Trees getting a nudge to help them adapt to warming climate

By Nelson Bennett
As the northern hemisphere experiences earlier, hotter, drier summers and heavier precipitation in the winters, due to global warming, natural selection should eventually result in trees naturally adapting to changing climatic conditions.

Tree varieties that thrive in warmer, drier southern parts of the province, or on lower slopes, are likely to gradually shift further north and further up mountain slopes.

Scientists and foresters in B.C. are already beginning to give them a gentle nudge through assisted migration – one of the topics this morning at the University of British Columbia’s ongoing three-day Commonwealth Forestry Conference.

Using a variety of scientific tools and experiments, like genomics and provenance trials, scientists have already been able to identify which tree varieties have naturally evolved certain traits, like cold hardiness, disease resistance and drought tolerance, in different geographic regions.

Climate data can be matched with tree phenotype data to identify which trees will be best suited to climate conditions in the coming decades. Genomics is an additional tool that helps scientists identify key genetic characteristics.

These tools are used to develop seed lots that foresters can use to replant trees in a given area that are the same species, but different varieties that have traits that make them more suitable to a climate that is changing rapidly.

Interior varieties of Douglas fir, for example, are more cold hardy than coastal varieties. And Sitka spruce from California grow longer and bigger than ones that grow in Alaska. They are the same species of tree, but are different varieties that have naturally adapted to their particular environments.

Scientists and foresters are already using these tools to identify which varieties might fare better in certain areas, and use them in what is called “assisted migration” using a climate-based seed transfer program.

To date, the climate based seed transfer program in B.C. has been optional, but will become mandatory next year, said Sally Aitken, a forestry scientist at UBC’s department of forest and conservation science.

Source: Trees getting a nudge to help them adapt to warming climate – Prince George Citizen, 2021-12-18

Upward expansion and acceleration of forest clearance in the mountains of Southeast Asia

Yu Feng, Alan D. Ziegler, Paul R. Elsen, Yang Liu1, Xinyue He, Dominick V. Spracklen, Joseph Holden, Xin Jiang1, Chunmiao Zheng and Zhenzhong Zeng

Southeast Asia contains about half of all tropical mountain forests, which are rich in biodiversity and carbon stocks, yet there is debate as to whether regional mountain forest cover has increased or decreased in recent decades. Here, our analysis of high-resolution satellite datasets reveals increasing mountain forest loss across Southeast Asia. Total mean annual forest loss was 3.22 Mha yr−1 during 2001–2019, with 31% occurring on the mountains. In the 2010s, the frontier of forest loss moved to higher elevations (15.1 ± 3.8 m yr−1 during 2011–2019, P < 0.01) and steeper slopes (0.22 ± 0.05° yr−1 during 2009–2019, P < 0.01) that have high forest carbon density relative to the lowlands. These shifts led to unprecedented annual forest carbon loss of 424 Tg C yr−1, accelerating at a rate of 18 ± 4 Tg C yr−2 (P < 0.01) from 2001 to 2019. Our results underscore the immedi-ate threat of carbon stock losses associated with accelerating forest clearance in Southeast Asian mountains, which jeopardizes international climate agreements and biodiversity conservation.

Source: Upward expansion and acceleration of forest clearance in the mountains of Southeast Asia – Nature Sustainability, 2021-06-08

Fire Destroyed 10 Percent of World’s Giant Sequoias Last Year—Can They Survive Climate Change?

By Alex Fox
Last year, California’s Castle fire may have killed off ten to 14 percent of the world’s giant sequoias, reports Joshua Yeager of the Visalia Times-Delta.

The tally of dead trees comes from a new draft report that used satellite imagery, forest modelling and surveys to revise initial estimates of how many titanic trees were lost when flames ripped through parts of Kings Canyon and Sequoia National Parks. That initial estimate was around 1,000 dead sequoias, but now scientists with the National Park Service and U.S. Geological Survey (USGS) suspect between 7,500 and 10,600 mature trees may have died, reports Kurtis Alexander for the San Francisco Chronicle.

Per the Chronicle, among the fallen is the planet’s ninth-largest giant sequoia, nicknamed the King Arthur tree. Sequoias can live for thousands of years and grow to more than 250 feet tall and measure 30 feet in diameter, per the Chronicle.

“The whole thing is surprising and devastating and depressing,” Christy Brigham, chief of resources management and science at Sequoia and Kings Canyon National Parks and lead author of the report, tells Alex Wigglesworth for the Los Angeles Times.

Researchers were surprised by the death toll because of how adapted to living with fire giant sequoias are. Per the LA Times, sequoia bark can be two feet thick and their cones only release their seeds to spawn the next generation when they’re toasted by low intensity fire.

Brigham tells the LA Times that losing so many mature trees to a single fire signals the fact that climate change and a century of fire suppression have rewritten the rules that once governed the sequoia’s domain.

