Marie Jasieniuk is a professor with the Dept. of Plant Sciences at UC Davis.
A major pathway of introduction of non-native invasive plants into new geographical areas is the global horticultural trade in ornamental plants. Even though only a small percentage of ornamental species escape cultivation and become invasive, those that do can have major negative impacts. In California, more than half of the most invasive plants damaging the state's wildlands and natural areas are derived from horticultural ornamentals. PlantRight™ (
- Author: Scott Oneto
Yellow Starthistle is a plant of Old-World origin that arrived in California in the mid 1800's. It is believed that it made its way to California in contaminated alfalfa seed from Europe. It is one of California's worst noxious weeds, infesting parks, rangelands, pastures, hay fields, orchards, vineyards, canal banks, roadsides, and other disturbed areas. Since its introduction, yellow starthistle has spread steadily and now infests nearly 15 million acres throughout the state. Disturbances created by cultivation, poorly timed mowing, road building and maintenance, or overgrazing favor this rapid colonizer. It forms dense infestations and rapidly depletes soil moisture, thus preventing the establishment of desirable species. The spiny...
- Author: John Madsen
One response to the suggestion that an herbicide be used to control aquatic weed problems in water is concern that the treatment will reduce the dissolved oxygen content of the water, with possible adverse effects on fish and other aquatic biota. In fact, some herbicide formulations even have warnings on their label to only treat one-half of a pond. However, a recent study on treating water hyacinth (Eichhornia crassipes) in the Sacramento-San Joaquin River Delta demonstrates that a decrease in dissolve oxygen is not necessarily the outcome after an herbicide treatment.
Study sites were selected based on sites with water hyacinth growing along channels, and sites in which the water hyacinth grew in sloughs...
- Author: Guy B Kyser
This article from the Sacramento Bee describes the impact of annual grass weeds on sites in the Great Basin, and argues that herbicides can play a role in salvaging the local ecosystem. Another entry in the category of "Ecology is complicated."
- Posted by: Gale Perez
Thanks to Jim Farrar for sharing the announcement below. There are talks on CHEATGRASS and VENTENATA on Feb. 26.
SCIENCEx Invasive Species webinars
US Forest Service is hosting a week-long series of webinars on invasive pests: https://www.fs.fed.us/research/sciencex-webinars/
When: February 22-26, 2021 :: 12:30-1:30 Pacific / 1:30-2:30 Mountain / 2:30-3:30 Central / 3:30-4:30...