By Sam Lounsberry, Boulder Daily Camera
Even as Boulder County foresters press on in their fight against the invasive emerald ash borer harming the local tree population, officials acknowledge it is a losing battle.
But it is one lovers of ash trees don’t have to walk away from empty-handed, even as sickened trees are in line for removal or have already been sawed to stave off the infestation.
Woodworkers like Evan Kinsley, who started the Boulder-based business Sustainable Arbor Works several years ago, have turned to ash trees to supply their furniture and art crafting practices as a way to maintain the local benefit provided by the species slated for a countywide death at the hands of the insect. Emerald ash borer has already dramatically altered the composition of forests across the middle and eastern regions of the country.
“It’s a privilege to be able to work with a local hardwood like ash,” Kinsely said.
When he first learned of the 2013 detection of emerald ash borer in Boulder — it has since spread to Longmont, Lafayette, Lyons and Superior, but until last month, when it was first detected in Broomfield, Boulder County remained the only area in the Mountain West with a confirmed presence — Kinsley and his now-business partner Aaron Taddiken looked at each other and said, “We have to do something.”
The solution was to build a wood kiln to speed up the drying process for felled trees, and now Kinsely focuses on harvesting trees removed from the urban landscape, a large proportion of which are ash due to the pesky beetle’s invasion, and reusing them for wholesale lumber slabs and designing and building custom furniture.
“It used to be most of this time, that a lot of woodworkers got their wood from big wood suppliers. That would come from all over the country, all over the world,” Kinsley said. “It’s not a new thing to use local lumber. But it was a new idea for smaller woodworkers, smaller lumber mills to start working with tree (removal) companies.”
Supporting Kinsley’s living is not the life cycle he prefers for the trees, but he feels he is making the best out of a bad situation…
While the city and Boulder County continue treating public ash trees to keep them alive as long as possible using pesticide applications, tree adoption programs and biological weapons, enforcement against declining ash trees on private property continues to ramp up.
In 2018, Read said the city sent 182 letters to private property owners asking them to address declining ash trees posing safety hazard; in 2017 the number was 118, in 2016 it was 82. This year he expects to send a significantly larger number of such letters. The growing number of letters aligns with the advance of the beetle infestation. Tree owners who receive such a letter will have to show the city a good-faith effort is being made to remove trees considered dangerous.
But work to preserve ash trees still free of the emerald ash borer goes on, even as replanting species that won’t be affected by the invasive bug remains the focus of foresters for the future of Boulder’s canopy. The city’s Tree-Imagine campaign launched this spring is pushing city residents to collectively plant 25,000 new trees by 2025.
The county this summer introduced a swarm of a non-stinging, parasitic member of the wasp family on the Mayhoffer open space property in Superior, and also has enlisted 159 participants in its adopt-a-tree program for ashes slated for removal from public places. Program participants can choose to commit to pay for treatment to keep the trees alive.
“A lot of these ash trees are old and they’ve been with the community a long time,” Kinsley said. “Trying to protect them in every way is a valiant effort.”
By Chrissy Sexton
Professor Matthew Evans from the University of Hong Kong created a computer model to estimate how ash dieback disease may affect the UK’s 125 million ash trees.
Human-induced changes to the environment are increasing the rate at which pests and diseases are introduced, which is severely threatening to native species. Long-lived species that reproduce slowly, such as forest trees, are particularly susceptible to new pathogens.
It is estimated that in 2015, 100 million hectares of forest were affected by pests and diseases around the globe. However, the subsequent impacts to any given forest ecosystem cannot be detected for years, so experts use computer models to predict future outcomes.
In a recent study, Professor Matthew Evans from the University of Hong Kong created a computer model to estimate how ash dieback (ADB) disease may affect the UK’s 125 million ash trees.
ADB disease, which is caused by a fungus native to East Asia, was introduced to the UK seven years ago. This incurable infection leaves diamond-shaped scars on the bark and causes the leaves to fall off of the trees.
