Regenerative agriculture is a set of farming practices that increase biodiversity in soil organic matter.
Currently, most agricultural practices are devastating to biodiversity. Even organic agriculture, while not as bad, still does more harm than good. Regenerative agriculture is a way to reverse this trend, to actually make a positive impact on the land.
So what does regenerative agriculture actually involve?
Answering this question is actually pretty tricky, because the practices that work best largely depend on the land that’s being worked with, so the variety of different practices border on infinity, a bit more than this video can cover.
However, let’s look at three common forms that regenerative agriculture can take:
No-Till Farming
The soil is full of organisms which are helpful for plants. Some convert soil nitrogen into a plant-usable form. Some bring water to the plants that would otherwise be out of reach. Others loosen and aerate the soil, increasing water absorption and allowing plant roots to penetrate deeper.
When soil is turned over by a machine, most of these organisms are killed, so the crops must rely on chemical fertilizer which ends up leaching into the water. Central to no-till farming is to NOT DO THAT.
Instead of tilling, plant cover crops whose roots break up the soil. Let the worms aerate the soil and bring down nutrients. Keep the soil covered with an organic mulch which will break down over time, adding more organic matter to the soil.
Regenerative Grazing
From the release of methane, to clearing forests for pasture land, cattle raising is known for being very environmentally destructive. But this is not inherent to grazing animals!
If the right practices are put into place, enormous amounts of carbon can be sequestered into the ground, soil can be built, and even desertification can be reversed in a matter of years. Here’s how it works:
The growth of grass tends to start slow, accelerate, and slow down again. This middle area is where it accrues the most biomass the most efficiently. If it’s eaten before it gets to this point, its growth will never speed up.
This is what happens with traditional pastured animals: They eat all the grass, which doesn’t have the chance to grow back fast enough before getting eaten again, and we have overgrazing. This leads to soil erosion, drought, and desertification.
But if the animals are kept in a tightly packed herd, like they used to be in nature, the grass has time to grow before being eaten. All that biomass in the grass is carbon that comes from the air. Not all the grass gets eaten, however. Some of it gets pooped on and trampled, which ends up creating the perfect conditions for new topsoil to be built. This ends up happening incredibly quickly.
Agro-Forestry
This is one of the most complex and location-dependent practices there are. I will therefore be over-generalizing.
It always starts with observing a local forest and the relationships between everything in it–the plants, the animals, the fungi, the landscape, the soil, the water–and then re-creating these relationships in a way that’s just as ecologically resilient, but produces more food.
Food forests are often thought of as comprising seven layers: The root layer, the ground cover layer, the herb layer, the shrub layer, the low tree layer, the high tree layer, and the vine layer. Every one of these layers either produces some sort of food or medicine, or is in some way helpful to the system as a whole. The plants are mostly perennials, and include as many native species as possible.
Conclusion
These three examples of regenerative agriculture, plus all the rest of them, all have something in common: whereas in conventional agriculture you seek to create as many of one thing as possible, in regenerative agriculture you seek to create as many relationships between things as possible. You are one of those things! What sort of relationship with the land do YOU want to foster?
For a garden that supports birds, wildlife, and the food web, choose plants that are native to your area. Science has shown us that these can support more life than ornamental species from other regions.
What are native plants?
Native plants are those which naturally occur in a region. The opposite of a native plant is one from a different part of the world. Many people garden with species that are ornamental, rather than using natives.
Why are native plants important?
Many people wonder why native plants are better for the environment. All kinds of plants can produce oxygen. And many are attractive to pollinators. So what makes natives so important?
This native plants garden supports pollinators in middle Tennessee
The answer has to do with ecology. Native birds, wildlife, butterflies, and bees rely on your garden. And preserving these native animals requires gardening with plants that match their needs. Gardening with ornamental plants from other parts of the world can provide some food for local wildlife. But natives can support the most forms of life.
Check out local forests for an idea of what plants are native to your area
You can also check with your state or local university extension office to connect with other gardeners. Join local garden groups and explore opportunities for education related to sustainable gardening.
Where can I get native plants?
If you’re ready to add natives to your garden, shop at a nursery that specializes in native plants. You can also shop online nurseries that serve your area. Choose natives has a list of nurseries that do mail-order as well.
Other sources
Your soil probably contains seeds from many native species. If you’re adventurous and can learn to identify seedlings, try letting a section of your lawn grow out. Chances are, many of the naturally occurring sprouts will be natives.
Another way to acquire natives is to grow them from seeds. You can collect seeds in the spring and fall from areas around your home. And your local library or university extension office may host a seed-exchange program.
