Nature Net News
February 2009
Winter Trees & Shrubs
"Sometimes our fate resembles a
fruit tree in winter.
Who would think that those branches would turn
green
again and blossom, but we hope it, we know it."
Johann Wolfgang von Goethe
Dear Reader, With last month's bracing cold and winds, I found my head constantly bowed against the chill, tucked into my scarf - I barely paid heed to the world around me. What's there to experience in the dead of winter after all? Turns out there's plenty to discover despite winter's dormancy. In a brave excursion with the Aldo Leopold Foundation's Woodland School, students, like myself, were invited to examine layered bark, chambered pith, heart-shaped leaf scars and other tell-tale signs of tree and shrub species' uniqueness. With a scarcity of season colors, we delved into details often overlooked. In this month's Nature Net News learn how you too can distinguish tree and shrub species despite (or perhaps because of) winter's bareness. Start a winter twig collection for reference and learning, or for crafting a twig creature. And don't forget to lift your head from under your scarf and explore area Nature Net sites like this month's featured site, the UW Arboretum. Enjoy! Kathe & Betsy |
If a fruiting tree or shrub is a dioecious (pron. dahy-ee-shuh s) species (where male and female reproductive systems appear on separate plants), only the female tree or shrub will produce fruit? This is true of bittersweet, sumac, juniper, mulberry, boxelder and others.
What to Do This Month:
Look for animal tracks under a crabapple tree - often deer or even fox or coyote will visit these trees for a winter snack.
Try to identify trees by their shape or silhouette. Here's a few examples to get you started.
Search for winter berries, nuts and seed pods. Use this key to discover what you've found.
Take a "Trees in Winter" guided walk at the UW Arboretum on February 22nd.
Find other Nature Net events on the Nature Net Calendar.
Tricks of the Trail for Parents:
Winter Tree & Shrub Hike
Though a winter hike may differ - by necessity - from a summer hike, winter tree and shrub identification excursions can be fun and engaging if planned just right. Remember to bundle up (try dropping some hand warmers into your mittens and or boots) and keep the walk short. Bring binoculars (for looking at branches and buds at the tops of trees), a hand lens (for studying twig characteristics), and if you're in an area where collecting is allowed, a pocket knife or garden pruner (for snipping twigs to examine the pith). Because mittens may hinder the use of a field guide or notebook, you may want to take pictures as you go and have your guides and keys ready for indentifying when you get home. And because much can be distinguished from close inspection of a twig (see Instant Outdoor Expert), you may want to begin assembling a winter twig collection, labeling each twig once you've determined the correct species. Refer back to them before your next hike - can you spot your twigs in the wild?
Instant Outdoor Expert:
Winter Tree ID
Though the landscape is draped in white, winter is a fine time to learn the trees and shrubs in your neighborhood. We most often associate the task of identifying species with leaves and their distinct shapes. However, there are many other clues a good outdoor detective can use. Start by looking at how the twigs grow along the branch. If the twigs sprout across from each other (like our arms from our body), this is called opposite branching and only four native Wisconsin trees/shrubs grow this way: the Maple, Ash, and Dogwood. (You can easily remember these with the acronym MAD.) All other trees you find will have alternate branching, where the twigs sprout from alternating sides along the branch.
Next, look for any fruits, seeds or even leaves remaining on the plant over winter. This will help identify Sumac by the clumps of red berry-like fruits; Locust trees by the drooping legume-like pods; or Beech and some Oak trees by the dried leaves still hanging on the branch.