About one in every 100 ash trees is able to resist the fungus and avoid infection. This is likely due to a genetic advantage which allows the trees to shed their leaves earlier to prevent the fungus from establishing itself.
Professor Evans found that at the current level of resistance, 95 percent of the UK’s ash trees could be wiped out by the end of the century. He determined that breeding more ash trees with resistance will prevent millions of deaths.
By Bruce Scruton
MIDDLE SMITHFIELD, Pa. — Three species of a small wasp that can attack the eggs of the emerald ash borer were released by National Park Service biologists within the Delaware Water Gap National Recreation Area this past weekend.
The borer, an invasive beetle from Asia, is capable of killing a full-grown ash tree within a couple of years and has been found in several locations in Sussex County in the past two years.
The release was in the Mosier’s Knob area, just below the Walpack Bend of the Delaware River and across the river from Worthington State Forest where the New Jersey Department of Agriculture recently released its own biological agents to stem the invasion of the pest.
Kara Deutsch, chief of resource management for the park, said the emerald ash borer has been found on both sides of the river. The choice of Mosier’s Knob for the release came at the recommendation of regional NPS experts.
The wasps, known in scientific circles as “parasitoids,” were supplied by the United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) and came from the Plant Protection and Quarantine (PPQ) EAB Parasitoid Rearing Facility in Brighton, Mich.
There were three species of wasps released — one release was of adults and the others were pupae of separate species.
The three are themselves invasives, native to the Asian areas where the emerald ash borer are native. The borer was imported to this area first identified in the area around Detroit and believed to have arrived in 2002 inside of wooden packing material.
In less than two decades since, the borer, a type of beetle, has been found in the U.S. from the Atlantic Coast (except Forida) as far west as Colorado and has spread throughout the eastern two-thirds of Canada.
The wasp parasites — the adults are about the size of a mosquito and don’t sting — get the borer in both egg and larval states.
The adult Oobius agrili female will lay her own egg inside the egg of an ash borer and there are two life cycles of the wasp for one life cycle of the borer. In experiments and observation, more than half an emerald ash borer’s eggs became victims of the wasp.
The other two wasps attack the larval stage of the borer and it is that stage that causes the damage to ash trees.
By Michael MacDonald
HALIFAX — An invasive insect from Asia is expected to kill almost every ash tree in Canada, but Donnie McPhee has a plan to preserve the species.
Co-ordinator for the National Tree Seed Centre in Fredericton, McPhee is asking Canadians to help him find mature stands where seeds can be gathered and later stored for future generations in the centre’s deep-freeze vaults.
“We’re looking to protect the genetic diversity of the species,” McPhee said in an interview. “We’re looking for natural stands of trees that are in seed …. We want Canadians to be our eyes — to let us know they’re out there.”
And the time is right to start the search because the white ash and black ash — two of the most common species — are expected to produce a bumper crop of seeds this fall. The centre’s website provides details on what to look for, but seed collecting should be left to experts.
“We’ve already had people showing up with big bags of ash seed … but it’s too early in the season,” McPhee said.
Larvae of the emerald ash borer, a small beetle with an iridescent green hue, have already killed millions of trees in Canada and the United States, and the pest’s population is still growing.
The larvae make tunnels underneath the tree’s bark, cutting off nutrient flow to the canopy, which eventually kills the tree.
“The reports I’ve seen suggest that within 50 years, there might not be any ash trees anywhere in the country,” McPhee said.
McPhee’s long-term plan is to have the centre retrieve the collected ash seeds from cold storage in about 40 or 50 years, when the ash borer population has dwindled and safe planting can begin.
“The population of the insect will drop way down because the food supply isn’t there,” he said. “At that time, we want to go in and put the genetic diversity of the population back to where it came from.”
By Dean Mosiman
Threatened by infestations, climate change and competing demands for space, Madison’s tree canopy will shrink with “potentially disastrous results” unless the city invests more in its trees, a new report says.
