SUSTAINABLE FOREST MANAGEMENT:
Firmly rooted.
Thanks largely to sustainable forest management, the U.S. enjoys some of the most abundant and productive forest resources in the world.
To see why, let’s start by zooming out…
Here’s the total land mass of the United States:
For a better understanding, let’s visualize our forests this way:
= 1 million acres of forest
Forest acreage1 can be further divided into four categories2.
84 million acres
167 million acres
359 million acres
155 million acres
But don’t get lost in the woods…
Of U.S. forestland, just 2% are harvested8 and replanted each year to supply timber needed for essential wood products we rely on.
Now let this grow on you.
From tiny saplings to towering giants and everything in between, sustainability9 at a landscape level depends on a wide diversity of healthy forests and trees.
Cross your t’s, not your numbers.
Ok, now that we’ve covered the national overview using RPA figures, were going to dive into more detail. To do that we need to switch to FIA data, which informs RPA, but has slightly different figures and totals.
Don’t worry, there are scientific reasons for this. Read about them here.10
To help us understand what U.S. forests look like, we can categorize them into different age classes11.
Of course, forests aren’t arranged in neat, perfect hexagons12 where all the trees in an area are the same age, as depicted here. In reality, it’s messier13. This data visualization would be more accurate if all these hexagons were blurry or mixed up in a blender, but that would be a tad insane and make this illegible. Keep that in mind, and as you scroll, maybe squint your eyes.
Wildlife14needs these varied landscapes.
U.S. Forests
If we arrange U.S. forests from youngest to oldest, it looks like this.
From a landscape perspective16, the U.S. exhibits remarkable age-class diversity17.
Private Working Forests
When we zoom in on our private working forests, it’s clear that they’re younger than U.S. forests overall.
This makes sense because they’re managed to produce 90% of our timber harvest for U.S. forest products.
U.S. Forests
Looking back at the full forest resources of the U.S., we can see forests of various ages across the landscape.
Ready to venture deeper into the woods19?
Let’s look at today’s U.S. forest acreage by
age class, organized on a timeline20.
Forest acreage by age class
0-50 years
51-100 years
101-150 years
151+ years
0-50 years
51-100 years
101-150 years
151+ years
Forest acreage by age class
Now we’re going to add carbon.
Remember these blocks of CO2e?
We can see that age classes
sequester carbon at different rates.
Forest acreage by age class
0-50 years
51-100 years
101-150 years
151+ years
0-50 years
51-100 years
101-150 years
151+ years
Forest acreage by age class
Carbon stocks net change
(Sequestration)
Carbon stocks net change
(Sequestration)
We can see that age classes
sequester carbon at different rates.
Forest acreage by age class
0-50 years
51-100 years
101-150 years
151+ years
0-50 years
51-100 years
101-150 years
151+ years
Forest acreage by age class
Carbon stocks net change
(Sequestration)
Carbon stocks net change
(Sequestration)
Lastly, we can see how each forest category is sequestering and storing carbon21 per age class.
Forest acreage by age class
(Sequestration)
0-50 years
51-100 years
101-150 years
151+ years
0-50 years
51-100 years
101-150 years
151+ years
Forest acreage by age class
(Sequestration)
Total carbon stocks
(Storage)
Total carbon stocks
(Storage)
The carbon data we’ve seen so far is just a snapshot.
To really understand forests and carbon, we need to add a key ingredient: time.
Let’s look at sustainable harvesting23 of U.S. private working forests over successive “rotations.24”
But before we do that, keep this in mind…
Forests are not all managed25 the same way.
The forests that are managed the most intentionally for forest products include those owned and managed by members of the National Alliance of Forest Owners (NAFO).26
While just a drop in the bucket of overall U.S. forest acreage, NAFO members manage their forests on ongoing rotations of growth, harvests, and replanting. Through this management, their working forests provide sustainable forest products so others don’t have to. They also provide significant carbon and environmental benefits, and economic investment in rural areas.
Investments in forests are driven by healthy markets. Market returns can come from producing traditional products, like wood for buildings, and producing new products, like growing additional carbon.
Now, back to rotations24…
Harvest rotation cycles of private working forests generally occur as trees reach their maximum growth, which varies by ecological region. This impacts the rate of carbon sequestration throughout each cycle.
Here’s a closer hypothetical look based on real carbon data.
Each region33 demonstrates how 3 million hypothetical acres of working forests will sequester and store carbon in the forest and harvested wood products through harvest/replant cycles34 over successive years.
So what do these spinning rotations show us?
To understand forest carbon, we must consider countless successive rotations32 happening simultaneously across the landscape on different intervals and timescales. When we look across the landscape over time, we see that sustainable forest management can optimize carbon benefits27 both in the forest and in harvested wood products.
With that being said…
Some forests don’t “work.”
Nor should they.
Forests that are not managed for products also provide important climate mitigation benefits. However, despite popular belief, the sequestered and stored carbon in these unmanaged forests will not increase linearly over time. Natural disturbances35, death, and decay will occur.
Most people think forests will just continue to sequester more, and more carbon forever if we stop all harvesting.
The data show us that eventually, carbon sequestration rates will slow and the forest will become a source of carbon emissions21.
Some forests do “work.”
We need them to.
The reality is that society needs stuff. Sourcing from sustainably managed forests9 means those products can be natural, renewable, green, beautiful, biodegradable, and probably some other cool adjectives we haven’t even thought of yet.
AND, wood stores carbon.
