New Arrivals on the Chippewa - American Elms!

In 2007, the Chippewa National Forest (CNF) and the Northern Research Station (NRS) initiated a project to restore the American elm to the Forest's landscape.

In 2007, the Chippewa National Forest (CNF) and the Northern Research Station (NRS) initiated a project to restore the American elm to the Forest's landscape. Dutch Elm Disease (DED) has greatly reduced or eliminated the American elm component of hardwood forests and riparian ecosystems on the CNF. The objective of this project is to strengthen the tolerance to DED in the landscape of the CNF without narrowing the genetic base of the remaining elm population.

With a two-phase approach, the Chippewa National Forest intends to combine the DED tolerance of existing elm cultivars with the cold-hardiness and genetic diversity of local American elm populations. The hope is the effort will hasten natural selection for resistance, and the return of the American elm component in the landscape of the Chippewa.

Phase 1 - During the summer of 2007, known large living "wild" American elms on the Chippewa National Forest were evaluated and four of these "survivor" elms were selected to use in cross pollination. A team of biologists and silviculturists selected a planting site on each district on the Chippewa for a total of three sites. These sites are 1.2 acres each and are located in natural plant communities where American elm occurred historically.

During February 2008, branch material from the four survivor trees was collected and sent to the NRS office in Delaware, Ohio. There the branches were forced to bloom and cross-pollinated with trees known to possess high tolerance to Dutch Elm Disease. The seeds from these crosses were sown and grown resulting in 575 seedlings that should possess both cold hardiness and disease tolerance characteristics. Also during the summer of 2008 the three selected sites on the Forest were prepared for planting.

On November 6, 2008, 575 American elm seedlings arrive on the Chiipewa. These seedlings are trees produced from crosses between cultivars with known tolerance to Dutch Elm Disease and four surviving trees on the Chippewa. The potted trees will be stored on the Chippewa over the winter and they will be planted on the three prepared sites in the Spring of 2009. Fencing will be required for every tree to protect them from deer predation and rubbing, which can destroy these trees.

Tree growth and hardiness will be monitored on every tree each year. After growing for six years the elm trees will be tested for DED tolerance. This is done by putting the DED fungus into holes drilled into their trunks. The actual strain of fungus used will be collected on or near the Chippewa National Forest. Four weeks after the trees are inoculated with the DED fungus leaf wilting and foliage death will be recorded. The percent of crown dieback will be evaluated each year thereafter. Those individual trees that overcome the disease and survive will be known to have inherited DED tolerance from their disease tolerant parent. Trees that demonstrate both DED tolerance and good cold hardiness will be used in the second phase of this project.

Long term monitoring will be conducted by the Northern Research Station in Grand Rapids, MN, coordinating with the station in Delware. Young trees that die will be replaced through time as to maintain fully stocked plantings of at least 330 trees on each one acre site. Once established these trees should cross pollinate with each other and with other wild trees, strengthening the genetic tolerance to DED in the native population over time.

More branch material will be collected this winter and sent to NRS for more pollen collection and see production. Five hundred additional trees will need to be produced in 2009 to complete planting.