December 19, 2014

Controlling exotic grasses while maintaining native plant communities in fire- maintained wet prairies

Matt A. Bahm and Erin C. Gray | 2015

Lomatium bradshawii is found in wet prairie habitats, and protected, good quality wet prairie remnants like the Fern Ridge Research Natural Area (RNA) are critical for the recovery of this species.

Lomatium bradshawii is found in wet prairie habitats, and protected, good quality wet prairie remnants like the Fern Ridge Research Natural Area (RNA) are critical for the recovery of this species.  Wet prairie habitats at Fern Ridge RNA are currently managed using prescribed fire, which benefits the plant community by decreasing thatch and promoting germination by native species. Unfortunately, it has also been observed that the exotic grass Anthoxanthum odoratum (sweet vernal grass) can increase under a burning regime. There is a need for alternative management strategies to reduce the abundance of invasive grasses, particularly A. odoratum, without causing harm to native plants.

The ultimate goals of this project are to improve the diversity (both evenness and richness) of native species and decrease the cover of exotic species. We will compare various methods of control for these grasses in the presence of an unpredictable fire regime. This project has three main tasks:

  1. Determine appropriate treatment alternatives and experimental design for testing treatments.
  2. Monitor experimental plots and analyze data.
  3. Communicate results to partners and the scientific community.

Here we report on our progress on these tasks, and summarize the pre-treatment data at Fisher Butte (from 2014).