Plant community composition and structure at Theodore Roosevelt National Park: 2011-2016 summary report
Ashton IW and Davis CJ. 2017. Plant community composition and structure at Theodore Roosevelt National Park: 2011-2016 summary report. Natural Resource Report. NPS/NGPN/NRR—2017/1497. National Park Service. Fort Collins, Colorado
This report presents the results of vegetation monitoring efforts at Theodore Roosevelt National Park (THRO) by the Northern Great Plains Inventory and Monitoring Network (NGPN) and the Northern Great Plains Fire Ecology Group from 2010-2016. Field crews captured data relating to species richness, herb-layer height, and abundance of individual native and non-native species, ground cover, seedling and tree densities, and site disturbance at 81 plots in the North and South Unit and across 162 plot visits. We used these data to explore the differences across the two management units and between riparian and upland areas. We also compared our findings to the range of natural variability seen in other grasslands and management targets to develop summaries of natural resource condition (Appendix C). In addition to annual monitoring, NGPN also surveyed riparian forest condition in 2015 at 100 randomly located plots. We collected data on tree and seedling density, tree condition, disturbance, and the presence of exotic species of management concern, such as leafy spurge and Canada thistle. Our findings can be summarized as follows: Monitoring crews identified 361 vascular plant species, with an average of 9 native species occurring within any given 1 m2 quadrat sampled. Grasses, sedges, and forbs make up the majority of plant cover, while non-native species comprise about 24% of plant cover. Native plant diversity in upland areas is considerably higher and exotic plant cover lower, when compared with riparian areas. There is a general trend of increasing exotic cover over time in the riparian habitat, while Kentucky bluegrass is increasing in all areas of the park, and exotic plant cover is significantly greater closer to roadways. Both units show similar patterns in herbaceous vegetation, but juniper trees are more common and forests are denser in the North Unit. Finally, we found that North Unit riparian forests have denser and more widespread cottonwood forests, a more diverse tree assemblage, and lower cover of herbaceous exotic species compared with South Unit riparian forests. Overall, the park’s vegetation seems to be in good condition, though exotic plants pose a significant challenge to park management.
- Type
- Published Report
- Authors
- Ashton, Isabel; Davis, Christopher
- Date of Issue
- 2017-08
- Publisher
- National Park Service
- Units
- NGPN , NRSS , THRO
- Keywords
- badlands, cottonwood, Forest, Grasslands, mixed-grass prairie, Monitoring, monitoring report, plant community monitor, Plant community monitoring, Plant diversity, riparian, Vegetation
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Grassland/Herbaceous Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Forest/Woodland Communities