Source: Fire Destroyed 10 Percent of World’s Giant Sequoias Last Year—Can They Survive Climate Change? | Smart News | Smithsonian Magazine, 2021-06-11

As northern Michigan warms, scientists bring tree seedlings from the south

By Kelly House
shagbark hickory saplings he spent months growing from seeds collected 250 miles south of here.

It’s not a species commonly found among the maple, birch, cedar and white pines of northern Michigan. But on this 311-acre property known as Ziibimijwang Farm, few of the newly-planted seedlings are.

“I don’t think it’s been too cold for them yet,” Jansen said as a group of volunteer tree-planters prepared to tuck the saplings into the soil.

Jansen and his colleagues at the Little Traverse Bay Band of Odawa Indians have planted thousands of trees since the tribe purchased the property in 2013, transforming it into a small-scale experiment in girding northern forests against climate change.

Along with the shagbark and silver maple, there’s black walnut commonly found in southern Michigan, sassafras and swamp white oak that typically ranges only as far north as mid-Michigan, and a host of other species — about 30 in all — that Jansen hopes will become the feedstock for a diverse, climate-resilient forest.

“I don’t know which of these species are going to thrive in 50 or 100 years,” said Jansen, the tribe’s conservationist. “So we cast the net broad and try to have something there that creates habitat for wildlife, sources of cultural significance for tribal members and areas to hunt and gather.”

Intermixed with the species foreign to this area, crews on the property — about nine miles southwest of Mackinaw City — have planted more familiar northern species, such as white cedar and paper birch, using seeds drawn from trees at the very southern tip of their range. He hopes the cedar and birch will tolerate warmer conditions, buying time for two species that climatologists have cast as “climate losers” destined to lose footing in Michigan as the earth warms.

Source: As northern Michigan warms, scientists bring tree seedlings from the south – record-eagle.com, 2021-05-10

‘Ghost Forests’ May Become More Common as Sea Levels Rise

By Elizabeth Gamillo
Along the mid-Atlantic and southern New England coast, an eerie sight dots the changing landscape. Rising sea levels turn thriving green vistas of hardwood and evergreen trees into “ghost forests,” dried-up terrains filled with gnarled, dead, and dying timber. Under climate change, these could become an even more common sight, according to a new report published by Rutgers University.

Ghost forests are landscapes that form when saltwater begins to flood woodland areas that contain freshwater-dependent trees. The water high in salinity slowly poisons trees, and as they die, all that is left behind are ghostly gray trunks that resemble toothpicks. The trunks can last decades in this dried-up barren state, reports Dharna Noor for Gizmodo.

Researchers at Rutgers University, along with the United States Department of Agriculture, found that coastal woodland forests ranging from Virginia through Massachusetts are dying as a result of heavy rain, saltwater surges, and flooding from rising sea levels, reports Matthew Hart for Nerdist.

The rising salt water not only kills trees but leaves soil unhealthy and forests uninhabitable for new growth, Nerdist reports. This report is alarming as coastal forests are habitats for many rare plants and wildlife, such as the threatened swamp pink plant, Gizmodo reports.

Not only are the ghost forests expanding because of climate change, they could also be making hostile conditions worse through a feedback loop. Forests along the East Coast are riddled with evergreen trees that absorb carbon dioxide almost year-round, making them crucial carbon sinks that can lower carbon dioxide concentrations from the atmosphere, reports Gizmodo. With fewer evergreen trees, less carbon is removed from the air.

“One ecological benefit of healthy coastal forests is the sequestration and storage of carbon both aboveground and in soils. As coastal forests transition to marsh, we lose aboveground carbon. Some of that is released into the atmosphere, and some shifts to other carbon pools,” Lindsey Smart, a ghost forest expert at the North Carolina State University who was not part of the study, tells Gizmodo.ong the mid-Atlantic and southern New England coast, an eerie sight dots the changing landscape. Rising sea levels turn thriving green vistas of hardwood and evergreen trees into “ghost forests,” dried-up terrains filled with gnarled, dead, and dying timber. Under climate change, these could become an even more common sight, according to a new report published by Rutgers University.

Ghost forests are landscapes that form when saltwater begins to flood woodland areas that contain freshwater-dependent trees. The water high in salinity slowly poisons trees, and as they die, all that is left behind are ghostly gray trunks that resemble toothpicks. The trunks can last decades in this dried-up barren state, reports Dharna Noor for Gizmodo.

To mitigate ghost forests, coastal forests need protection from development, and proper planning and collaboration with landowners must be established, according to the Rutgers report. Solutions the researchers suggest include creating living shorelines by planting trees to slow erosion, depositing sediments to help marshes move to higher elevation as sea levels rise, and planting forest vegetation that can tolerate changes in soil.

