When you walk through a woodland, it’s natural to look up.

Towering tree canopies filter the sunlight overhead. Ferns unfurl along the forest floor. Birds call from the branches while butterflies drift between flowers.

But beneath your every step lies another world — one that’s just as alive and the part we never see.

Hidden underground is an incredible network of roots, fungi, insects, and microorganisms working together to support every tree, wildflower, and woodland creature above. While we rarely see this world, it’s the foundation of a healthy forest.

At Green Bay Botanical Garden, Woodland Wonders presented by Selner Tree & Shrub Care invites guests to discover the stories hidden among the trees.

Some of the most fascinating stories, however, are happening just beneath our feet.

Roots Do More Than Hold Trees in Place

When we picture tree roots, many of us imagine them as anchors holding a tree upright.

While they certainly do that, roots have many other jobs.

Every day, roots:

• Absorb water and nutrients from the soil.
• Store energy that fuels new leaves and spring growth.
• Help stabilize trees during Wisconsin’s strong winds and summer storms.
• Connect with fungi and other soil organisms.
• Support the health of the entire woodland ecosystem.

In fact, most tree roots grow within the top 12 to 18 inches of soil, where oxygen, moisture, and nutrients are most available. Instead of growing deep like a carrot, many roots spread outward well beyond the edge of the tree’s canopy.

That means the underground reach of a mature tree is often much larger than we realize.

A Woodland Is Alive Below the Surface

Healthy woodland soil isn’t simply dirt, it’s a living community.

Just below the leaf litter you’ll find:

• Fine tree roots branching through the soil.
• Fungi breaking down organic matter.
• Earthworms improving soil structure.
• Beneficial bacteria recycling nutrients.
• Countless insects and other tiny organisms.

Together, these living things form what scientists call the soil food web — a network of organisms that continuously recycles nutrients, builds healthy soil, and supports plant life.

Every handful of healthy woodland soil contains millions of living organisms working together in ways we are only beginning to fully understand.

Nature’s Best Partnership

One of the woodland’s most remarkable relationships happens between tree roots and fungi.

Many Wisconsin trees like oaks, maples, birches, and pines form partnerships with specialized fungi known as mycorrhizae.

These fungi attach to tree roots and extend far into the surrounding soil, acting almost like an extension of the tree’s root system.

The fungi help trees absorb water and nutrients that would otherwise be difficult to reach.

In return, the tree shares sugars produced during photosynthesis.

It’s a partnership that’s been evolving for millions of years, benefiting both organisms and strengthening the woodland as a whole.

Last Year’s Leaves Become Next Year’s Forest

One of the most important jobs in a woodland happens every autumn.

As leaves fall to the ground, they begin to decompose.

Instead of becoming waste, those leaves:

• Feed fungi and beneficial microbes.
• Return nutrients to the soil.
• Help retain moisture during dry weather.
• Protect roots from temperature extremes.
• Create rich organic matter for future plant growth.

What falls to the forest floor this year helps support next year’s growth, creating a continuous cycle of renewal.

What Home Gardeners Can Learn

You don’t need a forest to benefit from these natural systems. Many of the same principles apply in your own landscape!

To support healthy roots:

• Water deeply during extended dry periods rather than watering lightly every day.
• Avoid compacting soil around trees with heavy foot traffic or equipment.
• Leave space around trunks instead of planting turfgrass right up to the bark.
• Apply a light layer of mulch to help moderate soil temperature and conserve moisture — but keep it away from the trunk.
• Consider adding shade-loving native plants and groundcovers beneath trees rather than leaving bare soil.

Work with nature instead of against it. This creates healthier landscapes that require fewer inputs over time.

layer—from the canopy to the soil—plays an essential role.

The Hidden Wonder Beneath Our Feet

Some of the most important parts of a woodland are the ones we never see.

Roots quietly anchor towering trees. Fungi help forests share resources. Fallen leaves become fertile soil. Tiny organisms keep nutrients moving through the ecosystem.

Together, they remind us that healthy gardens aren’t built by individual plants — they’re built through relationships.

The next time you visit Woodland Wonders, take a moment to appreciate not only what’s growing around you, but also what’s happening beneath your feet.

Understanding these unseen relationships changes how we experience a woodland.

Sometimes the greatest wonders are hidden just below the surface.