Here’s the bottom line:
There is no single “best” forest type, category, or condition.
All forests provide carbon benefits39.
Diversity of forest types across the landscape is a good thing.
Big Huge Mega Caveat…
This website has shown a national representation37 because we’re trying to show these concepts. Across the landscape, forests are very different and regional and local data can tell a clearer picture38.
Downloads are available for regional data below.
Download PDFs to see how this breakdown looks for forests in the south, west, and north.
- How were the acreage totals calculated?
The forest category acreage was calculated using data from the U.S. Forest Service. It gets a littttttle complicated, so we recommend checking out this Methodology Explainer created by NCASI, Inc. to get the full explanation.
return - How are forests categorized?
Forests are grown and managed for all sorts of reasons, from recreation to carbon storage to wildlife habit to harvest for use in over 5,000 products. (See “Chapter 02: Forest Categories” for more info.) Sustainable Forest Management (SFM) is tailored to the purpose(s) of a specific forest along with its geography, geology, and other considerations. Age-classes are just one of the considerations taken into account in the SFM process.
Want to nerd out more? The Forest Service’s portal on sustainability reporting shows the broad array of considerations involved in SFM including soil and water health, ecosystem contributions, and contributions to the global carbon cycle.
return - Private Non-Working Forests
Forests under private ownership that are not harvested to produce products (think scrubby Texas dude ranch-type lands like in old western movies).
return - Public Non-Working Forests
Forests controlled by local, state, or federal government entities that are not harvested to produce products (think Yosemite). These lands include our treasured national parks and preserves.
return - Private Working Forests
The vast majority of our country’s working forests are on private land, owned by individuals, families, and small and large businesses. Private working forests are often part of a retirement portfolio. (Think pension funds.)
return - Public Working Forests
Public working forests include state and federal lands that permit logging and other commercial activities. National forests — which are different from non-working national parks — are a good example.
return - Recreation and Hunting
Recreation is available in various forms across many different types of forest – public and private, working and non-working. Recreation and hunting are compatible with sustainable forest management. Even on working lands there are many years during the cycle of planting and harvesting where forests are growing, allowing for a variety of recreation activities.
The recreation opportunities forestlands provide include hunting, fishing, foraging, hiking, forest bathing, camping, birding, mountain biking, searching for Sasquatch, and other sports and activities. Some private landowners, like their public counterparts, enhance recreational opportunities by building trails, installing safety features in highly trafficked areas, and enhancing scenic locations. (The fine print: many types of forests offer a mix of free and fee-based access to different activities.)
This access to forests is an important way for a growing and increasingly urbanized U.S. population to access nature. Research shows that communities with access to forests are healthier than those without.
Hunting is one way people access the outdoors that has conservation benefits. The Federal Aid in Wildlife Restoration Act, better known as the Pittman Robertson Act of 1937, placed an 11% excise tax on hunting equipment, ammunition, and firearms. The funds from this tax are given to states with the express purpose of supporting wildlife conservation. Since its inception, this tax has provided more than $12 billion in funding and is the most important source of funding for wildlife conservation and management. In addition, hunters spend time and resources improving habitat conditions either on their own or through conservation-oriented organizations, such as Ducks Unlimited, The National Wild Turkey Federation, and the Rocky Mountain Elk Foundation.
return - Where did we get the 2% figure?
This figure is calculated through an analysis of the RPA and FIA data. The analysis was done by the National Council of Air and Stream Improvement, Inc. (NCASI). You can read about it in full here.
Harvests of any type – thinning, road construction, fire fuel breaks, or final harvests – occur on less than 2% of working forests.
Acres where harvests occurred in 2018 totaled 7,878,000 acres (7,180,000 on private land, and 698,000 on public land).
The whole notion of how much we regrow is based on the fact that if it’s not regrown, then it’s no longer forest. If it’s no longer a forest, it’s no longer forestry we’re talking about, but land use conversion. The RPA tells us that overall, we’re not losing forest cover in the U.S. The numbers changed less than 1/10th of 1%, which is within our sampling error… So for every acre that might have been harvested and not regrown (i.e. turned into a neighborhood or big box store), there was another acre somewhere that someone let grow back into trees.
return - What is Sustainable Forest Management?
Sustainable Forest Management (SFM) is the long-term care and stewardship of our forest resources to balance and maintain their environmental, economic, and social benefits, both today and in the future.
The core principle of SFM is the continuous cycle of growth, harvests, and regrowth. This cycle ensures that forests can provide what’s needed today while remaining a renewable and abundant natural resource for future generations.
Sounds simple, right? Not quite. Forests are grown for all sorts of reasons, from recreation to carbon benefits to wildlife habit to harvest for use in over 5,000 products. (See “Forest Types[42] ” for more info.) So SFM will be tailored to the purpose(s) of a specific forest along with its geography, geology, and other considerations.
Private working forest owners view SFM as a vital part of their culture as stewards of the land, not just something that is good business or a social responsibility. Working forests are managed using scientifically rigorous standards, systems, policies, and procedures incorporated into forest management plans. These plans include: landscape-scale assessments with requirements addressing wildlife conservation; soil, water quality, and other best management practices (BMPs); regulatory compliance; and forest certification standards. Because timber takes between 25 and 100+ years to mature, forest plans cover decades-long timescales. A forest management plan established in 2024 considers impacts in 2049, 2074, and 2124.
