Natural Art

All nature is but art unknown to thee.

~Alexander Pope

Earlier this week, I accompanied some friends on a stroll through one of my favorite local natural areas РJohnston Mill Nature Preserve in Orange County.  This area is managed by the Triangle Land Conservancy and is one of their more popular sites. I love exploring this beautiful tract, especially in early spring when sections are carpeted with wildflowers like trout lilies and spring beauties. But, this time of year, a stroll through the bare forest allows you to notice and appreciate other details of the landscape Рtree bark, fungi, textures, shapes, and, on a warm day like last Monday, the early stirrings of insects, amphibians, and other animal life.

mossy tree trunk

Vibrant green moss at the base of a tree trunk (click photos to enlarge)

I appreciate the winter woods for their openness and the ability to see the bones of the landscape – the trees, vines, and boulders that give character to a forest. The trails at Johnston Mill are well-marked and pass through a variety of habitats from bottomlands to beech bluffs to open meadows along a power line. My favorites were the new Aphid Alley Trail (not yet marked on the kiosk maps but available on their maps online) and the Beech Loop. They highlight beautiful American beech trees and some steep slopes along creeks with wonderful vistas.

creek

A beautiful stream flowing through a beech forest is a trail highlight

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Boundary lines between crustose lichens on a tree trunk

Beech trees often provide a perfect canvas for a variety of interesting lichens. These flattened colonies of symbiotic algae and fungi are known as crustose lichens. I learned a new word when looking for information on lichen competition online – corticolous. This refers to lichen communities that grow on tree bark (those on rocks are known as saxicolous). Melissa mentioned she had learned in a lichen course that the distinct lines that you can see between some colonies could mark sort of a DMZ between warring lichens and that lichens may use chemical warfare to guard their boundaries. My online search shows some evidence for this but it still seems a bit controversial. It is a bit mind-boggling that these slow-growing assemblages set up zones of defense to ward off intrusions by their neighbors.

lichen patches on tree trunk

Modern art or lichen competition?

Tree trunks rarely get their due outside of winter, and even then, few hikers probably pay them much attention. But I find them fascinating, especially when covered in moss and lichen or when sporting unusual growths like the numerous burls we spotted on a few maples.

gnarly maple trunk

A knotty Red Maple trunk adds modern sculpture to the forest

Burls are a bit mysterious in origin with common causes believed to be infection by bacteria, virus, fungi, and perhaps certain insects.

shagbark bark

Peeling plates of bark help to identify this tree as Shagbark Hickory

The peeling bark of American sycamore and shagbark hickories are another tree trunk treasure easily observed in the winter woods. Once again, the reasons for this phenomenon are not clear cut. Some trees may exfoliate (the term that describes shedding of bark) to rid the trunk of parasites, others to increase gas exchange or photosynthesis of bark tissue, but I’m mystified as to the ecological advantage of peeling plates of bark on a shagbark. Undoubtedly, it makes for good habitat for a host of associated organisms from insects to bats, but I’m not sure what the advantage is to this species of hardwood (I welcome your thoughts or references).

odd hollow tree trunk

An unusual hollow trunk beckons a closer look

Sycaore roots in crrek

The gnarly texture of the root mass of a blown over sycamore along the creek bank

japanese honeysucj=kle vines twisted

Entwined honeysuckle vines

Celtis bark

One of the most noticeable tree textures along the trail – the warty bark of a Hackberry

I have  hard time passing by the knobby bark of a hackberry without pausing to look closely, or rub my fingers across it. I took a few quick images of the layered bark bits and moved on. As often happens, when I was reviewing images and adding some sharpness (I usually magnify the image for this), I saw something I had missed earlier. Even with magnification, I was lucky to notice these ragged shapes hidden among the stacked hackberry bark pillars. After searching online I believe they are larvae of fireflies in the genus Pyractomena. Their distinctive head shape and the fact that they were out this time of year is pretty diagnostic. Larvae from this group are known to climb tree trunks to pupate in late winter or early spring and emerge as the first firefly adults of the season. They apparently hunt snails and other soft-bodied critters.

insects hiding in Celtis bark

A closer look reveals some hidden surprises

lacewing larva

A lacewing larva carries its texture on its back wherever it goes

slime mold reproductive structures on tree trunk 1?

