Photo credit: Representative Cover Image Source: The frigid water of Niagara Falls empties into the frozen Niagara River on the Canadian side of Niagara Falls, Ontario, Canada. (Photo By Raymond Boyd/Getty Images) – Array
For centuries, Niagara Falls has witnessed some strange incidents. In 1827, a hotel owner sent a flock of wild animals down the falls in a cargo ship, and only a goose survived. But on June 12, 1969, something even stranger happened when the US Army Corps of Engineers stopped the waterfall’s flow. Scientists drained Niagara Falls to conduct research, reported Business Insider.
Representative Image Source: General View of Niagara Falls Park Before the total solar eclipse on April 8, 2024, in Niagara Falls, New York. (Photo by Joan Amengual/VIEWpress)
Niagara Falls is an impressive waterfall connecting three waterfalls at the southern end of Niagara Gorge, bordering Ontario in Canada and New York in the United States. The three water bodies are named Horseshoe Falls, American Falls, and Bridal Veil Falls, in order of their size. While the Horseshoe Falls is at the border of two countries, the other two are within the United States. Bridal Veil Falls is separated from Horseshoe Falls by Goat Island and from American Falls by Luna Island, with both islands situated in New York.
According to the Bright Side, Niagara Falls was first formed around 12,000 years ago, after the last Ice Age. The falls appeared after the ice sheets covered the area of Southern Ontario, and they started moving southward, creating basins of the Great Lakes on the way. They melted and released enormous quantities of water into the basins. As the ice melted, the resulting waters started to flow down through what is known as the Niagara River, Lake Erie, and Lake Ontario.
Representative Image Source: Frozen snow and ice cover the Niagara River on the Canadian side of Niagara Falls on February 28, 2015, in Niagara Falls, Ontario, Canada. (Photo By Raymond Boyd/Getty Images)
By the 17th century, Niagara Falls started gaining popularity as a tourist attraction. In 1842, author Charles Dickens visited the site, and describing the beautiful vista, he wrote “When I felt how near to my Creator I was standing, the first effect, and the enduring one — instant lasting — of the tremendous spectacle, was Peace.” The falls were not just a natural wonder, but also a bounty of natural resources.
A few years after King C. Gillette predicted Niagara Falls could become part of a city called Metropolis, Nikola Tesla designed one of the first hydroelectric plants near the falls. He considered it a significant achievement in human history, per Smithsonian magazine. Over the years, piles of boulders had been building up at the base of the falls. In 1931, almost 76,000 tons of rock slid downwards to the base, and in 1954, 185,000 tons fell, as per Business Insider. So, boulders were not only causing an unsightly appearance but also posed the risk that the falls would soon turn into rapids.
Representative Image Source: Sightseers take pictures of a nearly frozen Niagara Falls on February 20 2015 in Niagara Falls, Ontario, Canada. (Photo by Aaron Vincent Elkaim/Getty Images)
So, in the summer of 1969, some scientists were tasked with removing and examining these boulders. Their goal was to analyze how they could save the falls from erosion. To do this, the US Army Corps of Engineers brought 27,000 tons of rock loaded into thousands of trucks and used these to create a dam, blocking the waters. These waters were diverted to the Horseshoe Falls that absorbed the gushing stream diligently, according to the Bright Side.
When the waterfall was drained, researchers were surprised by what they found on its dried bottom. Plenty of coins sprawled on the waterless bed that people might have thrown in the waterfall to make a wish. Apart from coins, they found the bodies of two humans. In the following few weeks, more than 100,000 people visited the spot to witness the waterless falls from a bare cliff. Most of them were curious about why the water was stopped, and how long it would remain blocked. Meanwhile, for the next five months, engineers worked relentlessly to examine the bed of boulders, and in 1974, concluded that the boulders were necessary to maintain the posture of the waterfall. The American Falls International Board declared in a report that it was against their removal.
