Croatan Long Term Soil Productivity (LTSP) Study
Objectives
The Croatan National Forest Long Term Soil Productivity study site
is part of an internationally coordinated study whose objectives are
to:
- Measure the interactions of soil and site disturbance on long-term
productivity.
- Validate USDA Forest Service soil quality monitoring standards and
develop effective monitoring techniques for evaluating the long-term
impacts of management practices.
- Understanding how soil and site disturbances affect the fundamental
processes controlling productivity.
Design
The Croatan LTSP site is a 3 x 3 factoral split-plot design, replicated
in 3 blocks. The main effects are 3 levels of organic matter removal
and 3 levels of soil compaction. The split-plot effect is competition
control, usually in the form of chemical herbicide. In addition, 1 treatment
plot per block represents an ameliorated treatment of bedding and fertilizing.
View the Croatan LTSP map.
Each plot is numbered a certain way:
- The first number represents the treatment block. Since there are
three blocks they are numbered 1, 2, or 3.
- The second number represents a level of organic matter removal:
- 0 = Bole only removal
- 1 = Bole and branch removal
- 2 = Bole, branch, and 100 percent organic matter layer removal
- 3 = Bole and branch removal (ameliorated treatment of bedding
and fertilizing)
- The third number represents level of soil compaction
- 0 = No compaction
- 1 = Moderate compaction
- 2 = Severe compaction
- 3 = Moderate compaction (with ameliorated treatment of bedding
and fertilizing)
- The forth number represents herbicide treatment
- 0 = No herbicide
- 1 = Herbicide
For example, plot 2121 is in block 2, the tree bole and branches were
removed, the plot received severe compaction, and received herbicide
treatment.
Past Research and Measurements
- pre and post treatment bulk density measurements
- pre and post treatment plant community descriptions
- Measurements of nitrogen and phosphorus mineralization by treatment
- Soil microarthropod abundance
- Monthly apical bud growth
- Soil moisture using time domain reflectometry (TDR) probes
- Soil strength using penetrometer
- Needle carbohydrate and nutrient concentrations
- Root growth
Current Measurements and Studies
- Weather conditions
- Tree height growth
- Crown length and diameter
- Diameter at breast height
- Bulk density measurements at the 10th growing season
- plant community descriptions at the 10th growing season
- Whole tree planted pine bimass at the 10th growing season
- Soil nutrients at the 10th growing season
- Nitrogen forms
- Soil CO2 efflux
- Rotting log decomposition
- Litter decomposition
Cooperators
Other LTSP Site Locations:
- California
- Idaho
- Louisiana
- Michigan
- Mississippi
- Missouri
- Texas
- British Columbia, Canada
- Ontario, Canada
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