News
Trees ‘remember’ wetter times − never having known abundant rain could buffer today’s young forests against climate change
In a changing climate, trees exhibit “legacy effects” from past droughts or wet periods. Young trees, adapted to arid conditions, offer hope for future forest resilience amidst escalating climate challenges globally.
Alana Chin, Cal Poly Humboldt ; Janneke Hille Ris Lambers, Swiss Federal Institute of Technology Zurich, and Marcus Schaub, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)
What does the future hold for forests in a warmer, drier world? Over the past 25 years, trees have been dying due to effects of climate change around the world. In Africa, Asia, North America, South America and Europe, drought stress amplified by heat is killing trees that have survived for centuries.
Old trees may have grown through entire millennia that were wetter than the past 20 years. We are scientists who study forest dynamics, plant ecology and plant physiology. In a recent study, we found that trees can remember times when water was plentiful and that this memory continues to shape their growth for many years after wet phases end.
This research makes us optimistic that young trees of today, which have never known 20th-century rainfall, have not shaped their structure around water abundance and thus may be better equipped to survive in a chronically dry world.
What if we water the forest?
This study built on nearly 20 years of forest research in response to early warning signs of forest loss in the 1990s in the dry Rhône River Valley of the Swiss Alps. At that time, scientists observed that Scots pine trees that had stood for around 100 years were declining and dying. They wondered whether drought or other climate factors were driving this loss.
To tackle this question, researchers at the Swiss Federal Institute for Forest, Snow and Landscape Research designed an ecological experiment. To understand the impacts of drought, they would irrigate a mature forest, doubling natural summertime rainfall, and then compare how these water-rich trees fared in comparison with those receiving only natural precipitation.
The Pfynwald experiment, launched in 2003, has shown that trees survived at higher rates in irrigated plots. After 17 years of irrigation, the team found that irrigation didn’t just help trees survive dry phases – it also increased their growth rates. https://www.youtube.com/embed/OA7A-xWhDeo?wmode=transparent&start=0 Tree physiologist Leonie Schönbeck conducts research at Pfynwald, a natural reserve in southern Switzerland, to learn how trees take up and store energy and use their reserves to recover from drought.
Legacy effects are forests’ memories
Trees experiencing drought alter their leaves, wood and roots in ways that prime them for continued dry conditions. Wood under drought might have smaller cells that are less vulnerable to future damage, and roots might increase relative to leaf area. These structural changes persist after the drought has passed and continue to influence the tree’s growth and ability to tolerate stress for many years.
Known as “legacy effects,” these lingering post-drought impacts represent an ecological memory of past climatic conditions at the tree and forest level. Knowing that trees hold a persistent memory of past dry phases, researchers wondered whether they might also show structural changes in response to past wet periods.
Eleven years after summertime irrigation started in Pfynwald, scientists stopped irrigating half of each plot in 2013 to address this question. The formerly irrigated trees, which at this point were about 120 years old, had experienced a lasting period of irrigation – but now those times of plenty were over.
Would the trees remember? A decade later, we found out.
Trees, trains and particle accelerators
On an early March morning in 2023, two of us (Alana Chin and Marcus Schaub) met at Pfynwald to collect very fresh leaf and twig samples so that we and colleagues could look inside to search for signs of lasting effects of past water richness.
At the site, we climbed canopy access towers to collect newly grown treetop leaves and twigs from control trees that had never been irrigated; trees that had been irrigated every summer since 2003; and formerly irrigated trees that had not received irrigation water since 2013.
We took our samples to the Swiss Light Source, an intensely powerful synchrotron – a type of particle accelerator that produces the world’s most intense beams of light. This facility is the home of the TOMCAT, an extremely high-resolution X-ray that allowed us to look inside our leaves and twigs without disturbing their structure.
Scanning our samples took all night, but when we stumbled out of the building, we had images capturing every cell in exquisite detail.
The memory of water
We found that the new leaves of once-irrigated trees were different from both continually watered trees and never-watered control trees. Leaves carry out photosynthesis that fuels a tree’s survival and growth. Inside them, we could see the legacy of past water abundance, written in the size, shape and arrangement of cells.
Reading this cellular signature, we observed that, at the expense of structures promoting productivity, formerly irrigated trees showed every sign of chronic water stress – even more so than never-irrigated trees. In their anatomy, we saw why these trees that had it easy for 11 wet years were now growing slowly.
Every cell in a leaf comes with a trade-off. Trees must balance investments in rapid photosynthesis with others that promote leaf survival. Rather than building the cells used to harvest sunlight and ship sugar to the rest of the tree, leaves on the trees that had been irrigated showed every indication of drought stress we could think to measure.
