Across the Northwest, hotter and drier conditions are affecting tree health and stressing our forests, spurring scientists and forest managers to seek practices that help our forests cope under climate change. In a recent NW CASC-supported study, Aaron Ramirez and colleagues, with partners from The Nature Conservancy (TNC), set out to explore how trees respond physiologically to different restoration practices. They were particularly interested in how restoration practices influence the ways that trees use water. A tree’s water movement system, or its vascular system, is critical to its survival and also tends to be the first place where problems show up, serving as an early indicator of a tree’s overall health.
Checking out the state of a tree’s vascular system requires getting tissue samples, which is no small task when working with very big trees. Luckily, the research team had the help of drones, which can provide creative solutions to data collection challenges, especially as they become more available and affordable. In a new TNC story on this work, Ramirez explains, “Our trees in the Pacific Northwest are some of the largest in the world and often in rugged landscapes that might otherwise be inaccessible — that’s where the drones come in. They allow us to quickly and efficiently sample the tissue we need, opening up a whole world of opportunity for assessing the trees’ physiological health.”
The research team collected samples in the Ellsworth Creek Preserve in Southwest Washington, where ecological restoration practices are being used in previously logged forests, with the goal of restoring the structures and functions found in old growth forests. The researchers found that in addition to improving structural complexity and understory plant diversity, the restoration practices are also increasing the amount of water available to large and mature trees, potentially increasing the capacity of the trees to survive future drought conditions.
This study is one of the first to demonstrate these effects in a temperate rainforest ecosystem. The next steps of this research are to continue working with managers to provide data and information to help fine tune their management approaches and facilitate these kinds of positive effects on forest ecosystem function. Thanks to the drones, this type of precision forest restoration is not far off!