembolan is approached by a predator, it releases the free end, and the lever strikes the ground. Milligram for milligram, the strike is one of the most powerful locomotory forces in the animal world. It carries the collembolan high into the air and forward as far as, for humans, would be the equivalent length of a football field.” – E.O. Wilson
Wanting to learn more about springtails, I decided to talk to Greta Carrete Vega, one of our Science team colleagues, as she studied Antarctic biodiversity during her PhD. Here’s the conversation we had!
Hey Greta, I was re-reading E. O. Wilson’s book, and I realised he speaks about the animals you’ve studied for your PhD and how amazing they are at travelling through the air, isn’t that what the article you recently published is about.
Yes! I remember when I read the book a few months ago I got excited because “springtails in the air” were mentioned. Springtails are tiny arthropods that measure less than 1mm in length. They don’t have wings and they travel through the air by jumping. E. O. Wilson talks about the springtails from the Great Smoky Mountains (USA), while my PhD focused on Antarctic terrestrial biodiversity so it’s probably not the same springtails. Although… maybe there is one species in common, Hypogastrura viatica, which has been introduced into Antarctica and is cosmopolitan, meaning it’s found almost everywhere on the planet.
So there are alien species in Antarctica?
Yes. Relatively fewer than in other parts of the world but there are plants and invertebrate animals that are not native to Antarctica because they have been introduced inadvertently by humans.
How do you know they didn’t get blown there with the wind?
That is a fair question. Traditionally Antarctica has been thought to be physically completely isolated from the other continents because of the Polar Front. However, recently it has been shown that on a scale of millions of years there is some permeability, particularly through ocean currents.
What is the Polar Front?
It’s where two different currents border each other, and it’s supposedly impossible for passive elements to pass from one to the other. So birds and large animals like whales can actively cross but other organisms shouldn’t be able to.
What happens once something does pass the Polar Front?
That is exactly the question that one of the chapters of my PhD tried to answer. As part of my PhD, carried out at the BIOMA lab led by Miguel-Ángel Olalla Tárraga at Universidad Rey Juan Carlos, I spent four months at the British Antarctic Survey collaborating with Peter Convey and Kevin Hughes.
We attempted to disentangle the environmental and movement factors leading to potential range expansion in the Antarctic Peninsula of two native springtails. To do this we used the long term database of observations of terrestrial biodiversity and added some recent observations. We found that wind transport might result in range expansion very sporadically, while range expansion could occur through human activities particularly at the north-eastern tip of the Antarctic Peninsula.
So basically, everything that’s brought into Antarctica has to be cleaned before it arrives, and when it’s moved from one part of the continent to another?
Yes, the materials we used for sampling and also our clothes had to be cleaned, including our boots. Especially our boots. You have to clean your boots every time you step on and off a boat and when you step into or out of a building.
E.O. Wilson describes springtails as “tiny and very elusive creatures”. How do you sample them?
They are found in the soil so they have to be extracted from it. In the field, the soil is sampled and transported to the lab. Once in the lab, the soil is processed on a Berlese-Tullgren funnel, a system that is over 100 years old, but still super efficient. On top of the soil there is a source of light and heat which will gradually dry the soil. As the soil dries out the organisms will crawl down to the bottom where there is a sieve that allows the animals to drop into a container filled with alcohol. We then take the tube filled with alcohol and identify the soil organisms in it.
So how can this kind of research be applied to the conservation of wild places such as the Antarctic?
Understanding the mechanisms used by species to increase their range, i.e. how they move to a new place, is key to predicting their presence. In a place like Antarctica, such knowledge could help prevent the spread of non-native species. If you also take into account how climate conditions might change in the future, you can then begin to identify areas that could be important for the survival of a certain species and establish conservation areas.
For species adapted to cold environments (mainly polar and alpine), their chances of avoiding extinction are bleak. In Alpine regions, species are moving upwards into cooler altitudes as the global temperature increases. Once they reach the top of the mountain, they will have no where else to go. Antarctica also has a hard limit for how far a creature can move, but the movement is horizontal rather than vertical. We therefore need to predict where in the Antarctic landscape species will move to, and protect these places in a way that will prevent the introduction of competing non-native species.
Knowing where every species is, and where it might move to under future climatic conditions, is critical for conservation. The more we know about the planet’s species, the better we can decide which places to preserve. That’s why I’m so excited to be a part of the Half-Earth Project, because it uses species knowledge to identify which parts of the Earth should be conserved.
Awesome! Thank you, Greta!
Greta is a Scientist at Vizzuality who uses her GIS skills to help others understand biodiversity better. Maps are her favourite form of data visualisation and she takes a meticulous approach towards data analysis and interpretation.
Together with the E.O. Wilson Foundation, Map of Life, and Esri, Vizzuality is mapping biodiversity data in a more compelling way that combines scientifically rigorous data with emotionally stimulating design. We can’t wait to show people the latest iteration of the Half-Earth Map on Half-Earth Day.