Inventory and Survey Methods for Nonindigenous Plant Species (PDF)

Chapter 3 • Landscape-Scale Wildland InventoriesThe USU method primarily uses English units(feet, yards, and acres). Metric conversionsare summarized here.YardsUnits of LengthMeters25 22.950 45.7100 91.4150 137.2200 182.9250 228.6300 274.3Units of AreaAcres Hectares Meters 20.001 — 4.00.01 — 40.50.1 — 404.70.25 0.1 1011.70.5 0.2 2023.41.0 0.4 4046.92.5 1.0 10117.15 2.0 20234.3usually mapped as a single population. The PSR for a typicalproject was 50 yards.Detection Confidence (DC): The percentage of the totalnumber of infestations that crew members estimate theywere able to find in a searched area, based on the likelihoodof seeing patches of the established minimum detectiontarget size of the least visible target species in that terrain.Detection confidence is essentially meaningless without alsostating the growth stage of the target species and the MDTSassociated with that DC. The minimum required DC set formost of our projects was 90%, based on an MDTS of 0.01acre for plants of the least visible target species in a matureor flowering stage of growth.Between-Feature Positions (BFP): A series of location pointsrecorded automatically by global positioning system (GPS)units that indicate daily search routes traveled by each crewmember. The distance interval for collecting BFPs was generallyset to correspond to the average effective detection swathwidth (EDSW) for each area inventoried/surveyed. The BFPcan be used to demonstrate that an area was searched but notarget species were located; i.e., to create presence/absencedata, which are useful for both future searches and statisticalanalysis of data.Case StudyPerhaps the simplest way to illustrate some of the methodsand standards used by USU is to provide an example of arecent NIS mapping project. It will also place readers in abetter position to decide whether or not the USU methodmight fit their own mapping needs. The following is takenfrom a report summarizing an NIS inventory conducted byUSU in portions of twelve national parks in southern Utah(Dewey et al. 2003). This project would probably fall into theextensive mapping category (see Chapter 1).Utah State University conducted a two-year project toinventory and map selected NIS targeted for control bythe Northern Colorado Plateau Network of the NationalPark Service in selected areas of the network. The projectincluded portions of Arches National Park, Black Canyonof the Gunnison National Park, Bryce Canyon NationalPark, Canyonlands National Park, Capitol Reef NationalPark, Cedar Breaks National Monument, Colorado NationalMonument, Dinosaur National Monument, HovenweepNational Monument, Mesa Verde National Park, NaturalBridges National Monument, and Zion National Park.The principal objective of this project was to documentthe distribution and abundance of the targeted species ona total of 95,738 acres within the designated parks. It wasanticipated that these data would provide baseline informationuseful in the development and implementation ofeffective vegetation control strategies.Areas to be inventoried were determined on the basisof what was considered to be the most likely NIS habitat,with priority given to areas of present or anticipated parkdevelopment and high visitor use. Areas of likely NIS seedintroduction as well as sites already known to contain NISseed sources, or vector areas, were also given priority(Figure 1).Forty-seven NIS were included in the GPS data dictionary,representing all species targeted for inventory by the twelveparks included in this project, plus some additional speciesof regional or national concern.Categories of data collected in this project are listed inTable 1. GPS-entered data included the location and sizeof each infestation, percent canopy cover, phenology of thetarget species, woody growth stage (if a woody species),presence of site disturbance, hydrology, dominant nativespecies present, date, time, and any other pertinent notesabout the site. Data entered in the office during postprocessingincluded ecological status, park code, record numbers,detection confidence for inventory area polygons, scientific23Inventory and Survey Methods for Nonindigenous Plant Species