Species: Draba weberi




Дата канвертавання19.04.2016
Памер73.02 Kb.
REGION 2 SENSITIVE SPECIES EVALUATION FORM

Species: Draba weberi, DRWE



Criteria

Rank

Rationale

Literature Citations

1

Distribution within R2



A

Previously there was only one known population, located on private land, approx. 0.1 from FS land. A new population has been found on FS land. Only one individual found in 2010, no collections were made. More surveys are needed in 2011.
Confidence in Rank High

2

Distribution outside R2



A

Species is restricted to Region 2
Confidence in Rank High

  • CNHP 2006

  • Decker, K. 2006. Draba weberi

  • Price & Rollins. A technical conservation assessment

3

Dispersal Capability



A


Dispersal is possible through three possible routes: water borne, carried by browsing animals (rodents), or attached to animals by a mucilaginous seed coat (common in Brassicaceae). These dispersal methods will display different patterns of dispersal. Water borne will result in downstream dispersal, browsing animal will likely keep the dispersal within the same drainage, and the mucilaginous seed coat could result in long distance dispersal if attached to a highly mobile animal (bird), but there is no guarantee of suitable habitat in other locations.
Confidence in Rank High

  • Lyon, p. Personal observation

  • Decker, K. 2006. Draba weberi

  • Price & Rollins. A technical conservation assessment

  • Ladyman 2004a

  • McNeill, R. 2010. Personal observation

4

Abundance in R2



A

There are only two known populations, with approximately 30 individuals. This species is ranked G1/S1 by CNHP.

Confidence in Rank High


  • CNHP database

  • CNHP Rare Plant Survey for WRNF 2006

  • Decker, K. 2006. Draba weberi

  • Price & Rollins. A technical conservation assessment

  • McNeill, R. 2010. Personal observation

5

Population Trend in R2



A

The original survey in 1991 estimated the population as “perhaps 100 individuals”, the latest published survey in 2006 found 31 individuals.


Confidence in Rank High

  • Decker, K. 2006. Draba weberi




6

Habitat Trend in R2



B

The previous known occupied habitat is apparently stable, but may be subject to changes with manipulation of the water source and maintenance of the roads and dam. The new population is near a popular recreation trail.


Confidence in Rank High

  • CNHP database

  • CNHP Rare Plant Survey for WRNF 2006

  • Decker, K. 2006. Draba weberi

  • Price & Rollins. A technical conservation assessment

  • McNeill, R. 2010. Personal observation

7

Habitat Vulnerability or Modification



A

The previously known habitat has been substantially modified the dam upstream. It is unknown if the species was more widespread before the modification. The new population is near the McCullough Gulch trail (see attached map). Threats include habitat alterations from dam and road maintenance, exotic species, recreation and mining.
Confidence in Rank High

  • CNHP Rare Plant Survey for WRNF 2006

  • Decker, K. 2006. Draba weberi

  • Price & Rollins. A technical conservation assessment

  • McNeill, R. 2010. Personal observation

8

Life History and Demographics



A

This species is believed to be apomictic, not requiring pollination. Successful reproduction is probably limited by scarcity of suitable sites for seed germination.
Confidence in Rank High

  • CNHP 2006

  • Decker, K. 2006. Draba weberi

  • Price & Rollins. A technical conservation assessment

Evaluator(s):
Rick McNeill, EZ Botanist, WRNF

Date:

Oct. 26, 2010




National Forests in the Rocky Mountain Region where species is KNOWN (K) or LIKELY (L)1 to occur:


Species Name:

Colorado NF/NG

Known

Likely

Kansas NF/NG

Known

Likely

Nebraska NF/NG

Known

Likely

South Dakota NF/NG

Known

Likely

Wyoming NF/NG

Known

Likely

Arapaho-Roosevelt NF







Cimarron NG







Samuel R.McKelvie NF







Black Hills NF







Shoshone NF







White River NF

X













Halsey NF







Buffalo Gap NG







Bighorn NF







Routt NF
















Nebraska NF







Ft. Pierre NG







Black Hills NF







Grand Mesa, Uncompahgre, Gunnison NF
















Ogalala NG
















Medicine Bow NF







San Juan NF


































Thunder Basin NG







Rio Grande NF











































Pike-San Isabel NF











































Comanche NG











































Pawnee NG













































Draba weberi from McCullough Gulch, Dillon RD, WRNF


1 Likely is defined as more likely to occur than not occur on the National Forest or Grassland. This generally can be thought of as having a 50% chance or greater of appearing on NFS lands.

USDA-Forest Service R2 Sensitive Species Evaluation Form Page of


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