Posts tagged trees
City, county, state declare war on Emerald Ash Borer
Nov 13th
The Colorado Department of Agriculture (CDA) today issued an emergency quarantine in the Boulder County area related to the recent discovery of the Emerald Ash Borer (EAB) beetle in Boulder in late September. The quarantine is effective immediately.
“Our urban trees provide enormous environmental, economic and social benefits to our community, and ash trees contribute greatly to our urban tree canopy,” said City Forester Kathleen Alexander. “We are currently developing a plan to minimize the impact of the highly destructive Emerald Ash Borer to the city of Boulder, and the quarantine is an important step to limit the infestation and slow the spread, which allows other Front Range communities time to prepare.”
The emergency quarantine prohibits the sale and/or movement of all plants and plant parts of ash trees, including but not limited to:
· Logs and green lumber
· Nursery stock
· Chips and mulch, either composted or uncomposted
· Stumps, roots and branches
· Firewood of any non-coniferous (hardwood) species (Because ash is difficult to distinguish from other hardwood species when cut into firewood, the quarantine is for all hardwood firewood.)
The following areas are included in the emergency quarantine:
· Boulder County
· The entire town of Erie
· The area extending east from Boulder County to the south including Highway 7, to the north including Highway 52 and to the east including Weld County Road 7
· Highway 93 extending south from the Boulder County line to the entrance of Republic Landfill, including the entire landfill property, and including the entire property at 11218 Highway 93 on which the business of the Singing Saw Woodworks is operated
· The 15-acre, fenced Community Sort Yard located at 8200 Highway 7 in Allenspark, on the Boulder/Larimer county line
Quarantined items may be transported within the quarantined area but may not be moved outside its borders without specific authorization from the commissioner of agriculture or the United States Department of Agriculture. Any person violating this quarantine is subject to civil penalties up to $1,000 per violation. The full text of the quarantine, including additional restrictions, can be found at www.EABcolorado.com.
EAB in Colorado
A suspect ash tree was spotted in Boulder County on Sept. 23 by City of Boulder’s Forestry staff. Insect specimens from the ash tree, located near the intersection of 30th and Iris, were collected and sent to the United States Department of Agriculture (USDA) Systematic Entomology Laboratory, where the identity of the insects was confirmed. The confirmation of EAB in Colorado marks the western-most occurrence of this invasive pest in North America. Colorado is the fourth state to detect EAB in 2013.
Ash trees are popular in Colorado with an estimated more than 90,000 in the city of Boulder alone; the Denver metro area has an estimated 1.45 million ash trees.
EAB general information
EAB is an invasive insect that has been responsible for the death or decline of more than 50 million ash trees in 21 states. It is a small, green metallic beetle, originally from Asia, first detected in North America in 2002 in southeastern Michigan. The emerald ash borer attacks only ash trees and all ash species – including green, white, black and blue – are at risk. Signs of emerald ash borer infestation include a general decline in the appearance of the tree, thinning of upper branches and twigs, loss of leaves, and serpentine tunnels produced by EAB larvae under the bark. Woodpeckers may often be observed removing the bark of infested trees to access the larvae.
It is possible that EAB could infest an ash tree for three or four years before visible signs of decline of the tree. If you suspect your ash tree maybe infested with EAB, residents are encouraged to have it inspected by a city of Boulder licensed certified arborist , contact CDA at 888-248-5535, or the City of Boulder Forestry office at 303-441-4406. Infestation signs include:
· Sparse leaves or branches in the upper part of the tree
· D-shaped exit holes about 1/8 inch wide
· New sprouts on the lower trunk or lower branches
· Vertical splits in the bark
· Winding S-shaped tunnels under the bark
· Increased woodpecker activity
How You Can Help
“The public can play a vital role in preventing the spread of this destructive bug by simply not moving firewood,” said Mitch Yergert, CDA’s Plant Inspection Division director. “EAB larvae can survive underneath the bark of ash firewood, and when it’s moved from one place to another, the pest can hitchhike to a new location. Furthermore, it’s important to note that trees begin to decline a bit during fall months but there are certain features of an EAB-infested tree that residents can look for.”
