Pesticides Significantly Affect Soil Life and Biodiversity

70 percent of European soils are contaminated with pesticides with a major impact on various beneficial soil organisms, such as mycorrhizal fungi and nematodes, impairing their biodiversity.
Image Credit: Scientific Frontline / AI generated (Gemini)

Scientific Frontline: "At a Glance" Summary

• Main Discovery: A comprehensive European study reveals that 70% of soils are contaminated with pesticide residues, which significantly suppress beneficial soil organisms like mycorrhizal fungi and nematodes, thereby impairing essential soil biodiversity and function.
• Methodology: Researchers from 10 European institutions analyzed 373 soil samples collected from agricultural fields, forests, and meadows across 26 countries to measure the presence and impact of 63 common pesticides.
• Key Data: Fungicides accounted for 54% of detected active ingredients, followed by herbicides (35%) and insecticides (11%), with glyphosate being the most prevalent substance found.
• Significance: The presence of these chemicals drastically alters soil communities and disrupts key genes responsible for nutrient cycling (such as nitrogen and phosphorus recovery), potentially forcing a reliance on additional fertilizers to maintain crop yields.
• Future Application: These findings provide the first quantitative evidence of this scale and are intended to directly influence and tighten current pesticide regulations to better protect soil biodiversity.
• Branch of Science: Soil Ecology / Environmental Science / Agricultural Science
• Additional Detail: Contamination is not limited to treated agricultural land; residues were also detected in forests and meadows where pesticides are not applied, indicating widespread transport via spray drift.

Silky Shark Study Reveals Deadly Gaps in Marine Protected Areas

The Silky Shark (Carcharhinus falciformis)
Photo Credit: Alex Chernikh
(CC BY-SA 4.0)

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Silky sharks predominantly migrate west and northwest from the Galápagos Marine Reserve into unprotected high-seas corridors, exposing them to industrial fishing fleets despite the existence of nearby Marine Protected Areas.
• Methodology: Researchers deployed fin-mounted satellite tags on 40 adult silky sharks (33 females and 7 males) off Wolf and Darwin Islands, tracking their movements and residence times within protected versus unprotected zones for up to 1.75 years.
• Key Data: The tagged sharks spent more than 50% of the study duration outside Marine Protected Areas, with one individual traveling a record 27,666 kilometers; global populations of the species have declined by 47% to 54% in the last 40 years.
• Significance: The study reveals a critical misalignment between current conservation boundaries and shark behavior, as the animals rarely use the recently established eastern protected areas, preferring instead to travel into high-risk fishing zones.
• Future Application: Conservation planners can utilize this migration data to shift or expand Marine Protected Areas toward the west and northwest to cover the actual pelagic pathways used by the species.
• Branch of Science: Marine Ecology and Conservation Biology
• Additional Detail: Silky sharks are the second-most common species found in the international fin trade, driving their classification as vulnerable with a high risk of extinction.

Changes to cougar diets and behaviors reduce their competition with wolves in Yellowstone

Researcher Wesley Binder climbs a tree to reach a cougar to be collared with a GPS device.
Photo Credit: Jake Frank, National Park Service

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Interactions between Yellowstone wolves and cougars are driven by wolves usurping cougar kills, prompting cougars to adapt by shifting their diet to smaller prey that can be consumed quickly and utilizing escape terrain to avoid fatal encounters.
• Methodology: Researchers analyzed nine years of GPS telemetry data from collared animals and conducted field investigations of 3,929 potential kill sites to train machine learning models capable of predicting interaction drivers and kill site locations.
• Key Data: Interactions were highly asymmetric, with 42% occurring at cougar kill sites versus only one recorded event at a wolf kill site; simultaneously, cougar predation on elk declined from 80% to 52% while deer consumption increased from 15% to 42% between study periods.
• Significance: The study establishes that the coexistence of competing apex predators relies heavily on prey diversity and the availability of complex landscape features, such as climbable trees or cliffs, rather than simply the overall abundance of prey.
• Future Application: These findings will inform management and recovery efforts for overlapping carnivore populations in the Western United States by highlighting the necessity of preserving diverse prey bases and habitat structures to reduce interspecific competition.
• Branch of Science: Ecology and Wildlife Biology

Study finds fisheries management—not predator recovery—drives catch levels in the North Sea

Harbour seals (Phoca vitulina) basking on a rocky shore. Recent data shows these charismatic marine mammals have surged in the past few decades. However, new research suggests this increased population size remains compatible with sustainable fisheries.
Photo Credit: Jeremy Kiszka, Ph.D., Florida International University.

