Tree Thinning, The Federal Government & NEPA – How It All Works

Editor’s Note: The following is the last of three in a series of articles by Colorado State University’s Karissa Courtney covering important forest topics facing the United States. Part I covered the intricacies of the Wildland Urban Interface (WUI) and looks at some recent very large fires in the West. In Part 2, Courtney argued that Smokey the Bear has worked “too well” with recent forest fires increasing in intensity and severity. Part 3 (below) focuses on tree planting and thinning — and how government agencies get projects like this done thanks to the National Environmental Policy Act…

Being an environmentalist is currently a popular thing- and rightly so. Climate change is happening and is only going to get worse if we continue the way we’re going. However, the typical “tree hugger” trope is one that, while it has good intentions, actually isn’t always the best for the environment. There are countless stories of protestors sitting in trees as bulldozers wait below to take them out. These are moving and important stories, but cutting trees down isn’t always a bad thing. Yes, trees are great carbon sinks (they can store a lot of carbon and carbon is a problem when it’s in the atmosphere in too large of quantities), but in some cases it can actually be beneficial for the environment. This is not an advocation for clearcutting logging efforts, but rather an argument for the practice of forest thinning. While it was mentioned in Part II that some areas actually don’t experience less severe wildfires even if thinned (this could just be due to climate), it has been found in many other cases that thinning is beneficial. Thinning can mitigate tree drought stress (Sohn et al. 2016; Bradford and Bell 2017), perpetuate tree migration as climate changes (Renwick and Rocca 2015), restore an area to low-severity fire (Fule et al. 2012), and increase biodiversity (He et al. 2019).

Because forest thinning and/or prescribed burns can be so beneficial, broad and large-scale tree replanting efforts could be in vain. It’s quite popular these days to include as part of a business model, a promise to plant “x” number of trees when consumers purchase an item. The intention behind this model appears to be a good one, but one has to question where these trees are being planted, if they will be planted in monocultures (which could be more susceptible to disease, beetle outbreaks, and wildfire), and if that ecosystem actually needs more trees (Fig. 1). That’s not to say that this can’t be done in a productive way that’s good for the environment, but something that should be regulated and kept an eye on. So how does forest thinning or replanting actually get done at the federal level in the United States?


Figure 1. a) an example of an open, dry ponderosa pine forest that would not need forest planting (from Woodland Fish and Wildlife, n.d.) and, b) an area of the High Park Fire near Fort Collins, CO where there is very little to no regrowth 5 years after the fire (photo taken in 2016, from USDA 2017).

There is a lot of distrust when it comes to the federal government and land management. When reading comments from US Forest Service (USFS) projects, the public is apprehensive, skeptical and critical. There also are others who just simply don’t like the projects being taken on. But many people often wonder, how do federal land management projects actually get done?

To start off, we have to understand the National Environmental Policy Act (NEPA) of 1969. The Act was signed by President Nixon and started a wave of other environmental acts, such as the Clean Air Act, Clean Water Act, Endangered Species Act, etc. NEPA is a regulatory policy that requires federal agencies to use a “systemic” and “interdisciplinary” approach when they are making decisions for actions that might impact the environment (Luther 2005). The Act seeks to: a) have only beneficial uses of the environmental without unwanted consequences to environmental or human health, b) preserve natural, historical, and cultural components of our planet, c) create better renewable resources, and d) involve the public in the process (USFS 1969). Also a part of NEPA is the establishment of the Council on Environmental Quality (CEQ) in the Executive Office of the President (USFS 1969). The CEQ is a small group of people appointed by the President who submit annual Environmental Quality Reports (EQR), gather information regarding environmental issues, and provide advice to the President on these topics (USFS 1969).

NEPA itself simply requires actions of federal agencies to be identified and evaluated, and to submit an Environmental Assessment (EA) or Environmental Impact Statement (EIS) (Fig. 2). An EA is a shorter document that shows why the proposed action for the project does not have any environmental impacts. An EIS must be done when there are environmental impacts from the proposed action, and alternatives must be explored. The Act does not require federal agencies to change their actions, only to consider and recognize what their action is having on the environment. The National Forest Management Act (NFMA) of 1976 is another regulation that calls for new forest planning processes and increased public participation that the US Forest Service also has to abide by.