Choosing the right plants for the right place
You’ll need to consider factors like light levels, wet and dry areas, and the pH of your soil when choosing what species of plants to buy. If you need help, unlawn experts can create a plan for you.
Biodiversity supports our food systems, clean air, and clean water. Local biodiversity is key to protecting these resources in your community. Communities with plentiful and diverse natural areas enjoy a higher quality of life and a healthier environment.
What is local biodiversity
Local biodiversity is a measure of different types of life in an area. Ecosystems like rainforests are known for having very high levels of biodiversity. And deserts tend to have fewer species overall. However, within a desert ecosystem, biodiversity is higher in areas that are undisturbed or contain additional resources. And in the rainforest, areas closer to towns and roads will be less biologically diverse than average.
Species richness
Measuring biodiversity is difficult, because it includes plants, animals, fungi, bacteria, and all the kingdoms of life. To measure biodiversity, scientists use species richness. Species richness is the number of species that are found in an area. Scientists make a list of all the species that have been observed in the study area and count them.
Comparing species richness across ecosystem types doesn’t account for differences in resources. So, scientists will sometimes use a biodiversity index that can be applied across ecosystems.
Examples of local biodiversity
In different parts of the globe, biodiversity looks different. In the deep south, longleaf pine savannas are home to species that can only live in the sandy, sunny forests, like the gopher tortoise.
The Appalachian Mountains have numerous cold mountain streams that provide habitat for trout and hellbenders.
An eastern hellbender. Photo by: Ryan Wolfe/Flickr
Along the West Coast, redwood forests contain rare birds like the marbled murrelet.
What are the benefits of local and global biodiversity
Global biodiversity is important because many species play a role in natural processes that benefit humans. From clean air and water to the productivity of soil for agriculture, we rely on biological systems to support life on our planet – life that includes us!
Water is filtered by vegetation in forests. Photo by Kavindu Kaushalya on Pexels.com
When a species goes extinct, its role in the ecosystem is sometimes left empty. In some cases, another species can step in to do the same role, but not in the same way.
As the number of species on Earth drops each year, how much longer can the globe support life? Ecological systems and processes are threatened by every extinction.
Why is biodiversity important?
Biological diversity allows species to work together to increase the productivity of an area. In nature, competition and cooperation are the defining forces. Greater biological diversity increases the opportunities for both competition among similar species and cooperation between species that play different roles.
Apex predators, like wolves, play an invaluable role in ecosystem health. Photo by Natalia García Prieto on Pexels.com
Greater cultural diversity can make a city more lively and productive. Similarly, greater biological diversity helps to maximize the productivity in an area. This productivity is measured in the form of ecosystem services.
Ecosystem services include things like food, clean water, clean air, flood prevention, recreation opportunities, and resistance to extreme weather events. One of the clearest examples of ecosystem services is the pollination of farm crops by native bees, butterflies, and other pollinators.
How to protect biodiversity
Unfortunately, Earth has now entered it’s 6th mass extinction event. Meaning we are losing species faster than at any other time in recorded history. Global biodiversity outlook analyses show a major decline. So, how can we protect biodiversity? Conservation groups and events like the convention on biological diversity are working to do just that.
University research findings on the subject show us that traditional knowledge and local communities can inform a multinational strategic plan. As we search for ways to improve the global biodiversity outlook, science and data are the key to a sustainable future.
Why does biodiversity need to be protected?
Species extinctions are happening at an unprecedented rate due to human activity. In many places, local biodiversity trends are not great. And in some of the most biologically diverse ecosystems, like the Amazon Rainforest, human activity is destroying the remaining habitat that species depend on. Species have fewer places to live because land is developed or converted to agricultural uses, like pasture.
In many countries, indigenous peoples are fighting to protect both biological diversity and their way of life. Colonialist attitudes and markets change the use and extraction of biological resources. Competing interests, especially in the Global South, have led to a decrease in cultural diversity and biodiversity change. In addition to species loss, globalization has also introduced non native species. Many local communities are losing traditional knowledge while the sudden biodiversity change makes sustainability more difficult than ever.
According to time series data, the implications of biodiversity change are frightening. The global biodiversity outlook is not good. And the research indicates that as the abundance of species declines, so will the productivity of nature.
What does local biodiversity depend on?
The path forward is clear. To protect global biodiversity, ambitious conservation efforts are needed. Renowned conservationist E.O. Wilson proposed protecting at least half of the planet in his groundbreaking book, Half Earth. And the Aichi targets propose a similar, though less ambitious effort along with economic and political contributions into the future.
What is a protected area?
The definition of a protected areas varies by location. Protection can mean the designation of parks and forests, or the use of specific tools like conservation easements. Ultimately, the right kind of protection is up to local communities. Spatial comparisons show that the local biodiversity outlooks improve in protected areas.
