Arboriculture

Our new division, Bluegrass Urban Wood, is now shipping products. We make fine wood products from trees growing in the streets, yards and horse farms of the Bluegrass region of central Kentucky. Presently, we are making flooring from red oak, walnut and other species, with more products to come. Read more about it here.
	Select red oak
	Quarter sawn red oak (vertical grain)
	Street grade red oak

Like much of the midwest, Chicago has been suffering from a hot, dry June. Arborists and city authorities there are urging homeowners to water trees but to forget about the grass. Early summer droughts are bad for trees, especially newly planted saplings that lack an adequate root system. By using limited water resources to keep trees healthy, survival and growth in the following years is more likely. Grass can enter a resting state during drought and will recover once cooler wet weather returns. Trees that lose leaves and fine roots in early summer may not fully recover and are more susceptible to future stresses.

Chicago is also deploying fire boats along the waterfront and Chicago River to soak young trees.

A Hawaiian company is making wood products from trees cut as part of safety programs in Hawaii's Polipoli State Park and Kula Forest Reserve. The company, South Pacific Lumber Co. is providing wood for furniture, millwork and timber framing. The trees are being felled because they pose a risk to cabins and other facilities in the park, but they present a fire hazard if left on the ground. The company has paid $2000 to $3000 to the state to mill 20 pine and cypress trees and will return to mill about 25 more. The fire danger in these forests is very high. Milling the trees prevents fuelwood buildup and provides useful products in a state that lacks available wood resources.

The US Army Corps of Engineers is planting American elms, Ulmus americana, on a man-made island in the Mississippi River. The Corps planted 21 American elm saplings on Eagle Island to replace other species washed away in a flood. Elms once were a dominant species on Mississippi River bottomlands until they were nearly wiped out by Dutch elm disease. The new saplings come from trees with at least some resistance to the disease. The planting program is part of the US Forest Service American Elm Restoration Project.

Georgia residents are being asked to watch plants in their yard for signs of disease in an attempt to detect infection with Phytophthora ramorum, the fungus the causes sudden oak death. Special attention is being paid to camellias, lilacs, viburnum, azaleas, rhododendron and mountain-laurel. These plants are known hosts for the fungus, which usually causes leaf spots or twig dieback. The fungus can be fatal to oak trees, and the program is an attempt to eliminate the disease from home gardens before Georgia's valuable and extensive oak forest is infected. Ornamental plants were sent to Georgia from infected Monrovia nurseries in California, so state agriculture authorities suspect that infected plants are in the state. Georgia authorities quarantined plants shipped from Monrovi and other California nurseries, but not until over 49,000 plants had been sold.

Scouts in Washington D.C., equipped with handheld computers, are surveying 8.500 American elms, Ulmus americana, on streets and city property. The scouts are looking for symptoms of Dutch elm disease. Trees with symptoms are reported to urban foresters, who then examine the trees further and prescribe treatment if necessary. The city, which once had over 25,000 American elms, has not surveyed trees in several years. With the infusion of funds from Casey Trees, scouting is now possible. American elms can be conserved through a combination of treatment and sanitation, but scouting is the first requirement. The National Park Service has a comprehensive program to preserve elms on Federal property

National Public Radio has a story by Margot Adler about smoke jumpers climbing trees in and around Central Park looking for Asian longhorned beetle. The story includes vivid descriptions of tree climbing. Previous story: Smoke Jumpers in Central Park

Adult Asian longhorned beetle, Anoplophora glabripennis. Photo courtesy APHIS, US Department of Agriculture

The city council of Havering, East London, has allocated funds to replace dozens of fruit-bearing trees along city streets. The trees, including flowering crab and pear trees, will be replaced with trees that don't bear fruit. Why? The council is afraid the city might be sued if trees drop fruit onto pavement (sidewalk or street) and someone slips on the fruit!

