David Magney Environmental Consulting - California Native Plant ...

Comments on Draft EIR for Newhall Ranch Mission Village Development
DMEC Project No. 10-0181
1/3/2011
Page 42
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DMEC
time honeybees are mentioned is on page D-25 of the Adaptive Management Program Module, Loss of
Genetic Diversity:
“European honeybees have been observed visiting spineflower’s at the Laskey Mesa site (Jones et al.
2002) and may be able to transfer pollen between preserves. It is believed that European honey bees
currently may be experiencing colony collapse syndrome, and pollination relying upon them therefore
may be tenuous.”
Page 5, paragraph 2, Section 3.8 Phenology, Seed Production and Pollination, states, “However, ants are
not efficient pollinators, and the rate of fruit set measured by researchers was high, which would indicate
another, more effective pollinator was visiting the plants (USFWS 2004)”. This statement alone is strong
evidence that the SCP should have examined in greater detail what other pollinators are present, and the
EIS/EIR should have assessed how the proposed project would impact those pollinators.
The preserves need to be large enough to ensure viable populations of SFVS pollinators existing onsite, and
will persist onsite over the long term.
4. Seed Dispersal
Little is known about dispersal of SFVS seeds. As discussed above, Argentine Ants may pose a threat to
native SFVS seed dispersers. Potential interactive effects of granivory and invasion by the Argentine Ant,
which may displace native invertebrate granivores, could be significant. In addition, trapping studies
conducted by Sapphos in 2001 on Ahmanson Ranch did not clarify whether small mammals play a role in
SFVS seed dispersal (SCP, page 4.9-27).
DMEC believes that the buffer areas as proposed under the current plan will be inadequate protection from
the invasion of the Argentine Ant within the preserves areas. There will be further discussions on the threat
of Argentine Ant and a critique of the Integrated Pest Management (IPM) proposed later in the letter.
5. Soils
With the use of a representative model described later, Dudek found that SFVS occurrences varied among
combinations of sandy and gravelly silt and clay loams as discussed in Section 5.3.2 of the SCP. Soil
texture and soil chemistry both proved not to be good predictors of whether a site represents potentially
suitable habitat for SFVS.
On both the Ahmanson Ranch and Newhall Land properties, SFVS is also in areas with disturbed soils and
in areas disturbed by fossorial rodent activity. The SCP suggests that soil disturbances might also directly
facilitate spineflower performance by increasing soil nutrients (J. McGraw, unpublished data) (Adaptive
Management Module D-51). It is possible that SFVS relies on fossorial rodents since SFVS was found
often occurring in areas disturbed by fossorial rodent activity. The size of the preserves may impact the
rodent populations if they are too small.
It is clear that more investigation needs to focus on the soil requirements of the SFVS, especially since SCP
suggests that enhancement should occur if there is a decrease in SFVS populations within the preserves.
There is not information to make these important decisions.