The long-term benefits of SFM are made possible by healthy markets for renewable forest products. Markets connect the economic power of millions of consumers to the natural power of private working forests. Financial returns on forest products drive investment in SFM and keep the cycle of growth, harvest, and regrowth going. This alignment of economic and environmental benefits is unique to forestry, where the byproducts of ongoing forest management are forest health and resilience, clean air and water, unmatched carbon benefits, abundant wildlife habitat, and good paying American jobs.
Want to learn more about SFM? The United Nations Food and Agriculture Organization has organized a series of learning modules you can explore here.
return - RPA and FIA
This data visualization uses the best available data sets, most of which are provided by the U.S. government. Here, we’re looking at RPA and FIA.
RPA
This website provides forest resource statistics contributing to the USFS 2020 Resources Planning Act (RPA) Assessment to provide current information on the nation’s forests. Resource tables present estimates of forest area, volume, mortality, growth, removals, and timber-product output in various ways within the context of changes since 1953.
U.S. Department of Agriculture, Forest Service. 2023. Future of America’s Forest and Rangelands: Forest Service 2020 Resources Planning Act Assessment.
FIA
USDA’s Forest Inventory and Analysis (FIA) is widely regarded as the best strategic forest inventory in the world. FIA collects, analyzes, reports, and distributes data about the nation’s forests: how much forest exists, who owns it, what condition it’s in, where it’s located, and how it’s changed.
To better understand RPA and FIA data, check out Differences in Forest Area Estimates from US Federal Agencies, created by the team at NCASI, Inc.
return - What is an age-class distribution?
An age-class distribution describes the setup for a lush, upstairs-downstairs style British drama starring Dame Judi Dench as the matriarch of a rich but dysfunctional family struggling to adapt to a post-World War I evolving social hier—
Whoops, that’s not it. From the top:
Age is one way to categorize forests, and an age-class distribution describes the ages of trees in a specific part of a forest or across a landscape. Age can be a useful metric because it can indicate different stages of a forest that all provide specific climate and wildlife benefits. Not all forests are grouped into patches where the trees are the same age. To determine what age-class bucket to sort each acre of forest, this visualization has relied on the methodology of the Forest Service’s Forest Inventory and Analysis program (FIA), which looks at the predominant overstory to determine a forest age.
Typically, scientists, like foresters, don’t consider single trees in isolation. Instead, they might look at seres, different plant and tree communities. Seral stages (early, mid, late, and climax stages) characterize the way different plant and tree communities change over time. For instance, early seral stage forests are characterized by plants and animals that thrive in sunlight, while late and climax seral stages may have a variety of species that depend on tall forest canopy for shade and shelter.
They might also look at successional stages. This approach focuses more on describing what the forest stand looks like and less on the communities they create. The stages range from grass-forb to pole-sapling all the way to older trees. (Did you know that “forb” is the term for non-grass plants like clover or sunflowers? Now you do!) By the time a forest stand reaches the mature stage, some trees will have died, some will be very large and distinguished, and others may be young or even saplings.
Another way to think about forests is the structural stage they’re in. When you see lots of grass and/or saplings, the forest is in the stand initiation structural stage. When the saplings are fully grown and start to crowd out other growth, the forest is in the stem exclusion structural stage. These stages can continue until they reach old forest.
We could keep going but it all comes down to this: In seral, successional, and structural stages, scientists consider whole populations, not individual trees. Go deep: Read more about different types of stages in this USDA white paper.
return - Management Regimes
The National Association of State Foresters (NASF) notes that “active forest management is central to the health, productivity, and resiliency of all forests.” When forest owners identify the best way to ensure long-term care and stewardship of our forest resources, they will develop a plan of action called a “management regime.”
Management regimes are the plans used to operationalize Sustainable Forest Management (SFM). These can include a variety of techniques to create healthy forests and mitigate risk from fire, insects, and disease. A silvicultural system is also often part of a management regime. It all fits together!
Explore more: NASF recently published a series of recommendations on management regimes that can improve forest resilience in light of climate change, which you can explore here.
return - What is even / uneven age management?
Forest owners make detailed plans for tending, harvesting, and reestablishing a stand of trees, which is called a silvicultural system. There are three main silvicultural age-class forest systems used in U.S. working forests. You can think of them (if you like) as different types of hairstyles.
Even-aged system: A management approach designed to create a single age class across a tree stand, which creates a single canopy. Trees will all be similar heights but may have different diameters. We’ll call this the flat top.
Two-aged system: An approach that creates two predominant age classes. Trees will mainly be two distinct heights, with different diameter trees and a multilayered canopy. This is without a doubt a mullet .
Uneven-aged system: In this system, trees will represent at least three distinct age classes and often many more, including old trees and new saplings. Picture a shag, the perennial favorite of musicians.
These distinctions are clear on paper. But in reality, there will be gradations and variations in each hairstyle every tree stand. Also, landscape scale is critical here. The variations in ownerships and management plans keeps the diversity of our forests – and the associated benefits from that diversity – strong.
If you’d like to learn more about even- and uneven-aged management click or tap here.
return - What does this mean for wildlife?
Different animals and insects don’t all appreciate the same habitat. Deer enjoy interspersed habitats that include a mix of forest, brushland, and open clearings. Gopher tortoises need sunlight-filled open canopy conditions to find food to eat. Turkeys like to roost in trees overnight, while chickadees require cavities like you usually find in dead or dying trees. For this reason, an important part of forest management is to create a variety of attractive habitats for different types of wildlife.
