New research categorizing certain landscapes as “disturbance refugia” shines a light on an important ecological concept. These areas have also been called “lifeboats” or “slow lanes” because of the safe haven that they provide for species in our rapidly changing climate. The recent study on this topic was published in Frontiers in Ecology and the Environment, which is dedicating its June issue to refugia science.
Why is it that change doesn't happen as rapidly in some landscapes as it does in others nearby? Natural disturbances can create patchwork quilts across a landscape, sometimes disrupting biodiversity and at other times supporting it. Nevertheless, disturbances that fall outside the historical scale of space, time, and severity can do short- and long-term ecosystem damage, reports Science Daily.
Oregon State University forest ecologist Meg Krawchuk led the research team. She commented on the applicability of refugia science, saying, "We're increasingly realizing that refugia science might provide theory and analysis of the critical role of refugia in social and ecological resilience. For example, as resistance to diseases that can be transmitted from animals to humans, pandemics like COVID-19, political turmoil, violence, and land use issues, particularly in the context of extreme events. Refugia are areas of resistance that contribute to system-level resilience."
For this study, Krawchuk and her colleague Garrett Meigs looked at disturbance refugia from the perspective of old-growth forests and the impact fires have on them. "In the Pacific Northwest, the iconic northern spotted owl relies on refugia in the form of old-growth forests," said Krawchuk. "These forests are refugia from previous stand-replacing disturbances -- that's how they got to be old -- but they're slowly being nibbled away by recent high-severity fires."
The researchers explain that it is difficult to break down the influence of fires alone on refugia forests because of all the factors at play (terrain, erosion, drought, insect outbreaks, climate change, etc.). Their findings allude to this, highlighting how the overlapping of disturbances produces complex feedback mechanisms, both positive and negative, that in turn impact the refugia itself.
"Detecting refugia in multiple places and at different times and understanding what's behind their occurrence, persistence and value in sustaining biodiversity are important frontiers in science and land management," Krawchuk said. "Developing a disturbance refugia framework that recognizes multiple types of forest disturbance under one banner is an important step for research and management of forest ecosystems that are changing as the planet warms."
Furthermore, she adds, refugia science is a crucial lens through which to look at conservation efforts. "Identifying disturbance refugia locations within climate change refugia spots would lead to a deeper understanding of refugia," Krawchuk said. "In this era of rapid environmental change ...there are many iconic and special forest landscapes being confronted with increasing disturbance pressures, including harvest and conversion to agriculture or other uses."