Figure 2. Diagram of the NEPA process, from NASA (n.d)

With that background in mind, we can now better understand what federal agencies (US Forest Service, US Fish and Wildlife, Bureau of Land Management, etc.) have to go through to get a project approved and done. The process for getting an EA or EIS approved can take years. The public is allowed time to make comments and be a part of the process, and if the public feels that the federal agency was wrong in some way, they can take the agency to court and have the courts hold them accountable. It’s not the most efficient system, and many have criticized how the process works (Nie 2004; Shepherd and Bowler 1998), but it’s what we have to work with currently. Specifically, Nie’s (2004) main argument for public lands governance, is that individual agencies are given too much authority with vague guidelines from non-specific language in the Act. Nie (2004) offers some possible solutions though, such as enacting prescriptive law (for Congress to have sole responsibility to make hard decisions); administrative leadership and discretion where agencies would have even more discretion; decentralization of public lands management to state and local governments; a comprehensive public lands law review to focus on the vague language; and finally policy experimentation where other approaches to public land management could be explored at a small scale. Even though the NEPA process could be better, it’s a good tool for holding agencies accountable and allows the public to be heavily involved, especially when controversial projects such as thinning come up.

Although there is some dispute on whether forest thinning prevents severe wildfire, it’s important to keep in mind that it depends on the forest type and plot in question. Because of this, thinning is prescribed in many different areas of federal lands. However, to get these thinning projects approved, the agency has to go through the NEPA process, which we recall can take years. This is not especially conducive to fast action in our race against climate change. Again, remember from Part II that climate change is a major factor affecting fire severity, and if we can’t get in fast enough to thin stands out, then the problem could keep getting worse (and it probably will). On the other hand, this can provide assurance to those that are skeptical of federal land management practices. In some of the comments on EISs in the works, like mentioned before, members of the pubic seemed worried that the agency was going to just steamroll through and do what they want with zero regard for the environment. Because of the systems in place, this is not actually very possible, but could also be why the project you want done might take many years to achieve.


Bradford, J.B., and Bell, D.M. 2017. A window of opportunity for climate-change adaptation: easing tree mortality by reducing forest basal area. Frontiers in Ecology and the Environment 15: 11-17.

He, T., Lamont, BB., and Pausas, J.G. 2019. Fire as a key driver of earth’s biodiversity. Biological Reviews 94: 1983-2010.

Fule, P.Z., Crouse, J.E., Roccaforte, J.P., and Kalies, E.L. 2012. Do thinning and/or burning treatments in western USA ponderosa or Jeffrey pine-dominated forest help restore natural fire behavior? Forest Ecology and Management 269(1): 68-81.

Luther, L. 2005. NEPA background and implementation. CRS Report for Congress.

Nie, Martin. 2004. Statutory detail and administrative discretion in public lands governance: Arguments and alternatives. Journal of Environmental Law and Litigation 19(2):  223-289.

Renwick, K.M., and Rocca, M.E. 2015. Temporal context affects the observed rate of climate-driven range shifts in tree species. Global Ecology and Biogeography 24: 44-51.

Shepherd, A. and Bowler, C. 1998. Beyond the requirements: improving public participation in EIA. Journal of Environmental Planning and Management 40(6): 725-738.

Sohn, J.A., Saha, S., and Bauhus, J. 2016. Potential of forest thinning to mitigate drought stress: A meta-analysis. Forest Ecology and Management 380: 261-273.

USDA. 2017. Learn from the burn: The High Park Fire five years later. Rocky Mountain Research Station: Science You Can Use Bulletin 25.

USFS. 1969. National Environmental Policy Act, 42 U.S.C. §§ 4321-4370m.

USFS. 1976. National Forest Management Act, 36 C.F.R. § 219.19

NASA. N.d. NASA and the National Environmental Policy Act.

Woodland Fish and Wildlife. N.d. Managing ponderosa pine woodlands for fish and wildlife.