Representative Image Source: Pexels | Chaifaastic
So, on November 25, 1969, a crane arrived at the Niagara site and drilled a hole in the dam. Through the hole, water began to surge in torrential streams. The American Falls was freely gushing once again. However, scientists have estimated that the falls might need to be blocked again at some point, to repair the surrounding bridges.
Across Appalachia, rust-colored water seeps from abandoned coal mines, staining rocks orange and coating stream beds with metals. These acidic discharges, known as acid mine drainage, are among the region’s most persistent environmental problems. They disrupt aquatic life, corrode pipes and can contaminate drinking water for decades.
However, hidden in that orange drainage are valuable metals known as rare earth elements that are vital for many technologies the U.S. relies on, including smartphones, wind turbines and military jets. In fact, studies have found that the concentrations of rare earths in acid mine waste can be comparable to the amount in ores mined to extract rare earths.
Scientists estimate that more than 13,700 miles (22,000 kilometers) of U.S. streams, predominantly in Pennsylvania and West Virginia, are contaminated with acid mine discharge.
We and our colleagues at West Virginia University have been working on ways to turn the acid waste in those bright orange creeks into a reliable domestic source for rare earths while also cleaning the water.
Experiments show extraction can work. If states can also sort out who owns that mine waste, the environmental cost of mining might help power a clean energy future.
Rare earths face a supply chain risk
Rare earth elements are a group of 17 metals, also classified as critical minerals, that are considered vital to the nation’s economy or security.
MP Materials’ Mountain Pass Rare Earth Mine and Processing Facility, in California near the Nevada border, is one of the few rare earth mines in the U.S. Tmy350/Wikimedia Commons, CC BY-SA
China controls about 70% of global rare earth production and nearly all refining capacity. This near monopoly gives the Chinese government the power to influence prices, export policies and access to rare earth elements. China has used that power in trade disputes as recently as 2025.
The United States, which currently imports about 80% of the rare earth elements it uses, sees China’s control over these critical minerals as a risk and has made locating domestic sources a national priority.
The U.S. Geological Survey has been mapping locations for potential rare earth mining, shown in pink. But it takes years to explore a locations and then get a mine up and running. USGS
Although the U.S. Geological Survey has been mapping potential locations for extracting rare earth elements, getting from exploration to production takes years. That’s why unconventional sources, like extracting rare earth elements from acid mine waste, are drawing interest.
Turning a mine waste problem into a solution
Acid mine drainage forms when sulfide minerals, such as pyrite, are exposed to air during mining. This creates sulfuric acid, which then dissolves heavy metals such as copper, lead and mercury from surrounding rock. The metals end up in groundwater and creeks, where iron in the mix gives the water an orange color.
Expensive treatment systems can neutralize the acid, with the dissolved metals settling into an orange sludge in treatment ponds.
For decades, that sludge was treated as hazardous waste and hauled to landfills. But scientists at West Virginia University and the National Energy Technology Laboratory have found that it contains concentrations of rare earth elements comparable to those found in mined ores. These elements are also easier to extract from acid mine waste because the acidic water has already released them from the surrounding rock.
Acid mine drainage flowing into Decker’s Creek in Morgantown, West Virginia, in 2024. Helene Nguemgaing
Experiments have shown how the metals can be extracted: Researchers collected sludge, separated out rare earth elements using water-safe chemistry, and then returned the cleaner water to nearby streams.
It is like mining without digging, turning something harmful into a useful resource. If scaled up, this process could lower cleanup costs, create local jobs and strengthen America’s supply of materials needed for renewable energy and high-tech manufacturing.
But there’s a problem: Who owns the recovered minerals?
The ownership question
Traditional mining law covers minerals underground, not those extracted from water naturally running off abandoned mine sites.
Nonprofit watershed groups that treat mine waste to clean up the water often receive public funding meant solely for environmental cleanup. If these groups start selling recovered rare earth elements, they could generate revenue for more stream cleanup projects, but they might also risk violating grant terms or nonprofit rules.
