[PCA] Great Basin ecosystems and cheatgrass fires

[Craig Dremann]

Robert wrote:

Will someone please clarify how wildfire in sagebrush steppe kills all
the native perennial vegetation? ...

Robert Dana
MN DNR
---------------------------
Dear Robert and All,

What has happened to the poor, unfortunate Great Basin ecosystem, is
that prior to the 1840s, it was a shrubland with a perennial native
grass understory in the shrub interspaces.  

Between 1840 and modern times, the cattle and sheep grazed out a large
percentage of the perennial grass understory, and from my 1997
Megatransect at http://www.ecoseeds.com/megatransect.html you can see
the percentage that remains in each area that I surveyed:

Yellowstone NP 89%
Colorado------ 44%
So. Dakota---- 43%
Wyoming------- 40%
Nevada-------- 40%
Utah---------- 34%
Utah---------- 32%
Southern Idaho  6%
California---- <1%

In the Great Basin, the cheatgrass has been moving in, to fill the empty
spaces between the shrubs where the native grasses used to grow.  

The native perennial grasses originally provided significantly less
fire-fuel than the cheatgrass, and the hotter cheatgrass-fueled fires
are killing the shrubs.

Once the native shrubs are killed, that beings a snow-balling effect,
where the cheatgrass has more area to move into, etc.  

The unfortunate part of the story, is that there are no longer viable
native grass and forb seeds in the soil-seedbank in many areas where
these fires are occurring. 

What BLM and the other land managers of the Great Basin must do very
soon, is calculate how many years the seeds of the various native
grasses species in the area are viable, let's say 10 years.  

Then once every five years, rest the land during a good-rainfall season,
completely removing all grazing, to allow the native grass plants to
produce seeds, to replenish the soil-seedbank.  

Then the ecosystem will be reseeded for free, with the proper local
genetic material, and you won't have to buy those million pounds or so
of exotic seeds that the government purchases for the Great Basin public
lands every year.

Sincerely,  Craig Dremann, Redwood City, CA (650) 325-7333