[APWG] NEWS: Invasive mustard strongarms desert plants, animals

[Wayne Tyson]

APWG:

While I strongly agree that this plant is a truly aggressive colonizer that 
needs to be eradicated, not merely "controlled," I also doubt that it can 
be, especially given the lack of a coordinated program. Of course, getting 
rid of colonies, particularly on the fringes of infestation centers (then 
working backwards into the center until the last one is gone, then keeping 
up a "seek and destroy" program to kill emerging seedlings at the earliest 
possible moment), is still better than nothing, but the most economical (the 
cost still will be astronomical). This problem has been going on far too 
long already, with the potential cost increasing exponentially every year, 
so making the most out of every penny, and every minute of volunteer time is 
essential.

While "we" need more and better science on this subject, an initial 
management approach can be sketched out if everyone recognizes the need for 
continual improvement in the approach (strategy, based as much as possible 
on good science) and techniques (tactics, tested for each context). Here are 
some suggestions as examples of specifics, but I haven't time to write an 
entire management plan. However, a good management plan need not be 
voluminous or complicated. A pretty good one could be written and refined 
right here on APWG.

This plant favors disturbed environments, so infested areas need to be 
closed to vehicular traffic. Management should minimize disturbance (for 
example, avoid pulling large plants by treating soon after seedling 
emergence with environmentally safe techniques (such as, but not limited to, 
very low doses of degradable herbicide, applied only to the target plant, 
not, under any circumstances, by spraying). There are commercial wands that 
employ a wick to accomplish this quickly; I suspect that they could be made 
with plastic pipe if the commercial product is too expensive. Cutting off 
the vertical stem, if it is large, followed by a dab of herbicide is an 
option later in the season. Cheap, effective, fast, and safe. Easier and 
faster, therefore more effective, than pulling out the entire plant, while 
minimizing disturbance. Volunteers should be trained to tread softly too, 
especially at emergence time, when even foot traffic can adversely affect 
indigenous species and increase germination of dormant weed seeds.

Yes, as the article reflects, dispose of stems that have anything close to 
mature pods on them. The dried plants do break off and "tumble," so even 
collecting these while the pods are present, possibly using a drift fence to 
"catch" them, could be worth the effort to minimize dispersal. Dispersal by 
vehicles and other anthropogenic means is probably a major means of 
dispersal too. Volunteers might set up free wash-down stations for off-road 
vehicles (particularly when mud is present) to remove pieces of plants and 
seeds. Picking up every piece of pod will save much greater effort later.

The seeds are tough and long-lived, but as far as I know, are not 
(apparently--no study) either eaten or dispersed by animals to any great 
extent.

I'm sure others will have other suggestions; this is just to prime the pump.

WT

----- Original Message ----- 
From: "Olivia Kwong" <plant at plantconservation.org>
To: <apwg at lists.plantconservation.org>
Sent: Thursday, February 10, 2011 7:36 AM
Subject: [APWG] NEWS: Invasive mustard strongarms desert plants, animals


> http://www.hidesertstar.com/articles/2011/02/09/the_desert_trail/features/doc4d532335ee508828361225.txt
>
> Invasive mustard strongarms desert plants, animals
> By Courtney Vaughn
> The Desert Trail
> Published: Wednesday, February 9, 2011 5:38 PM CST
>
> MORONGO BASIN -- The Morongo Basin's ecology is under siege by non-native 
> Sahara mustard plants that are cropping up in greater numbers throughout 
> Joshua Tree National Park and on other lands across the Hi-Desert.
>
> See the link above for the full article text.
>
>
>
>
> _______________________________________________
> PCA's Alien Plant Working Group mailing list
> APWG at lists.plantconservation.org
> http://lists.plantconservation.org/mailman/listinfo/apwg_lists.plantconservation.org
>
> Disclaimer
> Any requests, advice or opinions posted to this list reflect ONLY the 
> opinion of the individual posting the message.
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3434 - Release Date: 02/10/11
>