Tuesday, December 4, 2018

Episode 449 (12-3-18): Tree Buds and Water

Click to listen to episode (4:47).

Sections below are the following:
Transcript of Audio
Audio Notes and Acknowledgments
Related Water Radio Episodes
For Virginia Teachers (Relevant SOLs, etc.)

Except as otherwise noted, all Web addresses mentioned were functional as of 11-30-18.


From the Cumberland Gap to the Atlantic Ocean, this is Virginia Water Radio for the week of December 3, 2018.

MUSIC – ~ 10 sec

This week, that excerpt of “Hiking in the Highland Firs,” by Timothy Seaman of Williamsburg, Va., opens an episode on a tree structure that’s prominent during wintertime in temperate climate zones, like that of Virginia.  Have a listen for about 15 seconds to some of the weather that trees endure during a Virginia winter, and see if you can guess this structure.  And here’s a hint: if you don’t know this, you might ask a buddy.

SOUNDS - ~15 sec - Wind in oak leaves

If you guessed tree buds, you’re right!  Buds are one of woody plants’ adaptations for surviving winter’s cold temperatures, drying conditions, and damaging winds.  Buds contain meristematic tissue, the tissue that will be future growing stems or flowers.  Sometimes woody plant buds include only the meristematic tissue, but more typically that tissue is covered by small, folded leaves and modified leaf structures called bud scales.  Just like a tree’s leaves, buds have distinctive shapes and colors, allowing tree identification when leaves are gone.

Flowering trees form both vegetative and flower buds.  The vegetative buds can be at the end of twigs or along the length of twigs in the axils where leaves attach. Flower buds may look very different from vegetative buds, for example, as in the Flowering Dogwood.  Various other kinds of buds can occur, as well.  Non-flowering trees—that is, conifers, the cone-bearing trees, such as pines, spruces, and firs—also have vegetative buds that can develop into stems or into cones.

In temperate climates, buds typically form at some point during the growing season and then become dormant—that is, stop actively growing—during the winter.  In spring, in response to hormones and environmental conditions, bud dormancy ends as the buds open and the enclosed tissues begin developing and growing.  But there’s much variation among species, and even among individuals within a species, in patterns and timing of bud formation, dormancy, and activity.

Now, what makes woody plant buds particularly a water story?  Here are three answers to that question.  First, the availability of water during bud formation in one year can affect how much tissue is stored in the bud for growth and development the following spring.  Second, the meristematic tissue in a bud is protected from drying out by the covering bud scales and undeveloped leaves.  And third, while buds don’t protect plant cells from freezing, their role in preventing dehydration contributes to the plant’s ability to withstand injury from freezing temperatures.

As winter covers Virginia, some of the history—and water—of last summer, along with the future of next spring are already folded into the buds of the Commonwealth’s trees.

Thanks to Timothy Seaman for permission to use this week’s music, and we close with about 20 more seconds of “Hiking in the Highland Firs.”

MUSIC – ~ 22 sec


Virginia Water Radio is produced by the Virginia Water Resources Research Center, part of Virginia Tech’s College of Natural Resources and Environment.   For more Virginia water sounds, music, or information, visit us online at virginiawaterradio.org, or call the Water Center at (540) 231-5624.  Thanks to Stewart Scales for his banjo version of Cripple Creek to open and close this show.   In Blacksburg, I’m Alan Raflo, thanking you for listening, and wishing you health, wisdom, and good water.


“Hiking in the Highland Firs,” from the 2001 album “Common Wealth,” is copyright by Timothy Seaman and Pine Wind Music, used with permission.  More information about Timothy is available online at http://www.timothyseaman.com/.   “Hiking in the Highland Firs,” written in honor of Virginia’s Grayson Highlands State Park, was previously featured in Virginia Water Radio Episode 320, 6-13-16, on Virginia’s state parks.

The sound of wind in oak leaves was recorded by Virginia Water Radio in Blacksburg, Va., on March 15, 2013.

Click here if you’d like to hear the full version (1 min./11 sec.) of the “Cripple Creek” arrangement/performance by Stewart Scales that opens and closes this episode.  More information about Mr. Scales and the group New Standard, with which Mr. Scales plays, is available online at http://newstandardbluegrass.com.

Virginia Water Radio thanks Jen Gagnon, John Peterson, and John Seiler, all of the Virginia Tech Department of Forest Resources and Environmental Conservation, for their help with this episode.


Yellow Buckeye leaves in an opening bud in Blacksburg, Va., April 1, 2010.

The four photos below, all of buds of native Virginia trees, are courtesy of the Virginia Tech Department of Forest Resources and Environmental Conservation, “Dendrology Fact Sheets,” online at http://dendro.cnre.vt.edu/dendrology/factsheets.cfm.

American Sycamore

Black Walnut

Shagbark Hickory

Shortleaf Pine


Used for Audio
Paul J. Kramer and Theodore T. Kozlowski, Physiology of Woody Plants, Academic Press, New York, 1979.

