Invasive Species Control

Overview

Biological diversity is built on biological diversity. Where there are plant communities with large numbers of native species, there are healthy and diverse populations of animals and insects; and having a diversity native animal and insect species helps maintain a diverse plant community. The plants support the animals, and the animals help keep dominant plants in check, providing a measure of stability to ecosystems. Indigenous species are much more likely to have evolved ecological relationships with predators and competitors that make them better able to coexist with a broad range of species. Exotics, released from their specialized natural enemies, have fewer restraints.

Managing Abundance

However, exotic species are not inherently a problem for land management - only a small number that are introduced become "naturalized," or free-living outside of cultivation. Of these, only a fraction spread to become dominant members of the ecosystem. While it would be unrealistic to assume that we can or should restore the Laguna to a community of entirely native species, the best way to protect biodiversity is manage the abundance of invasively-spreading plants and animals, whether these species are native or introduced.

Useful invasive species website and documents. PDF file opens in new window

General Management Philosophy

The primary focus for restoration and management in the Laguna is to enhance populations of desirable plant and animal species in order to maintain or restore ecosystem processes such as water recharge and purification, soil retention, and biological diversity. Controlling weedy plants and animals is a necessary part of land management, but the fundamental goal is to increase the ability of the Laguna’s ecosystems to resist invasion by weedy species, and to prevent the introduction of new weeds.

Prioritization for weed control activities is based on actual and potential impacts to native species and communities, especially when weeds threaten species at risk of extinction. Studies have shown that the cost of controlling invasive species increases exponentially as with the size of the infestation, and the likelihood of successful control declines. Therefore, it is best to take a precautionary approach, placing the highest priority on controlling small populations of aggressive species, even before their impacts become apparent.

Coming Soon! Invasive Species Management Plan for the Laguna de Santa Rosa.

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