Biological diversity is high in most protected areas. Photo by Lukas Kloeppel on Pexels.com
How to boost biological diversity
Protection is not always a viable strategy, because biodiversity may already be degraded on a site, especially in the Global North. Many areas need restoration efforts. University and NGO research has shown a positive response in species richness following restoration efforts.
Creating natural habitat at home
Native ecology is the key to making progress in protecting local biodiversity. Many government agencies and NGOs hope to meet goals like the aichi targets creating a strategic plan. But individual landowners are able to treat their property like protected areas today. Local communities and indigenous peoples are connected to the land. And these groups have a vested interest in protecting nature. Ethical stewardship of the land can provide contributions that go beyond political and economic forces.
Rewilding can have a greater impact on local biodiversity depending on the existing level of development. Rewilding is a way to bring nature into local communities and cities where it has been removed. Establishment of small pockets of nature is simple and cheap. Landowners should plant native plants on their land. Native plants evolved to be perfectly adapted to support the existing local biological diversity.
Native plants supporting biodiversity as home landscaping
Parks and protected areas
Much of the history of conservation in North America has been reactionary. The science surrounding species loss is mostly reactionary as well. In the United States, parks account for most public interest in conservation. Every state has a department of parks that provide protection for these recreation areas. Many states also have forestry, wildlife, and environmental agencies.
There seems to be a mismatch between the local demand for natural areas and their abundance. Most recreational natural spaces are in remote, rugged terrain. The accessibility of nature for the average American seems to be far below what is needed.
And any public recreation site that is easy to access for a large populated area tends to be overcrowded. As development increases in the future, access to additional recreational areas is desperately needed. Governments will struggle to acquire and manage additional land. Private landowners need access to resources that help them to protect and manage their land. And not just for recreational opportunities, but also to protect the ecological resources on private land.
Local biodiversity progress
Efforts by conservation groups and government agencies have sometimes been successful at saving individual species from extinction. But the implications of climate change on biological systems have not been tested. And we’ve been unable to slow down the Anthropocene extinction event.
We can’t predict the future. Additional time series data and summary analysis will help science to understand the potential futures of our environment. It has been difficult to predict the effects of climate change, but so far they have been very concerning.
Save local biodiversity now
We cannot wait for definitive science before we act to save our planet. Nor can we hope for a technological answer. Conservation of our remaining biological resources is critical, and restoration can boost depleted local biodiversity. Protected areas need additional funding and support, and every lawn is a potential restoration site.
The average homeowner has opportunities to boost their lawn’s biological value. And individuals can contribute to citizen science efforts to improve landscape-scale analyses by their state or local university. But the cultural pressure for development is immense.
We need to change
Housing, shopping, roads, farms, and warehouses are all in high demand in many places. Our priorities need to change. Market forces cannot continue to control how our land is used. Business as usual is no longer leading us toward progress, but rather toward a global ecological collapse. Nature must be front and center in our communities.
Indigenous peoples have largely been ignored in the conservation and restoration communities. And while many efforts are starting to seek contributions from local communities, both local conservation groups and the global community should look to indigenous peoples in their search for ways to live sustainably.
How to take the wet spot in your lawn from a muddy mess to a healthy habitat. Eliminate wet grass by embracing a different use for your soggy spots.
The wet grass headache
Mowing wet grass is a pain. And it’s bad for your grass and lawnmower. You’re more likely to stain your clothes and shoes when you mow wet grass. And it’s even worse if your grass is long overdue for a trim but it just keeps raining! Why do so many of us put up with the hassle of cutting wet grass? It seems like there’s no other option. But there is. Get rid of that section of grass! It’s easier than you think and it will look good. Plus, it can do some good for the Earth.
Grass grows in a wet field. Photo by Eva Elijas on Pexels.com
Replacements for grass in wet areas
If you want to keep that lawn appearance, or if HOA rules require you to keep the appearance of your lawn consistent(ly boring), then consider replacing the wet part of your lawn with a no-mow alternative. Grass alternatives let you continue to use your lawn in dry times and reduce the amount you need to mow.
Habitat types for wet areas
If you’re going to get rid of your wet grass for good, consider replacing it with something that will benefit wildlife and local ecology. By swapping your wet grass for wet habitat, you’ll turn your problem into a source of beauty.
Pollinator habitat
This wet grass replacement allows native bees and butterflies to take refuge in your lawn. You can create a mini-meadow or a pocket prairie to support a diverse array of native pollinators that are facing habitat loss and population decline.
