Agenda - Environmental Policy Board - 07/19/2021

Home

Title 190-Forestry Inventory Methods Technical Note Generally, survival should be assessed at 4 to 5 months after the initial planting and at least once a year until the trees and shrubs are established. This typically occurs within the first 3 years, but establishment may take longer in some geographic areas. o For evergreen plantations, it may be easier to see small trees in the late fall or winter, when the brown ground cover or snow provides more contrast to their green foliage. o For deciduous trees and shrubs, growing season (leaf -on) inspections may allow for better and easier species identification. o If very adverse conditions, such as dry weather, high predation, or heavy weed competition, are noted, a second inspection in the fall may be recommended. End of the growing season (early fall) inspections can also make it easier to locate trees and shrubs with contrasting fall foliage colors. o If deciduous trees and shrubs are inspected during dormancy, confirm survival by assessing the "suppleness" of the twig with presence of soft, current -year buds, or by scraping a very small patch to reveal green inner bark. Limit the number of scrapings by developing a general "feel" for which trees are alive. Plot Sampling Methods for Tree Planting Inventory • Circular Plots o This method is appropriate for all planting arrangements, including linear plantings, random spacing layouts, and direct seeding plantings. Generally, a 1/100th acre circular plot will work for most typical tree and shrub plantings. Larger 1/20th- and 1/5th-acre circular plots work well when tree plantings exceed a 10-foot by 10-foot spacing or for even wider spaced trees, such as those used in fruit and nut tree plantations (40-foot by 40-foot spacing). Refer to table 4 for the radii commonly used to construct plots of various sizes. Choose a plot size large enough to inventory several planted trees per plot. o Count and inspect all seedlings within the plot. If desirable natural tree and shrub regeneration help meet planting objectives, include those plants in the tally. Count every other seedling that falls directly on the edge of the plot. o To calculate the average number of seedlings per acre, total the number of live seedlings in all plots, then divide by the total number of plots. Multiply the average number of seedlings per plot by 100 (for a 1/100th-acre plot) to obtain the average number of seedlings per acre. • Linear Plots o Linear plots can be used for plantings that were installed with uniform row widths and evenly spaced trees and shrubs, (for example windbreaks, hedgerows, and other linear plantings). This method is often preferred in narrow plantings or under dense vegetation conditions, when a planting slit (or furrow) can be located. o Several variations of linear plots may be used depending on field conditions and planting scenarios. The two most common types of linear plots are assessing 10 consecutive seedlings in a row and assessing a row of seedlings over a distance of (Technical Note No. 190-FOR-01, Jul 2018) 15