Forest Soils RRET 2274

Upon successful completion, the student will be able to:

Module 1 - Introduction to Forest Soils

• Discuss the meaning and value of soil science.
• Describe why geomorphology can be important to soil science.
• List the five factors responsible for soil formation.

Module 2 - Physical Properties of Soils

• List the names and particle sizes of the soil separates used to analyse soil texture.
• Determine the textural class of a soil, given the use of a texture triangle and adequate information concerning the percentage of coarse fragments in the total soil and the percentage of clay and sand in the fine earth fraction.
• Determine the textural class of a soil, given data collected by hand texturing.
• Determine the structural class of a soil.
• Discuss the effects of particle density and bulk density on the volume of soil pore space and root penetration.
• Describe the meaning of each of the symbols used to represent soil colour in the Munsell system of notation.
• Provide definitions of soil texture, separate, soil structure, coarse fragments, fine earth fraction, aggregate, bulk density, particle density, mineral soil, organic soil, hue, value, and chroma.

Module 3 - Soil Water Retention and Flow

• Explain the importance of adequate drainage and aeration to plants.
• Compare samples and descriptions of different soils according to how well they will:
• Retain water,
• Conduct water in response to comparable driving forces,
• Supply oxygen to plant roots,
• Resist frost heaving and surface frost,
• Resist damaging increases in temperature at the surface,
• Warm and cool in the root zone.
• Discuss the effects of:
• Soil water tension on soil water content, and vice versa,
• Soil water tension on the availability of water to plant life,
• Soil structure and texture on soil water tension and water content,
• Soil water content on hydraulic conductivity,
• Soil texture on hydraulic conductivity,
• The available water storage capacity,
• Hydraulic conductivity on frost heaving,
• Water or organic matter content on thermal conductivity and heat capacity, and on the ratio between these two.
• Define the terms aerobic, anaerobic, hydraulic conductivity, hydraulic equilibrium, soil water tension, permanent wilting point, available water storage capacity, field capacity, high and low heat capacity, low and high thermal conductivity.

Module 4 - Engineering Classification of Soils

• Perform related operations based on an understanding how soil information has been collected, namely:
• Recognize and (or) describe the sieves and the procedures used in particle-size grading,
• Determine whether a soil is well or poorly-graded by plotting its grain-size curve from a table of appropriate sieve data,
• Determine whether a poorly-graded soil is uniform or gap-graded on the basis of its grain-size curve,
• Recognize and describe the equipment and procedures used to determine plastic and liquid limits,
• Calculate the plasticity index of a soil provided you are given its plastic and liquid limits,
• Describe the characteristics of the organic soils introduced in the module,
• Classify a soil according to the Unified system, provided you are given its sieve and consistency data together with adequate information concerning the proportion of organic matter it contains.
• Define the following terms: plastic limit, liquid limit, well-graded, uniform, gap-graded, non-plastic, clean (as with gravel or sand).

Module 5 - Soil Chemical Properties and Soil Fertility

• List the names and standard symbols of the fifteen most important chemical elements necessary to tree growth.
• List the major sources of most forest tree nutrients.
• Describe how the availability of selected nutrients can be estimated through an evaluation of:
• Soil pH,
• Soil drainage,
• Soil colour and texture,
• The C/N ratio.
• Describe the effects of poor drainage on soil toxicity.

Module 6 - Forest Floors and Soil Organic Matter

• Describe the horizon sequences and the conditions which account for the formation of:
• A mull forest floor,
• A mor forest floor,
• A moder forest floor.
• Discuss the conditions which favour the formation of an organic soil.
• Describe the conditions which affect the rate at which a forest floor accumulates.
• Describe the effects of the forest floor on:
• Soil temperature,
• The cation exchange ratio,
• Soil water retention and soil erosion,
• The C/N ratio,
• Soil pH.
• Define the following terms: L Horizon or Litter layer, forest floor, F Horizon, H Horizon, Mull, Moder, Mor, steady state, Folisol.

Module 7 - Soil Horizons

• Explain the meaning of the symbols used to classify the organic horizons and the master mineral horizons.
• Explain the reasons for using lower case and Arabic numeral suffixes and Roman numeral prefixes to classify soil horizons.
• Explain how to classify a soil horizon, given its description and an appropriate classification table.

Module 8 - Introduction to Soil Classifications

• Explain the five levels of soil classification and how they are related to one another.
• Explain how to determine the order, great group, and subgroup classification of a forest soil, given its description and the appropriate tables.
• Explain how the factors of soil formation affect soil classification.
• Explain the uses and limitations of classification at the order, great group, and subgroup levels.

Module 9 - The Field Examination of Forest Soils

• List sources of published information that should be consulted in preparing for a field examination.
• Explain the properties and characteristics that should be recorded during a short examination.
• Explain what other clues to productivity might be utilized.
• Explain how to determine the drainage class of a soil.

Module 10 - Soil Survey Reports

• List the kinds of information recorded in a soil survey report.
• Describe the implications of map scale.
• Describe the implications of soil variability.
• Explain how the mapping of small units is accomplished.
• List the sources of error in soil identification.
• List common deficiencies in soil maps and survey reports.
• Complete a sample soil report.

Effective as of Fall 2003