After nearly two years of study, the city’s Urban Forestry Task Force is making a series of recommendations — some with potentially significant price tags — to nurture and dramatically increase the area covered by trees from 23% to 40% of Madison’s 80 square miles.
Already, the city has had to deal with infestation by the emerald ash borer that’s forcing the removal of thousands of trees, as well as disease, climate change, loss of mature trees to development, road salt, and cramped space for planting and growth in the public right of way.
On private property, where most of the trees in the city are located, uneven care is also affecting the urban canopy, the report said.
The task force, created by the City Council on Aug. 1, 2017, has offered a 25-page report and recommendations aimed at elevating the importance of trees in the city’s planning, investments and operations and creating a new city role in expanding the canopy on private property.
“We have a quality urban forest in the city,” parks superintendent Eric Knepp said. “However, there are many opportunities to improve it.”
The 46 recommendations call for a preservation ordinance to protect mature trees; a yet-to-be defined grant program for planting trees on private property; focusing attention on neighborhoods that need trees; written standards for how to care for trees; hiring a forestry outreach and education specialist; revisiting old sites that don’t require much landscaping, such as parking lots at big shopping malls, and bringing them up to current standards; and planting more trees in parks than needed to replace those that are lost.
Jeff Mulhollem, Pennsylvania State University
Genes in green ash trees that may confer some resistance to attacks by the emerald ash borer express themselves only once the tree detects the invasive beetle’s feeding, according to Penn State researchers.
Knowing this, geneticists may be able to selectively breed trees to strengthen them and perhaps move the resistance response earlier to ward off the beetles’ onslaught, explained John Carlson, professor of molecular genetics.
Green ash, an ecologically and economically valuable tree species native to eastern and central North America, is under severe threat from the rapid invasion of emerald ash borer, a wood-boring beetle native to Asia. Penn State scientists and others are trying to save the species.
Prior observations in a green ash provenance trial—an experiment to see how plants adapt—planted at Penn State in 1978 by Kim Steiner, professor of forest biology and director of The Arboretum at Penn State, and colleagues in the U.S. Forest Service, show that a very small percentage of ash trees survive emerald ash borer infestations, seemingly because their tissues do not nourish and perhaps even sicken the beetles.
“Emerald ash borer probably entered the provenance trial unnoticed around 2008 and trees started showing symptoms of attack by 2012,” Carlson said. “All but eight or nine of the approximately 1,800 trees that Kim planted have subsequently been killed by the beetles.”
Ash trees succumb after adult beetles lay eggs on their bark. When the eggs hatch, the larvae bore into the bark and feed on the transportation tissues of the tree. This disrupts the movement of nutrients and water within the tree, girdling it and causing death.
“To better understand the response of green ash trees to emerald ash borer, we compared gene expression data for resistant versus susceptible green ash genotypes exposed to attack by the beetles,” said Carlson, director of Penn State’s Schatz Center for Tree Molecular Genetics. “By comparing RNA-sequence data from stems attacked by emerald ash borer to multiple tree tissues under other stresses, we could identify differences in the gene expression profiles specific to emerald ash borer resistance.”
By Amanda Kolson Hurley
In the 1960s, America fell in love with a new tree: the Bradford pear. Cultivated from Asian stock by scientists at the U.S. Department of Agriculture, Bradford pears display clouds of pretty blossoms in the spring and garnet leaves in the fall, and are hardy enough to grow just about anywhere. Thinking they had found the perfect ornamental tree, homeowners and public-works departments planted Bradford pears up and down the nation’s streets for decades, especially in the East, South, and Midwest.
Then the relationship soured. Bradfords are apt to split and break during storms, and they have a short life span, only 15 or 20 years. Although they are technically sterile, the trees cross-pollinate with other cultivars of the Callery pear species (Pyrus calleryana), producing fruit that splats all over sidewalks. And despite their delicate appearance, the blossoms emit a foul odor that’s been compared to rotting fish (among other things).Cities and states are trying to remove Bradford pears‚ but the “weed trees” have already intruded deep into some forests, a biologist warns.
