We’ve discovered that nearly a quarter of desert plant species can be seen at springs. This is remarkable, given what a small footprint the springs cover.
To: Bluedot Living LA
From: Dr. Sophie Parker, The Nature Conservancy
Subject: Desert springs are the sentinels of a warming, drying climate
It sounds like a riddle: How is a pool of water in the desert like a canary? But just as coal miners monitored the health of canaries to detect dangerous increases in carbon monoxide levels in coal mines, so can we look to desert springs as sentinels of a warming, drying climate.
Sentinel species, like the canary, are those whose sensitive response to environmental changes can provide signs of impending hazards. Recently, scientists have begun to discuss the idea of “sentinel ecosystems.” These environments show climate change impacts before they are apparent elsewhere: Think mass die-offs of coral reefs, or the dramatic retreat of glaciers.
Desert springs can be similarly sensitive. Their condition and ability to support plants and animals can show us how climate change is not something we can put off worrying about until the distant future, but something that is starting to have impacts right now.
But what is a desert spring? And how can it act as a sentinel ecosystem?
For the past five years, I have led a group of researchers from The Nature Conservancy, UCLA, the California Botanic Garden, and the environmental firm Roux Associates, Inc. to better understand desert springs in the Mojave Desert. These are places where groundwater comes to the surface in the desert. They are beautiful, and they are rare, constituting only a tiny fraction of the landscape. They can be vibrant oases of life and biodiversity, and critical stopover points for animals on the move.
Some springs have features that are shockingly understudied – sites where no one has ever taken a water sample or scientifically identified a plant. Our Mojave Springs Research Team has done much more than that. We’ve used environmental DNA techniques to find traces of plant and animal use of springs. We’ve generated full floristic surveys of each spring site so that we know which plants are present. Our hydrological work has included measuring stable isotopes to detect the age and origin of spring waters. And we’ve used remote sensing to map the extent of vegetation supported by springs. With these methods, we have set an ecological and hydrological baseline for the spring systems we’ve studied. Once baselines are set, researchers can monitor changes over time.
We’ve discovered that nearly a quarter of desert plant species can be seen at springs. This is remarkable, given what a small footprint the springs cover. We’ve discovered that each spring, like a snowflake, is unique in terms of its water flow and chemistry, and in terms of the plants and animals it supports. This means that when a spring is destroyed by human activity such as groundwater pumping or water diversion, we cannot count on other springs to provide the same habitat values or support the same organisms.
Our research team began its work because springs in the desert are threatened by water pumping. If the sources of water that support desert springs are used up, not only will unique and precious ecosystems be destroyed, but our early detection system for the impacts of climate change will be compromised as well. This would be like poisoning your canaries before entering the mine.
We have the opportunity now to save desert springs and heed their warnings. The work that my colleagues and I are doing has helped to provide the first data points for many of these sites. If we learn more about these systems and revisit them over time, we can protect them from groundwater pumping and preserve not only their unique beauty and biodiversity, but also their ability to act as natural sentinels in an uncertain future.