Managing Invasive Species and Connecting with Nature

Jasper Ridge Biological Preserve ('Ootchamin 'Ooyakma) hosted a Contemplative Stewardship French Broom Pull event, led by volunteers Kelly Chauvin (former Jasper Ridge postdoc, Fig. 1), and Oriane Lavolé (PhD student, Religious Studies). Kelly has hosted French broom pulls at Jasper Ridge with her BIO101 class in previous years and heard from her students how much they appreciated being connected to the land through the actions of stewardship. From this emerged the Contemplative Stewardship Event held April 13, 2025, which invited volunteers to explore hands-on field work with a touch of mindfulness to remove invasive plant species and connect with nature. 

On the beautiful spring morning of the event, seventeen volunteers met at the field station and started the day with a guided meditation led by Oriane under the warm sun, light breeze, and chirping birds. Then everyone gathered supplies (gloves, bags, weed wrenches, clippers), and walked to trail 18, the site of previous volunteer broom pulls. With soil still moist from winter rains, volunteers were able to pull small to medium sized plants with roots using just gloved hands, while larger plants required weed wrenches and some muscle (Fig. 2)!

Figure 1. Kelly Chauvin reviewing broom identification before heading out into the field. Photo by staff.

This event also served as a pilot project for more data-driven volunteer-led invasive species projects. As Jasper Ridge is developing a more comprehensive approach to invasive species management at the preserve, it is clear that more hands are needed to accomplish this important work. As a place of research, Jasper Ridge staff would like to establish quantitative methods to evaluate success and track progress while minimizing the burden on volunteers in order to get more accomplished. To this end, Stewardship Scientist, Sheena Sidhu, tried out a method of measuring pull rate by volunteers: all participants were asked to count how many French broom plants were pulled in 5 minutes. Notably, this 5-minute measure was done after about an hour of pulling and a short break, which allowed volunteers, especially those new to broom pulling, the chance to develop a rhythm to their pulling. At this event, small/medium broom plants were pulled at an average rate of 18 plants/min (n=16), and large broom plants (requiring weed wrenches) were pulled at a rate of 5 plants/minute (n=3).

Figure 2. Time lapse taken by volunteer Patricia of approximate 1 hour of broom pulling by 6 volunteers off trail 18.

After the measurements were taken, some volunteers offered suggestions on additional low-burden metrics that could supplement and support data collection, with valuable insight coming from experienced docents who have worked on other invasive species projects (Jerry Hearn, Rebecca Reynolds, Claire Elliot, and Meredith McClintock). Future work might include measuring average density of small/medium and large broom patches to easily extrapolate and estimate the number of broom plants pulled by volunteers, or balancing how to distribute volunteers among patches of small/medium sized broom (which are easier to pull, but produce less seed) and patches of large broom (which are harder to pull, but may produce thousands of seeds per plant). Other suggestions included questions and ideas about tracking seed bank and project success over time. 

The event included a guided movement meditation half way through as a break, and concluded with a one-word reflection on the morning event. Words offered by participants included “community”, “accomplishment”, “peace”, “reciprocity”, and “gratitude” (Fig. 3).

Figure 3. Oriane Lavolé leading a movement meditation in the field. Picture by staff.

For those interested in learning more about the concept of Contemplative Stewardship, please check out the readings offered to volunteer participants before the event: Returning the Gift, This Land Was Made, Poem: To Be Held, and I Am a Body on the Earth.

Stewardship Scientist Sheena Sidhu and Program Manager Elise DeBuysser supported this event. Sheena welcomes docents/volunteers to brainstorm project ideas and possible events to support invasive species management at the preserve. Please reach out to Sheena if  you have ideas for data-driven projects featuring some of our top invasives: French boom, stinkwort, slender false-brome, and yellow starthistle.

By Sheena Sidhu

 Sheena Sidhu is the Stewardship Scientist at Jasper Ridge Biological Preserve ('Ootchamin 'Ooyakma).

cssidhu [@] stanford.edu