Sustainable forest management (SFM) creates a mosaic of interconnected, high-quality forest conditions for native plant and animal species, including those that are common, at-risk, threatened, and endangered. Thousands of species rely on private working forests for a wide variety of forest conditions, including young stands, open canopy pine stands, mature forest, and riparian areas protected using state approved water quality Best Management Practices (BMPs). SFM creates and maintains a full range of biodiversity benefits while keeping forests healthy and productive. On all land, forest managers take extra steps to ensure the welfare of endangered and protected species.
Want to learn more about SFM? The Society of American Foresters provides guidance on best SFM practices for wildlife here.
return - Why are there different age classes, BTW?
We’re missing an important starting point that’s easy to overlook but necessary: Why are there different age classes? Because trees are living, growing organisms. Different age classes are correlated with different tree diameters, how dense a forest might be, and what its ecosystem services look like.
In even-aged forests, most of the trees in a forest are the same age. This might happen when a forest is replanted with seedlings after a disturbance like harvest, a hurricane, or a fire. Uneven-aged indicates a forest where trees are a variety of ages, either because of natural regeneration (trees regrow on their own) or because of selective harvest and replanting.
Of course, age is relative! A fast-growing loblolly pine in the hot and sunny U.S. Southeast will reach maturity much faster than a slower-growing Douglas fir in the colder, more mountainous Pacific Northwest. Go deeper: This 2023 study in iScience provides a meta-analysis of tree age data reported in the International Tree Ring Data Bank that shows the wide array of tree ages found in North America and around the world.
return - What does “landscape scale” mean?
Landscape scale means “really big.” How big is the “landscape”? Opinions and literature vary; some people say it counts all land as far as the eye can see. Gutzwiller (2002) says a landscape can be thought of in relation to other levels in the hierarchy of a space: a landscape is larger than an ecosystem but smaller than a biome.
Why is landscape scale useful to consider? It shows how different types of land use interact with each other. Different land use decisions can lead to different outcomes for communities, agriculture, recreation, and of course forests.
Let’s say you’re in Loudoun County, Virginia, and looking out a window (this is about 15 miles west of Washington, DC). We’ll call all of Loudoun County your landscape. Depending on what window you’re looking from, you might see:
Nothing but a huge airport (IAD) or mile after mile of windowless data centers.
OR
Cute little antique shops and a quaint small town.
OR
Houses nearby, with bucolic farms a bit further off in the distance.
OR
Nothing but forest in any direction.
All of these are Loudoun County. All of your perceptions would be correct. But if you’re surrounded by data centers, you might be unaware that 32% of Loudon County is forested or that 39% of the county consists of farmland. Similarly, when you consider forests at a landscape scale, you’re considering forests in a variety of locations, some of which may be out of sight or may look different from what you see in front of you.
All these different land uses provide important functions, and by looking at them at a landscape scale, you can understand how they interact.
Here’s some extra credit, you eager beaver: Many land managers are now considering land conservation and management at a landscape scale. Trees, plants, water, and wildlife have very little (some would say zero) understanding of human-created boundaries, so it makes sense that there is an increasing focus on taking a holistic view. The Virginia Natural Landscape Assessment shows how data collection can identify specific landscapes that would benefit from a landscape scale approach. This assessment from Maine provides an introduction to landscape scale management and includes a variety of case studies and community considerations.
return - What do these age classes look like?
An age-class distribution describes the ages of trees in a specific part of a forest or across a landscape. This means age-classes will look different as they age.
But! Trees generally grow at different rates in different parts of the country, and different tree species will grow at different rates. Trees that grow close to each other tend to have narrower trunks and put out fewer branches, while a lone tree in a field is more likely to spread out more. Some regions will have more vigorous undergrowth, grasses, and forbs, while those might be sparse in other regions.
All of this is to say that you can make a guess of what a forest stand looks like based purely on its age-class, but you won’t know for sure without more details. According to the successional stage model as discussed by USDA, age-class stages include:
Grass-forb: Most vegetation is herbaceous (you know what a grass is, and now you know that a forb is a non-grasslike plant like clover!)
Shrub-seedling: Vegetation is a mix of…wait for it…shrubs and tree seedlings.
Pole-sapling: Trees are usually less than 40 years old and form a single canopy. Self-thinning hasn’t happened yet.
Young: These trees are usually less than 80 years old; self-thinning is beginning and we are starting to see understory vegetation.
Mature: We like to call this the “silverfox stage.” These trees are usually less than 140 years old; there is self-thinning and established vegetation in the understory, and these forests are known to cut loose on New Year’s Eve.
Old-growth: The forest has developed without disturbance (human, fire, telemarketers, etc.) for a long period of time. There are trees of all ages, including rotting and decaying trees and snags. Understory vegetation is well established.
As stands progress through these stages, you’ll see them go from a clearing to a single-canopy forest to a multi-strata young and then mature forest where a variety of tree heights, vegetation, and tree decay is present.
In a large forest, there may be stands of different age-classes next to each other, with a clearing next to a multi-strata forest next to a stand of saplings. These different landscapes create a variety of beneficial habitats for different types of wildlife.
return - Future projections based on USFS models
These projections are based on FIA data and were calculated by the team at NCASI, Inc., you can read more about the methodology here.
This future projection is not certain. These projections could be significantly affected by disturbances like wildfire and storms (which are exacerbated by climate change).
return - Is Sasquatch real?
