Vegetation Community Monitoring at Hot Springs National Park

Mountain landscape at Hot Springs National Park.

NPS-Photo

Hot Springs National Park has many forested hills and valleys. These woodlands provide important ecosystem services for the hot springs. They serve as a “recharge zone,” where surface water seeps into the water table. Healthy forests protect groundwater and springs from contaminated surface water. Logging and settlement preceded the National Park. Now, natural community management is a priority. Scientists measure the woodlands to learn about changes over time.

Scientists began measuring plants at Hot Springs National Park in 2007. Seven permanent locations are deployed to observe woodland plants over time. Scientists use these data to describe and detect changes in the forest.

Graph of basal area, the area occupied by tree stems, at Hot Springs National Park. 2007 and 2014
Diameter at breast height (cm) size class ranges for overstory trees.
Class 1 = 5-15 cm, 2 = 15-25 cm, 3 = 25-35 cm, 4 = 35-45cm, 5 = 45+cm

NPS

The forests at Hot Springs National Park have a relatively closed canopy. Medium-sized trees dominate the overstory. Both tree density and basal area were greater in 2014 than 2007. Standing dead trees, called snags, are also important in woodlands. In 2007 snags made up approximately 8% of the basal area, compared to approximately 20% in 2014. Oaks, hickories, and pines are the most common trees. In 2014, scientists observed more slippery elm, hawthorn, Eastern redcedar, and red maple trees.

Graph of Site Cover at Hot Springs National Park. 2007 and 2014

NPS

The understory was similar between 2007 and 2014. Woody plants dominate the understory. About 30% of herbaceous plants are common. Scientists obseved few invasive species in low numbers at the monitoring sites. Arkansas bedstraw, Siberian elm, honeysuckle, prickly lettuce, and Nandina are the only invasive plants found. These data help managers assess goals and develop future action plans for protecting the park’s woodlands.

View the Full Report. (pdf)

Learn more about the Heartland Inventory & Monitoring Network.


Data in this report were collected and analyzed using methods based on established, peer-reviewed protocols and were analyzed and interpreted within the guidelines of the protocols.