To better understand the policy challenges, we surveyed mine water treatment operators across Pennsylvania and West Virginia. The majority of treatment systems were under landowner agreements in which the operators had no permanent property rights. Most operators said “ownership uncertainty” was one of the biggest barriers to investment in the recovery of rare earth elements, projects that can cost millions of dollars.
Not surprisingly, water treatment operators who owned the land where treatment was taking place were much more likely to be interested in rare earth element extraction.
Map of acid mine drainage sites in West Virginia. Created by Helene Nguemgaing, based on data from West Virginia Department of Environmental Protection, West Virginia Office of GIS Coordination, and U.S. Geological Survey
West Virginia took steps in 2022 to boost rare earth recovery, innovation and cleanup of acid mine drainage. A new law gives ownership of recovered rare earth elements to whoever extracts them. So far, the law has not been applied to large-scale projects.
Across the border, Pennsylvania’s Environmental Good Samaritan Act protects volunteers who treat mine water from liability but says nothing about ownership.
Map of acid mine drainage sites in Pennsylvania. Created by Helene Nguemgaing, based on data from Pennsylvania Spatial Data Access
This difference matters. Clear rules like West Virginia’s provide greater certainty, while the lack of guidance in Pennsylvania can leave companies and nonprofits hesitant about undertaking expensive recovery projects. Among the treatment operators we surveyed, interest in rare earth element extraction was twice as high in West Virginia than in Pennsylvania.
The economics of waste to value
Recovering rare earth elements from mine water won’t replace conventional mining. The quantities available at drainage sites are far smaller than those produced by large mines, even though the concentration can be just as high, and the technology to extract them from mine waste is still developing.
Still, the use of mine waste offers a promising way to supplement the supply of rare earth elements with a domestic source and help offset environmental costs while cleaning up polluted streams.
Early studies suggest that recovering rare earth elements using technologies being developed today could be profitable, particularly when the projects also recover additional critical materials, such as cobalt and manganese, which are used in industrial processes and batteries. Extraction methods are improving, too, making the process safer, cleaner and cheaper.
Treating acid mine drainage and extracting its valuable rare earth elements offers a way to transform pollution into prosperity. Creating policies that clarify ownership, investing in research and supporting responsible recovery could ensure that Appalachian communities benefit from this new chapter, one in which cleanup and clean energy advance together.
Photo credit: Mickey Pullen/Smithsonian Environmental Research Center –
A long-running experiment is testing tree mixes to develop the healthiest forests.
Around the world, people plan to plant more than 1 trillion trees this decade in an ambitious effort to slow climate change and reduce biodiversity loss. But if the past is prologue, many of those planted trees won’t survive. And if they do, they could end up as biological deserts that lack the richness and resilience of healthy forests.
However, many tree-planting commitments have a critical flaw: They rely too heavily on monoculture plantations – vast areas planted with just a single tree species.
A grove of commercially grown poplar trees, planted in lines with not much active beneath them. Mint Images via Getty Images
Rather than gambling on a single species and hoping for the best, science now points to a smarter path that captures both ecological and economic benefits while minimizing risk: mixed-species plantings that mirror the biodiversity of a natural forest, ultimately creating forests that grow faster and are more resilient in the face of constant threats.
The long-running BiodiversiTREE study compares forest plots containing several tree species with single-species monocultures. The results, illustrated here, show that mixed-species plots, right, produce 80% larger trees compared with monocultures, left, resulting in denser canopy growth that creates cooler understory microclimates, leading to more abundant and species-rich communities of insects, spiders and birds. Sergio Ibarra/Smithsonian Environmental Research Center
We are community and landscape ecologists at the Smithsonian Environmental Research Center. Since 2013, we and our colleagues have been rigorously testing this idea in a large, ecosystem-scale experiment called BiodiversiTREE. The verdict is striking: Trees in mixed forests don’t just survive – they outgrow their monoculture counterparts and support dramatically more biodiversity.
