For a property owner, having information on tree density and timber characteristics on a tract of land is valuable for many reasons:
ELOS has years of experience providing this information to clients in preparation for a sale; to assess compliance with permitted wetland/upland enhancement (including supplemental planting or thinning); for habitat management; and to provide information for mitigation planning.
How ELOS environmental scientists perform timber assessments varies, depending on the size of the land. Normally, a complete site review is possible. However, in cases where the property is too large for this to be feasible, more than sufficient data can be gathered using a statistically based arrangement of sample plots.
When this approach is required, ELOS uses one of two types of plots: fixed-area plots or variable-point sampling.
Fixed-area plots are typically round with a specified radius from the plot’s center point. This type of plot sampling is most effective in areas with variable tree densities.
Variable-point sampling uses a prism that designates the trees to be tallied based on the distance from the center point of the trunk relative to tree’s diameter. Typically these use a 10 basal-area factor (BAF) prism. Basal-area factor is a measurement of the cross-sectional, square footage of wood within an area of the tree. The technique used varies, depending on the purpose of the assessment or applicable agency requirements.
Plots are arranged systematically, typically in a grid. If stand characteristics are known and sufficiently variable, plots may be stratified so that sampling intensity is highest in areas with greater variability.
ELOS staff members have significant educational background and experience in collecting this information, including the arrangement of a sampling system, data collection, and data analysis. Depending on field conditions, plot types, and the type of data to be collected, approximately 10-20 plots can be completed in a day.