Agenda - Planning Commission - 08/26/2021

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Title 190-Forestry Inventory Methods Technical Note FORESTRY INVENTORY METHODS General Information Title 180, National Planning Procedures Handbook (NPPH), Part 600, Subpart C, Section 600.23, "Inventory Resources," describes the resource inventory process used to collect information about a planning area's resources and related offsite information. Inventory information is used to determine the condition and trends of the resources, identify resource concerns and opportunities, and formulate and evaluate the effects of alternatives. The level of detail needed for an inventory depends on the level of planninga forest management plan may utilize generalized information while a practice implementation plan will often require greater detail and statistical reliability. This technical note provides a description of the common inventory methods and tools used in forestry and agroforestry applications and describes the methods used to conduct resource inventories that support planning processes for forestland. Forest land is defined in Title 440, Conservation Programs Manual, Part 502, Subpart A, Section 502.0, "Definitions," as "a land cover/use category that is at least 10 percent stocked by single -stemmed woody species of any size that will be at least 4 meters (13 feet) tall at maturity. Also included is land bearing evidence of natural regeneration of tree cover (cut over forest or abandoned farmland) that is not currently developed for nonforest use. Ten -percent stocked, when viewed from a vertical direction, equates to an aerial canopy cover of leaves and branches of 25 percent or greater. The minimum area for classification as forest land is 1 acre, and the area must be at least 100 feet wide." Forest Stand Inventory Stand Mapping Prior to conducting an inventory, forested areas are mapped into relatively homogenous units (i.e., stands). Stands are relatively uniform with respect to aspect, dominant crown class, stocking density, species composition, landforms, etc. Information used for stand mapping includes using orthophotos, topographic images, soil maps, and ecological site descriptions. Information on geology, wetlands, and vegetation may also be useful. Refer to Web Soil Survey at website https://websoilsurvey.sc.egov.usda. og v/App/HomePage.htm for detailed soils information. Stand boundaries can be refined in the field with spatial data. Choice of Inventory Methods Generally applied methods for inventorying forest stands include point sampling (also known as variable -radius plot sampling) and fixed plot sampling. Methods applicable to specific situations, depending on stand conditions and objectives of the inventory, include strip sampling, line transect sampling, crop -tree inventory, and the zig-zag transect. The method chosen must be appropriate for the geographic location and condition of the stand and efficient with regard to information collected in a given amount of time. ❑ (Technical Note No. 190-FOR-01, Jul 2018)