Summary: A remarkable ecological experiment from 1982 has revealed its lasting impact four decades later. Scientists found that introducing
Ecology is one of those disciplines where there is just so, so much we don't understand yet. Yes, we know that the many species within a given ecosystem have a widespread, complex network of interrelationships, but we only have the barest understanding of a fraction of them. It's like having a symphony where you've heard everyone playing, but you only have some notes from some of the musicians' sheet music, and so you can't yet put together how it all works.
In this case, we're seeing just how important northern pocket gophers (Thomomys talpoides) are to their ecosystems. After the devastating eruption of Lawetlat'la/Loowit/Mt. St. Helens in May 1980, the land was left burned and covered in tons of ash and tephra. While some zones further out from the mountain were replanted by timber companies, the area directly around the eruption site has been allowed to recover naturally because this offers North American scientists an unprecedented chance to see how an ecosystem recovers after such a large eruption, at a place that is easily accessible.
When a small number of gophers were returned to an ash-covered area of the mountain for just twenty-four hours in 1982, they kicked off what would be a forty-year study in ecological resilience. In areas with no gophers, there were only a few struggling plants born from seeds transported by birds, while in places where the little mammals were able to burrow and turn over dirt, scientists found 40,000 individual plants. This was due to the fact that the gophers were able to free soil fungi and other microbes beneath the ash and give them a chance to repopulate closer to the surface where they normally would be found. In turn, seeds of plants that had mycorrhizal relationships with the fungi, or which otherwise benefited from the increased microbial biodiversity, flourished.
And forty years later, the pattern still stands, with the gophers' work reverberating to this day. If one small mammal can have such a profound effect in a miniscule amount of time, imagine what happens when we reintroduce extirpated species to other eplaces. The volcanic area may be left to repopulate naturally as scientists continue to study it, but there are countless badly damaged ecosystems in need of restoration. The results of this experiment clearly support the importance of returning as many native species to an ecosystem as possible, because even those that may seem insignificant have invaluable contributions to make to the whole.
