The State of Missouri’s Forests
program, begun in 1989, is designed to sample publicly owned trees in urban settings every 10 years. In 1999, we measured over 600 plots in 44 Missouri communities. Some changes in sample methodology make comparisons with 1989 data difficult (although the changes will give us a clearer picture next time, in 2009).
Still, the study has provided some clear results. In 1989, foresters found there were two empty planting spots, places where a tree would thrive, for every tree that was actually in the ground. By 1999, that ratio had gone down to one empty space for every tree already planted. In other words, our communities have done a great job planting trees over the last 10 years.
Most trees surveyed were of smaller size. It takes a long time to grow a big tree, and trees in urban settings often don’t live long enough (often less than 15 years) to reach the largest size class. Unfortunately, the average quality of the trees surveyed has declined slightly over the 10-year period. Perhaps this reflects the fact that planting trees is popular, but maintaining them is less glamorous.
The most popular urban trees were silver maple, pin oak, green ash, sugar maple, Siberian elm and sweetgum. But these six most poplar species made up only 37 percent of the total in 1999, while in 1989 they made up 53 percent of the trees surveyed. We’re seeing more diversity in our urban forests, and that is good both aesthetically and for the long term health of the resource. The more diverse our urban forests become, the more resistant they will be to diseases and pests.
Overall, the survey indicates that Missouri is home to 1.14 million urban street trees. Economists and foresters working with the International Society of Arboriculture (ISA) have even come up with a way to estimate how much those trees are worth to Missouri. The ISA formula factors in tree species, size and condition, as well as the location where the tree is planted and local prices.
- The survey suggests that the average urban street tree is now worth $1,167! That’s up from $525 10 years ago - a great investment for the future.
- Forest crews use high-tech computer and low-tech tape measures to inventory trees in selected plots. Each year provides 20 percent of forest data for a repeating 5-year study
- Missouri's forest products drive industries that support thousands of workers. Thanks to careful management and stewardship, our forests are increasing in value and can support a continuing harvest. The most recent data shows that Missouri has 13.9 million acres of forests, nearly 32 percent of the state's total acreage.
- Our forests are growing at a rate of at least 267 million cubic feet per year, so the harvest of 140.5 million cubic feet is easily sustainable.
- Urban trees increase property values, clean the air and provide cooling shade. Urban foresters have determined that communities have increased their tree planting efforts in the last decade. Air pollution, root pollution and paving over soils stresses urban trees and likely contributes to their relatively short lifespan.