What is reality anyway? Since you’re here… we will tell you that we (the National Alliance of Forest Owners) have been secretly photoshopping big foot/sasquatch/whatever you want to call them into everything we have published since about 2018. After you finish memorizing the content on this website, go look through all our content. We promise it will be more fun than your actual job… happy hunting!
return - What will forest age-classes look like over time?Forests look different as they age. Successional stages as discussed by USDA include grass forb, shrub-seedling, pole-sapling, young, mature, and old-growth. (For a deeper understanding of each successional stage, see this citation.)As stands progress through these stage, you’ll see them go from a clearing to a single-canopy forest and then mature forest where a variety of tree heights, vegetation, and tree decay is present.In a large forest, there may be stands of different age-classes next to each other, with a clearing next to a multi-strata forest next to a stand of saplings. These different landscapes create a variety of beneficial habitats for different types of wildlife.return
- Why are older trees emitters?
Some people believe that forests will continue sequestering carbon indefinitely if left alone. However, data shows this isn’t the case. As forests age, their carbon sequestration rates slow, and eventually, they can even become sources of carbon emissions. This happens due to natural disturbances, rot, and decay. Generally speaking, at a national level, once a forest passes the 100-year mark it can transition from absorbing carbon to releasing it.
Where it gets confusing is when folks mix up sequestration and storage. Older forests are certainly capable of storing the greatest amount of carbon. This, of course, makes sense, older trees are usually… big! Where we see a trend line showing sequestration slow and eventually flip into being sources of emissions also makes sense, because as trees age, their growth slows, and old forests decay.
This does not mean that older forests are not important. Of course they are! A diverse landscape of forests in different ages and conditions can provide diverse and balanced environmental benefits.
return - Sequestration vs. Storage
A lot of people mix up sequestration and storage, and even smart people use them interchangeably when they’re actually quite different – kind of like when moms call every gaming console a “Nintendo.” Don’t do that.
Sequestration is a natural, active process by which carbon is captured. A sequestration rate is an accounting for how much carbon was captured from the atmosphere over a specific period of time. Storage refers to how much carbon is stored at a specific point in time, like a snapshot. It’s always best to ask for clarification if forest carbon data is presented to you and sequestration/storage is unclear.
return - Tell me about clearcuts.
Clearcutting is a harvesting practice that removes most of the standing trees in a contained area within a larger forest at the same time. It can be jarring to see a clearcut area and people have strong opinions about the practice, but when done in line with sustainable forest management practices, clearcutting is the fastest way to help forests regrow and the safest way for work crews to harvest trees. It is an essential step in making sure our forests keep thriving on a continuous cycle of growing, harvesting and replanting.
Clearcutting is the least disruptive method of harvest in a large forest, as it limits trips in and out of the forest. Tree stumps and roots are left to stabilize the soil and prevents erosion, while dead trees, select live trees and logs are left for wildlife habitat. It is common practice in the U.S. and Canada for forest managers to carefully plan harvests to ensure the welfare of endangered and protected species.
Clearcutting also creates beneficial habitats for different types of wildlife, both common and at-risk, by mimicking the types of disturbances naturally created by hurricanes or wildfire.
See for yourself: Watch this forest in Oregon as it regrows after a best practice clearcut.
return - What is a rotation?
A rotation is the planned period of growth of a designated area of a forest before harvest. Rotations can vary in length, but the period of growth is typically decades long. It will vary depending on ecosystem, region, tree species, and the purpose of the rotation.
Regrowing the next rotation of trees as soon as possible after harvest is good business and good for the environment. Maintaining a continuous cycle of growth, harvest, and regrowth is a core tenet of sustainable forest management and ensures a diversity of forest ages important for wildlife, water quality, and carbon removal. Robust sustainability assurances like certification and state-approved best management practices (BMPs) require that forests are regrown after harvests.
return - What are management regimes?
The National Association of State Foresters (NASF) notes that “active forest management is central to the health, productivity, and resiliency of all forests.” When forest owners identify the best way to ensure long-term care and stewardship of our forest resources, they will develop a plan of action called a “management regime.”
Management regimes are the plans used to operationalize Sustainable Forest Management (SFM). These can include a variety of techniques to create healthy forests and mitigate risk from fire, insects, and disease. A silvicultural system is also often part of a management regime. It all fits together!
Explore more: NASF recently published a series of recommendations on management regimes that can improve forest resilience in light of climate change, which you can explore here.
return - What is NAFO?
The National Alliance of Forest Owners (NAFO) is a national advocacy organization committed to advancing federal policies that ensure our working forests provide clean air, clean water, wildlife habitat and jobs through sustainable practices and strong markets.
NAFO member companies own and manage more than 43 million acres of private working forests across the United States – forests that are managed to provide a steady supply of timber.
Also, the incredibly smart, good looking, talented, and humble communications team at NAFO created this website.
return - What is Climate-Smart Forestry?
What is Climate-Smart Forestry? How do you solve a problem like Maria? How do you catch a cloud and pin it down? These are difficult questions.
Climate-Smart Forestry (CSF) is a dynamic and adaptable approach within sustainable forest management that optimizes climate adaptation and mitigation outcomes. Sustainable forest management (SFM) can maximize a forest’s ability to sequester (capture from the atmosphere) and store carbon, mitigate the risk of severe wildfire, and adapt to a changing climate.
CSF is guided by science and can adapt to different regions, forest types, and conditions. There are multiple ways to achieve climate-smart outcomes and a one-size-fits-all approach won’t work for every forest in every part of the country.
