The Life in Dead Wood

In my last post, Dead Wood in the Landscape, I shared the biological benefits of leaving dead wood in our gardens and landscapes.  In this post, I want to get more specific, describiing a sampling of the species that we see in our yard BECAUSE we have left dead wood where we can.

Before I start, I want to share a quote with you from Peter Wohlleben.   In The Hidden Life of Trees, The Illustrated Edition, he writes of a tree that suddenly dies, "For centuries, the tree sucked nutrients from the ground and stored them in its wood and bark.  And now it is a precious resource for its children.  But they don't have direct access to the delicacies contained in their dead parents. To access them, the youngsters need the help of other organisms.  As soon as the snapped trunk hits the ground, the tree and its root system become the site of a culinary relay race for thousands of species of fungi and insects.  Each is specialized for a particular stage of the decomposition process and for a particular part of the tree.  And this is why these species can never pose a danger to a living tree--it would be much too fresh for them.  Soft, woody fibers and moist, moldy cells--these are the things they find delicious. ... In total, a fifth of the animal and plant species in Central European forests--that's about six thousand of the species we know about--depend on dead wood." (p. 78-81)

That same general richness of species depends on dead wood all over the world.  Let's look at some of the ones I see in our yard, here in the eastern deciduous forest of North America.....

Pileated Woodpeckers could serve as the charismatic poster child for an animal that needs dead wood to have a healthy habitat.  These big, beautiful woodpeckers not only nest in dead trees, but they obtain a large portion of their food in dead wood.  Their diet is primarily made up of carpenter ants, along with wood-boring beetle larvae, termites, assorted other insects, and sometimes fruits and nuts.

Pileated Woodpecker foraging on downed wood along the paths
April 26, 2023

Although Pileated Woodpeckers are fairly wary, it is not unusual for us to see them foraging on the dead wood in our yard.  Getting decent photos can be a lot trickier, though, than simply seeing them!

Other woodpeckers use dead wood, too.  Downy Woodpeckers, Red-bellied Woodpeckers, Hairy Woodpeckers, and Northern Flickers all nest in dead wood, sometimes in dead branches in living trees.  Several of these species will also nest in living trees that are infected with heart rot fungus.

Every summer we see juvenile Red-bellied Woodpeckers, 
which means that their parents were able to build a successful nest
in dead wood somewhere nearby.
June 5, 2022

Mom is feeding her daughter (on the left).
We see juvenile Downy Woodpeckers every year 
because they've been able to successfully build their nest
in a large dead branch nearby.
May 22, 2022

One year we even had this beautiful adult Red-headed Woodpecker stop by,
another species that nests in dead wood.
June 20, 2022

Woodpecker nest holes are frequently reused as nest sites by other cavity nesting birds such as Bluebirds, Great-crested flycatchers, Chickadees, Tufted Titmice, Screech Owls, White-breasted Nuthatches, Wrens, Swallows, and even Wood Ducks.  During cold weather, woodpecker nests are often used as roosting sites for protection from the temperatures.

Birds aren't the only animals that reuse woodpecker nest holes. Squirrels, Flying Squirrels, even some species of bats will use these valuable spaces for nesting or winter shelter.

Skinks love to use the logs in our yard as basking sites and as pathways. As I shared in my last post, one pair nested in the rotting roots of the dead black gum tree.

An immature and a mature male Broad-headed Skink
using logs as a basking site and pathway.
May 18, 2023

I haven't found any in our yard yet, but many salamander species are found under or in rotting wood, too.

Many, many insect species spend at least part of their life cycle in dead wood.  (Note:  these insects use dead wood, not living wood, as the fibers are softer and decomposition is already occurring in the dead wood.)

Many beetle species lay their eggs in snags, logs, or dead branches and their larvae eat the decaying wood, then pupate there, all safely protected from prying eyes.  Protected from prying eyes...but not from woodpecker bills and tongues!  Beetle larvae are prime woodpecker food, and the woodpeckers help keep the beetle populations balanced and under control.

Last year I noticed a big jump in beetles feeding at and pollinating flowers in our yard.  It turns out that most of the new species I saw have larval stages that develop in dead wood.  One of my favorites is the uniquely marked Delta Flower Scarab (Trigonopeltastes delta).  I also saw Tumbling Flower Beetles (Mordella sp.) and Emerald Flower Scarabs (Trichiotinus lunulatus).

A Delta Flower Scarab on Meadowsweet (Spiraea alba)
June 11, 2024

An Emerald Flower Scarab and a Tumbling Flower Beetle
on Meadowsweet (Spiraea alba)
June 8, 2024

There are several species of flower longhorn beetles that showed up last year, too, all of whom spend their larval stage in dead wood:  Slender Flower Longhorns ((Strangalia famelica), Red-winged Longhorn Beetles (Brachyleptura rubrica), and Red-shouldered Flower Longhorns (Brachyleptura vagans).