Though some winter sleuths use tree bark as another indicator of species, you may find the details of a twig (along with a good key) the best tools to identifying the tree/shrub in question. Start by familiarizing yourself with the anatomy of a twig. Look for buds (which will become next years leaves and flowers) along the branch (lateral buds) and at the tip (terminal bud). Many of these buds are protected by bud scales. And below the buds are scars where last year's leaves were attached. Looking closely at these scars, you can often sight where the xylem and phloem entered the leaf to transport water and organic nutrients to and from the leaf respectively - this is called the vascular bundle scar. While some twigs are smooth, others have raised spots, termed lenticels, through which air and gasses pass. And at the core of every twig is the pith. The various expressions of these parts of twig anatomy make each unique and identifiable. Some interesting examples include the heart-shaped leaf scar of the Hickory; the sharp pointed buds of the Sugar maple; the pitchfork shape of the terminal and first lateral buds on the Ash; the chambered pith of the Walnut; and the horizontal lenticels along young Cherry bark. Find more examples from About.com.
You may also find these photographs of winter twigs (arranged by species name) or this Dormant Tree ID Gallery useful.
Educators, here's a great lesson plan for winter tree identification for grades 3-5.
Featured Nature Net Site
Nature Craft
UW Arboretum
Widely recognized as the site of historic research in
ecological restoration, the UW Arboretum includes the oldest and most
varied collection of restored ecological communities in the world,
including tallgrass prairies, savannas, several forest types and
wetlands. It also houses flowering trees, shrubs and a world-famous
lilac collection. Educational tours for groups and the general public,
science and nature-based classes for all ages and abilities, and a wide
variety of volunteer opportunities for groups, families and individuals
are available.
Once a month the Arboretum offers an Earth Partnership for Families program with hikes, crafts, stories and other kid- and family-friendly activities geared to the seasons. Don't miss this month's "Sky Stories" on February 14th. You'll also want to check out weekly naturalist-guided walks on Sundays or take part in a Saturday morning Volunteer Workday.
The Visitor Center is open weekdays from 9:30 a.m. to 4 p.m. and weekends from 12:30 to 4 p.m. (excluding holidays). Arboretum trails and the Visitor Center parking lot are open year-round from 7 a.m. to 10 p.m. Other Arboretum parking lots are open from dawn to dusk.
Twiggy Creatures
After collecting twigs, nuts, seeds and other
natural materials, have fun creating all-natural animals and accessories. You can
fashion your own or use some of the ideas below to get started.
To make a horse, use a hot glue gun to glue three twigs together to make
the body. Glue a twig at one end for the neck, then add another twig for
the head, and four twigs on the bottom for the legs. Add some moss for
the tail and mane.
If you prefer a reindeer, make a body just as you did for the horse but
with a smaller head. Do not add a mossy mane or tail but affix a tiny
piece of twig standing upright for the tail. Now, add antlers by gluing
branched twigs to the head.
You can also make mini furniture. Try crafting a stool from an
upside-down acorn top or a hickory nut shell glued to three twigs formed
in a tripod. Now add the table by cutting or breaking six twigs to the
same length and gluing them together as the tabletop. Fill in the cracks
with moss and glue four small twigs to each corner for the legs.
Tip: It is better to use twigs that you find on the ground than to cut
green ones because they break more easily and are already dried and will
not shrink.
)
Suggested Reading:
"Winter Eyes" by Douglas Florian (age 4-8)
"Winter Trees" by Carole Gerber (age 4-8)
"Snow Tree" by Caroline Repchuk (age 4-8)
"Discover Nature in Winter: Things to Know and Things to Do" by Elizabeth P.
Lawlor (age 6-12)
"Winter Tree Finder" by May T. Watts (age 6-adult)
"Berry Finder: Eastern" by Dorcas S. Miller (age 6-adult)
"Winter Weed Finder: A Guide to Dry Plants in Winter" by Dor Miller (age
6-adult)
"A Kid's Winter EcoJournal: With Nature Activities for Exploring the Season"
by Toni Albert (age 9-12)
"Fruit Key and Twig Key to Trees and Shrubs" by William M. Harlow (adult)
"Wonders of the Winter Landscape: Shrubs and Trees to Brighten the
Cold-Weather Garden" by Vincent A. Simeone (all ages)