We thought at first that these tiny fruiting bodies were from a slime mold, but experts are now suggesting otherwise…

During a brief pause, I glanced down and saw a line of tiny mushroom-like structures on a nearby tree trunk. Our first thought was slime mold fruiting bodies. My friend, Jerry, submitted some pictures to his local fungi expert who thinks it is probably a fungus, maybe Phleogena faginea. One common name I saw for this species is Fenugreek stalkball. When warmed, the fruiting bodies apparently smell like fenugreek (another new word for me), a curry-like powder derived from a plant of that name.

slime mold reproductive structures on tree trunk close up?

A local mushroom expert suspects these are the fruiting bodies of a fungus,

fungi on log

Patterns of fungi on a fallen log

slime mold?

That same log had a patch of what looked to me like a slime mold…but…

It’s not only upright, living tree trunks, that are adorned with interesting garb, but also fallen logs in various states of returning to the soil. One large log had a variety of mosses, lichens, fungi, and a mysterious orange blob that we thought might be a slime mold. It turns out to be a fungus in the genus, Phlebia (thanks, Van Cotter, for the fungi ID assistance). Once again, when I looked at the image on my laptop in higher magnification, my eye caught something I had missed in my quick field photo. Along the upper edge of the picture are some dark elongate “mini-bugs”. They look like springtails of some sort.

slime mold close up with springtails?

When I looked at the image on my computer, I saw some tiny dark-colored organisms along the edge – Springtails

Springtails are members of the Class Collembola and most are defined by an usual forked appendage called a furcula. The furcula is tucked up under their abdomen and acts like a spring to propel these tiny beasts many times their body length (not all Collembola can spring). These are abundant creatures and play an important role in decomposition and may also graze on molds and mildews. Many species are aquatic and some are active in the dead of winter where they aggregate on the surface of snow (snow fleas).

ceramic fungi (Xylobolus frustulatus))

The aptly named Ceramic Fungus looks like broken pottery

deer skull

An eight-point buck skull found near the trail

running cedar

Discovering a patch of Running Cedar always brings a smile

Spissistilus festinus - Three-cornered Alfalfa Hopper ?

I believe this is a Three-cornered Alfalfa Hopper, Spissistilus festinus

Three-cornered alfalfa hopper

Characteristic shape of this hopper group can be seen from above

spring beauty

My first spring ephemerals of the season, a few Spring Beauties in bloom along the trail

We ended up spending a few hours hiking a little over 4 miles (a naturalists’ pace) and found several mysteries, natural sculptures, and other natural art to provide a memorable sensory experience on a warm winter walk.

Bee-autiful and Bee-zarre

…even the insects in my path are not loafers, but have their special errands.

~Henry David Thoreau

About two weeks ago, we took a hike at one of our favorite springtime destinations, Johnston Mill Nature Preserve, one of the many wonderful properties owned and managed by the Triangle Land Conservancy. We have been impressed and amazed by the variety and abundance of spring wildflowers that carpet the ground here and were hoping to catch the flowers at their peak. This year, we were lucky, and hit the trout lilies at their height of bloom. While Melissa and her sister went off for some exercise with a brisk hike along the trail, I did my usual snails pace walk/crawl, camera in hand, looking for anything interesting along the way.

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Windflower, Thalictrum thalictroides (click photos to enlarge)

Many flowers (especially the spring beauties and trout lilies) were still closed due to the chilly temperatures and overcast skies. But the windflowers were doing their thing, quivering in the slightest breeze, flowers (with their white sepals, no petals) facing skyward.

hepatica entire plant

I found a few hepatica, Anemone americana, with their newly emerging fuzzy leaves

spring beauty bee?

