National Park Service

Mojave Desert I&M Network (MOJN)

Invasive & Exotic Plants

Jim Hill mustard (Sisymbrium altissimum)
Jim Hill mustard (Sisymbrium altissimum)

There are currently no publicly available documents pertaining to this monitoring topic, but you may want to check out the MOJN Invasive Plant Guide

For more information contact: Nicole Hupp

Importance/Issues

An invasive plant is a non-native species that aggressively spreads when introduced to a new range. In the MOJN, invasive plants are one of the single largest threats to the integrity of our desert ecosystem and our cultural resources; therefore, they have been identified as a high-priority vital sign. Once established, invasive species negatively impact park resources and visitor enjoyment in complex ways (see Brooks and Pyke 2002). For example, invasive grasses such as red brome and cheatgrass (Bromus spp.) do not simply displace native plants, they alter the ecological processes in the region by creating larger, more frequent wildfires once uncommon in the desert southwest (D'Antonio and Vitousek, 1992). Slow growing and long-lived native desert plants are generally not adapted to wildfires and thus may be incapable of persisting in areas susceptible to a grass-fire cycle. Additionally, woody invaders such as Tamarisk (Tamarix spp.), alter hydrological function and threaten high-value indigenous biodiversity in riparian areas. Other examples of desert invasions include thistle species (Salsola spp.)in sensitive dune systems, and mustards (particularly Sisymbrium spp. , and Brassica tournefortii) in a variety of park ecosystems.

Comprehensive monitoring of the distribution and abundance of all exotic plant species within MOJN is beyond the capabilities of the Network and parks. The network is currently developing a cost-effective approach for early detection monitoring of invasive plants. Early detection efforts increase the likelihood that invasions will be addressed while populations are localized and population levels are small enough to be contained or eradicated. This method targets a prioritized list of incipient and established species through monitoring efforts, and integrates information from existing park programs and network-sponsored vegetation monitoring efforts (e.g. Integrated Upland monitoring and Riparian Vegetation monitoring).

Preliminary Monitoring Objectives

  • Where are incipient populations of targeted (high-priority species of greatest management concern) invasive plants located in MOJN parks?
  • What is the trend in abundance and frequency of established target invasive plants in MOJN parks?
  • What is the relationship between pest management practices and target invasive species?

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Last Updated: December 30, 2016 Contact Webmaster