Converting your wet lawn to a pollinator habitat can be as simple as planting some bunches of Joe-pye weed, swamp milkweed, and bee balm. Plant your native plants together in groups a few feet apart. For less weeding, spread some cardboard or newspaper in between bunches, and cover it with mulch.
Rain garden
If your lawn gets wet enough to turn into a muddy mess, consider adding a rain garden. Adding a depression to collect water can help to mitigate flooding during wet seasons. And a water source on your property can support local bird and pollinator populations.
A rain garden is a little more involved than a simple pollinator habitat. It involves some digging, which means you should call 811 before you dig. Rain gardens can be enhanced if shrubs or small trees, like witch-hazel, are planted on the banks. Use the pollinator plants from above for a bonus ecological benefit.
Forested wetland
If your wet spot stays wet for most of the year, it can support some unique and beautiful tree species. Cypress, black willow, and river birch only grow in the wettest spots. These trees act as a filtration system for groundwater, which benefits wildlife and your community. Plus, they all have medicinal uses.
Red cedars grow in a wet area with rivercane
Planting a grove of trees is the easiest option on this list, but can take up a weekend day or two. And trees can be expensive. But if you can get your hands on enough of these trees, you can plant them 8 to 12 feet apart. In between, add shrubs and native pollinator plants.
Say goodbye to clumping, staining, and squelching
If you’re ready to be done mowing wet grass forever, make a plan to unlawn that spot. Wet spots in your lawn are hard to use and a pain to maintain. Instead, switch to a lower-maintenance option that benefits nature locally. Unlawning is easy, cheap, and attractive!
Deforestation is one of the primary global threats to biodiversity. Forests improve our air and water quality, and support diverse ecosystems. But growing a forest requires more than just planting trees. To grow forest like a pro, you’ll need to think like a forester.
Steps to grow a forest
During my time as a professional forester, I would grow hundreds of acres of new forest each year. But even if you only have half an acre, following these steps will ensure you end up with a healthy mature forest on your property.
1. Site-preparation
One of the biggest mistakes you can make when creating a forest is to just start planting trees. This can lead to damage to the trees and other common mistakes like over-mulching and root compaction. But it’s easy to avoid this mistake by considering what your trees need to grow.
Trees grow if they get a combination of sunlight, water, nutrients, and air. That’s all. Air is probably not going to be a limiting factor for your trees, so let’s talk about the other three: sunlight, water, and nutrients. Sunlight comes from above. But plants get water and nutrients from below, in the soil.
So, competition above (older trees) will restrict a tree’s access to sunlight. And competition below (smaller plants and younger trees) will restrict access to water and nutrients.
Set your forest up for success
Site-prep is the method foresters use to increase access sunlight, water, and nutrients just before planting trees. Unfortunately, in the world of commercial forestry this often involves spraying herbicides and plowing soil. Burning debris or existing vegetation is also considered a site-prep technique, and is appropriate in some cases.
Site-prep is an issue of scale. If you are planting a few individual trees for a mini-forest, you can site prep by hand in the area immediately surrounding them. But, if you want to convert a 10-acre field to a forest, you might need a tractor.
It’s important to use the right site-prep technique for your project to avoid unnecessary damage to the environment. Common forestry site-prep techniques include:
Chemical herbicide use
Broadcast or debris burning
Raking and piling
Plowing or bedding
Disking/harrowing
Chopping
Some of these techniques only affect vegetation, while others move around debris or the soil. For converting grass, surface-level tilling to break up the grass root-mat is a good technique. If the area is small enough, covering the tilled soil with newspaper or cardboard can prevent erosion and keep weeds down.
How to pick the right site prep technique
Answering a few questions can help you figure out what kind of site prep to use.
Is there debris on the site that will make it hard to plant trees? If so, you will need to either clear it away or speed up the decomposition process by burning it. You don’t need to clear all of it, though, because your trees will need some space between them. We’ll revisit this idea in the planting step.
Is there woody competition? For seedlings of most tree species, dense woody vegetation is a major problem. You will need to kill or clear away some of the existing vegetation to create space for your trees. The more competition you kill, the more sunlight, water, and nutrients are available for your trees. But it comes with a financial cost and environmental impact.
Are there nonnative invasive plants on the site? This is when chemical herbicide can start to look like a good idea for some sites. Nonnative invasive plants can do irreparable harm to a forest if left unchecked.
Some other considerations that will impact your choice of site prep technique include
cost
timing
need for future actions (e.g. burning more than once may be needed)
equipment and labor availability
a need to manipulate the water table (this is only common along the coast)
a need to break through a rock or hard-pan layer
The best site-prep technique for mini-forests and lawns
If you’re growing a mini-forest or converting your lawn to a forest, this is the best site-prep technique. Use this technique at least 3 weeks up to 3 months before planting.
