Invasive Species

Since the establishment of Jasper Ridge as a research preserve in 1973, the intention has been to manage the preserve’s ecosystems in as natural a state as possible to allow scientists to quantify changes observed in similar ecosystems affected by human impacts, including the spread of invasive species (see summary in 2004 JRBP Strategic Plan). There has always been some effort to control invasive species, but efforts have been dispersed and sporadic given resource availability. However, throughout Jasper Ridge’s 50+ years of history, it has become clear that a revised stewardship approach is needed resulting from the accumulated and ongoing effects of past management practices inside and around the preserve, especially under the impacts of landscape and climate changes.

At a time when the preserve is going through major landscape changes related to as related to both the Stanford Wildfire Management Plan (i.e. fuel reduction), and the Searsville Watershed Restoration Project (SWRP), and increased use, Jasper RIdge has created its first integrated invasive species management plan for long-term management and in support of the preserve’s mission of research, education, and conservation. 

Invasive species at Jasper Ridge

For the purpose of stewardship at Jasper Ridge, pests are defined as species that negatively impact other organisms or disrupt the ecosystem functions and environmental health, and negatively impact the core mission of research, education, and conservation. Invasive species are further defined as plant, animal, or pathogenic species that have intentionally or unintentionally been introduced into our ecosystem and interfere with natural processes and threaten biodiversity. These species tend to share some or all the following characteristics: non-native species, ability to spread rapidly and outcompete native species, freedom from natural enemies, disruption of local habitats, and negatively impacting other organisms. 

An Integrated Pest Management (IPM) plan is a comprehensive, science-based decision-making strategy for long-term pest management. In the 2025 iteration of the invasive species management plan, Jasper Ridge focused on using IPM for invasive plant species, and will start with a few species of top concern. These have been identified by Jasper Ridge staff and the Oakmead Herbarium team based on current management, population location, and population size. Future iterations may expand to management strategies for invasive animals and pathogens. 

Current priorities

1. French broom (Genista monspessulana)
2. Slender false-brome (Brachypodium sylvaticum)
3. Yellow starthistle (Centaurea solstitialis)
4. Stinkwort (Dittrichia graveolens)
5. Fuller’s Teasel (Dipsacus fullonum)

Volunteers are needed!

Join one of our scheduled stewardship days to learn new skills, meet fellow Jasper Ridge affiliates and docents, and help protect Jasper Ridge’s habitats. Please contact Elise Debuysser for more information on upcoming dates and help the team tackle invasive species at the preserve!

Research projects at the preserve related to invasive species:

• Control of yellow starthistle by herbivory
• Nitrogenous air pollutant monitoring
• Disturbance and Resources Across Global Grasslands (DRAGNet) at Jasper Ridge
• Longterm study of invasion by Argentine ants
• The effects of an invasive ant Linepithema humile on a lycaenid butterfly Plebejus acmon
• Oakmead Herbarium