Emergency Quarantine Issued to Protect Colorado Ash Trees in Boulder County, parts of Larimer, Jefferson, Weld Counties
Boulder County, Colo. – The Colorado Department of Agriculture has established an emergency quarantine in and around Boulder County including parts of southern Larimer, western Weld and northern Jefferson Counties (see quarantine map) related to the recent discovery of the Emerald Ash Borer (EAB). The quarantine is effective immediately. Boulder County is working with the Colorado Department of Agriculture, the City of Boulder, and other affected entities to address the quarantine and plan for the potential impacts of the EAB in Boulder County.
“We have cooperated with the state on the implementation of the temporary quarantine and will continue to work to understand the potential impacts of the EAB in Boulder County,” said Boulder County Commissioner Elise Jones. “Boulder County, in conjunction with the state and affected local partners, has begun to develop a response plan that will outline potential actions on county owned lands and provide guidance for private residents.”
The emergency quarantine prohibits the sale and/or movement of all plants and plant parts of the genus Fraxinus, including but not limited to:
· Logs and green lumber
· Nursery stock, scion wood, and bud wood
· Chips and mulch, either composted or uncomposted
· Stumps, roots and branches
· Firewood of any non-coniferous (hardwood) species
Quarantined items may be transported within the quarantined area but may not be moved outside its borders without specific authorization from the Commissioner of Agriculture or the United States Department of Agriculture.
Quarantined items can be transported within the quarantined area to:
· Denver Regional Landfill, 1441 Weld County Road 6, Erie
· Front Range Landfill, 1830 Weld County Road 5, Erie
· Republic Landfill, 8900 Colorado Highway 93, Golden
Residents participating in Boulder County operated flood-debris removal programs, including curbside debris collection do not have to take any special steps to maintain compliance with the quarantine. Debris collected by Boulder County is being treated and transported according to the requirements of the quarantine.
Any person violating this quarantine is subject to civil penalties up to $1000 per violation. The full text of the quarantine, including additional restrictions, can be found at www.EABcolorado.com.
If you think you have EAB in your ash trees, or if you have any questions or concerns, or would like additional information, please contact the CSU Extension in Longmont at 303-678-6238, email EAB@BoulderCounty.org or visit www.bouldercounty.org/property/forest/Pages/eab.aspx.
A plague of ash borers? Not yet.
Nov 7th
In late September, the emerald ash borer (EAB), an invasive pest of ash trees was identified within the city limits of Boulder. Since that time, staff from the City of Boulder Forestry Division and the Colorado Department of Agriculture (CDA) have worked cooperatively to complete a visual assessment of all public and private ash trees within a half mile of the initial infestation.
Staff visually assessed hundreds of ash trees from the ground, looking for symptoms of infestation, which include large branch dieback in the tree crown, woodpecker damage and excessive sprouting. Fortunately, no obviously symptomatic ash trees were discovered outside of the initial cluster of infested trees, however; EAB is very difficult to detect in early stages. To determine the full extent of infestation, a delimitation survey begins this week. The survey is being conducted by staff from city forestry, CDA, Colorado State University Extension, and forestry staff from other Front Range cities who have graciously offered to assist. It is anticipated to take up to six weeks to complete.
For the delimitation survey, the city has been divided into plots or grids of one-square mile each. Crews will remove two small branches from each of 10 ash trees near the center of each plot. The branch samples will be peeled and examined closely for the presence of emerald ash borer life stages. The branch sampling protocols were developed by the Canadian Forest Service (CFS). The CFS found by performing random branch sampling on asymptomatic trees with this technique, they were able to detect EAB several miles away from the original location before trees become symptomatic. The goal is to determine the full extent of infestation within the city limits. The results of the survey will also help guide the future city of Boulder EAB Response Plan to manage the infestation within the city and potentially slow the spread to nearby communities.
On Tuesday, Nov. 5, the city of Boulder is hosting an EAB “tree dissection” for forestry staff from other Front Range cities and Wyoming. Staff from CSU Extension, Colorado Department of Agriculture and U.S. Department of Agriculture, Animal Plant Health Inspection Service, Plant Protection and Quarantine (USDA APHIS PPQ) will be on hand to teach other forestry professionals what EAB looks like and to demonstrate branch peeling techniques to find EAB larvae. More dissections are planned to educate tree care companies.
There are approximately 38,000 city park and public street rights-of-way trees under the jurisdiction of the Boulder Parks and Recreation Urban Forestry Division; approximately 6,000 are ash trees (15 percent of the public tree population).
For more information, please contact the City of Boulder Parks and Recreation Department’s Forestry Division at 303-413-7245.
