A huge amount of attention has been paid to the issue of California’s deepening drought. The New York Times has made it a major and continuing focus of their reporting. California Governor Jerry Brown and the mayors of every major city in California have pushed for water restrictions and other urgent measures (http://ca.gov/drought/). Farmers, crops and livestock are suffering. California’s human inhabitants are on borrowed time, living off the dwindling water storage of our reservoirs and aquifers.
Yet California’s forests don’t have the luxury of reservoirs, and they can’t reach most aquifers. Snowpack in the Sierras is at a radical low, so there’s very little help coming from uphill to the trees down below. What can be done to protect California’s forests, including its fabled giant and coastal redwoods? These are the tallest trees on Earth.
One practical approach could be to discover where the “best” remaining forest stands are located so that fire breaks could be created before the annual dry heat of July-August-September arrives. This alone could be enormously helpful in protecting Californian forests. Detailed maps of best remaining forests would also empower communities with the geographic information needed to reduce pressure on the most sensitive and drought stricken forests. Many other measures could be put in place to mitigate negative feedbacks of the drought on our forests, if we know where the best forests remain.
But defining and then finding the “best” remaining forests in California is not going to be easy. Field work, no way — too big an area and too complicated are the terrain and local climate patterns that strongly affect whether a tree is in trouble or not. Satellites — too myopic. Current satellite technology wasn’t built to deliver the level of ecological detail needed to identify tree condition in this type of drought mitigation situation. It is not just about spatial resolution, but rather about tree chemistry, which we can now measure with a few types of aircraft sensors — a very few. Getting a handle on a tree’s chemistry is like going to the doctor and getting a blood test. We can use it to assess current tree health, and we can even predict which trees are likely to die from the drought. Now is the time for a state-wide forest “blood test”.
To do so, we need high-resolution, 3D chemical imaging to find the best remaining forests to protect. And we need the same technology to find the forests that are worst off in this drought too. We need a full, rapid, repeatable accounting.
CAO was built precisely for this type of mission, carried out in places like the Amazon Basin and African savannas. With the recent launch the third generation CAO-3, the team ran a pilot study to sample about a million acres of forest around California, mostly in the Sierras and Coastal Range. This CAO WingCam photo says it all. Yet Google Earth shows this forest as dense green and highly foliated.
In this case, the team found a tinderbox, and many more forest landscapes were just like this one. CAO’s spectral mapping sensors were blaring with red warning pixels once tuned to measure how much water was (missing) in the canopies.
Now is the time for a state-wide 3D chemical assessment of California’s forests to determine which trees are in the most trouble, which are doing best, and thus where to put limited mitigation and conservation funds as nature’s water supplies dwindle. The CAO Team is ready, and looking for collaborators and support.