Till the top 2 inches of soil using a roto-tiller or farm tractor to disturb the grass’s root-mat across your planting area
Cover the exposed soil with cardboard, newspaper, or another biodegradable material
Wet thoroughly
Optional: add mulch or topsoil to hold everything down
2. Planting
Planting trees is a crucial step in establishing your forest, for obvious reasons. But, some forest regeneration can happen naturally if nearby trees drop fruit and nuts into the area. Planting offers a few advantages over natural regeneration, such as:
control over tree spacing (to manage competition and get even coverage)
control over genetic stock
a head start after site-prep
Natural regeneration is made more difficult due to the prevalence of nonnative invasive species today. And even strictly managed forests are prone to invasive plants, except in the most remote locations.
Logistics
Planting is, like site-prep, an issue of scale. If you are planting 10 or 20 acres, it is doable by hand or with a tractor. If you are planting 200 or 1,000 acres, you will need professional help that can be expensive and hard to find.
Planting seedlings can be time-consuming and expensive. Photo by Lara Jameson on Pexels.com
Different species of trees are planted with different spacing and techniques. And site conditions can also dictate which technique is appropriate. But the most important factor for choosing a planting technique is definitely the cost.
Planting trees is expensive! Hand planting pine trees will cost at least $50 per acre (with higher costs for smaller jobs), if you can even find anyone to do the difficult labor. Planting machines can be used on some sites for improved survival and more accurate spacing. But they are more expensive.
If you want to plant the trees yourself to save money, expect to cover less than an acre per day until you get the hang of it. You’ll need a tool like a dibble bar or a hoedad (or just a shovel) to open and close your planting holes. Tree roots need to be kept wet or they’ll die off, killing the tree.
If you don’t have the budget to pay for planting over your whole project area and can’t do it yourself, you might want to consider natural regeneration. You can always supplement with a few older seedlings, especially if you aren’t trying to grow timber.
How to make natural regeneration work
To grow a forest while planting no (or just a few) trees, you need two things to happen. One is a seed source. Often a nearby forest can drop or blow in seeds, and sometimes seeds can remain dormant in soil for decades. So, if your land was formerly a forest, you might luck out. But if your future forest is located somewhere with no trees and no seeds, natural regeneration might not be right. Spreading purchased or collected seeds to grow a forest might work, but it will probably take a lot of babysitting, weeding, and luck.
The second requirement for natural regeneration is competition management. In the natural process of forest development, forests colonize grassland very slowly. A gradual shift in light levels and soil makeup allows tree species to move into an area in stages. To speed this process up (to happen in less than a human lifetime), you’ll need to control competition.
Controlling competition
Controlling your trees’ competition is important whether you are planting or using natural regeneration. First, you need to be able to identify and decide which plants are competition and which ones are trees. But not all trees are “trees.” If 3 trees pop up within a few inches of each other, only one of those is considered a tree, and the others are its competition and should be removed. And you may want to select for desired species. So, marking your “crop trees” early on is a good idea.
Culling the weeds
Next, you should apply control techniques to individuals or groups of competing plants. The correct control technique will vary depending on the type of competition. For example, if invasive tree species are competing with your crop trees, using the “hack-and-squirt” method to apply herbicide will kill them without impacting other plants. But if fast growing vines are climbing your trees, herbicide would do more harm than good. Using clippers or loppers to cut and manually remove the vines would be more effective. Herbaceous plants competing for water and soil (space and nutrients) can be mowed or trampled.
In 2018 I burned the understory of a 12-year old loblolly pine plantation on a State Forest to control competition from gallberry and vines.
On larger and more remote tracts, fire might be an effective tool for managing competition, if your crop trees can survive a low-intensity burn. But use caution! Fire is dangerous, and some species are not adapted to fire and will die. Bush hogging is also effective for covering a lot of ground, but your crop trees are at risk of accidental chopping. Common techniques for controlling competition are:
selective herbicide use
prescribed fire (for some species)
bush hogging
mowing
mulching/debris spreading
trampling/crushing
manual removal using machetes or other tools
Thankfully, you don’t need to be very diligent about controlling competition, especially if you did site prep. For the first year, you will want to check your crop trees and “release” them from competition once in the spring and again in fall. The second year, repeat your spring and fall evaluation and release treatments. For the greatest survival and growth, continue to evaluate and release your trees for the first five years.
3. Maturation
As your forest grows taller than you, your role in keeping it healthy shrinks. But there are still some situations that can call for intervention to keep your forest healthy. Specifically, there are threats to mitigate and opportunities to seize.