CSF is something builders and architects ask about. If they’re building a beautiful new office building out of mass timber, for instance, they might need to meet the specific climate or sustainability goals set by their clients.
As stated by the Intergovernmental Panel on Climate Change, “In the long term, a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks, while producing an annual sustained yield of timber, fiber, or energy from the forest, will generate the largest sustained mitigation benefit.”
The Sustainable Forestry Initiative (SFI) and Forest Stewardship Council (FSC) have recently included climate outcomes in their certification standards. SFI’s 2022 standard includes a CSF component. FSC’s new National Forest Stewardship Standard, still undergoing final approval, would incorporate climate outcomes in several spaces where they did not appear before.
Go deeper: We capture numerous resources, definitions, and FAQs at ClimateSmartForests.org.
return - Harvested wood products store carbon
The carbon storage pool data is from table 6-12 in the Inventory of U.S. Greenhouse Gas Emissions and Sinks. Table 6-12 lists the total weight of carbon (MMT C) stored in harvested wood products (solid wood products + solid waste disposal sites).
The weight of carbon (MMT C) shown in table 6-12 for 2018 is converted to MMT CO2e by multiplying the weight of carbon by 3.67.
How do we know about wood products carbon storage?
Estimates of carbon storage in harvested wood products (HWP) depend on how much of the wood is used in what types of products: those stored for long periods of time (e.g., construction lumber), or those stored for short periods of time (e.g., packaging). The size of the HWP carbon pool depends on historical rates of home building, the average lifespan of those homes (which changes over time), the amounts of wood using in typical construction, the rates of recycling of wood and paper products, the disposition of products after their useful lifespan (e.g., burned, mulched, landfilled, dumped), the characteristics of landfills in the region (whether they are capped to prevent emissions, whether any methane is burned or released to the atmosphere, etc.). For HWP carbon stocks, we used estimates derived by the U.S. Forest Service for EPA’s annual inventory of greenhouse gases.
return - Annual Harvested Product Net Change
This figure represents the carbon stored within newly created wood products, minus the wood products that have decayed and released their carbon back into the atmosphere. Yes… it is a little hard to wrap your head around.
The EPA and USFS work together to calculate different rates of decay or a “half-life” for various wood products categories. Think of it this way, a paper bag from McDonalds will biodegrade faster than the lumber in a house, or your grandmother’s kitchen table. Using those calculations, we can determine how much carbon has been released back into the atmosphere and subtract that from the carbon found in new products.
Obviously, a 2×4 is not going to continue growing, but this concept is analogous to sequestration – its the amount the carbon storage pool is growing each year – all the emissions.
For more information about how wood products carbon is computed in this dataviz, check out our Methodology Explainer.
return - Wood Product Sink vs. National Parks
Wood products store more than double the carbon stored in all national parks.
National Parks store 3,465 MMT of CO2e (See Table 4, showing National Parks C stocks as 945 MMT C, which is 3,465 MMT CO2e)
Wood products store 10,010.0 MMT of CO2e. The carbon storage pool data is from table 6-12 in the Inventory of U.S. Greenhouse Gas Emissions and Sinks.
return - How is climate change impacting forests today?
Climate change is already impacting forests in several ways. First, climate change is increasing the frequency and severity of disturbances like wildfires, drought, floods, hurricanes, insects, and disease. Climate change takes a toll on forest health, making forests more vulnerable to disturbances and disasters.
Climate change is also affecting the mix of species that can flourish in specific regions. Some species are migrating northward as temperatures get warmer. Species that currently flourish in New York might start doing better in Maine or Nova Scotia, for instance.
Carbon storage in forests may be decreasing as the earth warms, as well. Trees in some regions are growing more slowly, in part due to less precipitation. This means they are sequestering and storing less carbon than forests in the same place did in prior years.
Drought, insects, and disease have killed millions of trees in the intermountain West, primarily on federal land, with some reports indicating there are more than 6 billion standing dead trees in the 11 Western states. In some states, the high rates of tree mortality on federal land will continue to fuel severe wildfires and erode the many climate benefits healthy forests provide. In fact, a 2024 Forest Service report noted that wildfire, exacerbated by climate change, presents the most urgent threat to forests.
More active forest management and efforts to mitigate wildfire, insects and disease can help slow these negative effects of climate change. Active management to improve forest health and resilience is imperative as the climate changes. Given how far out of balance some of these forest ecosystems are today, it is anticipated that conditions in some regions will continue to deteriorate before they start to improve, even with intervention.
Go deeper: Visit the EPA’s portal on the impacts of climate change on forestry and actions forest owners can take.
return - What is the ideal rotation length?
This is the million dollar question! No, really. Paul Samuelson wrote a famous paper on this question back in 1976. If his name sounds familiar, he is the first American to win the Nobel Prize in Economics and his survey economics textbooks have tortured educated generations of college students, possibly including you.
Anyway. There are a variety of factors to consider when determining the ideal forest rotation length. The length of time will largely depend on the region and species – it could be as low as 15 years for loblolly pines in the Southeast and much, much longer in the Northeast. Forest managers also consider a variety of additional factors including forest health, ecosystem services, region, and other sustainable forest management issues as they determine the desired rotation length for a specific part of the forest.
Go deeper: Literature reviews of scientific articles have found hundreds of recommended approaches, which are increasingly including considerations about optimizing carbon sequestration and storage (see Climate-Smart Forestry, above).
return - What’s the deal with the three regions?
