Townsend’s Community Forest Part 5
 | Author:
Pat Plantenberg, Tree Board Chair
Townsend Tree Board Chair, Townsend Rotary Club |
Townsend’s Community Forest Part 5
Pat Plantenberg
Tree Board Chair
Note: This is the fifth in a series of articles from the Townsend Tree Board reporting on the status of the community forest in Townsend.
Last week, we discussed how the number of tree species in Townsend has increased from 15 to over 70 since 1990. There are new cultivars of tree species being developed all the time and the Tree Board will continue to try new species over time.
This week, we will discuss how we have reduced the dominance of the species that dominated our community forest in 1990.
Townsend Public Tree Species Over Recommended Guidelines
Urban tree planting guidelines recommend that no single tree species should represent more than 10 percent of the tree population. This diversification will be more aesthetically pleasing and will minimize future insect, disease, and weather damage. Townsend had little variety of street and park tree plantings in 1990. In 1990, 80% of the trees were dominated by three species: green ash (48%, 161 trees), Siberian elm (22%, 73 trees), and white poplar (10%, 35 trees) (Figure 1).
Townsend has made significant progress in 33 years to achieve proper tree planting guidelines. As mentioned above, in 1990, three species exceeded the 10% guideline. In 2005, only two species exceed the 10% guideline and they totaled only 36% of the total number of trees: green ash (24% 197 trees) and Siberian elm (12%, 98 trees). In 2011, only green ash exceeded the 10 percent guideline and made up 19% (194 trees) of the total number of trees. Finally, in 2020, only green ash exceeded the 10% guideline and made up 16% (182 trees) of the total number of trees.
To highlight these diversification changes over time, in 1990, the top three species totaled 80% (267 trees) of all trees (Figure 2). In 2005 and 2011, the percentage of the top three species dropped to 44% (354 trees) and 37% (370 trees), respectively. Finally, in 2020, the percentage of the top three species dropped to 31% (353 trees).
This reduction in individual species' dominance over time is important. Chestnut blight wiped our American chestnut trees over 100 years ago. Dutch elm disease has wiped out large percentages of elm trees across the US as seen in Great Falls. The current threat looming in urban forestry is the emerald ash borer, an invasive insect from Asia that is decimating ash trees in over 35 states. When it arrives in an area, it kills 99.9% of the ash trees. Cities dominated by ash trees have had to spend millions of dollars to remove and replace ash trees with new species.
Townsend is in great shape and continues to reduce the ash tree population each year.
Researchers continue to try and develop a chestnut tree resistant to chestnut blight. Several new cultivars of Dutch elm disease-resistant American elms and elm hybrids are now available and are being planted in Townsend.
Research has begun to try and identify emerald ash borer-resistant ash trees. Hopefully, a new ash tree cultivar will be developed so we don’t lose this important tree species in our planting palette.
Next week we will discuss urban forestry guidelines and how Townsend is doing in meeting those guidelines.
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