Slender Flower Longhorn on Meadowsweet (Spiraea alba)
June 5, 2024

Red-winged Longhorn Beetle on Meadowsweet (Spiraea alba)
June 5, 2024

Red-shouldered Flower Longhorn on Meadowsweet (Spiraea alba)
June 11, 2024

The larvae of these species are some of insects that woodpeckers and other animals are eating when they feed on snags or logs.

It's not just woodpeckers that prey on beetle grubs, though.  There are other beetle species whose larvae are predators on the wood-boring beetle larvae.  An example of a beetle species with predatory larvae is the Eyed Click Beetle (Alaus oculatus).   

Eyed Click Beetle, whose larvae are predators on the larvae of wood-boring beetles
July 14, 2020

There are also parasitoid wasps that specialize in using the wood-boring beetle larvae as hosts for their developing larvae, including the species pictured below which specializes in laying its eggs in longhorn beetle larvae.  That long ovipositor is designed to pierce decaying wood to reach the beetle larva and lay an egg on it.

An Ichneumon Wasp (Spilopteron occiputale) that lays its eggs
in the larvae of longhorn beetle larvae.
July 2, 2024

Then there are yet other beetles whose larvae develop in dead wood, beetles like False Mealworm Beetles (Alobates pensylvanicus) who are predatory on other insects, or like Horned Passalus Beetles (Odontotaenius disjunctus), who live in small colonies in dead wood and whose adults feed their larvae pre-chewed rotting wood.

False Mealworm Beetle that was living under the bark
in the dead black gum trunk.
August 11, 2023

Horned Passalus Beetle, a species that lives in colonies in dead wood.
June 30, 2022

About 30% of the solitary native bees nest in places like stems or in beetle larvae tunnels in dead wood.  Pure Green Sweat Bees (Augochlora pura) are one of the species that I see in the yard that use beetle galleries in dead wood for their nests and whose fertilized females overwinter under logs.  Seeing these jewel-like pollinators gives me a real lift. 

Pure Green Sweat Bee on Wrinkle-leaf Goldenrod (Solidago rugosa)
October 13, 2023

Eastern Carpenter Bees (Xylocopa virginica), who are fabulous pollinators, excavate their own tunnels in dead wood to use as nest sites.  It's disconcerting to have Eastern Carpenter Bees use a railing or the eave of a house, but they naturally use dead wood in the landscape for their tunnels.  Keeping your wood surfaces well painted can encourage these guys to nest elsewhere.

Eastern Carpenter Bee on
Hairy Elephant's Foot (Elephantopus tomentosus)
August 20, 2023

I really dislike disturbing animals, so I haven't actually broken into or looked under the dead wood, standing or downed, to see what animals I can find by direct observation.  Someday I may.  Meanwhile, throughout the year, I'm enjoying the various species that I see specifically because we have logs and snags in our yard.

I've talked about some of the animals we see in our yard because of dead wood, but there are many fungi, mosses, and lichens we see for the same reason and it's been fascinating to see how many there actually are.  I know little about fungi, so I can't identify most of these, but I still enjoy looking at them.  Learning more about them is definitely on my "to do" list.

The first photo is of a slime mold rather than a fungus.  Slime molds are unique, with some characteristics of fungi and some characteristics, believe it or not, of animals.  I've only seen these "chocolate pom-poms" once, on a decaying stump, but when I looked them up, they are a well known species called Chocolate Tube Slime Mold (Stemonitis splendens).  Although some slime molds can look gross, they are decomposers and are not dangerous.  They disappear when environmental conditions change.

These "chocolate pom-poms" are actually Chocolate Tube Slime Mold
June 19, 2023

On that same stump, about 10 months before the Chocolate Tube Slime Mold appeared, I found a fungus known as Black-staining Polypore (Meripilus sumstinei).  This cluster was young, and I find it very elegant looking, especially from the side.  This species is considered edible, but I'm not good enough at identification to take a chance on eating it.

Black-staining Polypore
August 21, 2022

The same clump of mushrooms, Black-staining Polypore,
photographed from the top.
August 21, 2022

I have no idea what species this fungus is, but I love the lacy texture. Note the bit of lichen at its base.

Unknown lacy fungus with lichen at its base,
found on a dead hardwood branch.
August 8, 2024

To myself, I call the round clusters of fungal structures that are found in the next photo, "fungal roses".  That is, you understand, a totally unscientific name but they remind me of the paper flowers that I used to make when I wanted a pop of color on a table or bookcase. As with the fungus above, I do not know the name of this species.