After receiving extra water for an 11-year stretch and then losing it, the trees were producing new, tiny leaves that invested mostly in their own survival. The leaves were structured to protect themselves from insects and drought and to store water reserves. Compared with leaves on trees that had never known irrigation, these looked as though they were in the middle of the drought of the century.
While this memory of water might seem negative, it likely once helped trees “learn” from past conditions to survive in variable environments. The formerly irrigated trees did not know that humans had played a trick on them. Like trees experiencing climate change, they had no way of knowing that the water was not coming back.
When trees experience a drought event, recovery can mean reaching a “new normal” state, in which they are prepared to survive the next drought, with smaller, less vulnerable cells and increased energy reserves to ‘save up’ for future dry periods. They may have deeper roots or a smaller pool of leaves to support, helping them prepare for an unstable environment.
We wanted to know whether the same was true of trees that had experienced water abundance. Were they waiting in distress for the water to return?
Hard times may make tough trees
In some temperate forests, like the ones we studied in Switzerland, old trees once knew levels of water abundance that now are gone, thanks to climate change. That past abundance may have locked into place structural and epigenetic changes in the trees that are mismatched to today’s drier world. If this is true, then some of today’s devastating global tree mortality events may be, in part, due to the legacy effects of past water abundance.
In most of the world’s temperate forests, however, the current cohort of young forest trees – those sprouting in the past 15 to 20 years – has managed to establish itself under conditions that once would have been considered chronic drought. Those young trees, which have survived an endless dry period, will form the forests of the future.
In all, our observations in Pfynwald have provided us some room for hope that young trees currently taking their place in many forests worldwide may be better prepared to cope with the world as humans have shaped it. Climate shifts in recent decades have primed them for hard times, without the lingering memory of water.
Alana Chin, Assistant Professor of Plant Physiology, Cal Poly Humboldt ; Janneke Hille Ris Lambers, Professor of Environmental Systems Science, Swiss Federal Institute of Technology Zurich, and Marcus Schaub, Group Leader, Forest Dynamics and Ecophysiology, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)
This article is republished from The Conversation under a Creative Commons license. Read the original article.
The science section of our news blog STM Daily News provides readers with captivating and up-to-date information on the latest scientific discoveries, breakthroughs, and innovations across various fields. We offer engaging and accessible content, ensuring that readers with different levels of scientific knowledge can stay informed. Whether it’s exploring advancements in medicine, astronomy, technology, or environmental sciences, our science section strives to shed light on the intriguing world of scientific exploration and its profound impact on our daily lives. From thought-provoking articles to informative interviews with experts in the field, STM Daily News Science offers a harmonious blend of factual reporting, analysis, and exploration, making it a go-to source for science enthusiasts and curious minds alike. https://stmdailynews.com/category/science/
Daily News
Major Construction Begins on Metro’s East San Fernando Valley Light Rail Line
LA Metro has moved the East San Fernando Valley Light Rail Transit Project into major construction. The 6.7-mile Van Nuys Boulevard line will add 11 stations, connect with the G Line and regional rail services, and is now targeted for completion in early 2032.
After years of utility relocation and planning, LA Metro is moving into major construction on a new rail line along Van Nuys Boulevard. The milestone also comes with a revised early-2032 completion target.
LA Metro has officially marked the beginning of major construction on the East San Fernando Valley Light Rail Transit Project, moving one of the region’s most important rail projects from preparatory work into full-scale construction.
Metro held a groundbreaking ceremony on October 19, 2026, for the 6.7-mile line, which will run along Van Nuys Boulevard from the G Line busway north to San Fernando Road in Pacoima. The project will add 11 light-rail stations serving Van Nuys, Panorama City, Arleta and Pacoima.
This was not the project’s first groundbreaking. Metro held an earlier ceremony in December 2022 when crews began relocating utility infrastructure. The new milestone is more consequential for riders: the major-construction phase covers the guideway, stations, traction-power substations, rail systems and a maintenance and storage facility.
From utility work to a new rail corridor
The project has spent several years in utility relocation, property acquisition, design and other early work. Metro’s current construction timeline shows major work continuing from 2026 through 2032, with phased traffic changes and K-rail installations expected along Van Nuys Boulevard.
When completed, trains are expected to operate every seven to 10 minutes during peak periods. The line will connect directly with the G Line and provide access to the Van Nuys Metrolink and Amtrak station. It is also expected to become an important transfer point for the future Sepulveda Transit Corridor and a planned Metrolink station in Pacoima.
