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Biological Surveys Continue to Reveal Rare Habitats in Open Space

2/2/2011
This article is essentially a sequel to my article “Endangered Plant Found
in Ken-Caryl’s Foothills” Life at Ken-Caryl July, 23, 2009. That article
described my quest to find the rare (Birdfoot violet) Viola Petatifida and
my eventual success here at Ken-Caryl. I didn’t realize then that the
discovery would only be the beginning of uncovering a wealth of
ecological treasure in Ken-Caryl’s Open Space.

Due to the uniqueness of Ken-Caryl’s habitats and the rare violet
discovery, I requested that a rare plant and critical habitat survey be
started in Ken-Caryl Open Space. During that same time I heard a talk
from Susan Spackman Panjabi from the Colorado Natural Heritage
program (CNHP), regarding rare plant and habitat surveys that had been
done for several different agencies along the Front Range. A
collaborative request was made by the Open Space committee and open
staff to have the CNHP perform surveys in Ken-Caryl’s Open Space.
The request was approved through the Board of Directors and field work
started in the summer of 2010. A final biological survey report will be
finished by the end of February.

I will emphasize the rare plant portion, which I was directly involved with,
even though a raptor survey was also completed. Fortunately the
Heritage program was already scheduled to perform inventories for
Jefferson County, so information gathered at Ken-Caryl was valuable for
the overall survey of Jefferson County. Before I describe the habitats
that were found I would like to explain some nomenclature used by the
Heritage program.

S1. Critically imperiled in state because of extreme rarity (five or fewer
occurrences, or very few remaining individuals, or because of some
factor of its biology making it especially vulnerable to expiration from the
state. (Critically endangered).

S2. Imperiled in state because of rarity (six to 20 occurrences) or
because of other factors demonstrably making it very vulnerable to
expiration from the state. (Endangered or threatened in the state)

S3. Vulnerable in state (21 to 100 occurrences).
Global Conservation Status Definitions. These ranks reflect an
assessment of the condition of the species or ecological community
across its entire range (G-ranks).

G1. Critically imperiled
G2. Imperiled
G3. Vulnerable
G4. Apparently secure
G5. Secure
GU. Status uncertain

Due to the sensitivity of some sites, exact locations will not be given
when describing select species.

Pam Smith was the field biologist who was working on our surveys and
Jefferson County’s surveys. In fact Pam was featured in YOUR HUB for
her rare plant survey work. Pam has extensive botanical experience and
knowledge and I was able to expand my own botanical knowledge by
working with her.

We started in areas of the South Hogback. A delicate annual plant,
Claytonia rubra (Red-stem Spring beauty) was discovered. The plant is
not currently ranked but was confirmed to be rare and is currently being
assessed by the CNHP. A previously discovered rare grass, the forked
three awned grass (Aristida basiramea) G5S1 was also verified. Xeric
Tall Grass Prairie with Populations of Big Blue stem (Andropogon
gerardii) were also documented and the rare plant community of
Andropogon gerardii/Calamovilfa longifolia, a GUS2 listed community
was documented in the North Hogback.

From the hogbacks we moved into the foothills. Known populations of
the Wood Lily (Lilium philadelphicum) were verified. This is a rare plant
that is especially sensitive because of its beauty and history of being
picked and eliminated from certain habitats. Perhaps the rarest
community that was documented was the Aspen/ Beaked Hazelnut
(Populous tremuloides/ Corylus cornuta) which has a G3S1 ranking.
Individual Hazelnut shrubs had been documented in the past but the
discovery of the Hazelnut shrub alongside aspens in the riparian zone
resulted in an increasingly rare rating. Along with the rare plant and
community discoveries, a rare song bird, the Oven Bird (Seiurus
aurocapilla) G5S2 was identified in the same area.

The 2010 field season was one full of exciting discoveries. The CNHP
will be back in the summer of 2011 to conduct additional surveys. I look
forward to searching for more hidden ecological treasures in the Open
Space.

by KCRMA Open Space Ranger Gary Norton

Ken-Caryl Ranch