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Anthropogenic fishing effort, driven by management decisions, serves as the primary determinant of fishery yields in the North Sea rather than predation pressure from recovering large marine mammal populations.
• Methodology: Researchers constructed a comprehensive ecosystem model of the southern North Sea and eastern English Channel, integrating data from 12 commercial fishing fleets and the complete marine food web, ranging from microscopic plankton to apex predators like gray seals and harbor porpoises.
• Key Data: The model synthesized extensive real-world datasets, including predator diet studies, fish stock assessments, and historical fisheries catch records, to accurately simulate the interplay between ecological dynamics and human harvest rates.
• Significance: This analysis demonstrates that the conservation of protected predator species is compatible with sustainable seafood production, challenging the prevailing assumption that recovering predator populations inevitably compromise commercial fishery viability.
• Future Application: Findings support the broader implementation of ecosystem-based fisheries management (EBFM) strategies that prioritize regulating human fishing pressure to balance economic objectives with ecological recovery.
• Branch of Science: Marine Ecology and Fisheries Management.
• Additional Detail: Published in the Canadian Journal of Fisheries and Aquatic Sciences, the study indicates that while total consumption by predators increased alongside their population growth, its impact on fish stocks remained subordinate to the volume of biomass removed by commercial fleets.

Meet the marten: Oregon State research provides updated look at rare, adorable carnivore

Humboldt marten.
Photo Credit: Ben Wymer, A Woods Walk Photography

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Genetic analysis confirmed the presence of 46 individual coastal martens within a 150-square-mile Northern California study area, establishing their habitation of both high-elevation forested ridgetops and lower-elevation riparian ravines.
• Methodology: Researchers deployed non-invasive survey tools, including 285 PVC pipe hair snares for DNA collection and 135 remote cameras, across ancestral Yurok and Karuk lands to accurately map distribution and demography.
• Key Data: The study identified 28 males and 18 females, revealing a specific preference for forest stands exhibiting greater than 50% canopy cover and complex structures like large-diameter trees, snags, and hollow logs.
• Significance: This research provides essential baseline estimates for the Humboldt marten, a species listed as threatened under the Endangered Species Act that was considered extinct until its rediscovery in 1996.
• Future Application: Findings will directly guide land management decisions for the Yurok Tribe and U.S. Forest Service, helping to prioritize the conservation of old-growth forest characteristics against threats like wildfire and climate change.
• Branch of Science: Wildlife Ecology and Conservation Biology
• Additional Detail: The study highlights the resilience of the species in a mixed-use landscape involving timber harvesting and cattle grazing, emphasizing the need to mitigate modern risks such as rodenticides and vehicle strikes.

Positive Interactions Dominate Among Marine Microbes, Six-Year Study Reveals

Lead study author Ewa Merz conducting maintenance on a pump below the Scripps Pier, which brings seawater to the surface for sampling.
Photo Credit: Riley Hale

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Marine microbial communities are driven primarily by positive, mutually beneficial interactions rather than competition, a trend that intensifies during periods of elevated ocean temperature.
• Methodology: Scientists utilized a six-year time series of high-frequency seawater sampling from Scripps Pier combined with DNA sequencing and computational analysis to map interactions among 162 abundant microbial taxa.
• Key Data: Analysis revealed that 78% of microbial associations were positive; specifically, warmer waters caused a 33% drop in total interactions but drove an 11% shift toward facilitation among the remaining connections.
• Significance: These findings challenge the traditional ecological emphasis on competition and predation, suggesting that cooperative networks are critical for microbiome stability and ecosystem function.
• Future Application: Integrating these positive interaction dynamics into climate models will enhance the accuracy of predictions regarding carbon cycling and food web stability in warming oceans.
• Branch of Science: Marine Microbial Ecology
• Additional Detail: The study identified specific "keystone" microbes that disproportionately influence community structure, noting that the identity of these critical species shifts in response to temperature changes.

