Inventory and Survey Methods for Nonindigenous Plant Species (PDF)

Chapter 3 • Landscape-Scale Wildland InventoriesTable 1. Description of data fields used in USU inventory of NIS in national parks, continued.Data Field Description Options/Values Priority EntryNotes Additional comments Can include compass bearing for photos,description of plant community other thanNIS, etc.OptionalArea ID Unique identifier for inventory area Required GPSDisturbanceCommentsComments on type and extent ofdisturbance noted in inventoryarea. If area is undisturbed, noteas such.Agriculture/Livestock grazingConstruction/DevelopmentFireFire suppressionFloodingWindGeothermalAnimal disturbance (e.g., gopher mound, buffalowallow)Irrigation/DitchesMining and quarriesOil and gas exploration/ProductionHabitat improvement projectRecreation/Visitor useRight-of-way construction/MaintenanceUtility construction/MaintenanceTrail/Outfitter/Off-road vehicle useRequiredGPS andfield notesField notesname, Integrated Taxonomic Information System (ITIS)code, life form of species, county, state, and country.Additional data elements such as datum, UTM (UniversalTransverse Mercator) zone, and source of data that pertainto the spatial data set as a whole were provided as metadatafiles.A six-person crew conducted the inventories in mostparks. When arriving at a site, crews would discuss thebest method for searching the area to achieve the requiredlevel of detection confidence for the established minimumdetection target size. Consideration of terrain, vegetationcover, expected visibility of target species, and crew sizewere all factored into setting effective detection swath widthsand other mapping techniques and standards used for eachsite. In areas that were open and in which visibility wasgenerally good, systematic coverage of the entire area wasachieved using the EDSW method. When inventorying areaswider than a single swath width, multiple parallel passesby a lone crew member (or multiple crew members walkingparallel transects or contours) were made as contiguousor slightly overlapping strips to avoid coverage gaps. Onflat or gently sloping terrain, surveyors usually searchedon parallel swaths determined by compass bearings orGPS UTM eastings/northings. This method is particularlyuseful in timbered flat terrain where it is not possible topick out landmarks on a distant horizon or to see the pathof previous swath passes. In hilly country we usually findcontouring swaths to be preferable. Contouring is definedas walking as perpendicular to the slope as possible,thus maintaining a relatively constant elevation. Havingcompleted a full pass across a slope, the surveyor movesupslope or downslope a distance equal to the swath spacingor EDSW for that terrain, and repeats the process in theopposite direction. This creates a series of parallel contiguoussearch swaths that completely cover the landscape. Thecontouring method results in representative sampling of allmicrohabitats associated with the terrain—ridges, draws,and side slopes over the full range of aspects, elevations, andplant communities. Compared to normal grid or straightlinetransect search methods, contouring also minimizesthe greater physical exertion required of surveyors on hillyterrain. Daily inventory routes of each crew member wererecorded and mapped using the BFP tracking function of theGPS units (Figure 2). The BFP tracking distance setting wasadjusted as needed to correspond to the EDSW distance.Field searches were conducted at the scale required to27Inventory and Survey Methods for Nonindigenous Plant Species