Lijing Wang is a climate and hydrology researcher. He’s currently looking at the local scene in New England—he’s recently begun to track local beaver ponds. His latest research, published in Water Resources Research, uncovers powerful new evidence about how these natural structures affect the movement of water. It looks at their impacts on the surface as well as underground. Wang and his co-authors employed some cutting-edge methodologies, including geophysical surveys and machine learning techniques. In her underwater adventure, they illustrated the multifaceted relationships of water movement in ecosystems formed by beavers.
Beaver ponds have an important role to play in maximizing ecological benefits. A major gap still persists in understanding their effects on water quality and fiscal budgeting. Wang’s creative practice and scholarship aims to fill that void. He looks at the surface effects and subsurface interactions that happen in these one-of-a-kind habitats.
Methodology and Findings
The research used a trifecta of in-situ observations and triangulations to study the flux of water movement through soils and subsurface environments. Wang and his team used a novel machine learning technique known as the neural density estimator. They paired this pioneering social science methodology with conventional hydrologic data and modeling practices. This cross-cutting approach enabled them to get a more complete picture of how these beaver ponds fit into broader groundwater systems.
“Our work here develops one of the first hydrologic models that helps us understand what happens from the beaver inundation to the subsurface system under different subsurface structures,” Wang explained. This unique approach combines field data with model simulations, improving our knowledge about how water moves through these complicated ecosystems.
Another one of the most important discoveries found that water moves freely underneath river systems through active gravel beds. It’s an energy that is never standing still. It moves downstream much faster than originally believed. “Thinking of the gravel bed as ‘a thick river’ underneath the stream bed, there’s more water flushed downstream in the subsurface than we thought,” Wang stated. This highlights the importance of detailed pre- and post-project monitoring to understand impacts of beaver ponds on local hydrology.
Ecological Benefits and Challenges
Beaver ponds foster biodiversity and promote healthy, wide floodplains and wetlands. If used carelessly, they can create enormous challenges, particularly in communities hurt by a legacy of former industrial activity. Wang said that the ecological benefits were likely more pronounced in pristine areas where such disturbances don’t occur as frequently.
“If you are in a pristine area with no previous industrial activity, that may not be a huge problem,” he said. He warned that areas upstream of AML sites could experience adverse changes in water quality. This is because the increased concentration of soluble metals carried by the flow downstream. “If you are in an area like our site in Colorado that is near abandoned mines, we can see more soluble metals downstream,” Wang added.
To protect vital subsurface environments, these findings highlight the need to recognize the complex interplay between surface land use practices and subsurface spaces. “We need to understand the trade-offs and benefits,” Wang emphasized.
Implications for Water Management
Real world effects
The implications of Wang’s study go far beyond academic curiosity – they have practical applications for water management strategies. In areas such as New England, which contain intricate river systems, beaver ponds can add up to 55% of their area’s ecological diversity. These complex systems of tributaries, creeks and channels help improve the resilience of coastal wetland regions to drought and climate-linked wildfire.
“Evapotranspiration is particularly important in water-limited regions like the U.S. West,” Wang pointed out. Finally, since the presence of beaver ponds can increase local evapotranspiration, their contribution to overall water availability in these dynamic habitats is complex. He noted that “thinking about the water budget, beaver-induced inundation may reduce how much water is in the system where a lot of water evaporates.”
Wang’s research indicates that these thick, fetchable soil profiles over gravel beds can significantly impede groundwater recharge. This is due to increased evaporation from vegetation and the atmosphere that pulls moisture away. While beaver ponds provide many important benefits, they can sometimes create challenges, such as decreasing water supplies in the dry season. In short, this creates an interesting potential trade-off.