REFORESTATION: NOT JUST FOR FORESTS
When you first hear the word reforestation, you may imagine a large group of foresters in a national park trudging through burnt forestland, laying down tree seeds. Although this image accurately portrays one type of reforestation technique, you might be surprised to learn that developers and contractors, public and private alike, find reforestation helpful in other settings, as well. Reforestation is a process that is used on a day-to-day basis to replace stands of trees that were cut for development, as well as augment existing trees on site.
Why is reforestation used? When a site is being developed, the usable areas may not align in a way to promote tree growth. When that occurs, smaller areas of trees that get cut off can be replanted through reforestation techniques to correct such deficits and aid in the survivability of existing mature trees. Landscape architects are often tasked with allocating areas of reforestation plantings for many different reasons. Reforestation in a new development like a park is typically used for the following reasons:
screening of undesirable views
cover from the elements
In addition, developers often use reforestation to meet jurisdictional codes that require minimal tree coverage for a new development and steep slopes that need protection from erosion and cannot be mowed with conventional mowers.
How does reforestation work? Most of the roots of a tree can be found in the top 12” of soil. These roots need oxygen to survive, and by spreading out instead of down, nutrients near the surface of the soil can be absorbed much easier into the root systems. Picture a matrix of trees on a hillside that had been previously stripped of plant material. This image includes many small trees planted closely together that quickly intertwine their roots and act like a net to protect the soil from erosion. A common question people ask is, “Why are the trees planted so closely together?” Most of the public will look at hundreds (or even thousands) of small saplings in an area and wonder what the designer was thinking. The intent of planting like this is to mimic the natural selection process that occurs in forests all across our planet. Many of these small trees will die within the first few years, but many will grow, expand their roots and mature into a healthy stand of trees
What is the cost for reforestation? Though the upfront cost of planting this number of trees can seem high, cost, effort, and maintenance are minimal by comparison. The average reforestation tree is 1-3 gallons, which is considerably cheaper than the parking lot trees we use on a regular basis for new developments. The effort to plant small trees is minimal due to the nature of the size of the tree. Maintenance is minimal due to the built-in selection process of reforestation. Maintenance is weighted mostly in the first 6 months after planting occurs. This gives contractors time to water in the trees and then let nature run its course. In addition, it may come as no surprise that anywhere sod can be eliminated on a site will greatly reduce water usage and save money.
How do you know which trees to select? Reforestation requires carefully selected varieties of trees. Choosing a tree for its characteristics is key in any design, but tree selection is particularly important in reforestation. The reason why greater care must be exercised when choosing tree varieties is not only because the quantities are higher, but also, as mentioned previously, the intent is to mimic nature and natural selection in order to achieve the correct final outcome years later. For example, planting 600 Bradford Pear Trees in the suburbs of Chicago will only produce a lot of firewood after the first year of spring winds. In another example, imagine a large stand of Loblolly Pine Trees planted on a steep slope. Loblolly pines concentrate their branches and needles near the top and derive their strength from their ability to grow closely together in great numbers. What happens, though, if these trees are planted on the side of a mountain in Kentucky? At the first ice storm, these pines will succumb to the weight as the ice builds. When thinking about which trees to use for reforestation, it is best to err on the side of caution and specify native trees.
Hopefully this narrative has broadened your knowledge of the types of reforestation, as well as the thinking behind how design is used. And the next time you see a mass of small trees on a site, you will know why and how it got there.
About Anthony Pappas, RLA
Anthony Pappas, RLA, ASLA, is a Project Manager for the Greenspace and Land Design Division at Foresite Group. He graduated from University of Georgia with his Bachelor’s degree in Landscape Architecture, and has been working at Foresite Group for over 8 years. Anthony loves his work because he loves the outdoors. He is often found exploring the North Georgia Mountains for great hikes or bike trails with his family. He also has special interests in park and trail design and historic preservation projects.