What is a tree?

Though easily recognizable by their general impression, size, and shape (GISS), have you ever thought about what it IS to be a tree? Trees can be described by their physical characteristics, categorized by their taxonomic place in the Kingdom of plants, and understood by their function and value in natural and human communities.

Physical Characteristics: Mature trees have a single woody stem, are taller than 15 feet, and have a trunk greater than 3 inches in diameter. Together, these three features set trees apart from shrubs (multiple woody stems, between 3-15 feet high, each trunk less than 3 inches) and other plants (wildflowers, ferns and fern allies, grass-like plants, and mosses). Young trees that spring up in dense groves might be confused with shrubs, and some trees barely exceed the height requirement even at maturity. Together though, these three criteria will almost always help distinguish trees from shrubs.

Taxonomy: Trees, like other living organisms, can be categorized and given a unique scientific name. At the top of the taxonomic hierarchy are four Kingdoms: plants, animals, fungi, and protists. Plants get divided into Divisions with trees falling into either Coniferophyta (cone-bearing) or Magnoliophyta (flower-bearing) groups. The groups continue to be divided into Class, Order, Family, and finally the Genus and Species.

The Genus and Species are the scientific (technical, botanical, Latin) name. For example, the common names sugar maple, rock maple, or hard maple are all the same tree with one unique scientific name: Acer saccharum. You'll notice that the scientific name is italicized - it can also be underlined (Acer saccharum) to alert the reader to its binomial nomenclature (two names). Acer is a genus in the Division of Magnoliophyta.

Magnoliophyta are deciduous, and the seeds develop inside an ovary to produce some type of fruit rather than a cone. There are 16 families of Magnoliophyta in Maine: Sapindacea (maple and horsechestnut), Oleacee (ash), Cornaceae (dogwood), Adoxaceae (viburnum), Betulaceae (birch, hornbean, hophornbeam, and alder), Salicaceae (willow and aspen), Hamamelidaceae (witch-hazel), Ulmaceae (elm), Malvaceae (tilia), Fagaceae (oak, beech, and chestnut), Juglandaceae (hickory and walnut), Platanaceae (sycamore), Lauraceae (sassafras), Rosaceae (cherry, hawthorn, shadbush, and mountain-ash), Fabacee (locust and honeylocust), and Ericaceae (laurel and rhododendron).

Coniferophyta are evergreens with seeds developing on the scales of cones - "naked" seeds since they don't have a fleshy exterior. In Maine, Coniferophyta are represented in two Families: Pinaceae (pine, fir, hemlock, spruce, and larch) and Cuppressaceae (white cedar, redcedar, and juniper).

Functions and Values: In a landscape, trees provide vertical structure and habitat for wildlife. Contributions to wildlife habitat include shelter and food, and large tracts of forest provide the large range needed for bigger animals. Trees filter light to influence ground cover and intercept rain to minimize erosion. Their extensive root structure holds soil in place, further minimizing erosion. For humans trees provide building material, pulp for paper, sap that boils down to maple syrup, turpentine from pine trees, and the astringent witch-hazel - to name just a few important products.

What is a tree to you?

Human relationships in nature

I had an idea this past week, to use naturalist quotes at critical transitions during the graduation festivities of the latest group of Maine Master Naturalist students. I was drawing from the class's assigned reading list and thought I'd find quotes appropriate for breaking bread together, for collaborative study, and for celebrating one another's achievements. What I found was a lot of individual's writings about their experiences with elements of nature - observations of a firefly, insights on the behavior of a porcupine, or seasonal changes of a maple tree. Although these are important topics that help us better understand the natural world, and though I know there are other works that do indeed bring human relationships into the discussion, it made me think more deeply about establishing and nurturing our human relationships as we figure out what it means to be a naturalist.

Generally, a naturalist can be defined as an expert in, or a student of, natural history. Myself, I fit into the student category with aspirations of becoming more well versed in a particular topic or two while being conversant in others. This seems to characterize most of my fellow naturalists who have graduated from the Maine Master Naturalist Program. Another quality of my peers is to strengthen and engage in shared, collective learning through book clubs, impromptu study groups, and trail walks during the year. Hurrah for MMNP whose goal is to "create an ever-widening ripple, a network of citizen-naturalist volunteers who share their knowledge, insights and enthusiasm about Maine's varied natural communities to a broad array of individuals." It's the network that captures my interest right now.

Being a naturalist means many things to many people but at it's core I think it's a blending of natural science and social science. In my corner of the world, we naturalists are part of a dynamic network of individuals that go out of network for a time to make personal observations and take time to reflect - and then return to the fold to share what we've seen, heard, and experienced - and then move along within the fold to learn and experience more through each other's eyes. That's the piece I missed in the small sub-set of books I reviewed - the human interactions. If I used these half-dozen books to model my naturalist behavior, I'd be living a solitary life indeed.

Now, I know that naturalists, including the authors of this short list of books, have relationships in which they share their observations. Edwin Way Teale's naturalist travels included his wife and the many friends and colleagues that they visited from coast to coast. I like reading about the building and nurturing of the relationships that go along with identifying, documenting, and modeling the technical aspects of being a naturalist. To experience our human connections with the natural world, but to also connect with other like-minded souls within those experiences.

Big Night

It was big night in the vernal pool closest to our house. 

A rainy evening, warm air temperature, and natal waters to come home to created just the right conditions for wood frogs and yellow-spotted salamanders to hold their annual congress. 

By midnight the rain stopped and the starlit sky made conditions pretty sweet for us humans, too.

Headlamps in place, we tromped out to the woods.

Each yellow-spotted salamander has a unique placement of spots. In theory, we can tell them apart from one another by the size and location of the school-bus yellow markings.

These large head markings seem easy enough to recognize in the future. 

I wonder if I'll see this salamander again next year.

Vernal pools are productive components of a forested ecosystem.
Our home pool is one of four situated in the woods on our property.

There are others on neighboring parcels, and we've walked out to some of them in the pitch dark - usually during a rainstorm.

The quacking of wood frogs and the squeaking of spring peepers halt as we approach. If we stand still enough for long enough, the chorus resumes.

Over the years, we've come to realize that our home pool is one of the most productive in terms of adults and egg masses. 

The noise level is pretty competitive, too.

The tromp through matted leaf litter is a peaceful adventure.

We make the rounds through the woods, return to our home pool, and stand in the quiet cool air.

Listening to the trees shed droplets from the evening's rain.

Scanning for spermataphores, little white packets of sperm.

Watching salamanders slither while frogs kick their way through the water.

Nourishing our inner wild.

Pileated Scat

If you ever happen to pass by fresh shavings beneath a tree, take a closer look. 

Gently poke through the wood chips and you may find woodpecker scat. Such was the case under a Big-toothed Aspen (Populus grandidentata) recently worked on by a Pileated Woodpecker (Drycopus pileatus), 

I recommend that you wear gloves, or use a turned-inside-out baggie to protect yourself from exposure to pathogens. 

Look closer at the scat and you'll likely find that it's textured by exoskeletons of the ants which are the Pileated's favorite prey. 

Pileated Woodpeckers excavations are obvious - long and rectangular. Pileated woodpeckers are large birds that require large trees - conifers or broad-leaf flowering species - in which to dig their holes. Large sized Big-toothed Aspen are common in late-stage Early Successional Forests, and the Pileated Woodpecker is a common visitor in search of its dinner.