Threats to your forest
Your trees are always vulnerable to individual diseases, pests, and weather. But your forest should be able to survive the loss of a few individuals thanks to the natural resistances it has to these threats. Trees tend to be most resistant to these dangerous forces when they are growing vigorously.
Most mortality will happen when one stressor causes growth to slow down, then another comes in for the kill. The clearest example is during a drought or flood, when trees are vulnerable to insects or pathogenic fungi. The stress caused by having too much or too little water forces your trees to lower their defenses, and a beetle infestation or root rot finishes them off.
Defending your forest
You can’t do much to protect your forest from bad weather. Choosing native species that are well suited to your site and using good planting techniques gives your forest the best chance of surviving. So, plan accordingly. Don’t plant a dry-site species in a swampy area, or vice-versa.
Some other threats to your trees include:
damage from wildlife (especially deer)
invasive nonnative insects and diseases
severe storms including ice and wind
wildfire
You should expect your forest to experience some tree mortality, even when everything goes smoothly. The reason for this is straightforward: older trees take up more space than younger trees. So, as your trees age they will start to bump into one another and compete for sunlight and resources. Individuals that grow slower or are in a worse spot will become suppressed and lose out on vital resources and eventually die. Culling diseased or suppressed trees is called thinning.
Thinning
Thinning is one of the most effective tools at your disposal for growing a healthy forest. It promotes increased growth of the remaining trees, and reduces the overall susceptibility of your forest to threats like insects and fire.
It may seem counterintuitive to cut trees down to benefit the forest. But if you want your forest to reach a mature state, you’ll have to see plenty of trees die along the way. Deciding which ones will take the hit and beating nature to it is a powerful strategy.
Speeding up selection
Part of the reason thinning works so well is because of the pattern of growth that forests exhibit. To summarize: young forests have lots of little stems, old forests have a few big stems. If all of the trees in the forest are the same age or age-class, then a few of them will die over the years to make space for the remaining ones to grow larger. If the forest is grown with two or more age classes, then a few of the older trees will die every few years to make room for younger trees to grow. Of course, some of the younger trees may also die before reaching maturity.
This study by the U.S. Forest Service shows how even in a healthy forest, plenty of trees will die over the years. Reukema, D. 1979. Fifty-year development of Douglas-fir stands Planted at Various Spacings. USDA For. Serv, Pac. Northwest PNW-253.
Thinning is a way to speed up the process by identifying individual trees that are unlikely to survive long enough to meet your goals – whether that means sexual maturity for a self-sustaining forest habitat or commercial viability as timber. Removing these trees at the correct time keeps your crop trees growing vigorously and reduces competition. This can be enough of a leg-up to protect them from diseases and droughts.
4. Age-class establishment
In the world of forestry, research time and money tends to go towards one particular goal: growing as much timber as possible as quickly as possible. To that end, most commercial forests are usually made up of one cohort of trees. All the trees are planted within a few days of one another, thinned once or twice as they mature, and then clearcut when they have grown large enough to do so. The process is then repeated.
Forest forever
I’m going to assume that some readers will have different goals in mind from the timber industry. How can you sustain the forest you grow so that it will always be a forest? If individual trees die off over time, where does that leave your forest long-term? To remain sustainable in a forested state, your forest will need diverse cohorts (groups of around the same age) of trees. This is called uneven-aged management.
Textbook examples of the diameter distributions in even-aged and uneven-aged forests.
In an uneven-aged stand, you will have lots of small stems, AND a few big stems. So, parts of your forest appear young, and other parts appear old. Of course, these terms are relative. Your forest doesn’t need to always have trees in the 0-3 years age-class. Generally speaking, having cohorts separated by 10 or 20 years is sufficient to achieve a sustainable population. But it can depend on the species and site.
Achieving an uneven-aged state is tricky. Younger cohorts are shaded by older cohorts, and they are usually isolated in dense, small groups. So, they can be vulnerable to threats. And planting trees in the middle of a forest is much more labor-intensive, because site-prep may not be possible.
Creating an uneven-aged forest
To get your forest in a state that will support multiple cohorts, you’ll need to cut trees selectively. Thinning is one type of selective cut. But select cuts can be dangerous for the forest. And irresponsible select cutting has led to major problems for the timber industry across much of the Eastern U.S. High-grading is the practice of removing only the largest and most valuable trees. This practice allows loggers to extract the most value from a forest, but it can jeopardize the future of the forest. High-grading removes the best genetic material for future generations. The trees that are left tend to be slower growing and more susceptible to pests and diseases. Not the best genetic stock for the next cohort.