Seawater microbes offer new, non-invasive way to detect coral disease

This brain coral shows the effects of stony coral tissue loss disease. The brown areas are healthy, the white areas are newly dead from the disease, and the light yellow areas are dead and colonized by endolithic algae.
Photo Credit: Amy Apprill ©WHOI

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Microorganisms in seawater immediately surrounding corals act as superior, non-invasive biomarkers for detecting diseases like Stony Coral Tissue Loss Disease (SCTLD) compared to microbes within the coral tissue.
• Methodology: Researchers performed a four-year longitudinal analysis (2020–2024) of brain coral (Colpophyllia natans) in the U.S. Virgin Islands, using genetic sequencing to compare microbial shifts in coral tissue versus adjacent seawater throughout a disease outbreak.
• Key Data: Microbial communities in seawater remained stable near healthy corals but shifted dramatically during disease infection, whereas internal coral tissue microbiomes varied inconsistently regardless of health status.
• Significance: This approach overcomes the limitations of traditional visual assessments by enabling non-destructive, presymptomatic detection of reef health declines, allowing for timely intervention.
• Future Application: Development of automated, rapid genetic monitoring systems to provide early warning signals for reef managers to mitigate disease spread.
• Branch of Science: Marine Microbiology and Coral Ecology.
• Additional Detail: The study, published in Cell Reports Sustainability, suggests seawater microbes respond to specific materials released by diseased corals, offering a clear signal even before visual lesions appear.

Old diseases return as settlement pushes into the Amazon rainforest

Yellow fever cases have begun to rise, spilling over the expanding border between the forest and urban areas.
Photo Credit: Thiago Japyassu

Scientific Frontline: "At a Glance" Summary

• Main Discovery: The expansion of human settlements into the Amazon rainforest, specifically the growing interface between urban areas and forests, is the primary driver behind the recent resurgence of human yellow fever spillover cases.
• Methodology: Researchers analyzed yellow fever case records from Brazil (2000–2021), Colombia (2007–2021), and Peru (2016–2021) alongside land-use data from the MapBiomas Project, modeling the relationship between disease rates and geographic metrics such as forest patch size, edge density, and forest-urban adjacency.
• Key Data: A 10% increase in forest-urban adjacency raised the probability of a spillover event by 0.09, equivalent to a 150% increase in the number of spillover events annually; notably, this high-risk borderland is expanding by approximately 13% per year.
• Significance: Proximity between human settlements and forest edges is a significantly stronger predictor of disease spillover than ecological forest fragmentation alone, raising critical concerns that urban transmission cycles—independent of non-human hosts—could reemerge.
• Future Application: Findings indicate a critical need to realign public health infrastructure and vaccination stockpiles to specifically target expanding forest-urban interfaces, rather than relying solely on broad ecological conservation metrics.
• Branch of Science: Disease Ecology and Epidemiology
• Additional Detail: Recent data highlights the urgency, with confirmed yellow fever cases in 2025 showing a threefold increase compared to 2024 and shifting geographically to areas outside the Amazon basin.

Hot spring bathing doesn't just keep snow monkeys warm

Video Credit: Abdullah Langgeng

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Hot spring bathing behaviors in Japanese macaques actively reshape the host "holobiont," specifically modifying lice distribution and gut microbiota composition beyond simple thermoregulation or stress relief.
• Methodology: Researchers conducted a comparative study over two winters at Jigokudani Snow Monkey Park, utilizing behavioral observations, ectoparasite monitoring, and gut microbiome sequencing to analyze differences between female macaques that bathed regularly and those that did not.
• Key Data: Bathers exhibited distinct lice distribution patterns (suggesting disruption of activity or egg placement) and a lower abundance of specific bacterial genera, yet showed no increase in intestinal parasite infection rates or intensity despite sharing communal water sources.
• Significance: The study provides empirical evidence that voluntary animal behaviors act as direct drivers of host-parasite and host-microbe interactions, challenging the assumption that shared water sources in the wild necessarily amplify disease transmission risks.
• Future Application: Insights from this research will aid in modeling the co-evolution of behavior and health in social animals and offer comparative frameworks for understanding how cultural practices, such as communal bathing, influence microbial exposure in primates.
• Branch of Science: Primatology, Ethology, and Microbial Ecology
• Additional Detail: The findings underscore the concept of the holobiont—an integrated system of the host and its symbiotic organisms—as a dynamic entity modulated by behavioral choices rather than solely by environmental constraints.