"Fungal rose" on log
May 29, 2023

I'm including this last photo as much for the moss as for the fungus.  This is another fungus for which I do not know the name, nor do I know the name of the moss, but they both were growing on the same stump where I found the Chocolate Tube Slime Mold and the Black-staining Polypore cluster.  Moss and lichen are both frequently found on dead wood.

"Prickly fungus" in a bed of moss
on a stump by our driveway.
October 25, 2023

When we remove dead wood from the landscape, we are effectively starving the ecosystem.

Why do we instinctively feel that dead wood needs to be removed? Well, probably at least in part because it's "dead" and we generally don't like to be reminded of death as a part of life.  In our phobia about death, we've trained ourselves to think that any dead plant material is "ugly" - and ugly things need to be removed from our surroundings. 

However, dead wood isn't ugly, and it's chock full of nutrients that will feed a broad range of other life forms, including other trees.  Scientists have learned that even dead limbs shed by trees actually decompose into extra food that ends up feeding the tree from which they fell.  If the tree is stressed, shedding limbs can reduce the amount of living tissue it has to support during the stressful time as well as give it that boost of energy and nutrition as the dead wood decomposes.

In Victorian times, "stumperies" became popular in gardens - think of a rock garden, but using stumps and dead wood instead of rocks. Stumperies are making a comeback in some gardens and can be very attractively planted, benefitting both human aesthetic sensibilities and ecological needs.

In whatever way works for your garden aesthetic, I hope that you'll seriously consider adding a snag or some logs to your garden.  In doing so, you'll be adding important habitat for a wide variety of species.

Then and Now: A Living Explosion

"The yard is alive, with the sound of music!  With songs that've been sung for a million years...."  (My deepest apologies to Rodgers & Hammerstein for that abysmal rewording of their song.)

The yard IS alive, now, but when we moved in, it was quiet and boring.  Here's a summary of our journey so far....

THEN:    

    When we moved to southeast Virginia in fall 2019, our "new" yard challenged us. 

    The Prairie Boy was overwhelmed by the trees, 100+' giants that dwarfed the prairie trees he grew up with.  He likes to see the horizon, and you basically can't do that when you are surrounded by giant trees.  The yard was an enigma to him.

    The Druid was excited about having real, live, BIG trees in her everyday life again, having a true forest garden.  Her elementary school days had been spent in the eastern deciduous woodlands and she missed the ambiance and the ecosystem.

    However, the yard has ended up stymying both the Druid and the Prairie Boy.  These weren't just tall trees, these were TALL trees.  The neighbors told many tales of trees falling unexpectedly and hitting houses, so every time the wind blew, a sense of uncertainty swept in as well.

    There were remnants of prior landscaping in the yard, but they were truly remnants:  solo large shrubs, deer pruned and lonely, unsupported by companions and some seemingly placed almost at random.  In the spring, daffodils emerged and bloomed beautifully, but there were no flower beds, there was no lawn, and there was little discernible landscape design of any sort.

    Making matters even less promising, the vast majority of the huge shrubs were non-natives:  Chindo Viburnum, Camellias, Burford Hollies, Little Leaf Hollies, evergreen Azaleas, (small) Boxwoods, and a huge Rhododendron.  For native shrubs, there were a couple large Yaupon Hollies, planted way too close to the old greenhouse wall, and 3 Yellow Anise Shrubs.  Neither of these species are technically native to southeast Virginia, but at least they were "near natives".  There were no true native shrubs.

    As far as the "forest floor" was concerned, the yard had a lot of Japanese Stiltgrass and other non-native weeds, a few huge clumps of old fescue, a bit of Poison Ivy, and not much else besides the springtime daffodils and summer snowflakes.

    How in the world could we bring this space to life?  How could we create cohesion, and even beauty, in this struggling and rather awkward space?  In the spring of 2020, shown in the photo above, our newly acquired yard felt barren, despite the towering 100' tall trees that graced it.  We'd been feeding birds all winter, but there was precious little other wildlife to be found:  a skink or two, squirrels (of course), and honeybees from neighbors' hives, but almost no native insects.  That summer we had an Eastern Ratsnake show up one day, only to be found dead in the neighbor's driveway not long after.  A Leopard Frog made a brief appearance, as did a toad or two.  That was about it.

   I started pulling out the Japanese Stiltgrass the first summer, sitting directly on the ground, clearing out that invasive annual a few square feet at a time.  I'd researched stiltgrass and I'd learned that it didn't bloom and set seed until late summer or fall, but at that point it seeded prolifically;  I was determined to avoid new seed falling in as large an area as possible.  As I sat on the ground working, I got to know our yard "up close and personal".  