Trees with diverse neighbors grow larger
Thirteen years ago, we teamed up with volunteers to plant nearly 18,000 tree seedlings on 60 acres of fallow fields on the Smithsonian Environmental Research Center campus near the Chesapeake Bay.
We didn’t plant just a single species. We planted 16 different native species from all walks of tree-life. Some species were fast-growing timber species, some were mid-story species, and some were slow-growing species that might not reach full size for a century or more.
Some plots we planted with just a single species – homogenous rows of the same species over and over again. But others were planted with random allotments of four and 12 species, reflecting the middle and upper ends of tree diversity in similar-sized areas of our local forests.
We asked a simple question: What would happen if we tried to mirror nature and plant a mixture of species instead of a monoculture?
A drone image shows some of the BiodiversiTREE plots, including monocultures, outlined in white, and mixture plantings, outlined in green. Mickey Pullen/Smithsonian Environmental Research Center
The monoculture plots – those that survived – resemble traditional plantation forestry that historically has dominated rural lands in the Southeast and Pacific Northwest in the U.S. They contain rows of tall, narrow trees with sparse canopies and little life below.
The mixed-species plots, by contrast, are layered, complex and dynamic, with foliage filling the canopy and a diversity of plants and animals thriving underneath.
These visual contrasts reflect real ecological gains. Trees grown in mixtures, including important timber species like poplar and red oak, are up to 80% larger than the same species when grown alone. Mixed plots supported fewer leaf pathogens, more abundant caterpillar communities that provide food for birds, and increased phytochemical diversity in their leaves. We hypothesize that these leaf chemicals, some of which deter animals from eating them, reduced browsing damage from hungry deer, ultimately leading to higher tree growth in the mixed plots.
Plots with several tree species also had much fuller, denser leaf canopies, leading to cooler, shadier conditions that help understory plants flourish and support up to 50% more insects, spiders and birds.
The fuller canopy of 12-species forest plots like the one above supports more insects and birds than the monoculture plots. John Parker/Smithsonian Environmental Research CenterA sycamore monoculture plot at the BiodiversiTREE project provides little canopy cover. John Parker/Smithsonian Environmental Research Center
This pattern isn’t unique to our site. The BiodiversiTREE project is part of TreeDivNet, a global network of large-scale experiments spanning more than 1.2 million trees and hundreds of species. Across continents and climates, the results are consistent: Forests with a mix of species tend to grow larger, store more carbon and better withstand stress from drought, pests and disease.
So why are monocultures still common?
Despite decades of evidence, mixed-species plantings remain relatively rare in practice. Most commercial forestry operations still rely on monocultures, and these plantations are counted toward international planting campaigns aimed at slowing climate change and reversing biodiversity loss.
Technician Shelley Bennett uses high-resolution GPS to lay out plots for an experiment at the Smithsonian Environmental Research Center in Maryland. Regan Todd/Smithsonian Environmental Research Center
A new experiment at the Smithsonian Environmental Research Center called “Functional Forests” aims to bridge some of the gaps between science and practice. We’re developing intentionally designed combinations of trees to test whether specific mixtures of species can contribute ecological benefits while also providing timber and other services that humans need to support a thriving, sustainable economy.
Each of the 20 tree species in the Functional Forests project was chosen to provide one or more benefits, including timber, wildlife habitat, food for people, resistance to deer and climate resilience. But no single species provides all of these benefits.
Some of the nearly 200 plots will contain a single species, while others include carefully selected combinations of five species assembled based on the functions they provide. Some plots are protected from deer browsing, while others are left exposed.