Freshwater browning threatens growth and populations of economically important fish

Smallmouth bass
Image Credit: Scientific Frontline / stock image

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Freshwater browning stunts the growth of specific fish species and alters community composition by favoring distinct traits, ultimately shifting population dynamics in north-temperate lakes.
• Methodology: Researchers synthesized data from 871 lakes across North America and Europe to analyze population trends and further examined a subset of 303 lakes to assess functional traits, such as eye size, in relation to water color gradients.
• Key Data: Browner waters correlated with increased abundance of northern pike and walleye but declines in lake trout, brook trout, yellow perch, largemouth and smallmouth bass, and whitefish; communities in darker waters were significantly more likely to feature species with large eyes.
• Significance: This phenomenon, driven by climate change and land use, disrupts aquatic food webs and creates cascading ecological effects that extend to terrestrial systems, such as altering the diets of birds dependent on specific fish populations.
• Future Application: These findings enable improved forecasting models for fisheries management, allowing for better prediction of ecosystem shifts and biodiversity loss under continuing browning scenarios.
• Branch of Science: Ecology and Limnology
• Additional Detail: The study confirms that freshwater browning is a widespread, transcontinental issue affecting biodiversity across North America and Europe, rather than a localized anomaly.

What Is: Invasive Species

Image Credit: Scientific Frontline / stock image

Scientific Frontline: Extended "At a Glance" Summary

The Core Concept: Invasive species are non-native organisms that, upon introduction to a new environment, escape the evolutionary checks of their native ranges to cause significant ecological, economic, or human health harm. This phenomenon represents a systemic disruption of biophysical systems rather than merely the presence of an unwanted plant or animal.

Key Distinction/Mechanism: The defining characteristic separating "invasive" from "non-native" is impact; while many non-native species (like agricultural crops) are beneficial, invasive species actively dismantle native ecosystems. They often succeed via the Enemy Release Hypothesis, flourishing because they have left behind natural predators and diseases, or through Priority Effects, such as leafing out earlier than native flora to monopolize resources.

Origin/History: While natural translocation has occurred for eons, the current crisis is driven by the "relentless engine of human globalization" in the Anthropocene. The concept is underscored by the "Ten Percent Rule," a statistical filter noting that roughly 10% of transported species survive, 10% of those establish, and 10% of those become destructive invaders.

Long-term pesticide exposure accelerates aging and shortens lifespan in fish

Notre Dame biologist Jason Rohr
Photo Credit: Barbara Johnston/University of Notre Dame

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Chronic exposure to low levels of the pesticide chlorpyrifos accelerates biological aging and reduces lifespan in fish, occurring at concentrations previously considered safe and distinct from acute toxicity.
• Methodology: Researchers combined field studies of over 20,000 lake skygazer fish (Culter dabryi) across lakes with varying contamination levels in China with controlled laboratory experiments that exposed fish to chronic low doses (10 and 50 ng/L) over 16 weeks to verify causal links.
• Key Data: Fish exposed to these low concentrations exhibited significantly shortened telomeres (protective chromosome caps) and increased lipofuscin (cellular waste) accumulation; notably, these aging markers appeared at levels below current U.S. freshwater safety standards.
• Significance: This research challenges the prevailing regulatory assumption that chemicals are safe if they do not cause immediate death, revealing that "silent" cumulative damage can drive population declines through accelerated aging rather than acute poisoning.
• Future Application: Regulatory frameworks for chemical safety assessments may need to be overhauled to include long-term markers of biological aging rather than relying solely on short-term lethality tests.
• Branch of Science: Environmental Toxicology and Ecology
• Additional Detail: As telomere biology and aging mechanisms are highly conserved across vertebrates, the findings suggest that chronic low-level pesticide exposure could pose similar aging-related health risks to humans.

