The 3-Rs of Healthy Woodlands

Posted: December 9, 2013

What can you do to increase the health of the trees and woodlands that give so much to you? You might consider the 3-Rs that underpin helping to improve the vigor and health of wooded landscapes: Resistance, Resilience, and Response.

We are fortunate to live in a state that boasts so many trees and acres of woodlands. The benefits we derive from our woodlands are innumerable and greatly enhance our quality of life. Whether you have a small woodlot, trees in your yard, a tree-lined street, or access to acres of public lands, you likely recognize how trees contribute to your well-being.

Have you ever turned this around? How do you contribute to the well-being of the forest? Many people believe that trees and woodlands left alone will take care of themselves. We believe that Mother Nature knows how to do this. Unfortunately, our impact on the environment makes her job increasingly more difficult. We pollute the air and water, abuse the soil, introduce insects, diseases, and plants that injure and kill trees. The list of evils we do to trees and woodlands is long, diverse, and growing.

What can you do to increase the health of the trees and woodlands that give so much to you? You might consider the 3-Rs that underpin helping to improve the vigor and health of wooded landscapes. Rather than reading, writing, and arithmetic, think Resistance, Resilience, and Response.
Resistance is about helping trees and woodlands defend against change. There are several ways to look at this. From the perspective of the individual tree, it might be as simple as protecting it from damage such as wounding and physical damage during construction or when doing maintenance. It might also mean addressing stresses such as competition from competing plants and other trees, providing water during droughts, or selecting the correct growing site. At the woodlot level, you move from the individual tree to the larger and more complex interactions that lead to natural changes as plants compete with each other and together face stresses together, as well as issues related to changes in the environment brought on by climate, weather, harvesting, and losses due to insects and disease. The intent here is to help the woods return to pre-disturbance conditions by controlling plants competing with regeneration, reducing competition between trees to increase crown vigor, or removing damaged trees to benefit those of better health and vigor.

Resilience involves taking steps that improve the ability of trees and woodlands to withstand anticipated changes or to directly defend them from disturbance to stay relatively unchanged. This involves watching, learning, and planning. In Pennsylvania, several tree species are struggling with life-threatening insects -- hemlock wooly adelgid and emerald ash borer for example. Individually, you can protect trees from both of these problems, but such decisions will involve continued maintenance. Within the woodlot, hemlock wooly adelgid might be held at bay for a while by judicious thinning related to site conditions to increase residual tree vigor. In the case of emerald ash borer, it might involve salvaging and encouraging regeneration of other tree species to replace lost trees. It also means thinking about what you can do in the woodlot to improve native plant diversity representative of what might have grown there in the past or what might be better suited to future conditions.

Response again involves watching, learning, and planning; however, the purpose is to monitor and understand how decisions work in an adaptive context. That is, you have made decisions and implemented them -- how have they worked out? With the individual tree, have you seen an improvement in vigor? What else might you do to increase resilience and build resistance? As you move from the individual tree to the woodland the complexity increases, but so do the options. As woodlands grow and age, change does happen. Individual trees and species grow at different rates, they compete for resources, and they affect each other’s health and condition. Essentially, the individuals who together grow in a place drive change among themselves, which in an undisturbed woodlot is a natural process. But as we anticipate change, such as changes in long-term weather patterns or major insect impacts, how can we help the forest to adapt to what might happen in the near or long term? Such preparation might involve changing species composition by adding or subtracting those that might compete poorly, introducing individuals of a species adapted to areas with climate similar to the anticipated change, or doing work to increase natural diversity.

Trees, woodlands, and forests are important to us in varying ways. As we move along a spatial continuum from the individual tree to a functioning forest, the decisions and considerations become increasingly complex. We know that people have and will continue to influence forest growth and development. To ensure that our forests remain healthy and have the capacity to meet our myriad needs, recall the 3-Rs of forest health – Resilience, Resistance, and Response. We owe it to ourselves and all those who benefit from our good forest stewardship.

John Elders wrote in  a 1997 essay entitled Inheriting Mount Tom that “We must conceive of stewardship not simply as one individual’s practice, but rather as the mutual and intimate relationship extending across generations, between a human community and its place on earth.” We need to care for the trees individually and together to ensure that they provide benefits from our stewardship.

The Pennsylvania Forest Stewardship Program provides publications on a variety of topics related to woodland management. For a list of free publications, call 800 234 9473 (toll free), send an email to, or write to Forest Stewardship Program, Natural Resources Extension, The Pennsylvania State University, 416 Forest Resources Building, University Park, PA 16802. The Pennsylvania DCNR Bureau of Forestry and USDA Forest Service, in Partnership with Penn State’s Department of Ecosystem Science and Management, sponsor the Forest Stewardship Program in Pennsylvania.