Forests vary dramatically between regions of the U.S. in terms of tree species, growth rates, ownership, and management techniques. For these reasons, the U.S. Forest Service FIA program administers the program in a regional structure (see their listing of states by region). For this data visualization, we summarized state-level data by regions of the country relevant to the distribution and management of forests.
The Southern region includes fast-growing forests of pine and hardwood and is predominantly (86%) owned by private landowners. Active markets for timber products mean that forest management is practiced on much of the private lands in this region.
The Northern region is dominated by hardwoods, with generally slower growth due to climate; 72% of northern forests are privately owned. This data visualization combines the Rocky Mountain and Pacific Northwest USFS regions into a single Western region.
Most National Alliance of Forest Owners land in this region is in the Pacific Coast states, where growth may be very fast and species like Douglas-fir and western hemlock can continue growing to older ages than in the South. Forests in the West are largely publicly owned (70%). Markets for timber are sparse in the Rocky Mountain region, so harvesting is, by comparison, rare and mortality through drought, insects, and fire is widespread.
For all these reasons, it is challenging to get a complete view of the carbon dynamics of U.S. forests using nationwide averages. Critical portions of the carbon picture (like harvest, mortality, natural disturbances, forest ownership and management) show important differences between regions, so we have elected to show some of those differences by summarizing regionally.
return - What are the three rotation lengths being depicted here?
Even though rotation lengths vary depending on species and geography, it’s possible to make some generalizations.
Fastest
In the Southeast, the weather’s warm, the soil is fertile, the tea is sweet, and the types of trees there grow fast. Softwood pines (loblolly, longleaf, etc.) are the tree species typically grown here, and rotations are usually 15-35 years.
Intermediate
The Northwest and intermountain West has slower growing trees because of the colder weather, poorer soils, and higher elevations. Trees like Douglas fir thrive in this kind of climate. A typical rotation age might be 45-65 years.
Slower
In the Northeast and Great Lakes states, hardwoods like oak and maple are more frequently grown for harvest than in other regions. Hardwoods grow more slowly than pines, so often harvests will take place when trees are 65-85+ years old.
return - What are natural disturbances?
Disturbances are events or factors that harm the vigor of forests, often by killing a significant portion of the trees in a forest. Disturbances can include wildfire, hurricanes, floods, avalanches, mudslides – basically, they read like a list of the ways Wile E. Coyote got got by Roadrunner. Major disturbances impacting forests (rather than cartoon critters) include:
Wildfire – Wildfire occurs naturally and provides benefits including clearing underbrush, improving soil quality, and creating openings in forest canopy. However, climate change and decades of fire suppression have created conditions for a higher frequency of larger, hotter, and more intense fires. Danger to humans has also increased as there are more people than ever living near the wildland-urban interface. Sustainable forest management (SFM) can help reduce the risk of fire, and can also help re-establish a forest after a fire. Go deeper: National Interagency Fire Center
Insects and disease – Native species like the southern pine beetle and invasive species like the emerald ash borer are threatening tree species across the U.S. Climate change can increase the threat of these insects and pathogens as their range increases or as tree species become less resilient. The U.S. Forest Service provides a wealth of resources on the topic, including specific in-depth pages on invasive and native insects and pathogens.
Hurricanes – The winds and sustained flooding from hurricanes can cause serious damage to forests. In particular, flooding that lasts more than a day or two can smother a tree by preventing oxygen from reaching its roots. For an explainer on hurricanes’ impact on forests, visit this explainer from North Carolina State University.
Ice Storms – Beautiful and weird, ice storms can have lasting effects on forests. They open up canopies and kill more dominant species to allow other species to quite literally have their moment in the sun. Yet they also kill or damage a lot of trees, and can make forests less resilient—especially when the forests are exposed to multiple ice storms. Researchers at Hubbard Brook Ecosystem Study wanted to understand the impact of ice storms, so they actually created their own as part of the Ice Storm Experiment.
Just like one could argue that disasters actually brought Wile E. Coyote and Roadrunner closer together, so too are disturbances an essential part of the forest ecosystem. Disturbances create openings in the forest valued by a variety of wildlife. Different animals and insects don’t all appreciate the same habitat. Deer enjoy interspersed habitats that include a mix of forest, brushland, and open clearings. Turkeys like to roost in trees overnight, while chickadees require cavities like you usually find in dead or dying trees.
Climate change is amplifying the frequency and severity of many types of disturbances. Drought, insects, and disease have killed millions of trees in the intermountain West, primarily on federal land, with some reports indicating there are more than 6 billion standing dead trees in the 11 Western states. In some states, the high rates of tree mortality on federal land will continue to fuel severe wildfires and erode the many climate benefits healthy forests provide.
return - What is forest certification?
Everyone wants to do the right thing. People often want to make sure that the forest products they use come from sustainably managed forests – which is a good thing. Sustainability assurances in the U.S. include a mosaic of overlapping and mutually reinforcing local, state, and federal environmental laws and regulations, state-approved forestry best management practices (BMPs), and third-party forest certification programs.
Forest management certification programs provide assurance that a forest is managed sustainably through independent third-party audits, extensive record keeping, public disclosures, and on-the-ground evidence. Auditors review both active and completed operations or harvests, interview employees and contractors, and inspect the integrity of water quality BMPs and other measures to conserve wildlife habitat, biodiversity, and soil health. On-the-ground verifications of sustainable forestry practices ensure the long-term health, vitality, and resilience of forests across the landscape.
