3: How Trees and Woodlands Grow

Activities: How Trees and Woodlands Grow

How these activities will help you as a woodland owner:

This chapter and its activities help you learn about the parts of a tree so you can better communicate with a forester, logger or other forestry professional. These activities will help you determine which tree characteristics you want to encourage on your land by considering genetically controlled characteristics, live-crown ratio, and shade tolerance. Learn how soil type, topography, and climate must be considered when determining the most appropriate tree species to encourage on your land. Finally you will learn that managing a stand is easier when you let the natural ecological trajectory occur.

Step 1: Learn more about the parts of a tree

  • Step 1A: Read the section “How Trees Grow: Parts of a Tree”.
  • Step 1B: Review Figure 3-1, then find a standing tree and a fresh-cut log or stump and identify their parts:
      • Crown
      • Trunk
      • Roots
      • Outer bark (phloem)
      • Inner bark (xylem)
      • Cambium layer
      • Sapwood
      • Heartwood
  • Step 1C: If you are not certain about the location of these tree parts, talk to a forester when one visits your property.  Knowing these terms and being able to find these tree parts is helpful for communicating with a forester, logger, or other woods worker and these terms are used elsewhere in this book.

Step 2: Find out how genetics affects tree form and growth

  • Step 2A: Genetics affects many aspects of tree form and growth, including, but not limited to, the rate of height and diameter growth, stem form, crown form, tendency to self-prune, angle of branch attachment, and tolerance to insects and diseases. Considering your goals for your property, make a list of tree attributes that you want to encourage in your woodland. Discuss these attributes with your forester and agree on which ones are best for your property.
  • Step 2B: Use the tree attributes identified in Step 2A when conducting timber stand improvement (TSI) practices and timber harvests. They will guide which trees are cut because of poor quality and which trees are left because they exhibit the traits you want to encourage in the present stand or through natural reproduction. For example:
    • During TSI, remove trees with undesirable attribute because they are competing with other trees with more desirable attributes.
    • During a harvest that leads to natural regeneration, remove undesirable trees so they do not pass on their poor genetic attributes in their seeds, stump sprouts, or root suckers.
  • Step 2C: When planting seeds, seedlings, or cuttings, order planting materials from a reputable tree nursery that collects seed or cuttings from high quality trees growing as close to your planting site as possible.

Step 3: Determine live-crown ratio

  • Step 3A: Knowing the live crown ratio of your trees, especially conifer trees (e.g., pine, spruce, fir, tamarack), will help you judge whether a tree crown is too small or too large to foster rapid tree growth while producing as much knot-free wood on the main stem as possible. If you have a stand of conifers, evaluate the live crown ratio of that stand. Use the text and Figure 3-2 as a guide to measuring live-crown ratio. Research or ask a forester what live-crown ratio is best for the tree species you are growing.If the live-crown ratio is too big (say 60%), that may mean the stand is fairly young and the crowns have not begun to compete. You may need to allow the stand to continue growing. Or to produce high quality wood on potentially valuable trees, you could consider clear-stem pruning to eliminate limbs and encourage more knot-free wood in the main stem.

    If the live-crown ratio is too small (say less than 30%), tree growth may be too slow. Thinning the stand will provide more space for crowns to expand and thus stimulate growth of your best crop trees.

  • Step 3B: Ask your forester for guidance on how to manage your stand with thinning and/or pruning to achieve a desirable live-crown ratio for optimum growth and wood quality.

Step 4: Determine shade tolerance of your trees

  • Step 4A: Review the text on shade tolerance and Table 3-1.
  • Step 4B: Note the shade tolerance rating for tree species that you want to favor in your woodland.
  • Step 4C: If there are important tree species on your land that are not listed here, you can look up those species in Silvics of North America and read about their shade tolerance (see Additional Resources section).
  • Step 4D: Shade tolerance is an especially important factor when you are trying to regenerate a stand.  If you have a stand that is ready to regenerate, walk through the stand and identify the species of seedlings and saplings growing there.If the canopy is very dense, the seedlings and saplings will likely be shade tolerant tree species. Depending on your objectives and the site conditions, these may or may not be the most desirable species. If these are desirable species, a harvest will release them to produce your next stand. If these are undesirable species, you may need to control them and open the stand to give adequate light to desirable species. Planting trees or seeds is another means to regenerate desirable species, but they must have appropriate amounts of light to sustain growth. Regeneration systems are explained in Chapter 4: Regenerating Woodland Stands and regeneration systems appropriate for each forest type are explained in Chapter 6: Managing Important Forest Types.
  • Step 4E: Ask a forester to help you develop a plan to regenerate a stand. That plan should spell out how light will be managed to encourage the new trees.

Step 5: Determine how site characteristics influence your trees and woodlands

  • Step 5A: Read the section “Effects of Site Characteristics: Soil Depth, Texture, Moisture, Fertility, and pH”.
  • Step 5B: It is important to match tree species to the soils on which they grow best, but soil types vary across the landscape, especially as topography changes. Learn about the soil types on your land. A good source for soil type maps and descriptions is the USDA Natural Resources Conservation Service (NRCS), Web Soil Survey. You can also ask your local soil and water conservation district for a soil type map that covers your property and a description of each type, including which tree species grow best.
  • Step 5C: Read the section “Effects of Site Characteristics: Topography”.
  • Step 5D: Evaluate soil texture in different areas of your woodland where there is a change in landscape position, slope, and aspect. It may help to dig a three-foot hole where possible to verify soil texture at different depths and match that information with the soil descriptions for your property.
  • Step 5E: Using NRCS information about the tree species best suited to soils that occur on your property, make a list of those tree species for each soil type. Review this list with your forester to verify its accuracy.
  • Step 5F: Make a list of which tree species to encourage on each part of your property, taking into consideration, the forest type, soil type, landscape position, and your property goals.

Step 6: Determine how your woodland grows

  • Step 6A: Read the section “How Woodlands Grow”.
  • Step 6B: Ask your forester to evaluate the natural ecological trajectory of each stand on your property.  Consider that information when choosing goals for each stand on your property.It usually is appropriate to choose management practices that encourage tree species that are best adapted to your sites. Sometimes management practices can interrupt the natural ecological trajectory to encourage a different species mix that better meets your goals for a stand, but this may come at a higher cost and with ecological tradeoffs.
  • Step 6C: Ask your forester to recommend different management options for each stand that considers its ecological condition and your management goals.


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Woodland Stewardship: A Practical Guide for Midwestern Landowners, 3rd Edition Copyright © 2019 by University of Minnesota Extension is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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