Spring beauties, Claytonia virginica, opened up as the day warmed

Trout lilies in bloom

Trout lilies, Erythronium umbilicatum, with their dappled leaves (resembling the pattern of a trout)

After an hour or so, the sun started to shine and the flowers opened, beckoning the early season pollinators.

honeybee on trout lily

Honeybee visiting a trout lily

I was hoping to observe and photograph some of the elusive pollinators, so I was alert for any movement near the open blossoms as I eased along the trail.

native bee visiting spring beauty in Piedmont of NC

Small native bee on spring beauty

I searched for spring beauty bees, a specialist on their namesake spring ephemerals with pink pollen. I did capture one photo of what I think is a spring beauty bee (see the first photo of spring beauty above), but the bee on this plant looked different.

 

native bee collecting pollen from trout lily in NC Piedmont fore

A small native bee with a full pollen load

I started seeing this bee on many plants, especially the abundant trout lilies.

native bee visiting spring wildflowers in Piedmont of NC

We found a group of bees flying low over the ground near the trail juncture

At one point along the trail, we noticed a concentration of these bees flying low over the ground. I knelt down to photograph one on the leaf litter, and as I focused for another shot, it disappeared into the leaves. That’s when I noticed a nearby mound of soil with a pencil-sized hole and a pair of large eyes peering out at me.

native bee at entrance to nest tunnel in sandy soil near creek w

Bee looking out of its burrow entrance

And this is where my photos of this amazing creature end, but its fascinating story begins. We watched these bees for quite awhile and discovered what looked like a colony scattered over a large swath of ground in the floodplain of the creek. Many of the entrance mounds to their burrows were partially hidden in the leaf litter, but all were about the size of a golf ball with one hole near the top. The bees appeared to be going in laden with pollen and then exiting free of that cargo, presumably having stored it for their soon to be developing young. That night, after trying to identify the bees with various online resources, I uploaded a few images to Bug Guide and heard back the next day from a couple of their helpful experts. These are a type of plasterer bee (also called cellophane bees) – the experts best guess is this one is Colletes inaequalis, the unequal cellophane bee. The reason for their groups’ unusual common name is that females produce a secretion from their abdomen that is a type of polyester which becomes the brood cell for their young. Though these bees are solitary (a female digs her own burrow and tends it herself), they tend to nest in aggregations (sometimes in groups of hundreds or more nests), especially in sandy soil on south-facing slopes. She creates several brood cells that resemble small plastic bags in side chambers of her one-foot deep tunnel, stocks them with a liquid pollen and nectar mix, and then suspends one egg above the food larder in each cell. The more I learned about this species, the more fascinating it became. Some researchers are studying the brood cell material to see if it can be synthesized for a biodegradable plastic! To learn more about the biology of this fascinating bee (and to see some amazing photos of an excavated nest chamber and brood cell) visit these two links – Polyester bees: Born in a Plastic bag and Nature Posts: Bees That Dig Holes in the Ground.

native bee at entrance to nest tunnel in sandy soil near creek

Closer view of a docile cellophane bee

There were quite a few references to people being alarmed at finding aggregations of these bees in their yards, but there is no need to be concerned about them as they tend to be quite docile. They are among the earliest bees to be(e) active and then only for a few weeks before the entire colony is reduced to the developing larvae and pupae being underground until the following spring. Plus, they are important pollinators of early spring wildflowers, so let them be(e). One other interesting note, and an indicator of how climate change is impacting species large and small – researchers using historical museum datasets and more recent bee-monitoring data looked at the timing of spring emergence of this (and several others) species of native bees. Over the past 130 years there has been a significant shift toward earlier spring time emergence with an average ten days earlier now than in the late 1800s. That trend has been most pronounced in the last 40 years. With all these bees are doing for us (pollination services), telling us about our changing climate, and the possibility of synthesizing their unique polyester secretions, we should appreciate these fascinating master burrowers and protect them and their kin.