Steven G. Pallardy, Physiology of Woody Plants, Third Edition, Elsevier/Academic Press, Burlington, Mass., 2008.  (This book is a revision of the 1979 book by Kramer and Koslowski listed above.)

Texas A&M University AgriLife Extension, “How Trees Grow,” online at https://agrilife.org/treecarekit/introduction-to-tree-care/how-trees-grow/.

University of California-Davis/Fruit and Nut Research and Information Center, “Vegetative and Floral Tissue Development,” online at http://fruitandnuteducation.ucdavis.edu/generaltopics/AnatomyPollination/VegetativeFloral_Development/.

For More Information about Trees

Sanglin Lee and Alan Raflo, “An Introduction to Trees in Virginia and Their Connections to Water,” Virginia Water Resources Research Center, December 2011; available online from the Virginia Water Central News Grouper, at http://vawatercentralnewsgrouper.wordpress.com/2011/12/07/an-introduction-to-trees-in-virginia-and-their-connections-to-water/.

T.J. Brandeis et al., “Forests of Virginia 2012,” U.S. Forest Service, published 2017, online at https://www.fs.usda.gov/treesearch/pubs/54555.

Virginia Tech Department of Forest Resources and Environmental Conservation, “VTree,” online at http://dendro.cnre.vt.edu/dendrology/index.html.  This is the Web site for the dendrology course by Dr. John Seiler in Virginia Tech’s Department of Forest Resources and Environmental Conservation.  It offers identification keys and fact sheets to trees and other woody plants throughout North America. This site also has links to download the VTree Mobile App.

Virginia Department of Forestry, “Virginia’s Forests,” online at http://dof.virginia.gov/stateforest/index.htm; and “Forest Facts,” online at http://dof.virginia.gov/stateforest/facts/index.htm.


All Water Radio episodes are listed by category at the Index link above (http://www.virginiawaterradio.org/p/index.html).  See particularly the “Plants” subject category.

Following are links to some other episodes relevant to trees or shrubs.
Ash trees – Episode 376, 7/10/17.
Flora of Virginia – Episode 354, 2/6/17.
Forestry – Episode 160, 5/6/13.
Maple trees – Episode 84, 10/17/11.
Rhododendrons – Episode 216, 6/2/14.
Sycamores – Episode 176, 8/26/13.
Tree colors and changes in fall – Episode 285, 10/9/15.
Tree structures for water movement – Episode 285, 10/9/15.
Trees' human and ecological benefits – Episode 153, 3/18/13.
Witch Hazel – Episode 238, 10/31/14.


The episode—the audio, extra information, or sources—may help with the following Virginia Standards of Learning (SOLs).

2013 Music SOLs

SOLs at various grade levels that call for “examining the relationship of music to the other fine arts and other fields of knowledge.”

2010 Science SOLs

Grades K-6 Earth Patterns, Cycles, and Change Theme
3.8 – Basic patterns and cycles in nature.

Grades K-6 Earth Resources Theme
4.9 – Va. natural resources, including watersheds, water resources, and organisms.

Grades K-6 Life Processes Theme
K.7 – basic needs and processes of plants and animals.
2.4 – life cycles.
4.4 – basic plant anatomy and processes.

Grades K-6 Living Systems Theme
5.5 – cell structures and functions, organism classification, and organism traits.

Life Science Course
LS.1 – understanding of scientific reasoning, logic, and the nature of science, including current applications to reinforce science concepts.
LS.3 – cellular organization, including cells, tissues, organs, and organ systems.
LS.4 – organisms’ classification based on features.

Biology Course
BIO.1 – current applications to reinforce science concepts.
BIO.8 – dynamic equilibria and interactions within populations, communities, and ecosystems; including nutrient cycling, succession, effects of natural events and human activities, and analysis of the flora, fauna, and microorganisms of Virginia ecosystems.

Virginia’s SOLs are available from the Virginia Department of Education, online at http://www.doe.virginia.gov/testing/.

Following are links to Water Radio episodes (various topics) designed especially for certain K-12 grade levels.
Episode 250 (1-26-15) – on boiling, for kindergarten through 3rd grade.
Episode 255 (3-2-15) – on density, for 5th and 6th grade.
Episode 282 (9-21-15) – on living vs. non-living, for kindergarten.
Episode 309 (3-28-16) – on temperature regulation in animals, for kindergarten through 12th grade.
Episode 332 (9-12-16) – on dissolved gases, especially dissolved oxygen in aquatic habitats, for 5th grade.
Episode 403 (1-15-18) – on freezing and ice, for kindergarten through 3rd grade.
Episode 404 (1-22-18) – on ice on ponds and lakes, for 4th through 8th grade.
Episode 406 (2-5-18) – on ice on rivers, for middle school.
Episode 407 (2-12-18) – on snow chemistry and physics, for high school.