Insects are victims too, not just invaders, says study

Harlequin larva and moth eggs.
Photo Credit: Bill Phillips

Scientific Frontline: "At a Glance" Summary

• Main Discovery: A groundbreaking global analysis led by the UK Centre for Ecology & Hydrology (UKCEH) establishes that insects are major victims of invasive alien species (IAS), significantly exacerbating global population declines and compromising biodiversity.
• Specific Detail/Mechanism: The reduction in native insect populations is driven principally by invasive animals outcompeting or directly preying upon them, alongside invasive vegetation displacing the native flora that insects rely on for nutrition and habitat.
• Key Statistic or Data: The study, which analyzed data across six continents, indicates that invasive alien species reduce the abundance of terrestrial insects by an average of 31% and decrease species richness by 21%.
• Context or Comparison: Vulnerability varies significantly by order: Hemiptera (true bugs) experienced the steepest decline in abundance at 58%, followed by Hymenoptera (ants, bees, wasps) at 37%, while Coleoptera (beetles) were the least affected with a 12% reduction.
• Significance/Future Application: These findings highlight a critical risk to essential ecosystem services such as pollination and pest control, necessitating urgent prioritization of biosecurity measures and habitat management to mitigate the introduction and spread of damaging invasive species.
• Methodology: This research represents the first comprehensive study to quantify the impact of invasive alien species on insect populations on a global scale, filling a significant gap in the understanding of drivers of insect decline.

Study shows that species-diverse systems like prairies have built-in protection

The Rainfall and Diversity Experiment, where the study is based, was established at the KU Field Station in 2018. The site includes 12 constructed shelters, each with 20 plots planted with differing levels of plant species diversity and allowed different levels of precipitation. Research at the site continues.
Photo Credit: Courtesy of University of Kansas

Six years into a study on the effect of plant pathogens in grasslands, University of Kansas researchers have the data to show that species diversity — a hallmark of native prairies — works as a protective shield: It drives growth and sustains the health of species-diverse ecosystems over time, functioning somewhat like an immune system.

The research findings, just published in the Proceedings of the National Academy of Sciences (PNAS), have implications for management of native grassland, rangeland and agricultural lands. The results support regenerative agricultural approaches that strengthen the soil biome long-term, such as intercropping, rotation of different cover crops and encouraging a variety of native perennials (prairie strips) along field margins.

The study emphasized the interaction of changing precipitation and the loss of species diversity.

How light reflects on leaves may help researchers identify dying forests

Trees at UNDERC
Photo Credit: Barbara Johnston/University of Notre Dame

Early detection of declining forest health is critical for the timely intervention and treatment of droughted and diseased flora, especially in areas prone to wildfires. Obtaining a reliable measure of whole-ecosystem health before it is too late, however, is an ongoing challenge for forest ecologists.

Traditional sampling is too labor-intensive for whole-forest surveys, while modern genomics—though capable of pinpointing active genes—is still too expensive for large-scale application. Remote sensing offers a high-resolution solution from the skies, but currently limited paradigms for data analysis mean the images obtained do not say enough, early enough.

A new study from researchers at the University of Notre Dame, published in Nature: Communications Earth & Environment, uncovers a more comprehensive picture of forest health. Funded by NASA, the research shows that spectral reflectance—a measurement obtained from satellite images—corresponds with the expression of specific genes.

Reflectance is how much light reflects off of leaf material, and at which specific wavelengths, in the visible and near-infrared range. Calculated as the ratio of reflected light to incoming light and measured using special sensors, reflectance data reveals a unique signature specific to the leaf’s composition and condition.

Arctic has entered a new era of extreme weather

Cassiope tetragona killed by a rain-on-snow event.
Photo Credit: R Treharne

Extreme weather events have become significantly more common in the Arctic over recent decades, posing a threat to vital polar ecosystems, according to new research by an international team of scientists. 

Key Takeaways:

• New research by an international team of scientists has found that Arctic regions are facing unprecedented climate conditions 

• Study has found that extreme weather events have become more common over the past 30 years, threatening plants and animals 

• Findings show hotspots for extreme weather events are Western Scandinavia, the Canadian Arctic Archipelago and Central Siberia 

• Damage from extreme weather can also affect the livelihoods of Arctic people such as reindeer herders and may also harm the ability of the Arctic to absorb carbon and slow climate change. 

Extreme weather events have become significantly more common in the Arctic over recent decades, posing a threat to vital polar ecosystems, according to new research by an international team of scientists. 

