Quincy lupine (Lupinus dalesiae) monitoring
Meadow Valley Group Selection Units
Michelle Coppoletta
October 17, 2012
Background
Quincy lupine (Lupinus dalesiae) is a Forest Service Region 5 Sensitive Species that
occurs in Plumas County and in isolated occurrences in Sierra and Yuba counties in
California. Within its limited range, Quincy lupine is locally abundant. There are
currently over 200 occurrences documented on the Plumas National Forest (NF) and
approximately 22 occurrences outside of the forest boundary.
Quincy lupine is found in a variety of habitats that include undisturbed and disturbed
sites (such as old skid trails and road cut banks), openings in chaparral, cismontane
woodlands, and mixed conifer forests. Past observations have suggested that this
species tolerates and even thrives on disturbance; however the intensity, extent, or
frequency of the disturbance associated with these occurrences has not been quantified
in a manner that facilitates the development of prescriptions that consistently mimic
historical disturbance regimes.
In 2006, Plumas NF botanists and Sierra Cascade Province ecologists initiated a small
monitoring project to quantify the effects of different types of timber harvest activities,
specifically group selection and mechanical thinning, on Quincy lupine abundance. The
following summarizes the results of monitoring conducted between 2006 and 2012
within two group selection units. Although permanent monitoring plots were also
established within mechanical thinning units, these treatments were never
implemented.
Methodology
In May of 2006, two permanent rectangular macroplots were established within two
Meadow Valley group selection units (GS_242 and GS_256). Both units were surveyed
prior to establishment of the macroplot to document the distribution and abundance of
Quincy lupine. In GS_242, only one patch of Quincy lupine was identified. In this unit, a
100 x 20 foot macroplot was randomly placed to encompass all of mapped individuals.
In GS_256, more than one Quincy lupine patch was documented; therefore a 100 x 40
foot macroplot was randomly placed within the occurrence boundary. Each macroplot
was divided into 10 x 10 foot sub-plots to provide consistency in counting and data
recording, and to track changes in the spatial arrangement of plants. To record changes
in overstory canopy in response to treatment, canopy cover was estimated using a
densitometer at the corner of each sub-plot.
During the summer of 2007, GS_242 was mechanically treated using a group selection
prescription; the remaining plot, GS_256, was not treated and was used as a control for
comparison of treatment effects. Data were collected within the two macroplots prior
to treatment in 2006, and were revisited during the summer of 2008 and 2012.
Results
Number of Individuals
The following table and figure present the number of Quincy lupine within each
permanent macroplot prior to and following group selection treatment.
Table 1. The number of Quincy lupine within permanent plots prior to and following treatment.
plot #
242 (treatment)
256 (control)
pretreatment
count (2006)
7
41
posttreatment
count (2008)
posttreatment
count (2012)
8
25
54
52
Figure 1. The number of Quincy lupine plants within the treatment unit and control. Group
selection treatment occurred in 2007.
Neither the treatment plot, nor the control plot, showed a decrease in the number of
individuals between 2006 and 2008. Even in the group selection plot, where all of the
overstory trees were removed and the Quincy lupine were in an obvious area of
disturbance (i.e. in the middle of a skid trail), the plants were still present. In 2012, five
years after group selection treatment, there was a 200 percent increase in the number
of Quincy lupine plants within the treatment plot and a slight decrease (4 percent) in the
number of plants in the control plot. The sub-plot data for the macroplots indicate that
the Quincy lupine individuals were concentrated in the same general location for the
duration of the monitoring period.
Canopy cover changes
This environmental variable was chosen to document the change in canopy cover
following group selection treatment. As is illustrated in the table and figure below,
Quincy lupine macroplot GS_242 went from 70 percent canopy cover prior to group
selection treatment to 0 percent canopy cover following treatment. In comparison, the
control (GS_256) went from 71 percent to an average of 72 percent canopy cover over
the same time period, demonstrating a lack of overstory removal.
Table 2. Canopy cover in Quincy lupine permanent plots pre and post-treatment.
pre-treatment
Average post-treatment
% canopy cover
macroplot #
(2006)
(2008 and 2012)
change
242 (treatment)
70%
0
-70%
256 (control)
71%
72%
5%
Figure 2. Canopy cover within the treatment unit and control over time. Group selection
treatment occurred in 2007.
Figure 3. Macroplots GS_242 (treatment unit) and GS_256 (control) in 2012, five years after
treatment.
Summary
While not extensive, the results of this monitoring effort align with past observations,
which have suggested that Quincy lupine occurrences respond favorably to disturbance
such as timber harvest treatment. The presence of Quincy lupine individuals within the
group selection treatment plot, and the subsequent increase in number, indicates that
this species is tolerant of high levels of soil disturbance and overstory removal.
On the Plumas NF, Quincy lupine is most commonly associated with open habitats,
many of which have been previously disturbed. Although this species has been found in
undisturbed sites, it has not been documented in dense forest stands with high
overstory canopy cover. The ability of Quincy lupine to tolerate and even increase
within this group selection unit, suggests that this species may benefit from
management activities that create open conditions and increase light reception to the
understory.
Maps