When Giant Sequoia and Drought Don’t Mix

At Giant Forest, this middle-aged giant sequoia has lost most of its leaves at this point in the drought.
At Giant Forest, this middle-aged giant sequoia has lost most of its leaves at this point in the drought.

I roamed through a few giant sequoia groves over the last week and did find a few mature giant sequoia that aren’t weathering the four-year drought well. Some of these afflicted giant sequoia simply were shedding leaves and their crowns appeared thinner and less green than normal. Others, had lost nearly all of their leaves and appeared to be dying. These trees were mid-sized giant sequoia that are probably centuries old, but not millennia old. So why are the middle-aged giant sequoia showing the worst signs of drought stress?

A close up photograph of a dangerously sparse giant sequoia crown at Giant Forest. I'm crossing my fingers it pulls through.
A close up photograph of a dangerously sparse giant sequoia crown at Giant Forest. I’m crossing my fingers it pulls through.

Scientists don’t know why yet, but a few hypotheses have emerged. The one I find most interesting is that perhaps these giant sequoia grew to their current size without experiencing a drought of this magnitude before. Since in the past the water was plentiful, the trees may not have grown roots very deep into the soil. Now, water in the upper layers of soil is drying out and these “spoiled” trees don’t have access to deeper water that some of their larger giant sequoia neighbors have. Any other ideas? Have you seen any large giant sequoia in the groves show signs of decline?

Learn more about giant sequoia here.

Avatar

About the author

Emily Burns, the League’s former Director of Science, led the research program that includes the Redwoods and Climate Change Initiative. She holds a PhD in Integrative Biology on the impacts of fog on coast redwood forest flora from the University of California,...

bear reading the blog
Get the latest redwood updates in your inbox
   Please leave this field empty
▼ View/Leave Comments (0)

Join our newsletter

Get the latest redwood updates in your inbox
   Please leave this field empty