Iconic giant sequoia trees in California, once thought to be nearly invincible, are now facing unprecedented threats from climate change. Drought, wildfire, and pests, all intensified by rising temperatures, have damaged or killed thousands of these ancient trees in recent years. In just the past decade, sequoias have suffered major foliage dieback in 2014, insect-related deaths in 2017, and catastrophic fires in 2020-2021.  

Ecosystems are complex. Plants, animals, fungi, and microbes interact with one another and their surroundings (e.g., soil, air, water) in complicated ways. Traditionally, land managers tried to maintain ecosystems as they had existed in the past, but as ecosystems experience new and extreme conditions, their many inter-connected parts are responding in new ways. For example, forests are turning into grasslands or shrublands after wildfires and woody plants are moving into wetlands. How can park and forest managers deal with this type of unprecedented change?  

One powerful tool for dealing with uncertainty is scenario planning. This approach helps managers map out a range of possible futures, including the extreme and/or unlikely ones, so that they can prepare for as much as possible. At Sequoia and Kings Canyon National Parks – home of many of the largest sequoias – early scenario planning has already been helpful, with proactive prescribed burns helping reduce the severity of recent wildfires. 

North Central CASC supported researchers summarize some management considerations from a recent publication into the following three elements: 

1. Embrace multiple possibilities, not just the most likely 

2. Consider how ecological changes may unfold over time, not just the final outcome 

3. Prepare for sudden or surprising disruptions 

While climate forecasts are widely available, ecological forecasts are limited. Uncertainty won’t go away, but developing ecological forecasting tools through scenario planning can help managers navigate uncertainty to make smart investments and decisions that protect the natural benefits these ecosystems provide for recreation, clean water, and more.  

The journal article titled "Ecological scenarios: Embracing ecological uncertainty in an era of global change" is published in the journal Ecosphere. In addition to real-world examples of scenario planning, the publication offers a generalized workflow for developing ecological scenarios and a toolbox of approaches for addressing ecological uncertainties.