Lecture 3bWriting Soil Profile Descriptions and Forest Soils

Writing Soil Profile Descriptions

First step- prepare suitable pedon for describing

Stand back and view the horizons from a distance

Determine approximately how many distinct horizons are present.

Collecting the data to write the soil morphology description

Soil location – Pipestone County, SW Mn. This soil has 4

horizons Determine the

colors, structure, texture, add HCl, look for unusual features, Select the name of horizon, and classify the soil.

1 = 10yr 2/1 gr -Loam 2 = 10yr ¾ sbk -Loam 3 = 2.5y 4/4 and has

CaCO3 concretions – sbk Effervescence. -Loam

4 = 2.5y 5/4 massive structure and CaCO3 concretions and Effervsence.- Loam

Name the Horizons

A Bw

Bk

Ck

Forest Soils Forest trees depend

directly upon the soil for physical support, nutrition, and water

The importance of soils in the life and health of the forest has not been understood until recent years.

The need for management of agricultural soils has been studied for a hundreds years.

German scientists were the first to actively established the importance of soils and the role they play in forestry.

Other German scientists recognized that forest soils were most fertile where there were no

removals of forest products,

and poorest where removals were intensive.

Courses in Forest Soils in the U.S.

Forest soils courses were at Yale, Duke , Cornell, and Wisconsin prior to 1945.

As more observations were made of the relationship between soil properties and forest growth, the case for the study of forest soils was made.

Forest Soil Characteristics O Horizons- Duff

layer E horizons Leached horizons,

More acidic Drip Line influence

on soil

Drip Line – more water deposited under the tree due to the canopy catching water

Greater influence where trees are in the open – not a thick forest

Tree fall and root tip up

1. Tap root (hickory, walnut, butternut, white oak, hornbeam)

2. Heart root (red oak, honey locust, basswood, sycamore, pines)

3. Flat root (birch, fir, spruce, sugar maple, cottonwood, silver maple, hackberry)

Forests with more #3 will have more tip ups.

When a tree falls over and the root mass tips upward, the soil will remain in place for a few years. Gradually the soil is eroded around the decaying root mass.

Over time the area of root tip is left higher than the area from which it came. The forest gradually becomes a series of micro hills and swales.

http://www.hubbardbrook.org/yale/watersheds/w6/west-of-6-stop/soil.htm

DYAD

Describe where you have obtained an experience in a forest.

What do you remember most about this experience?

US Forest Service Research is centered on two areas of work: First is work on nutrient cycling, plant nutrition, soil moisture, plant growth relationships, soil microbiological

functions soil quality.

Second = general area of pollution involving:

Sedimentation from soil, chemical deposition and

water flow through ecosystems.

Main research objective : enhance soil and ecosystem sustainability.

This joint National Forest System and Forest Service Research and Development project was initially established to evaluate timber management impacts on long term soil productivity

To increase the accuracy of the study, monitoring efforts want to:

1) Calibrate changes in soil properties against: 1. stand productivity (trees only)2. total productivity (all forest vegetation)

2) Evaluate and improve field monitoring methods.

3) Find ways to extend results to other sites.

Objectives:

1. Quantify the effects of soil disturbance on soil productivity,

2. Validate standards and methods for soil quality monitoring, and

3. Understand the relationships between soil properties and forest management practices.

Findings from this research will show how changes in site

organic matter and soil porosity affect

forest health, productivity, and sustainability.

LTSP research focuses on the role of soil porosity and organic matter and their effect on the site processes that control productivity.

Long Term Soil Productivity (LTSP) system = experimental sites studied with universities, on the National Forests

The experiments are designed to create varying degrees of stress and to provide measures of biological response and soil recovery.

Sites are on soil types across the nation and are dedicated to long-term research.

Brian Palik and Randy Kolka Silviculture and Forest Soils Research

USDA Forest Service - Grand ,Rapids, MN 55744- stationed at Marcel, MN

http://nrs.fs.fed.us/people/kolkahttp://nrs.fs.fed.us/units/crec/

Principal Investigators for (LTSP) research in aspen forests of the Lake States Objectives :

(1) determine how changes in soil porosity and organic matter content affect the fundamental processes controlling forest productivity and sustainability;

(2) compare responses among major forest types and soil groups in North America

The experimental design is with three levels each of

organic matter removal and soil compaction.

Levels of organic matter removal are: (1) bole only harvest (10 cm top diameter); (2) total tree harvest (all aboveground biomass); and (3) total tree harvest plus forest floor removal.

Levels of soil compaction were designed to increase bulk density of the surface 30 cm of soil by 0%, 15%, and 30%.

Studies are in progress on the Marcell Experimental Forest (1991) and on the Ottawa (1992), Chippewa (1993), and Huron Manistee (1994) National Forests.

Similar Study on Commercially Logged Sites

Purpose: To establish linkages between experimental results and actual field conditions on commercially logged sites

Note: the study of forests soils is similar to the study of agricultural soils – determine the management needed for sustained yield and still protect the environment.

Forest Trail near Marcel, MN