National Park Service Vegetation Inventory Program Jean Lafitte National Historical Park and Preserve

Hop, Kevin; Strassman, Andrew; Sattler, Stephanie; Pyne, Milo; Teague, Judy; White, Rickie; Ruhser, Janis; Hlavacek, Enrika; Dieck, Jennifer

The National Park Service (NPS) Vegetation Mapping Inventory (VMI) Program classifies, describes, and maps existing vegetation of national park units for the NPS Natural Resource Inventory and Monitoring (I&M) Program. The NPS VMI Program is managed by the NPS I&M Division and provides baseline vegetation information to the NPS Natural Resource I&M Program. The U.S. Geological Survey Upper Midwest Environmental Sciences Center, NatureServe, NPS Gulf Coast Network I&M Program, and NPS Jean Lafitte National Historical Park and Preserve (JELA, also referred to as the “Park”) have completed vegetation classification and mapping of JELA for the NPS VMI Program. Mappers, ecologists, and botanists collaborated to affirm vegetation types of JELA and to determine how best to map the vegetation types by using aerial imagery. Analyses of data from 159 legacy plots had been used to describe an initial 18 vegetation types in the Park; this classification work was completed prior to beginning this JELA vegetation mapping project. Data were collected during this project from another 87 quick plots to support vegetation types not previously identified at the Park. Data from 61 verification sites were collected to test the field key to vegetation types and the application of vegetation types to a sample set of map polygons. Furthermore, data from 594 accuracy assessment (AA) sites were collected (of which 587 were used to test accuracy of the vegetation map layer). The collective of these datasets resulted in affirming 41 natural (including ruderal) vegetation types at JELA consisting of 34 association types in the U.S. National Vegetation Classification (USNVC), 1 provisional type (potential for USNVC), 4 park-special types, 1 alliance type in the USNVC, and 1 group type in the USNVC. To map the vegetation and land cover of JELA, 26 map classes were developed. Of these 26 map classes, 24 represent natural (including ruderal) vegetation types, most of which types are recognized in the USNVC. For the remaining 2 of the 26 map classes, 1 of the map classes represents a USNVC cultural subclass type for developed areas, and the other map class represents a non-USNVC type for nonvegetated open water. Features were interpreted from viewing 3-band digital aerial imagery using digital onscreen three-dimensional stereoscopic workflow systems in geographic information systems; digital aerial imagery was collected during July 25–26, 2014. The interpreted data were digitally and spatially referenced, thus making the spatial-database layers usable in a geographic information system. Polygon units were mapped to either a 0.5-hectare (ha) or 0.25-ha minimum mapping unit, depending on vegetation type. A geodatabase containing various feature-class layers and tables presents the locations of USNVC vegetation types (vegetation map layer), vegetation plot samples, verification sites, AA sites, project boundary extent, and aerial image centers and flight lines. The feature-class layers and related tables for the vegetation map layer provide 2,463 polygons of detailed attribute data covering 11,058.5 ha, with an average polygon size of 4.5 ha when physiognomic cover-density modifiers are not considered; with modifiers, the vegetation map consists of 2,867 polygons, with an average polygon size of 3.9 ha. The vegetation map includes the administrative boundary for the Barataria Preserve within JELA and the Fleming Plantation area. A summary report, generated from the vegetation map layer of JELA, concludes that the 24 map classes representing natural (including ruderal) vegetation types apply to 96.3% of polygons (2,372 polygons; average size of 4.4 ha) and cover 93.7% of the Park (10,357.1 ha). Further broken down, map classes representing vegetation types indicate that the Park is 27.0% forest and woodland (2,988.6 ha), 8.3% shrubland (912.9 ha), and 58.4% herbaceous cover (6,455.6 ha). A cultural map class representing developed areas applies to 2.9% of polygons

National Park Service Vegetation Inventory Program Jean Lafitte National Historical Park and Preserve

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