Hi all,

In the past month I’ve seen Dittrichia in Trione-Annadel State Park in areas burned by the October 2017 North Bay fires. This is the first time I have detected stinkwort within Annadel’s boundaries, but have found a few plants just outside in the year prior to the fire. I was hoping that regular diligence along roads, trails, and trailheads would help keep the plant out of the park for a while, but the fire may have changed all that in one season.

I am finding the plant widely distributed in burn areas that have bare ground and enough light. It is low in abundance but widespread in areas of high burn severity and little other herbeacous competition. It is not concentrated along roads, trails, and other human disturbed areas in the park. This leads me to think that the plant has dispersed by some means other than human disturbance (animals?) and found opportunities in the burned areas. I am thinking these plants may not persist as forest conditions return and the plants are shaded or out-competed. We may, however, do limited treatment near areas where the establishment of Dittrichia would be detrimental to conservation. For example, preventing it from gaining a foothold near ponds and wetland areas, like Ledson Marsh. From what I’ve seen of Dittrichia at Mt Diablo, it can take hold and persist in the margins of ponds and wet areas. These areas may be important as areas where animals gather and vector the plant to other areas.

Does anyone else have experience with Dittrichia post-fire?

William (Bill) Miller

Environmental Scientist

California State Parks – Bay Area District

845 Casa Grande Road

Petaluma, CA. 94954

william.miller@parks.ca.gov

ph: (707) 769-5652 ext. 214

fax: (707) 769-5675

Schedule: Mostly Mon Tues Wed and Thurs