      

In the two years since the "EAB" was first found in Ohio, over 200,000 trees have been cut down in an effort to confine the infestation. As we have reported previously, new outbreak areas have been found this year. Ash removal has been paid for by funds from the US Department of Agriculture. As the borer infestation spread, costs may be shifted to land owners. At least 10% of all trees in Ohio are ash trees (of several species). The Ohio state forestry division estimates that if the infestation spreads throughout the state, direct costs for removal could top $1 billion. This does not include the cost of the lost of ash trees in forests, including the timber value and the loss of ecosystem services. Nor does it include the cost of street tree removal by cities or the cost of increased heat loading of city buildings with the loss of shade trees. In Ann Arbor, Michigan, residents will probably vote in November on a referendum to allocate $4 million for ash removal in the city. This does not include the cost of tree replacement. Timely removal is critical for controlling the spread of "EAB" but also to remove hazardous trees. Ash trees attacked by "EAB" die quickly and become hazardous, with falling dead limbs and entire trees prone to falling. Some smaller towns are trying to head off the borer by using state and federal funds to replace ash trees before the borer arrives. Bowling Green, Holland, Rossford, Sylvania and Rossville Ohio are removing ash trees and replacing them with species that are not susceptible to "EAB". "EAB" information can be found at http://www.emeraldashborer.info.

Adult emerald ash borer, Agrilus planipennis. Photo by James Zablotny, US Department of Agriculture

      

Roving bug-detection patrols will be scouting southwestern Ontario this summer looking for evidence of "EAB". The inspection areas are mostly outside Essex County and Chatham-Kent, where thousands of trees have been cut to stop the spread of the Asian insect, which is lethal to ash trees. Inspectors will be visiting sawmills, private campgrounds and provincial parks looking for ash firewood that might have been brought in from infested trees. Last year, 22 fines of C$400 were imposed on people who illegally moved firewood out of the quarantined areas. Movement of wood by people is a much greater threat than natural movement of the beetle, since firewood can be hauled over long distance in a short time. Adult beetles have begun emerging in Ontario, and will be colonizing new trees However, the extent of new damage will not be known until fall or spring, after larvae have fed on the tree stems and girdled the trees. In Ohio, tree climbers have inspected trees in Maumee Bay State Park and found beetle larvae in seven trees. The trees have been removed. Ash trees within 200 yards of the infested trees were girdled to create 'trap trees.' Stressed trees are more attractive to ash borers than unstressed trees. Girdled trees are more attractive to adult beetles than ungirdled trees and trap trees may attract all the emerging adults, preventing them from flying further afield and spreading the infestation. Trap trees will be removed next spring before adult beetles emerge. The effectiveness of this strategy is not known. It is probably less effective than removing all ash trees in the area, but removal budgets are tight.

Adult emerald ash borer, Agrilus planipennis. Photo by James Zablotny, US Department of Agriculture

The latest Tangled Bank is up at Geomblog. Tangled Bank is a blog carnival for science writers. The current offering has lots of great articles and is worth a visit.

Rare and native plant species are more likely than abundant or invasive species to be lost from an ecosystem when nitrogen is made more available. Nitrogen increases plant growth, but appears to give a competitive edge to some plants, and a disadvantage to plants that are not adapted to take advantage of more nutrition. This is the conclusion of a wide-ranging nitrogen fertilization experiment by Katherine Suding and her colleagues at UC Irvine. The study was published in PNAS.

Nitrogen in soil comes from nitrogen fixation by certain plants and microorganisms, by lightning-fixation in rainfall, and from manmade sources. The most important manmade sources include fertilizer and acid rain. While fertilizer is not applied intentionally to natural ecosystems, it can arrive in the wind from agricultural sources. Acid rain contains sulfuric and nitric acids from industrial pollution, and is adding considerable amounts of nitrogen to natural ecosystems.

The ecological consequences of nitrogen addition are made clear by this study. Increased nitrogen from anthropogenic sources will reduce biodiversity, eliminate rare species and favor aggressive, fast-growing species including invasives.

As landscaping in urban areas moves toward native plants, it is important to recognize that excess nitrogen fertilization will promote the growth of weeds and non-natives, which have been selected to do well in high-nitrogen environments.

     

There are continuing conflicts between property owners and state authorities trying to enforce ash tree removal to prevent spread of "EAB". We have previously reported several stories on these conflicts. In Port Huron, MI, property owners are trying to stave off the ash removal program by treating the trees with systemic pesticides known to deter the beetle. However, the treatments are expensive and need to be repeated annually with no end in site. State authorities have not agreed to permit treated trees to remain. Since the state has no guarantee that the property owner will continue treatment, or that the treatment is 100% effective, authorities are unlikely to permit the trees to stand. The "EAB" control program requires removal of healthy ash trees within 200 ft. of infested trees (farther in some states). Property owners often do not recognize the need to remove apparently healthy trees. It is a difficult task for agricultural authorities to sell property owners on the need to remove trees, especially prized shade trees, when there is nothing wrong with them. This is a public relations problem for the states trying to prevent spread of the "EAB".

