A fire ravages the landscape. When it finally burns out, the plants slowly grow back in, and the animals gradually make their way back. But what happens when an environment experiences another fire, and then another? How do species adapt?
Changes are bound to happen. Xavier Santos and Marc Cheylan studied reptiles in the Mediterranean to see what kind of effects fires can have on their traits. What they found was that species are pros at Extreme Makeover: Reptile Edition.
The reptiles were separated into categories of unburnt, once burnt, and repeatedly burnt areas based on how many times their habitats felt the burn. Santos and Cheylan found that reptiles in areas with lots of fires are better at keeping their cool. When the fires burn down the foliage protecting them from the roasting sunlight, reptiles that can’t take the heat have to get out of the kitchen—they either have to adapt and get used to it or find a different place to stay.
Post-fire reptiles are also more prone to chowing down on bugs. Because the vegetation grows back at different rates and a certain favorite snack may not always be in supply, species that can adapt to crunchier grubs are less likely to go hungry.
The study also found that reptile species that live shorter lives fare better in changing environments. Shorter lives means less time until individuals reach reproductive age, which means more babies and more opportunities for helpful genetic variations.
Thus, when the blaze finally settles down and the glowing embers dim, the species that emerge and successfully dominate the new scene are quite different from the ones that ruled before.
Even though the changes in population would seem to increase biodiversity, they simply don’t. The researchers discovered that beta diversity decreases in each habitat after the fire runs its course.
Usually, the opposite is true; changing up the environment benefits species by keeping them on their toes evolutionarily. Unfortunately, in the case of reptiles and wildfires, it seems that the fires are too savage and decimate the populations beyond the level of diversity that adaptations could provide.
If fires canvassed the landscape and hit different places every time, then the diversity of the local would plummet. On the flip side, if they repeatedly occurred in one place, it seems that the amount of change added each time would lead to diversity on a larger scale. Each area would produce slightly different changes in the successful reptilians, leading to a spread of species with altered traits from one place to another.
In the end, Santos and Cheylan’s studies are basically looking at what happens after traumatic events. Fires are not all too different from what humans are capable of doing to animals’ natural homes, which makes it important to study how organisms recover.
Studying the Mediterranean reptilians essentially gives scientists a basis for predicting how other animals in similar ecosystems might react to disturbance, and understanding the impact that humans have on nature can bring about changes in the destruction and displacement that natural organisms suffer.
Xavier Santos, Marc Cheylan, Taxonomic and functional response of a Mediterranean reptile assemblage to a repeated fire regime, Biological Conservation, Volume 168, December 2013, Pages 90-98, ISSN 0006-3207 (http://www.sciencedirect.com/science/article/pii/S0006320713003170)
Photo by Alexandre Roux (http://www.flickr.com/photos/30142279@N07/8996686596/in/photostream/)