The corridor already has a substantial transit market. Metro reported that bus Lines 233 and 761, which serve Van Nuys Boulevard, recorded nearly 20,000 boardings in September 2026. The agency also says approximately 19 percent of households in the project area lack access to a car, compared with about 8 percent countywide.
Those figures help explain why this project matters beyond its construction footprint. It is intended to give residents in some of the Valley’s most transit-dependent communities more reliable access to jobs, schools, healthcare and the wider regional transit network.
The opening target has moved to 2032
Metro’s current project page lists an estimated completion date of early 2032. That is later than the 2031 opening forecast the agency publicized when it celebrated an $893-million federal grant in September 2024. Earlier plans were more optimistic still: when utility work began in 2022, Metro said the first segment could open between 2028 and 2030.
The project’s financial scale has also grown clearer. In May 2026, the Metro Board established a life-of-project budget of approximately $3.999 billion and authorized the next phase of its progressive design-build contract with San Fernando Transit Constructors, a joint venture of Skanska and Stacy and Witbeck.
That authorization increased the construction contract’s value to roughly $2.431 billion. Funding for the larger project combines federal, state and local sources, including revenue from Los Angeles County’s Measure M transportation sales tax.
Rail returns to Van Nuys Boulevard
The East San Fernando Valley line will restore passenger rail to Van Nuys Boulevard for the first time since Pacific Electric ended streetcar service there in 1952. It will also become the first major new Metro rail project in the San Fernando Valley since the subway reached North Hollywood in 2000.
The historical parallel is significant. Van Nuys Boulevard once developed around electric railway service before the region shifted heavily toward automobiles and buses. Metro is now rebuilding rail in the same broad corridor, but as part of a modern network designed to connect local riders with bus rapid transit, regional rail and future high-capacity projects.
The current project ends in Pacoima. Metro continues to study a separate 2.5-mile northern extension that would reach the Sylmar/San Fernando Metrolink station. That extension is not included in the segment now entering major construction.
For riders, the October groundbreaking does not mean trains are imminent. Several years of disruptive and technically complex work remain, and the schedule has already moved beyond earlier forecasts. Still, it represents a tangible transition: the East San Fernando Valley line is no longer primarily a planning exercise or utility-relocation program. Metro has begun building the infrastructure that will carry trains.
That makes this a major step in Los Angeles County’s long effort to restore frequent rail transit to communities that lost it generations ago—and another chapter in The Long Track Back.
Primary sources
- LA Metro: Major construction will soon be underway
- LA Metro project page: East San Fernando Valley Light Rail Transit
- LA Metro Board meeting, May 28, 2026 — project budget and contract authorization
- LA Metro: $893 million federal grant announcement, September 6, 2024
- LA Metro: Advanced utility-work groundbreaking, December 2, 2022
This article is part of The Long Track Back, STM Daily News’ continuing coverage of how Los Angeles is rebuilding and expanding a passenger-rail network after decades of automobile-centered grow
For generations, the Santa Monica Pier sign has marked the start of a day at the beach. Now, the familiar blue neon landmark is preparing for a journey of its own.
Santa Monica scheduled removal of the 1941 sign for October 20–22, with shipment to Las Vegas anticipated October 26. The timetable is subject to change, according to the city’s October 19 announcement.
The temporary removal accompanies replacement of the aging bridge connecting Ocean Avenue to the pier. It also creates an opportunity to preserve the historic sign.
YESCO will restore it at its Las Vegas facility. The company’s experience includes work on the “Welcome to Fabulous Las Vegas” sign.
Crews will repair neon tubing, treat rust, repaint components and address structural needs while retaining historic features. The sign will remain in secure storage during bridge construction.
Once the project is finished, it will return above the new bridge at a slightly greater height for visibility and vehicle clearance. The city’s latest announcement targets project completion by 2028, ahead of the Los Angeles Olympics and Paralympics.
Meanwhile, visitors can photograph a lighted, half-scale replica near Pier Burger.
For anyone who associates that glowing arch with Southern California memories, its absence will be noticeable. The restoration is intended to ensure future generations can make memories beneath it, too.
Source: City of Santa Monica — October 19, 2026 announcement
Related Links
- City of Santa Monica: Official sign restoration announcement — October 19, 2026. Primary source for removal dates, shipment to Las Vegas, YESCO’s restoration work and the sign’s planned return.
- Santa Monica Daily Press: Sign restoration during bridge rebuild — October 20, 2026. Additional local reporting on the project and visitor access.
- LAist: Sign removal and how to watch — Reporting on the removal schedule and public viewing opportunities.
Follow more Southern California stories at STM Daily News.