Adult emerald ash borer, Agrilus planipennis. Photo by James Zablotny, US Department of Agriculture

     

The "EAB" has spread in northern Ohio, and is now in downtown Toledo and Maumee Bay State Park. State officials are planning aggressive ash tree removal programs for both areas. The Maumee Bay infestation is particularly worrisome: "The most disconcerting news for state officials was the discovery of infested trees at Maumee Bay State Park in eastern Lucas County. That means the beetle has moved perilously close to the Lake Erie shoreline and could spread eastward across northern Ohio - something officials have been fighting to avoid. They fear the pest will be much harder to stop if it enters wetland areas in state preserves and the Ottawa National Wildlife Refuge in Ottawa County that have limited road access. "I can confirm it has been infested," Lee Anne Mizer, agriculture department spokesman, said yesterday of Maumee Bay State Park. She refused to elaborate, indicating the state plans to discuss details on Monday." - Toledo Blade

Adult emerald ash borer, Agrilus planipennis. Photo by James Zablotny, US Department of Agriculture

The winter moth, Opheroptera brumata, was introduced into North America from Europe. Caterpillars of the winter moth are summer defoliators of maples, apples and blueberries.  Long a problem in southern Canada, the winter moth has established itself in Massachusetts and Rhode Island. Winter moth adults emerge in November and December, and many communities in Massachusetts had dense flights of the moths last fall. These areas are now seeing extensive defoliation.

Defoliated trees are weakened somewhat, but spring defoliations are generally followed by a flush of new growth and recovery. Several years of consecutive defoliation can reduce tree vigor, especially if other stressors such as drought also reduce vigor. Defoliation can severely depress fruit production. The winter moth is unlikely to become as serious a problem as the gypsy moth, and effective biological control agents are already known. In Canada, winter moths have been controlled by the introduction of a predatory wasp, Cyzenis albicans, and Massachusetts authorities are raising trial populations of the wasp. It could take several years before wasp populations are high enough to control the winter moth.

The last few years have seen major increases in defoliation from multiple causes in New England. Defoliation by native insects is at all-time high levels. Insect outbreaks are often regulated by weather. Mild winters, such as we have had in recent years, permit higher insect populations to survive. Global warming is thus a likely cause of increased insect infestations.

Florida is facing an outbreak of dendrophobia, the fear of trees, following last years spate of severe hurricanes. Property owners frightened by the amount of damage done by falling trees to roofs, cars, and power lines are removing large trees or heavily pruning them. Combined with extensive construction-related tree removal, the result could be a dramatic reduction in tree cover in Florida's urban forests. Reduced canopy cover, especially in a hot climate, increases the urban heat island effect, creates higher demand for electricity, increases storm water runoff and erosion and damages the esthetic appeal of a city.

The Orlando Sentinel says, in an editorial, that Florida cities need tree management policies and regulations. They propose five policies:

• Require permits for tree removal. Orlando and Tampa already require permits but other cities do not;
• Identify tree species that should be protected and those whose removal should be encouraged. Alien invasives such as Brazilian peppertree and Australian pine should be targeted for removal;
• Pay particular attention to "grand" trees, those well-established trees of significant benefit to the community;
• Require government departments to talk with each other to protect trees during right-of-way construction;
• Establish crisis response policies to reduce hazards quickly after a storm. This could include lifting permitting requirements for a specified period.

In general, communities need to do more to teach citizens the benefits of trees. Dendrophobia is taking hold in many communities, and the result is a loss in canopy cover throughout a community.

I have been using the term 'dendrophobia' as a way to get people's attention focused on a serious problem. By dendrophobia, I mean the fear of trees described above that leads people to make the apparently rational decision not to have large trees in their lives. However, I recently became aware that dendrophobia is a real psychological disorder, an irrational fear of trees akin to agorophobia or ailurophobia. I probably will continue to use the term in its informal sense.