A06_Attachment_B_TreeDensity.pdf

Appendix: Tree Density Protocol

Forest Inventory Supplemental Methods

Adapted from the Interior West Forest Inventory and Analysis P2 Field Procedures V7.1, for use by the EYDO

Fuels Monitoring Program. Updated: March 2018.

1.0 Safety

1.1 Safety is the top priority at all times in the field. The amount of work accomplished does not supersede the practice of safe work habits. Proper protective field gear should be worn by all crew members.

Special attention should be given to inclement weather and terrain. Safety meetings will be conducted by crew leaders to address the hazards associated with each project location. Crew members are expected to take responsibility for their own personal safety.

2.0 Plot Layout

2.1 Plots consist of four subplots approximately 1/24 acre in size with a radius of 24.0 feet. The center subplot is subplot 1. Subplots 2, 3, and 4 are located 30 meters horizontal at azimuths of 360, 120, and

240 degrees from the center of subplot 1, respectively (fig. 1). If a 25 meter spoke design is being used for AIM plots, where the end of the transect is 30 m from the monument, the forest inventory subplot centers should be placed at the terminus of the AIM transects.

Figure 1: Forest inventory plot layout.

2.2 Each subplot contains a micro plot of approximately 1/300 acre in size with a radius of 6.8 ft. The center of the microplot is offset 90° and 12.0 ft horizontal from each subplot center. Microplots are used to select and collect data on saplings (DBH/DRC of 1.0 inch through 4.9 inches) and seedlings (DBH/DRC less than 1.0 inch in diameter and greater than 0.5 ft in length (conifers) or 1.0 ft in length (hardwoods).

*In post-treatment and burned area environments that have exceptionally low density of seedlings and saplings, the 24.0’ radius subplot may be used for seedling and sapling density to better estimate the density of trees for the area.

3.0 Tree Diameter

3.1 Live trees should be tallied as one of the following diameter classes:

• Seedlings 0.0 – 0.9 inch diameter

• Saplings 1.0 – 4.9 inch diameter

• Pole 5.0 – 8.9 inch diameter

• Medium 9.0 – 19.9 inch diameter

• Large 20.0 – 32.9 inch diameter

• X-Large 33.0 inches or greater

3.2 For all live trees not mentioned below, diameter should be measured at DBH (4.5 ft, on the uphill side of the tree). If the tree forks below DBH, the stems count as separate trees. If a fork is at DBH, measure the diameter just below and swelling caused by the fork. If there is swelling at DBH, measure just above the swelling.

3.3 With woodland species, diameter should be measured at the root collar (DRC). Measure at the ground line or the stem root collar, whichever is higher. For these trees, treat clumps of stems having a unified crown and common root stock as a single tree. Treat stems of woodland species as individual trees if they originate below the ground.

3.4 The following table includes a list of woodland species most likely to be encountered on the Ely District.

For the exhaustive list of trees to be measured at DRC, refer to Appendix 3 of the FIA P2 Field

Procedures.

Plant Code Genus Species Common Name

JUOS Juniperus osteosperma Utah juniper

JUSC2 Juniperus scopulorum Rocky Mountain juniper

PIMO Pinus monophylla singleleaf pinyon

CELE3 Cerocarpus ledifolius curl leaf mountain-mahogany

ACGL Acer glabrum Rocky Mountain maple

PUST Purshia stansburiana Stansbury cliffrose

3.5 When measuring woodland stem diameters: Measure just above any swell present, and in a location so that the diameter measurements are a good representation of the volume in the stems (especially when the trees are extremely deformed at the base). Stems must be at least 1 foot in length and at least 1.0 inch in diameter 1 foot up from the stem diameter measurement point to qualify for measurement.

Whenever DRC is impossible or extremely difficult to measure with a diameter tape (e.g. due to thorns or extreme number of limbs), stems may be estimated and recorded to the nearest 1.0-inch class.

3.6 The following figure provides examples of where to measure DRC with various branching forms.

3.7 When measuring multi-stemmed trees, compute DRC. Only count stems with at least one stem 1 foot in length at least 1.0 inch in diameter 1 foot up from the measurement point. DRC is computed as the square root of the sum of the squared stem diameters.

DRC = √∑ 𝑑𝑖

2𝑛 𝑖=1 n = number of live and dead stems at DBH or DRC with diameter 1 inch or larger di = stem diameter (inches)

4.0 Tally Trees

4.1 Trees are alive if they have any living parts (leaves, buds, cambium) at or above the point of diameter measurement, either diameter at breast height (DBH) or diameter at root collar (DRC). Trees that have been temporarily defoliated are still alive. Ignore dead trees.

4.2 Multiple suckers that originate from the same location, and stump sprouts are considered one seedling.

Do not tally any seedling that sprouts from a live tally tree.

4.3 Tree: Trees at least 5.0 inches in diameter are samples within the subplot.

4.4 Sapling: Trees with a diameter at least 1.0 inch but less than 5.0 inches are sampled within the microplot.

4.5 Seedling: Conifer seedlings must be at least 6.0 inches in length and less than 1.0 inch at DBH/DRC in order to qualify for tallying. Hardwood seedlings must be at least 1.0 ft in length and less than 1.0 inch at DBH/DRC in order to qualify for tallying. Seedlings are sampled within the microplot. They must be at least the specified height because many below the height will die off and therefore not correlate to regeneration.

4.6 A separate table should be used for each tree species.

Species:

dbh (in) Center Transect 1 Transect 2 Transect 3

X-Large > 33 total = total = total = total =

Large 21-33 total = total = total = total =

Med.

10-20 total = total = total = total =

Pole 5-9 total = total = total = total = sapling 1- 5 in total = total = total = total = seedling <1 in total = total = total = total =

Sample tree inventory data sheet.

4.7 Reporting of tree density uses two groupings. The seedlings and saplings (Seed_Sap) are grouped together to represent regeneration and the pole and larger (Pole_Plus) classes are grouped to represent established trees.