The opposite approach is usually the most desirable in terms of forest health. By removing ONLY the diseased and slow-growing trees, so-called “thinning from below” creates space for the offspring of the best trees to sprout. But, as usual, some degree of compromise is typically needed to make the project worthwhile for a logger while also improving the overall health and genetics of the forest.
Other types of select cut
Select cutting does not necessarily need to be a form of thinning, though. Other approaches, such as the patch or group clearcut and shelterwood, can be effective methods for growing multiple cohorts. But the bottom line is that you’ll need to remove some of your older trees to make room for younger trees. Some sunlight needs to reach the forest floor for seedlings to grow.
5. Long term management
Finally, we need to put it all together. Your forest should outlive you, and your kids, and your grandkids, unless someone along the way decides to cut it down. Those crucial early years get a lot of attention. And it’s hard to overstate the importance of starting your forest off on the right foot. But long-term management of the forest is just as important for keeping your forest healthy and sustainable over decades or even centuries.
Watch for weeds
Keeping nonnative invasive plants at bay is a constant battle in many forests. The earlier you spot and eradicate an infestation of these noxious weeds, the cheaper and more effective your treatment will be. Full eradication of invasive weeds is often a multi-year project (if it’s possible at all) once they get established in a forest. So walk your forest often and be ruthless with these pests.
Grow your soil
Growing a forest is more than growing some trees together. A rich soil ecology can support and enhance the health of your forest. Healthy soil will also sequester carbon from the atmosphere and improve the water quality of nearby streams and rivers. Avoid soil compaction by limiting heaving equipment use, especially during wet weather. And prevent erosion by following your state’s best management practices (BMPs) for any silvicultural management. Having a healthy O-layer (organic layer) on your soil’s surface will help your soil grow, hold more nutrients, and resist floods and droughts. Thankfully, you don’t need to add compost to create an O-layer. Just let leaves, twigs, needles, and roots decompose without too much disturbance.
Advanced regeneration
As you walk your forest, keep an eye out for the future generations of trees. Try not to trample the knee-high saplings that appear when an older tree dies and a new patch of sunlight appears on the forest floor. And try not to trample the ankle-high sprouts that grow in the shade of mature trees. These seedlings are the offspring of your oldest trees, and are poised to spring up if an older tree dies. In fact, scientists have found that the mother tree will often send nutrients to its offspring through their shared root network during times of stress.
Don’t panic
A little wetter than usual today.
Listen: bugs happen. Floods happen. Ice storms, tornadoes, droughts, and fires can all seriously harm your forest. But growing a forest often requires you to step back and be patient. See how your forest responds to these disturbances over the following growing season or two. Often, these types of disturbances end up significantly improving the long-term health of your forest. They not only create opportunities for new cohorts to spring up, they also cull the weakest members of the gene pool. Of course, if you’re only interested in timber value, the best response to a major event might be to salvage harvest and start over.
What kind of forest should you grow?
Forests come in all shapes and sizes. Your site is going to determine what kinds of forest are feasible on your property, but your vision and goals will ultimately determine what kind of forest you grow.
What are your priorities?
Are you growing a forest for financial gain? For scenic beauty? For wildlife habitat? Write down your priorities to help guide your forest planning. You will need to research forest issues in your state or region. If you’re interested in selling timber, find out what mills are near you and what species they accept. If you’re going for wildlife habitat, find out what kinds of forest habitat are disappearing from your area.
Types of forest
Forests are grown in a few broad categories. Deciduous forest is more prevalent in the temperate Eastern U.S. and in some wetlands. But conifers dominate in more extreme climates, both cold and hot. The deep south is excellent pine habitat. Pines also thrive in the high altitudes of the rocky mountains. In central and eastern Canada and the lake states, spruce performs well, although deciduous forests also make an appearance. Along the west coast, unique forests types like redwood and sequoias, as well as western hemlock (all conifers) find their niche.
The U.S. is also home to several temperate rainforests. The Great Smoky Mountains area of Tennessee and North Carolina, and the Olympic peninsula in Washington are home to rainforests.
Conifers evolved earlier than their deciduous cousins, and they behave a little differently. Conifers will generally grow straight and narrow in an effort to occupy the highest spot in the canopy. Many conifers also develop a taproot – a wide, tough root that penetrates straight down to seek the water table. Conifers are typically “soft” wood (as opposed to hardwoods). Additionally, conifers tend to grow needles instead of broad leaves. On pine trees, these needles fall off periodically, but never all at once, causing the soil pH to slightly decrease (become more acidic).
Conifer forests can be dense, like the Black Forest in Germany. They can also be very sparse, like the longleaf pine savannas in Florida. Softwood conifers dominate the timber market in much of North America, but most of that timber comes from commercial plantations. Conifer forests are on average less diverse than deciduous forests.