“This study adds to the growing evidence that this is not a localized phenomenon, given other reports up and down the east coast,” Smart tells Gizmodo. “While the rate and extent varies based on local site characteristics, it’s clear that sea-level rise and the synergistic pressures between sea-level rise and land use modification…are changing our coasts, impacting our coastal forests.”

Source: What is a Ghost Forest? – Smart News | Smithsonian Magazine, 2021-03-19

Austria’s ‘close-to-nature’ forests may hold secrets to fire prevention

By Amanda Peacher
In a region of Austria known as the wood quarter, a logger used a chainsaw to slice through the base of a 100-foot tall spruce tree on a recent foggy morning.

Herbert Schmid, a forester, watched from a distance as the big spruce dropped to the forest floor. Schmid handpicked that particular tree to be cut today. He manages this forest according to “close-to-nature” practices, or Pro Silva standards.

It’s an ancient technique of astute observation, low-intervention forestry that allows trees to grow and age before harvest. Forestry experts say it’s a valuable model as European forests face climate change and potentially more fires.

Source: Austria’s ‘close-to-nature’ forests may hold secrets to fire prevention – The World from PRX, 2021-01-06

The Survivors: Sugar Pine Trees and the Future Forest

By Kat Kerlin
CCalifornia’s drought and bark-beetle infestation killed more than 129 million trees between 2012 and 2016 in the Sierra Nevada. But amid the devastation stood some survivors.

At the time, UC Davis biologist Patricia Maloney and a team of researchers entered the forest to collect seeds from 100 surviving sugar pine trees. Alongside other parched sugar pines etched with the tell-tale tunnel marks of bark beetles, were green, healthy trees. The researchers spent the past two years raising 10,000 seedlings from 100 surviving mother trees around the Lake Tahoe Basin. They were first cultivated at the USDA Forest Service’s Placerville Nursery and then moved to the UC Davis Tahoe City Field Station.

This week, between 4,000 and 5,000 of the seedlings are being planted around Lake Tahoe’s North Shore as part of a restoration project funded by the Tahoe Fund and the California Tahoe Conservancy. About 1,500 will be used to study and identify important adaptive traits, and the remainder will be given to private landowners to plant.

f the seedlings turn out to be as genetically resilient as Maloney thinks and hopes they will be, these trees could represent the future forest, one better able to withstand the threats of climate change, including more droughts and bark beetle outbreaks.

“These survivors matter,” said Maloney, a scientist in the UC Davis Department of Plant Pathology and Tahoe Environmental Research Center. “Essentially, these are the offspring of drought survivors. This is hopefully the genetic stock of the future.”

Source: The Survivors: Sugar Pine Trees and the Future Forest – UC Davis, 2019-11-07

Oaks instead of palm trees? Florida’s iconic palms don’t cut it with climate change

urban palm trees
Peter Graulich, palmbeachpost.com

They are iconic to Florida, but palm trees offer little shade to urban heat islands and capture very small amounts of carbon, a greenhouse gas contributing to global warming.

South Florida’s palm trees are postcard promises of sighing sea breezes and sandy beaches, but the icon of the tropics may be an impractical adornment in an era of climate change.

From the regal royal palm to the sometimes shabby cabbage, the perennial symbol of the Sunshine State offers little shade to baking urban heat islands and captures minimal amounts of carbon — a greenhouse gas contributing to global warming.

As city officials look for more ways to cool concrete jungles and balance carbon emissions, the priority for new plantings is often broadleaf hardwood trees, not the idyllic palm.

Live oaks can absorb and store 92 pounds of carbon a year with a mature tree’s canopy spanning more than 100 feet. That’s compared to less than one pound of carbon for a royal palm and its compact crown of 15 to 20 fronds.

“People coming from up north or other parts of the country are expecting to see palm trees, so I don’t see them disappearing entirely from the landscape,” said Charles Marcus, a certified arborist who wrote an urban tree management plan for West Palm Beach. “But it would benefit most communities if they increased the percentage of hardwoods and I think it’s something cities will have to consider.”

Palms aren’t even an option at City of West Palm Beach community tree giveaways, and a 2018 city ordinance puts an emphasis on using more shade trees in new construction, especially parking lots where 75 percent of the required trees must now be shade trees.

“We’re not trying to seek out and replace palm trees with canopy trees, but we are looking at if we have to do a replacement, would a canopy tree fit,” said Penni Redford, resilience and climate change manager for West Palm Beach.

Three years of studies in cities including Baltimore, Richmond, Va., and Washington by the National Oceanic and Atmospheric Administration found that areas covered in concrete with few trees could be 17 degrees warmer than shaded areas.

The same study conducted in West Palm Beach this past August found a heat-index temperature of 122 degrees near downtown, compared to 92 degrees taken during the same time period near the wetlands area of Grassy Waters Preserve.

