Plant community composition and structure monitoring at Fort Union Trading Post National Historic Site: 2018 data report

Schaffner, Theresa

This report presents the results of the Northern Great Plains Inventory and Monitoring Network’s vegetation monitoring at Fort Union Trading Post National Historic Site (FOUS) in 2018. This was the eighth year that the Northern Great Plains Inventory and Monitoring Network (NGPN) conducted field work at FOUS. Crew members from NGPN visited nine long-term monitoring plots to collect data on the plant communities at FOUS. Six plots were part of the regularly scheduled monitoring interval. Three additional plots were read in the Bodmer Overlook Unit to evaluate the effects of cattle grazing in the unit. This work is part of a long-term monitoring effort designed to provide a better understanding of the condition of the vegetation community and how it changes over time. NGPN staff measured species richness, herb-layer height, native and non-native species abundance, ground cover, and site disturbance at each of the nine plots. In three plots where woody species were present or nearby, tree regeneration, tall shrub density, tree density, and woody fuel loads were also measured. In 2018, the NGPN monitoring crew identified 97 unique plant species in nine monitoring plots, compared to 71 unique species observed in six plots in 2017. Of the 97 species observed in 2018, 76 were native and 21 were exotic. The five plots located in the Bodmer Overlook Unit were more diverse than the four plots located in the Upland Terrace Unit near the fort. No trees or woody fuels were present in the nine plots, but the crew did identify two green ash (Fraxinus pennsylvanica) seedlings. The most commonly observed ground disturbances resulted from grazing in the Bodmer Unit.

Plant community composition and structure monitoring at Fort Union Trading Post National Historic Site: 2018 data report

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