View Full Version : Peirson's milkvetch

06-17-2004, 02:54 PM
From: michael.laycook@worldnet.att.net
Date: 10/24/00
Time: 10:46 PM

As a person that uses the sand dunes and is unhappy at the closure of some of the best riding area's with the newest land closure. I also understand we need to protect plants and wild life, so I write to ask what can the offroad community do to grow this plant and transplant it back at the dune.

06-17-2004, 02:54 PM
From: Chuck sbhrdcore@hotmail.com
Date: 08/16/01
Time: 04:05 PM

Its funny how no one answered this.

06-17-2004, 02:55 PM
From: Steve Hartman (naturebase@aol.com)
Date: 09/27/01
Time: 04:08 PM

Dear Michael and Chuck:

Thank you very much for your concerns. Your offer to help is appreciated. And there are things that people can do to protect Pierson's milkvetch.

Due to the persistence of the California Native Plant Society, in 1998, BLM began annual surveys of rare plants on the dunes. CNPS member volunteers, agency volunteers and paid staff walk multiple transects across the dunes north of Hwy 78, and vehicles have been used to drive transects on the south side. Counts of rare plants are made and used to compare to a 1977 survey as well as to determine recent trends. These counts will hopefully continue, and volunteers are needed.

While there isn't enough data to make conclusions yet, there will be a presentation at the upcoming Dunes Symposium (Oct. 20, 2001) by BLM state botanist John Willoughby entitled: Monitoring of Special Status Plants in the Algodones Dunes, Imperial County, California (1977, 1998, 1999, and 2000). [For more information about the symposium see http://www.cnps.org/alerts/ShiftingDunes2001.pdf]

The question might very well be: is there a big enough, secure enough population of Pierson's milkvetch in the wilderness area north of hwy 78 to ensure the survival of this species? Until we figure that out, we need to conserve the habitat of this plant that is only known to occur (on earth) on the Algodones Dunes and in one
location in northern Mexico. And this isn't a minor "technical" difference that separates this plant from all others of its type. This plant has the largest seeds of its type! In fact "gigantism" is a feature of plants that survive on the dunes.

You ask if you could grow this species elsewhere and transplant it back to the dunes. In theory, seeds could be gathered from the existing populations, if permitted by Federal and State agencies. Studies could be initiated, because little work has been done on the ecology of the species. However, studies reviewing the success of transplantation of sensitive species has indicated abysmal failures - less than 5% survival of populations, and few /none of those species were dune species.

In my view the issue is really habitat driven. Adequate habitat should be conserved with adequate carrying capacity during all years (drought and good rain) and persistence of their pollinators to ensure persistence of the species. Some of these questions could be answered by the current studies on the survival of the populations on the dunes.

It is possible that collection of seed would diminish the seedbank of this endangered plant. Although plants generally produce more seeds than have the opportunity to germinate and grow, some of those seeds may provide resources to mammals/birds/insects for survival. We don't even know the viability of the seeds - how long they live, what mechanisms are required for germination (could be scarification by blowing sand, but maybe its a process that takes place in the stomach of a kangaroo-rat). In addition, there is anecdotal evidence that year's with heavy rainfall (El Nino phenomenon) are very important to the long-term survival of dune dwelling species, as the years of extra rainfall "fill up" the dune aquifer that these plants tap into.

Regarding off-site growing of plant from seed, it might be possible to grow seedlings, but the next problem is how to successfully transplant the seedlings, as they most likely have a very long taproot. Also, many native plants require special mycorrhizal fungi in the soil in order to germinate. So, even if you could grow these plants from seeds, it is questionable that they could be successfully transplanted out into the dunes.

What we need is more information, so we encourage you to support research projects that could be undertaken to answer these questions led by various government agencies.