“These are samples taken in one time period and one day out of the year, but given the conditions, the difference is staggering,” said Michael Rittehouse, sustainability project coordinator for West Palm Beach.

Source: Oaks instead of palm trees? Florida’s iconic palms don’t cut it with climate change – Panama City News Heerald, 2019-11-10

Lost trees hugely overrated as environmental threat, study finds

Cutting down trees inevitably leads to more carbon in the environment, but deforestation’s contributions to climate change are vastly overestimated, according to a new study.

Deforestation for timber and farmland is responsible for about 92 billion tons of carbon emissions into the environment since 1900, found a study led by researchers at The Ohio State University and Yale University.

“Our estimate is about a fifth of what was found in previous work showing that deforestation has contributed 484 billion tons of carbon – a third of all manmade emissions – since 1900,” said Brent Sohngen, a professor of environmental and resource economics at Ohio State.He said that widely accepted estimate didn’t take into account the planting of new trees and other forest management techniques that lessen the environmental burden. The model used in this study did take those factors into account, which made a significant difference considering the intensive forest management happening in many parts of the world and the less-intensive, but not inconsequential, management that is happening elsewhere.

The study appears today (Nov. 4, 2019) in the Journal of Forest Economics.

“There was a significant shift toward treating forests as a renewable, rather than nonrenewable, resource in the last century, and we estimate that those reforestation and forest management efforts have led to a far smaller carbon burden on the environment,” Sohngen said, adding that the previous estimate was based on trees’ natural regrowth without any human intervention.

Source: Lost trees hugely overrated as environmental threat, study finds – Ohio State News, 2019-11-04

A Forest Expert Team In Spain Fights Fire With Fire — Literally

By Aaron Labaree
The biggest wildfire in 20 years in Spain’s Catalonia region began on June 26, when a pile of chicken manure, baking in record high temperatures, burst into flames.

Fed by strong winds, the flames spread quickly, igniting dry brush and pine forest. In three days the fire burned more than 16,000 acres, and it took more than 500 firefighters to put it out.

Fires in California and the Amazon rainforest have grabbed attention, but large areas of Europe’s forests also were consumed this summer. Blazes nearly the size of the one in Catalonia tore through Spain’s Canary Islands, the south of France and the Greek islands of Evia and Samos.

From January to mid-October, the European Union has had almost triple the average number of wildfires for the same period over the past decade, with more than 800,000 acres burned so far this year, according to the European Forest Fire Information System.

Heat waves like the ones Europe experienced in 2019 are far more likely to happen because of the changing climate. And hot, dry conditions contribute to making massive fires no longer just a southern European problem: Last year Sweden saw its biggest fires in modern history, and this year the United Kingdom had a record number of them.

Now, like in the United States, firefighters and ecologists in Europe are starting to realize that putting out each fire isn’t possible or desirable. To prevent megafires, experts say, the authorities have to let forests burn naturally — and sometimes even set fires on purpose.

“We need to learn to live with fire, the same way we do with tornadoes or snowstorms,” says Marc Castellnou, chief analyst for a special forest unit of Catalonia’s fire services, known by its Catalan initials GRAF.

The wildfire problem is partly a result of decades of prevention. Fire plays a natural role in a healthy forest, burning away brush, dead trees and plant debris, while leaving many mature trees alive. But to protect human habitation, officials have tried to allow almost no fires to burn. The result is forests that are packed with undergrowth providing kindling and enormous unbroken stocks of trees to burn — megafires waiting to happen.

Europe’s forests have reached this dangerous state for another reason not seen in the U.S.: rural abandonment.

“When I was growing up, all of this was harvest — hazelnuts and olives,” says Rut Domènech, a forest expert who lives in Ribera d’Ebre, the county in Catalonia’s Tarragona province where the recent fires took place, pointing at what is now continuous forest. In the 1950s, the price of these and other crops plummeted with international competition and farmers were forced to move to cities.

Over much of Europe, rural abandonment has led to once-cultivated fields being given back to nature. In the 50 years after World War II, Western Europe’s forest area increased almost 30%. The continent’s land is now more than 40% forested.

Mediterranean shepherds and farmers have been using fire to manage the landscape for thousands of years. But most techniques used by firefighters today were developed in the United States, where the record-setting blazes of the past 10 years have shown the limits of suppression alone. In the U.S. as well as Europe, the change in approach toward fire is just beginning.

“In the scientific community, it’s understood we need to get fire back on the landscape,” says Rod Linn, a climate modeler at Los Alamos National Laboratory in New Mexico. “And most fire practitioners have come to grips with fire having a lot of benefits. But with the public, there’s work to do to get it socialized, to get people aware that just because you see smoke, it’s not necessarily bad.”

Source: A Forest Expert Team In Spain Fights Fire With Fire — Literally – Blue Ridge Public Radio, 2019-10-23