Automotive
Slate Truck Gets Real: First Experience Center Opens Ahead of Planned Deliveries
Slate Auto’s first permanent Experience Center gives consumers an up-close look at its customizable electric truck ahead of planned customer deliveries.
Slate Auto’s new Chicago location gives prospective buyers a permanent place to see the minimalist electric pickup, explore customization options and learn about demo opportunities—but it is not yet proof that customer deliveries have begun.
CHICAGO — October 20, 2026 — The Slate Truck is moving out of computer renderings and temporary roadshow stops and into a permanent retail setting. Slate Auto opened its first Experience Center on October 15 at 1053 W. Grand Avenue in Chicago, giving consumers a year-round location to get an up-close look at the company’s highly anticipated electric pickup.
The Near West Side facility occupies a former Tesla location and includes showroom, retail and garage space, along with electric-vehicle charging infrastructure. For Slate, the opening represents an important step in turning strong online interest into a more tangible buying experience as the startup works toward launching its first vehicle.
Visitors can examine the truck’s compact dimensions, deliberately simple cabin and accessory-driven design in person. The center also showcases Slate’s personalization strategy, including exterior wraps, add-on accessories and digital design tools intended to let owners configure the truck around their needs.
Slate has also promoted demonstration opportunities connected with the location, although availability may be limited or appointment-based as the company continues to prepare its fleet. Early media access included passenger rides rather than unrestricted customer test drives, so prospective visitors should confirm current availability before making a special trip.
Why the Chicago opening matters
Until now, most consumers have encountered the Slate Truck through online reservations, media coverage or temporary appearances. A permanent showroom gives buyers a chance to judge details that are difficult to evaluate on a screen, including seating position, bed access, cabin materials and the overall size of the vehicle.
That is especially important for a product built around an unconventional value proposition. Slate is promoting a basic two-seat, two-door electric truck with manual crank windows and no factory-installed infotainment screen or stereo. The company’s strategy is to keep the starting price low and let buyers add features later through accessories and conversion kits.
The physical location also gives Slate a place to explain that approach directly. Rather than presenting the truck as an unfinished vehicle, the company can demonstrate how its modular accessories, wraps and planned SUV-style conversion components are meant to expand the vehicle’s usefulness over time.
Chicago is a logical first market for that effort. The city offers access to a large Midwestern customer base and is within the broader region of Slate’s planned manufacturing operation in Warsaw, Indiana. Reusing a former Tesla store also gives the startup a space already suited to displaying and servicing electric vehicles.
The roadshow continues beyond Chicago
The Experience Center is opening as Slate expands its public demonstration schedule. The company’s events calendar lists a Boston-area demo ride event from October 21 through October 25 at The Shops at Chestnut Hill, followed by an appearance at RADwood in Alameda, California, on October 24 and a New Jersey demo ride event in Freehold from October 28 through October 31.
Slate also lists future stops in Washington, D.C., Raleigh, Atlanta, Miami and Orlando. Together, the permanent Chicago center and the traveling events suggest the company is moving into a broader customer-education phase ahead of planned deliveries.
What has—and has not—changed
The showroom opening does not change Slate’s headline pricing or range claims. The truck is still advertised with a base price of $24,950 before taxes, registration and destination charges. With the currently listed $1,450 destination fee, the entry price would be approximately $26,400 before other costs or optional equipment.
Slate also continues to advertise an estimated range of up to 205 miles. That figure remains an estimate rather than a final EPA-certified rating.
Most importantly, Slate has not publicly confirmed that regular customer production has started or that the first retail deliveries have occurred. Limited deliveries have been reported as possible before the end of December 2026, while many reservation holders may receive later delivery windows in 2027. The Chicago opening is therefore a commercialization milestone, not a manufacturing milestone.
For customers and industry observers, the next major signals will be the start of production at the Warsaw factory, final specifications and EPA range ratings, and confirmed handoffs to paying buyers.
The bottom line
Slate Auto now has a permanent place where consumers can see and evaluate its unusually simple electric truck. That makes the product feel more real and gives the company a platform to explain a customization-heavy business model that may be unfamiliar to traditional truck buyers.
Still, the biggest questions remain unanswered. Opening a showroom demonstrates progress in marketing and customer engagement; producing vehicles at scale, holding the promised price and delivering a 205-mile truck to reservation holders will determine whether Slate can convert enthusiasm into a viable automotive business.
Sources and more information
- Slate Auto events and demo schedule
- Electrek: Slate opens its first Experience Center in Chicago
- Autoblog: Slate opens its first U.S. showroom
- Slate Auto
Category: Consumer Corner / Automotive
