The Floristic Composition of a Sierra Nevada Foothill Plant Community
Matthew Deuser, Darnisha Wiley, Skylr Lopez, Andrew Pacheco, Joanna Ochoa, Anyssa Frias, Alex Jamal, Yelena Martinez, Robert Urtecho
Department of Biological Sciences, College of the Sequoias, Visalia, CA
Results
OBJECTIVE
CONCLUSIONS
SCICON has a complex collection of floral elements composed of a variety of
species that have adapted to the xeric habitat. Along with common dryland trees
such as Blue Oak (Quercus douglasii), the higher elevated reaches of the SCICON
property have chaparral elements introducing Adenostoma fasciculata,
Arctostaphylos glandulosa, Fremontodendron californica, Cercocarpus
betuloides. Many of these species are associated with the Madro-tertiary
geoflora described by Axelrod and Raven.
This study aims to establish a comprehensive collection of the plant species
found on the SCICON property. Observations will be made of plant associations,
slope and soil conditions. The results will aid us in determining vegetation
composition and create vegetation profiles of the area.
INTRODUCTION
.
Materials and Methods
Plant collecting commenced in early spring 2016 and has continued on a
monthly basis. To date there have been 300 numbers collected of species that
are found within the SCICON property and the adjacent US Forest Service land.
Plants were collected using standard plant pressing and drying methods (Wood,
1979). Plant taxonomic names follow Baldwin, et.al. (2012). Voucher
specimens will be housed in the College of the Sequoias. Photographs of plants
encountered during collection runs were made using a Nikon camera and will
be used for both species identification and evidence for describing plant
community structure and vegetation type. Species occurrences were observed
in the field and recorded through both collections and field notes. Additional
information was derived from Google Maps that provided vital information on
vegetation distribution and extent of cover. Herbaria that are part of the
Consortium of California Herbaria provide online access to collections. The data
base will be mined for plants collected in the vicinity of SCICON. To this list will
be added our collections made at the SCICON property and adjacent forest
lands This study is a continuation of a project started in 2015.
To date there have been 569 taxa in 97 plant families identified as present at
SCICON and adjacent properties with the most common plant communities
Taxa
being:
Blue Oak Woodlands (South Facing Slopes)
Mesic Forest (North Slopes)
Riparian Forest
Valley Oak Savannah
Chamise Chaparral
Manzanita Scrub
200
Number of Taxa
•
•
•
•
•
•
250
150
100
50
0
Taxa
Shrubs
Trees
Annual Herbs
Perennial
Herbs
Annual Grasses
Perennial
Grasses
38
26
234
151
29
30
In our research, we have found 48 species being widespread invasive plants
belonging to the grass family (Poaceae) and 26 species that have been
recognized as trees, including various species of willow. Further, we have found
11 species of fern and fern allies, and 12 species of monkey flower (Mimulus,
Phrymacae) that have been found at SCICON. Of these collected species, the
largest group that was found was the sunflower family (Asteraceae) that is show
in table 1.1 with 85 taxa that a represents 15 percent of the flora within
SCICON.
The listed, additional families highlighted in the table 1.1 constitute
representative taxa in our survey of SCICON and have a significant increased
over the flora of the Tulare County portion of the San Juaquin Valley floor. We
have predicted that the differences in the distribution of the flora is due to the
amount of precipitation and temperature occurring at the mid-elevation level as
well as the complex granitic outcrops and soils.
Comparison of Valley Temperatures to Precipitation
High Sierra Max Temp
Valley Floor Max Temp
Sierra Foothill Max Temp
High Sierra Precipitation
Valley Floor Precipitation
Sierra Foothill Precipitation
40
Blue Oak were observed to drop their leaves by mid-June 2015. Although, with
higher than normal temperatures, collections of many of the specimens were
made at least a month earlier that they were commonly expected to flower.
Future studies of the property should focus on the species occupying the steep
slopes on either side of Bear Creek. Some of the rocks in the western property
also appear to be ultramafic and may produce potential additions to the species
list. The cool and noise northeast slopes may also be a source of additional
collections as these have proven to have many taxa with affiliations to mesic
northern floras (Arcto-tertiary geoflora). Additional attention needs to be placed
on more carefully mapping species distributions in the SCICON property.
LITERATURE CITED
Literature cited
Bruce G. Baldwin (Editor), Douglas Goldman (Editor), David J Keil (Editor), Robert
Patterson (Editor), Thomas J. Rosatti (Editor), Dieter Wilken (Editor). 2012. The
Jepson Manual: Vascular Plants of California, Thoroughly Revised and Expanded.
University of California Press. P. & 1 more1600.
Barbour, Michael and Jack Major. 1990. Terrestrial vegetation of California. New
Expanded Edition. California Native Plant society. Special Publication Number 9. P.
1020.
250
35
200
30
25
150
20
100
15
10
50
5
0
0
Jan
Feb
March
April
May
June
July
August
Sept
Oct
MONTH
Figure 1.2 Comparison of Valley Temperatures to Precipitation
Nov
Dec
MM IN PRECIPITATION
maps of the area
Figure 1.1 Largest Plant Families at Scicon
CELSIUS IN TEMPERATURE
Tulare County, with the exception of the National Parks, has one of the least
known floras in California. Since much of the valley floor has been converted to
agricultural purposes and the foothills dedicated to ranching, there have been
few botanical surveys performed. Evidence of gaps in collections are glaring
when one references the site localities of collections in the Cal Flora website.
The Sierra Nevada foothills are known for their high plant diversity (Barbour,
1990) and serve as an important ecotone between valley plant communities
and those of the mid-elevation Sierras. More information is needed on the
vegetation of the foothills (Sawyer, et.al., 2009). Surveys of the Sierra foothills
will prove to be important contributions to the literature on California floristics.
The SCICON Property is a large parcel that ranges in elevation from between
1800 and 3000 feet. There has been no systematic collection of the plant
species on this largely undisturbed Central California Sierra Nevada Foothills
locality. Although it is known that the property has both riparian and chaparral
elements, there has been no study that has collected voucher specimens for
herbarium mounts, recorded ecological data, and created plant community
Unfortunately, Tulare County as well as the rest of California is currently
experiencing extreme drought, and the evidence is very obvious on this section
of the Sierras. Widespread mortality of the following species was observed over
the past two years: incense cedar, pine and manzanita.
Wood, Emily. 1979. Herbarium Procedures: An Herbarium Guide and Training
Manual for the Herbarium at Carnegie Museum of Natural History, Pittsburgh,
Pennsylvania. CMNH Herbarium, Eds. D.E. Boufford and F.H. Utech
.
Sawyer, John O., Todd Keeler-Wolf, Julie M. Evans.2009. A Manual of California
Vegetation (2nd Ed.). California Native Plant Society and California Department of
Fish and Game, Sacramento, CA. p. 1300.