Invasive Species

An invasive species is a plant or animal species that is not native to the local ecosystem, and often causes ecological harm and degrades recreational enjoyment for park visitors. Most invasive species found in County Parks are noxious weeds that grow and reproduce rapidly, outcompeting native species and reducing biodiversity.

Santa Clara County Parks removes invasive species from its parklands whenever possible using an integrated pest management approach and partnering with other agencies such as the Santa Clara Agricultural Office or the California Department of Fish & Wildlife. Newly detected invasive species as well as invasive species that threaten rare or native plant species are priorities for management. 

1. Prevention: Santa Clara County Parks works to prevent the introduction and spread of pests to our parklands. For example, all watercraft are subject to inspection before launching in our park reservoirs to prevent the introduction of quagga/zebra mussels. Park field staff also make sure that equipment has been cleaned and sanitized so that it does not move weeds or pathogens including Phytophthora ramorum, the pathogen that causes Sudden Oak Death, to a new site.
2. Detection & Monitoring: Park staff are trained to identify and monitor new threats to our parklands.
3. Active Control: Controlling invasive species often requires using multiple methods together and adapting them over time. Examples of control methods include targeted grazing (cows & goats), prescribed fire, mechanical control (hand pulling, mowing, trimming, disking), and chemical controls (very selective application of pesticides or herbicides, used only when needed). The site is treated and monitored as necessary in subsequent years to first contain the spread of the invasive plant and, if possible, to eventually eradicate it completely from that site.
4. Restoration: If regeneration of native plants is the goal, sites are typically seeded or planted following control efforts.