The Functional Forests project includes trees with edible fruits like the pawpaw (Asimina triloba), one of 20 different tree species being planted there. Jamie Pullen/Smithsonian Environmental Research Center
By comparing these approaches, we can test how different planting strategies perform across a range of goals, from timber production to food production and from biodiversity to climate resilience.
Landowners and communities have different priorities, whether that’s producing wood, supporting wildlife or creating forests that can withstand a changing climate. The idea behind Functional Forests is to design plantings that can deliver these multiple benefits all at once, rather than optimizing for just one, essentially leveraging the positive effects of biodiversity to achieve real-world goals.
Planting 1 trillion trees wisely
The stakes are high. Restoration has become a major global investment, with hundreds of billions of dollars already being spent annually. Getting it wrong means wasted resources and missed opportunities to address some of the most pressing environmental challenges of our time.
If the world is going to plant a trillion trees, we believe it needs to do more than just put seedlings in the ground. It needs to rethink what a forest should be.
The goal isn’t just to grow trees. It’s to grow forests that last.
Plastic pollution has been a serious problem since the rise of fossil fuel-based manufacturing. As tiny plastic particles find their way into something as essential as drinking water, the world needs a solution quickly.
The answer may be simpler than we expect. Researchers testing a salt-based extract from Moringa oliefera seeds were able to remove over 98% of microplastics from drinking water. The study published in ACS Omega showed that the simple filtration system could be adapted for water treatment facilities at a lower cost and requires less energy.
A father shares drinking water with his son. Photo credit Canva
‘Miracle Tree’ produces miracle seeds
The Moringa oleifera is a tropical tree native to parts of South Asia. Today, it’s cultivated on a global scale. Thriving in harsh, drought-prone regions, this “miracle tree” has been used to treat hundreds of conditions. Healthline reported that it contains 90+ bioactive compounds that help combat everything from inflammation to stress. A 2023 study in MDPI showed medicinal properties could be utilized in nearly every part of the tree, from its leaves to its roots.
However, the solution to the plastic problem comes from its seeds. Researchers ground and mixed the seeds with a salt solution to pull out positively charged proteins. This mix attracts impurities, including microplastics, like a natural magnet. Clumping and binding with the impurities in a process called “coagulation,” they then sink to the bottom.
Microplastics on top of a father’s and a daughter’s fingers. Photo credit Canva
Microplastics removed from drinking water
Researchers tested this plant-based method against the industry-standard chemical alum: aluminium sulfate. The moringa extract worked across a wider range of conditions than alum, demonstrating reliability in real-world applications. As concerns grow over the long-term impact of chemicals used in water treatment, there is a clear need to shift toward safer alternatives.
Simplifying the filtration process can significantly reduce both costs and energy demands typically required on an industrial level. This approach enables communities lacking resources to have an effective solution for plastic pollution.
An industrial water treatment plant. Photo credit Canva
Treating plastic pollution is a global problem
Developing countries face major environmental and health threats from plastic pollution. A 2024 study in Science Direct showed 60% of global plastic consumption and production comes from countries lacking proper quality control. A 2023 study in MDPI revealed that even where infrastructure exists, it’s limited and overwhelmed. Facing 120 million tons of waste annually, the situation suggests pollution is widespread and underreported.
Offering a cheap and efficient option, Moringa oliefera seeds could be an invaluable solution. But it’s still not a perfect system. The seed extract is an organic material. That means proteins and fats can remain in the water after filtration.
A 2025 study in Scientific Reports found organic matter reacting with disinfectants like chlorine is linked to health risks, including cancer. Also, stored water would be susceptible to bacterial regrowth and become contaminated over time. Researchers on the study believe this is an area of ongoing work that requires more research.
Microplastics are everywhere. With inconsistent water treatment, less monitoring, and weaker waste systems, exposure is high and poorly controlled. Moringa oleifera isn’t a flawless fix, but it’s a promising study. The seeds could eventually work alongside modern systems, bringing us closer to tackling the complex problem of plastic pollution in our water.