Some forest owners certify their forests through more than one certification program to satisfy consumer and investor needs. On the other hand, some working forests are managed sustainably without securing third party certification, oftentimes because cost, complexity, and other factors are barriers for smaller landowners.
Go deeper: Common certification programs in the U.S. include the Sustainable Forestry Initiative, the Forest Stewardship Council, and the American Tree Farm System.
Wood fiber sourcing certification and other due diligence and risk assurance systems are used by suppliers and manufacturers to reduce the risk of irresponsible sources entering the supply chain. Examples are the SFI Fiber Sourcing Standard and the FSC Controlled Wood Standard.
Chain of custody requires the tracking of certified, recycled, and uncertified fiber as it moves through the supply chain so that manufacturers can credibly make certified content claims about their products. Both SFI and FSC have robust chain of custody programs.
return - National age-class distribution is just to explain the concept – to really get the picture, you have to look at the region.
When you look at the national age-class distribution, it gives the impression that all the older age-classes live together in a senior community at The Villages while the cool younger trees are partying in Coachella Valley.
In reality, of course, age-classes are distributed with much more variety around the country. This means that you really need to understand a region to get a better sense of what the age-class distribution looks like. Each region will have its own species mix and growth rates based on climate and ecosystem. At the same time, human impact on the country has imprinted on forests, too: Were forests converted to farmlands when the colonists came and then converted back to forest? Is the region home to many national or state parks and forests? Are there cities, towns, and farmland breaking up the forested landscape? All of these factors will impact the age-class distribution of a region.
Go deeper: For a look back at centuries of human impact on U.S. forests, check out this publication from the U.S. Forest Service.
return - Per-acre averages of carbon sequestration – are they accurate at a national scale?
Nope! One of the beautiful things about our country is the varied geography and ecosystems, from scrubby woodlands in Texas to cypress swamps in Florida to hardwood- and spruce-covered mountains in the Northeast.
All these locations will have dramatically different carbon storage and sequestration capabilities, making the math challenging. Beyond challenging, it’s not really that informative. What does the average really even mean if you’re averaging carbon storage and sequestration of a stand of California sequoias with aspen trees in Wyoming? Does the average equal out to some tumbleweed in Utah somewhere?
Instead, what the Forest Service prefers to do is present data according to region, forest type and predominant species, age-class, etc. This level of specificity produces tables such as “Regional estimates of timber volume and carbon stocks for maple-beech-birch stands with afforestation of land in the Northern Lake States.” The end result is a much more specific answer that tells a more useful story.
return - Carbon Benefits
There is no one-size-fits all “best” forest. Whenever you see claims that all our forests should be working forests, or all our forests should be unmanaged and preserved… just know the answer is complicated and somewhere in the middle.
The graph below shows a simplified and more traditional presentation of some of the data we’ve just visualized on this website. It shows total storage per age class in the bar chart coupled with annual sequestration rates per acre in each age class as a line graph.
return - Are working forests monocultures?
Many working forests are planted with a single native tree species for harvest, with the species varying by location and need. A single-species dominated overstory is often used, and it is intentional. The bottom line is some forests work so others don’t have to. The intentional and intensive management of planted forests, often seen as monocultures, are a critical part of sustainable forest management. In highly developed forest economies, like the U.S., these planted forests relieve economic pressure on natural or wilderness areas. The World Wildlife Fund recognizes the importance of plantation forestry in this report.
To clarify and address some common misconceptions:
- Note that we are NOT talking about palm oil plantations – that is not a thing in the United States. We are talking about planted forests consisting of native, non-GMO trees.
- Converting old growth stands to pine plantations, sometimes called forest degradation, is not a part of modern forestry.
- A monoculture in U.S. forests won’t look like a farmer’s crop. It will never look like a field of corn… where there is only corn. There is often great diversity below the overstory, and best management practices, like streamside management zones, ensure that there are usually more species diversity in adjacent stands.
Go deeper: The Society of American Foresters lays out its approach to managing forests for biodiversity here.
return - Where do animals go when you make a harvest?
Forests in the U.S. are home to countless critters. Actually, this one study tried to count them and found over 2,000 vertebrate and invertebrate species including 459 birds, 233 mammals, 226 reptiles, 216 amphibians, and 60 freshwater fish. And those are just the ones you can see with your eyeballs. There are even more insects and microbial critters not considered in that study.
A key tenet of sustainable forest management (SFM) is to responsibly steward forests—and their wildlife. This involves implementing state-approved Best Management Practices (BMPs) to ensure harvests are done responsibly to safeguard Bambi and his friends, meaning planning harvests around specific nesting seasons and using streamside management zones (SMZs) to keep water fresh and clear. On all land, forest managers take extra steps to ensure the welfare of endangered and protected species. Forest managers also constantly improve and adapt their management to better conserve species and the habitat they depend on. When they do learn how to better support a species they also share it. Here is one great example.
Crucially, different animals and insects need different habitats and conditions. Deer like Bambi enjoy interspersed habitats that include a mix of forest, brushland, and open clearings. Turkeys like to roost in trees overnight, while chickadees require cavities like you usually find in dead or dying trees. So an important part of forest management is to create a mosaic of attractive habitats for different types of wildlife.
Zoom out: The biggest threat to wildlife, according to the Society of American Foresters, is forest conversion to other land uses. Meanwhile, a recently released Forest Service report noted that wildfire, exacerbated by climate change, presents the most urgent threat to forests.
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