Island Press Field Notes

Unlike most annual crops, the roots of long-lived trees can penetrate through soils to great depth to reach water (Figure 1).  If we can’t tell how deeply roots penetrate, how do we determine when trees run out of water?  One way is to monitor the moisture status of leaves and twigs, because these are connected through the sapwood in branches, stems, and roots to water deep underground.

Most people now accept that the world’s climate is changing rapidly as a result of human activities — mainly the direct emissions of carbon dioxide and other gases that trap heat radiating from the earth, causing the temperature of our small blue planet to rise. This is leading to all sorts of political, economic and ecological problems.

Following a fortnight of negotiations, an unprecedented agreement has been signed by all the world’s 196 nations which identifies forests and ecosystems as fundamental to the world’s climate change response. For the first time, the UN’s Paris Agreement has formally recognized in international law that conserving ecosystem-based carbon stocks including forests is central to achieving climate mitigation goals and that both biodiversity and human rights must be protected when taking climate action.

I began my career as forest ecologist in the 1990s, cataloging the remarkable web-of-life in the old-growth rainforests of Prince of Wales Island. Since then, I have worked with rainforest ecologists around the world to document exceptional places like the Tongass and how they can contribute to a global climate change solution. Last April, hundreds of scientists, including myself, sent President Obama a letter asking him to include the Tongass as Alaska’s first line of climate defense.