Transcript Planning for Shrub Establishment on Former Crop

PLANNING FOR SHRUB
ESTABLISHMENT ON
FORMER CROP LANDS IN
THE CARRIZO PLAIN
Using Fine Scale VegCAMP and CNPS Data to Find Reference Sites
and ID Target Plant Species
Dave Hacker
WHY WE
ARE
TALKING
ABOUT
SHRUBS
Topaz Incidental Take Permit
(ITP) required
• 12,140 acres of mitigation land
• “allscale (Atriplex polycarpa),
California ephedra (Ephedra
californica), and/or other
perennial shrub species
appropriate to the HM lands
where the native shrub cover
has been removed or
adversely altered by livestock
grazing, fire, farming, or
other anthropogenic causes”
ITP
CONDITIONS
• use of a reference site to
determine target shrub cover
and species OR, if not
available, establishing 15-20%
perennial shrub cover on 50%
of the mitigation lands
• within 10 years of acquisition
MORE
BACK
STORY
• California Valley Solar
Ranch—9,157 acres, same
shrub requirements
• Topaz ITP mitigation lands
owned by CDFW
• CVSR ITP mitigation lands
owned by solar project owner
WHY DO WE WANT
SHRUBS?
•
A mosaic of grasslands and
shrublands provides a more diverse
prey base for kit foxes, which can
buffer against fluctuations in prey
base and habitat functions due to
stochastic events, and to allow
spatial partitioning between SJKF
and coyotes, which may reduce
predation on kit foxes.1
• Shrub cover associated with
persistent San Joaquin antelope
squirrel (State Threatened species)
populations.
1. Nelson, Julia L., B.L Cypher, C.D. Bjurlin, and S. Creel. 2007. Effects of
habitat on competition between kit foxes and coyotes. J. Wildlife
Management. 75(5):1467-1475.
• Pronghorn
– fawning cover
– late season forage
• Birds (e.g. LeConte’s thrasher)
– perch sites
– nest sites
– prey and forage diversity
• Reptiles
– shade for thermoregulation =
more time to forage on hot
days
– cover from predators and
photographers
– more insect diversity
Photo of LeConte's thrashers from http://data.prbo.org/apps/cplcth/.
Have lots of this
low diversity
grassland
Want more of this mix
of grassland and
shrubland
SOUGHT
REFERENCE
AREAS FOR
CDFW-OWNED
LANDS (TOPAZ
MITIGATION
LANDS)
Example at San
Andreas fault scarp
where full suite of
listed species occurs
in shrub/grassland
mosaic.
We wanted reference sites to tell us
1.
which areas might be suitable for
shrub establishment,
2. which shrub species the area could
support,
3. target shrub cover, and
4. approximate patch size.
VEGETATION
DATA
• The California Native Plant Society
(CNPS) and CDFW’s Vegetation
Classification and Mapping Program
(VegCAMP) produced a fine-scale
vegetation data set and map for the
nearby Carrizo Plain National
Monument (federal lands) and the
Carrizo Plain Ecological Reserve
(adjoining state lands) in 2013 (Stout et
al. 2013 and unpublished CDFW data).
• Includes
– plant comms to alliance level
– % cover by species
– area of each comm.
– disturbance levels
– and more attributes
• Used full spatial extent of data (the
whole National Monument) as the
reference site
SOILS
PRECIPITATION
• Natural Resource Conservation Service
soil map unit data—found types that
occurred both within extent of veg data
and the mitigation lands.
• Precipitation model data (30-year
normals) was also available in 0.64 km2
pixels from the PRISM Climate Group at
Oregon State University (PRISM Climate
Group 2013).
• Used only qualitatively, did not extract
values from spatial data (i.e. I just
looked at the values to see if they were
close).
In ArcMap GIS, intersected vegetation with soils
Gave us polygons with all
vegetation data per soil type
Plant Comms. by Soil Type, with Precipitation (mm) Overlay
veg alliance or
macrogroup
precipitation
soil map unit #
Example vegetation data for
311 Yeguas-Pinspring Complex, 2-9% slopes.
RESULTS
• 12 of the 17 mitigation land
soil types were found in the
reference area.
• Five of the mitigation land soil
types (next slide) supported
extensive shrublands in the
reference area and within the
target precipitation range,
comprising 37,348 acres of
reference site.
Atriplex polycarpa alliance in reference area occurred
on all five soil types common between reference
and mitigation areas.
• 4,432 acres, or 11.9%, of the
reference area was mapped
as Atriplex polycarpa alliance
MORE
RESULTS
• The Ephedra californica
alliance was abundant in four
of the five soil types and
covered a total of 1,541 acres.
• Other shrub alliances found in
some soils in much lesser, but
still considerable extents,
were, in order of abundance,
Ericameria linearifolia –
Isomeris arborea and
Eriogonum fasciculatum.
CONCLUSIONS
• Reference sites provided evidence
that 4,572 acres (38%) of the soil
map units on the mitigation lands
would likely support Atriplex
polycarpa and/or Ephedra
californica.
• Establishing 520 acres of Atriplex
polycarpa alliance with 14% shrub
cover on the mitigation lands would
replicate the proportion found in
the reference area
• Ephedra californica, Ericameria
linearifolia – Isomeris arborea and
Eriogonum fasciculatum alliances
were also found and would likely be
appropriate for some of the
mitigation lands soil types.
Mitigation area soil types which support extensive shrub
communities in the reference area.
DISCUSSION
• The extent of the mapped
shrub alliances should not be
equated with the extent of
shrubs because reference area
grasslands and forb lands
with 1-5% shrub cover were
mapped as non-shrub
communities.
• Similarly, the minimum map
unit in the vegetation data
was 1 acre, so patches smaller
than one acre were not
reflected in the results.
• i.e. shrubs occur in more areas
than were mapped
DISCUSSION
• Most areas with shrubs
showed no sign of mechanical
disturbance when visited
and/or none was noted in the
CNPS/VegCAMP data.
• Atriplex polycarpa has
recolonized some of the
former crop lands in the
reference area, apparently
where washes have
transported seed from higher
slopes that escaped
cultivation.
DISCUSSION
• Some of the soil types where no
shrub lands were found were the
same type as where shrubs were
extensive, but in lesser slope
classes.
• In general, the lesser slope classes
were farmed for longer and could
have therefore been more subject
to shrub eradication.
– The lack of shrubs in the lower
slope classes may be a result of
past land use rather than
unsuitability for shrubs.
– More areas of the mitigation
lands may be able to support
shrubs than just the areas for
which good reference sites
were found.
Atriplex polycarpa established on test plot on Yeguas-Pinspring complex,
0-2% slopes, Diefenderfer property (CVSR ITP mitigation lands)