The giant sequoias of the Sierra Nevada mountains in California could owe their life to events happening on another continent. Researchers have discovered that dust settling in the region has come from as far away as the Gobi Desert in Asia, and it's bringing with it nutrients vital for the trees' growth.
One curiosity about the giant sequoias that grow in the Sierra Nevada is how they manage it in a region so poor in phosphorus, one of the essential nutrients needed for plant growth. It seems counterintuitive that some of the largest organisms on the planet also happen to live in an environment containing so little of an essential basic element.
“In recent years it has been a bit of mystery how all these big trees have been sustained in this ecosystem without a lot of phosphorus in the bedrock,” explains Emma Aronson in a statement. “This work begins to unravel that mystery and show that dust may be shaping this iconic California ecosystem.”
Along with her colleagues, Aronson found that dust – containing that all important phosphorus – is being blown into the Sierra Nevada mountain range not only from other parts of California, but from much further afield. Their work is published in the journal Nature Communications.
The traps are elevated to prevent dust from the ground accidentally being kicked in. Chelsea Carey
By using the isotopic signature of the dust, collected in elevated non-stick pans containing glass marbles, they were able to trace massive amounts of settling dust from the Gobi Desert on the other side of the Pacific. The Asian dust was not even just a small trace, either. In the lower elevations, it accounted for around 20 percent of all dust that settled out of the air, but in the higher elevations this figure was more like 45 percent.
This finding goes to show how intimately such seemingly disparate ecosystems are connected. The researchers also highlight how this may impact the changing climate.
As the world’s temperature increases, droughts are expected to intensify, thus creating more desert-like conditions around the globe. This means that there will be a lot more dust kicked up into the atmosphere. This is likely to have far-reaching consequences, say the researchers, as it is blown into remote mountainous ecosystems.
The distribution of nutrients, such as carbon, nitrogen, and phosphorus, have a massive impact on how and where flora and fauna are distributed across the planet. Therefore, this influx of nutrients from deserts on the other side of the world to mountainous environments could have serious unforeseen impacts on the types of plants that then grow in these places.