Once admired for its hardiness, the Bradford pear is now considered an invasive species, which grows even in poor conditions, proliferates fast—thanks to birds that dine on its fruit and spread the seeds—and crowds out native species.
Cities are trying to put an end to the tree’s mischief. Pittsburgh’s Urban Forest Master Plan prohibits planting Bradford pears. This March, Fayetteville, Arkansas, started offering a bounty to anyone who cuts one down. (They can get a free native tree to replace it.)
The bad news is it’s not only in developed areas where the trees threaten to choke biodiversity. Theresa Culley, head of the Department of Biological Sciences at the University of Cincinnati, warns that wild Bradfords and other kinds of Callery pears are making inroads into Eastern forests.
The ʻŌhiʻa tree, with its companion lehua blossom, is found only in Hawaiʻi, and is the most common of our Islands’ native trees. It is the keystone of the Hawaiʻi forest, critical to the ecology of our watersheds and sacred in Hawaiian culture. And now it is under attack, with new species of fungi killing trees on two islands.
By Lucy Sherriff
The native ʻōhiʻa is sacred to Hawaiians as a cultural touchstone and ecological underpinning for the state’s lush forests and abundant wildlife.
HONOLULU — A deadly fungus threatens one of Hawaii’s most beloved and important species, the ʻōhiʻa tree, and those believed responsible for introducing the threat to the tree in the first place are now being asked to help save it — tourists.
The native ʻōhiʻa is sacred to Hawaiians as a cultural touchstone and ecological underpinning for the state’s lush forests and abundant wildlife. The flowering evergreens that can tower to 85 feet comprise 80 percent of the state’s canopy, covering 1 million acres, and its nectar sustains birds and insects found nowhere else on Earth.
Now, public agencies and private citizens are trying to avoid biological and economic catastrophe by proclaiming war against a deadly fungal disease coined “rapid ʻōhiʻa death,” or ROD, that is swiftly destroying the trees. What’s more, invasive species like the miconia tree, native to North and South America and called the “green cancer” of Hawaii’s forests, are choking out the ʻōhiʻa.
The federal government has attempted to stop the fungus and tackle invasive species by imposing a quarantine on Hawaii Island and carrying out extensive tests to learn how the fungus spreads, but it has yet to find a solution. Hawaiian organizations, communities and scientists are now stepping in.
Gunstock Ranch, a horse riding stable and tourist destination on Oahu, is replanting native trees, although not the ʻōhi‘a yet. After conducting a survey on 80 acres of its land in 2016, and finding just two native species, owner Greg Smith established a Hawaiian “legacy forest,” where visitors can plant trees and monitor their growth online.
“Our hope is that as our guests plant and dedicate a tree they will form a new connection to the land and Hawaii and leave knowing that they made a difference,” Smith said.
By Stephen Koranda
Plants sold at more than 60 stores in Kansas were infected with a disease that kills oak trees. The Kansas Department of Agriculture said sudden oak death was confirmed in hundreds of rhododendrons in the state, and the agency is asking Kansans to destroy any potentially infected plants.
The infected rhododendrons came from a nursery in Oklahoma and were sold in 10 states, including Kansas and Missouri. In Kansas, the plants were sold during April, May and June at 60 Walmart stores and the Home Depot in Pittsburg.
This is the first time sudden oak death has been found in the state. It’s a disease that has heavily damaged some forests on the west coast, where it was discovered in the mid-1990s.
“It is just devastating when it gets to oaks,” Kansas State University Professor Cheryl Boyer said in an interview. “It will kill the whole mature trees very, very quickly.”
Ryan Armbrust, with the Kansas Forest Service, noted in a statement that many of the state’s oak trees are from varieties that are less susceptible.
“But there are millions of red, black, pin, shumard, blackjack, shingle and other oaks that could be impacted should this disease gain a foothold in the state,” he said.