Deciduous forests
I much prefer the aesthetics of a deciduous forest
Deciduous forests are made up of trees that lose their leaves during the dormant season. There are conifers which aren’t evergreen, and there are broadleaf species that retain their leaves (like Magnolias). So, there is some overlap. However, deciduous forests are generally composed of a diverse mix of species working together.
Deciduous trees differ from conifers in that they will often spread their canopy horizontally at the top, rather than forming a Christmas-tree shape. Their roots will also spread horizontally under the soil surface, rather than penetrating straight downward. Because of this characteristic, hardwood forests tend to have an upper limit on stem density. They can still be very dense, though. Layers of vegetation under the canopy are usually full of shade-happy shrubs and trees.
Because of the high level of diversity in a deciduous forest, they are prone to changing cover types over time. For example, across the Eastern U.S. white oak forests are in decline. The reason for this is that shade-happy maples make up most of the understory in existing white oak forests, and slowly replace the oaks as individuals die out.
Species composition
Forests are largely defined by the dominant species in the overstory. The forest canopy and its characteristics can often define what other plants grow there and how the forest functions as a habitat. Some desirable species compositions, or forest types, include:
oak-hickory
spruce-fir
longleaf-slash pine
oak-gum-cypress
aspen-birch
There are many other types of forest native to the U.S. like pinyon-juniper and maple. No forest type is “bad,” but they all have different characteristics. Forests that are dominated by mast-producing species like hickories will support more and different types of wildlife than those that don’t, like maple.
Visit local forests and see what appeals to you and your priorities.
How many trees make a forest?
Where is the line between a grove of trees and a forest? Does it have to do with acreage or the number of trees? Some forests have as few as 10 adult trees per acre, while others can have hundreds.
There is probably some academic, research-based way to make a distinction between a group of trees and a forest. But for the purposes of an average landowner, it isn’t about size or the number of trees. The characteristic that defines a forest (in my mind at least) is that nature shapes a forest. While groves are intensively managed with pruning, mowing, fertilizing, and irrigation, forests are mostly left alone.
Don’t get me wrong – foresters frequently use techniques like fertilization, pruning, and passive irrigation in different parts of the world. But human intervention in forests is limited. In a given year, a forest might be burned and fertilized, resulting in obvious signs of human activity. But that activity takes place in an environment that is largely shaped by nature. In a grove, offending branches are removed. Infrastructure is built to support and enhance the purpose of the grove. Humans are needed to keep the system working. Not so in a forest.
Mini-forests
Because forests are defined more by their character than their size, the concept of mini-forests is often asked about. The invention and spread of Miyawaki Forests is redefining how human society sees forests. Many of these forests are a few hundred square meters or less.
Of course, a mini-forest lacks some of the benefits of a larger forest. Generally speaking, connections between good habitat are incredibly important ecologically. When a forest is larger, it is much easier to chart connections between the ideal habitat for a given species within that area and nearby forests. If a mini-forest is isolated from other habitat, its effect is limited.
Can you grow an old-growth forest?
Ask any forester about old-growth forests and you’ll probably get an eye-roll and a long explanation. Old-growth forests are some of the most important and rare resources on the planet, but misconceptions and myths about them abound.
Old-growth forest is a “climax community,” meaning it is a stable ecological state. This means that the forest will not undergo significant changes to its species composition or its ecological function unless some outside force causes a change.
Trees still die in an old-growth forest, and so young trees still sprout to keep the system stable. An old-growth forest is not just old trees. It is also many young and middle-aged trees, plus (usually) plenty of shrubs and herbaceous plants. So, if you want to grow an old-growth forest, you will need to plan carefully and get the right species composition.
How not to grow an old-growth forest
Many environmentalists I know believe that if landowners would just leave forests alone for a long time, it would result in plentiful old-growth forest. This is true, if by “a long time” they mean 500 years or longer. But because of introduced pests, many of the tree species that dominated old-growth forests when North America was re-discovered by Europeans are now extinct or in decline.
Since we cannot reproduce the old-growth that previously grew in America, we will need a different approach to growing forests if our goal is to create stable systems. Forests need to be evaluated regularly, and when problems arise they should be addressed. Leaving forests alone can result in overcrowding and homogenization, leaving the forest less stable. It can also invite unintended species composition shifts, as shade-tolerant species become dominant and prevent sunlight from reaching the forest floor.
Grow a forest at home
Even if you don’t have a few hundred acres in the country to play around with, you can still grow a forest. Start with a small planting, following The Unlawning Guide. Getting neighbors involved can expand your forest across property lines. And if your property backs up to stream or existing forest, the ecological benefits of planting trees will be enhanced.