–CITY–
CU researchers find hyper evolution in walking stick insects
Oct 21st
off a cascade of ecological impacts,
new CU-Boulder study finds
A California walking stick insect that has evolved to produce individuals with two distinct appearances—an all-green form that camouflages well with broader leaves and a form with a white stripe running down its back that blends better with needle-like leaves—can markedly affect its broader ecological community when the appearance of the bug is mismatched with the plant it’s living on.
The new findings, based on research carried out at the University of Colorado Boulder, illustrate the ability of rapid evolution to cause a cascade of ecological impacts.
The scientists found that a walking stick insect that is not well camouflaged is more likely to be eaten by birds, and in turn, those birds are then also more likely to feast on the spiders, caterpillars, plant hoppers, ants and other arthropods living on the same plant. The resulting overall reduction in bugs living on the plant also means that the plant itself was less likely to be attacked by sap-feeding insects.
“Our study shows that the evolution of poor camouflage in one species can affect all the other species living there and affect the plant as well,” said Tim Farkas, lead author of the study published in the journal Current Biology. “It’s intuitive, but also really surprising.”
Farkas led the study as an ecology and evolutionary biology doctoral student in Assistant Professor Patrik Nosil’s lab at CU-Boulder. Nosil and CU-Boulder doctoral student Aaron Comeault are also study co-authors. All three have since moved to the University of Sheffield in England.
Evolution is often thought of as a process that unfolds slowly over centuries if not millennia, as individuals with genetic advantages have a greater chance of surviving to pass down their genes to the next generation.
But scientists are increasingly identifying instances when evolution works on a much shorter time scale. An oft-cited example of rapid evolution is the peppered moth. The light-colored moths were historically able to camouflage themselves against lichen-covered tree bark in England. A darker variant of the moth existed but was more rare, since birds were able to easily spot the dark moth against the light trees. But during the industrial revolution, when soot blackened the trees, natural selection favored a darker variation of the moth, which began to flourish while the light-colored variant became less common.
Evolution on such a rapid scale opens up the possibility that the process could have ecological effects in the short term, impacting population sizes or changing the community makeup, for example.
Researchers have begun to compile examples of these “eco-evolutionary dynamics.” The new study offers some of the most comprehensive evidence yet that evolution can drive ecological change.
“We have combined both experimental and observational data with mathematical modeling to show that evolution causes ecological effects and that it does so under natural conditions,” Farkas said. “We also focused simultaneously on multiple evolutionary processes—including natural selection and gene flow—rather than just one, which affords us some unique insights.”
Farkas and his colleagues—including Ilkka Hanski and Tommi Mononen, both of the University of Helsinki in Finland—focused their attention on the walking stick Timema cristinae, which lives in Southern California. The flightless insect lives primarily on two shrubs: chamise, which has narrow, needle-like leaves; and greenbark ceanothus, which has broad, oval-shaped leaves. The variant of the walking sticks that have a white stripe down their backs are better camouflaged on the chamise, while the solid-green walking sticks are better camouflaged on the greenbark ceanothus.
The research team began by cataloguing the walking sticks living on the two types of shrubs in 186 research patches, and determined that the striped walking sticks were indeed more common on chamise and vice versa.
In a second experiment, the researchers artificially stocked the needle-like chamise with the different variants of walking sticks. A month later, they sampled the shrubs and found that more striped walking sticks survived than un-striped walking sticks. They also found that chamise stocked with striped walking sticks were home to a greater number of arthropods as well as a greater variety of arthropods than shrubs stocked with un-striped walking sticks. Finally, there were more leaves damaged by hungry insects on chamise stocked with striped walking sticks.
The scientists surmised that the differences were caused by scrub jays and other birds that feed on walking sticks. A group of easy-to-spot walking sticks could attract birds, which might then feed on other arthropods as well. To test their idea, the researchers repeated the experiment, but in this case, they caged some of the shrubs to keep the birds from feeding. As they expected, the caged chamise stocked with un-striped walking sticks did not have the same drop in numbers as they did when the bushes were not caged.
“Studies of how rapid evolution can affect the ecology of populations, communities and ecosystems are difficult to accomplish and therefore rare,” Farkas said. “We’re hoping our research helps biologists to appreciate the extent of dynamic interplay between ecology and evolution, and that it can be used by applied scientists to combat emerging threats to biodiversity, ecosystem services, and food security.”
Funding for the study was provided by CU-Boulder, the European Research Council and the Academy of Finland.
-CU-