Recovering reef fish populations could nourish millions of additional people each year

A new study led by King Abdullah University of Science and Technology (KAUST) Assistant Professor Jessica Zamborain-Mason shows that rebuilding depleted coral reef fish populations could significantly increase sustainable food supplies for millions of people worldwide. Published in Proceedings of the National Academy of Sciences (PNAS), the work provides the first global quantification of how much food is currently being lost due to degraded reef fish stocks and how much can be regained if reefs are restored to sustainable levels.

Drawing on one of the largest coral reef datasets assembled to date, the study analyzes more than 1,200 reef sites across 23 tropical jurisdictions. The findings come at a critical moment: reef ecosystems are experiencing widespread climate-driven impacts, and if reef fisheries are overexploited, ecosystem resilience and tropical food systems are at risk.  

“Our study provides clear, quantitative evidence of how much food tropical coastal communities are losing — and could regain — through sustainably managed reef fisheries,” said Zamborain-Mason. “These insights give governments the scientific foundation needed to strengthen food security and ecosystem resilience through effective fisheries management.” 

Plant science with a twist

Images of roots studied as part of new research exploring the molecular underpinnings to how plants twist their roots.
Image Credit: Dixit Lab / Washington University in St. Louis

From morning glories spiraling up fence posts to grape vines corkscrewing through arbors, twisted growth is a problem-solving tool found throughout the plant kingdom. Roots “do the twist” all the time, skewing hard right or left to avoid rocks and other debris.

Scientists have long known that mutations in certain genes affecting microtubules in plants can cause plants to grow in a twisting manner. In most cases, these are “null mutations,” meaning the twisting is often a consequence of the absence of a particular gene.

This still left a mystery for plant scientists like Ram Dixit, the George and Charmaine Mallinckrodt Professor of Biology at Washington University in St. Louis. The absence of a gene should cause all sorts of other problems for plants and yet twisted growth is an incredibly common evolutionary adaptation.

What Is: The Anthropocene

Image Credit: Scientific Frontline / stock image

At a Glance

• The Core Concept: The Anthropocene, or "Age of Man," is a proposed geological epoch positing that human activity has superseded natural forces to become the primary driver of Earth's geological and ecological systems.
• Key Distinction/Mechanism: Unlike the Holocene—the stable epoch of the last 11,700 years that fostered human civilization—the Anthropocene represents a fundamental rupture in Earth's history where humanity operates as a geological force rather than merely a biological one. It is characterized by the human-driven alteration of the atmosphere, hydrosphere, cryosphere, and biosphere, shifting the planet into a volatile and unstable interval.
• Origin/History: The term was popularized by atmospheric chemist Paul Crutzen at the turn of the millennium (c. 2000) to describe the profound impact of humanity on the planet.

Major Frameworks/Components

• A Diachronous "Event": The scientific community increasingly views the Anthropocene not strictly as a defined epoch with a singular start date (a "golden spike"), but as an unfolding, diachronous geological event comparable to the Great Oxidation Event.
• Planetary Health Indicators: The framework highlights critical shifts such as the disruption of nitrogen and phosphorus cycles, rapid ocean acidification, and accelerating species extinction.
• Stratigraphic Alteration: The concept suggests that humanity has fundamentally altered the physical stratigraphic record of the Earth.
• Why It Matters: The Anthropocene redefines the current environmental crisis not as a series of isolated issues, but as a systemic transformation of the Earth caused by a single species. It serves as the dominant conceptual framework for understanding planetary instability and signals that the conditions necessary for known civilization are ending.

Water’s Age and What It Can Tell Us

PhD student Joshua Snarski is using stable water isotopes to study how water is stored and released from soil in agricultural settings.
Photo Credit: Courtesy of University of Connecticut

When it rains, what happens to the water once it enters the soil? Does the new precipitation mix with all of the water that was already there? In their recent paper in Water Resources Research, Department of Natural Resources and the Environment Ph.D. student Joshua Snarski and assistant professor James Knighton show the answer is more complicated than previously assumed, but knowing the age of water gives a more accurate picture.

Hydrologists use models to simulate what is happening in natural systems. Since hydrologic processes are complex, researchers need to make assumptions about some aspects, such as how water mixes within the soil profile. Though previous hydrologic research is focused on the amount and timing of precipitation, Snarski says shifting the focus to the age of water within the soil profile can reveal more about what is happening beneath the surface.