For example, in the photo above, you can see the bloom of a Naked-Flowered Tick-trefoil and a sedge, both of which are native, interspersed with the invasive non-native Japanese Stiltgrass, which has the broader leaves.  These particular native plants aren't showy, but the native insects need and use them. 

    I found a few really nice surprises:  several Striped Wintergreen plants (two are shown above), Southern Adder's Tongue, a few native tree and shrub seedlings, 2 stunted Mayapple leaves,  2 or 3 single Bloodroot leaves, and some nice Partridgeberry vines.   Mostly, though, I found a lot of non-natives, some of which were problematic and a few of which were outright invasive.

    Most disturbingly, I found almost no life in the leaf litter.  We'd left the leaves on the ground in the fall, so we did have leaf litter itself, but despite hours of sitting on the ground, all I saw that summer were a few little black crickets.

NOW: 

    It's been 4 years since that first daunting summer.  The Japanese stiltgrass still shows up a little, but it's easily pulled as I meander in the yard.  I've moved on to actively extracting Asiatic Hawkweed, fescue clumps, and Ground Ivy.  Ajuga is on my radar screen.  We've left the leaves every year and a healthy leaf litter has started to develop, feeding and protecting the soil, as well as providing habitat for a myriad of little animals.

 We've established a series of paths in the front yard, outlining them with branches from the tree trimming that has occurred.  We've left a large log and several small sections of logs,  forming an impromptu "jungle gym" for our grandsons in the front yard.  These have become favorite seats for me, as well.  In the back yard, we have a brush pile that the birds and the skinks find irresistible.

    For the most part over these intervening growing seasons, I've welcomed whatever native plants wanted to show up in the yard, relocating a few of them, but generally just observing and enjoying.  Because we have many seedlings sprouting, I can tell which plants are the birds' favorites, species like Spicebush, Wax Myrtle, and Black Cherry.  We've also planted a lot of native plants:  ferns, Columbine, Beautyberry, Viburnums, Goldenrod, Mayapples, and Bloodroot, just to name a few.

    We fight the deer...and the voles...and even, for a brief time last spring, a groundhog.  The deer have kept our newly planted plants undersized, but with judicious and regular use of deer repellants, we're finally seeing some growth.  Last spring the voles set us back on our heels for a while, but they haven't been as bad this year.

    Most excitingly, our yard has come alive with animal life.  These days I hear bird song all day long from a variety of species, including Brown Thrashers like the one shown above.   Fireflies twinkle at night.  

Butterflies flit through the air.  During the summer, I see Zebra Swallowtails and Eastern Tiger Swallowtails almost every day, but to get both in the same photo last summer felt like a real coup!  

In the leaf litter, there are now millipedes (like the one in the photo above), as well as snails and centipedes and roly-polies and firefly larvae and a gazillion ants and ...and ....and crickets, too, of course.  Moths have FINALLY appeared, especially the drab little leaf litter moths that are so incredibly important as food for many other animals.  

Solitary native bees, like this Georgia Mason Bee (Osmia georgica), visit our flowers and nest in the yard, as do a variety of solitary wasps who feed their young with paralyzed spiders or crickets or caterpillars or beetle larvae, depending on the species, helping to keep those populations in balance.

    So far this spring, we've had the parent birds of 10 different species bring their young to our feeders, including Carolina Wrens, Hairy Woodpeckers, and Brown Thrashers.  The photo above is of a father Downy Woodpecker feeding his daughter last spring.

    Pileated woodpeckers forage regularly on the stumps and the decomposing wood logs lining our paths.  

, 

    We have an untold number of Broad-headed Skinks in the yard, including this pair who had set themselves up in a prime location at the base of a dead tree.  Last summer, I also saw a Little Brown Skink, a species that lives entirely in the leaf litter.

    Butterfly numbers and species have increased, including this Common Buckeye (Junonia coenia) from last August, but greedily I would love to see even more.  I'm hoping that my increasing numbers of native flowers and host plants will bring them in - and help raise up new generations of lepidopterans.

    Most excitingly, this spring we've now seen TWO Eastern Ratsnakes, a big one and a little one.  Presumably they are why the voles are less of a problem this year!

    I still feel like the yard's design is far from optimal, but I'm continuing to work on it, aiming for beauty and cohesion as well as for increasingly healthy native plant and animal populations.

    

Ours may not be the most classically beautiful yard in the neighborhood, but it's rapidly becoming a most vibrant one, our own fascinating wildlife preserve.