This document summarizes an analysis of northern coastal scrub community structure along the California coast. Axis 1 of an NMDS ordination correlated with higher abundance of coyote brush, which creates many canopy gaps. Species that prefer more open conditions correlated with Axis 1. Axis 2 differentiated sites based on differences in topography and zonation of plant species, with some species preferring lower elevations. Coastal environmental stresses like salt spray and wind also likely influence community composition along Axis 2.

1. Analysis of Northern Coastal
Scrub Community Structure
Robin Shin
May 13, 2016

2. Introduction
• Scrub vegetation is found along the coastline of California
• Northern Coastal Scrub is a major vegetation type along Northern California coastlines
• Can be found along a narrow and discontinuous region from Southern Oregon to Monterey,
County
• Pattern of mesic to xeric conditions as you go from North to South

3. North Coast Scrub Composition and Structure
• vegetation types occur in a patchy framework of coastal prairie, oak woodland, mixed evergreen forest, and close-
pined forest
• Low to moderate-sized shrubs with mesophytic leaves, flexible branches, semi-woody stems, and a shallow root
system
• Many species exhibit prostrate growth- horizontal growth of branches and stems, compared to erect growth.
• Overstory- generally consists of taller shrub species, Ex. Coyote Brush
• Understory- generally consists of perennial herb/sub shrub species ex. Beach aster

4. NMDS Indirect Gradient Analysis
• Dataset consisted of research performed by( Baxter and Parker 1999) on northern coastal scrub
community structure.
• Contains 58 (1x .75 m) plots at 3 coastal bluff sites in San Mateo, County
• Percent Cover, canopy gap, and site locations ( 1-3) were recorded in this data set.
• A NMDS ordination was run on PC-ORD Statistical Program with Sp.-Plot as the first matrix, and
Gap-Site as the second matrix

5. Q1AE1
Q1AE2
Q1AE3
Q1AE5
Q1AW1
Q1AW2
Q1AW3
Q1AW4
Q1BE1
Q1BE2
Q1BE3
Q1BE4
Q1BE5
Q1BE6
Q1BW1
Q1BW2
Q1BW3
Q1BW4
Q1BW6
Q1BW7
Q1BW8
Q1BW9
Q1BW10
Q1BW11
Q1BW12
Q1BW13
Q1C1
Q1C2
Q1C3
Q1C4
Q1C5
Q1C6
Q2A1
Q2A2
Q2A3
Q2A4
Q2B1
Q2B2
Q2B3
Q2B4
Q3A1
Q3A2
Q3A3
Q3A4
Q3A5
Q3A6
Q3B1
Q3B2
Q3B3
Q3B4
Q3B5
Q3B6
Q3C1
Q3C2
Q3C3
Q3C4
Q3C5
Q3C6
Distribution and Abundance of Northern Coastal Scrubs
Axis 1
Axis2
SITE
1
2
3

6. Q1AE1
Q1AE2
Q1AE3
Q1AE5
Q1AW1
Q1AW2
Q1AW3
Q1AW4
Q1BE1
Q1BE2
Q1BE3
Q1BE4
Q1BE5
Q1BE6
Q1BW1
Q1BW2
Q1BW3
Q1BW4
Q1BW6
Q1BW7
Q1BW8
Q1BW9
Q1BW10
Q1BW11
Q1BW12
Q1BW13
Q1C1
Q1C2
Q1C3
Q1C4
Q1C5
Q1C6
Q2A1
Q2A2
Q2A3
Q2A4
Q2B1
Q2B2
Q2B3
Q2B4
Q3A1
Q3A2
Q3A3
Q3A4
Q3A5
Q3A6
Q3B1
Q3B2
Q3B3
Q3B4
Q3B5
Q3B6
Q3C1
Q3C2
Q3C3
Q3C4
Q3C5
Q3C6
Distribution and Abundance of Northern Coastal Scrubs
Axis 1
Axis2
GAP
1
2

7. Exploratory Analysis
• Set a threshold of r value > 2.30, and analyzed 11 of the 23 plant species
Sp. Axis1 Axis2 Name Growth soilph salinity texture elevation note
BPL 0.939 0.74 BacharusP Tree/shrub 5.0-8.2 7.6slightlysaline fine+med+coarse shadetolerantlowwater
ESF 0 0.852 eriophyllum tree/shrub 5.6-6.8 14moderatesaline medium_coarse 0-510 lowwatertolerant,fullsun
EGL 0 0.495 Glaucus rhizomatousherb 5.6-6.8 1.6nonsaline mediumcoarse 0-440 lowwatertolerant,coastalbluffs
ABL -0.251 0 achilleaborealis rhizomatousherb 5.2-7.9 2.7veryslight fine+med+coarse 0-3000 shade/lowwatertolerant,1-3ft
GAP 0 -0.243 galiumaparine ANNUALHERB 5.0-8.2 3.3very slight fine+med+coarse 0-2550 lowwatertolerant
RUR -0.235 0 rubusursinus vine 5.1-8.0 non-saline fine+med+coarse 0-1880 shadetolerant2-4ft.
COB 0 0.239 carexobnupta rush/sedge acidic 0-900 verymoistconditions,saline
SCN -0.261 0 solidagocanadensis rhizomatousherb Nov-00 erect,notshadetolerant,needssun disturbance 3-5ft
AAV 0 -0.343 anagellisarvenis annualherb,invasive 1.6nonsaline fine+med+coarse 0-3300 lowgrowingannual,disturbedlands
AHE 0 -0.255 aneglicahendersoni non-rhizomeherb 9-230 erect4-5ft,notshadetolerant
SCA 0 0.3 scrophullariacalifornicaherb 2.6slightly fine+med+coarse 0-3600 shadetolerant

8. Axis 1
• Rubus ursinus (blackberry), Achillea borealis (boreal yarrow), Solidago canadensis spp. elongata (
golden rod) , Baccharis pularis ( Coyote Brush) were correlated with Axis 1.
• Coyote brush is a dominant over-story shrub species that accounts for a significant portion of
cover at all three sites. ( B. pularis + E.staechadifolium account for 67 % of all cover)
• Canopy gaps, were defined in this study, as contiguous openings in vegetation, devoid of leaves
and greater then 2m in diameter, are especially prominent among Coyote Brush crowns ( 45 % of
area were gaps).

9. Axis 1
• BFL- + .930
• RUR- -.235
• ABL- -.251
• SCN- -.261
• Axis 1 may be defined by the abundance of B.pularis.
• Since canopy gaps occur primarily within B. pularis crowns, a higher abundance of this species will also
correlate with more canopy gaps.
• Example from dataset - Q1AW1- 87 % BPL , Q2A2- 2 % BPL
• Additionally: RUR, ABL ( up to 3 ft. tall), and SCN ( up to 5 ft tall) are all species of plants which display more
erect growth patterns rather than prostrate.
• Though r value is low for these species, and the over all abundance of these species were low in all plots,
these species likely would not persist in canopy gaps which accommodate understory vegetation.

10. Q1AE1
Q1AE2
Q1AE3
Q1AE5
Q1AW1
Q1AW2
Q1AW3
Q1AW4
Q1BE1
Q1BE2
Q1BE3
Q1BE4
Q1BE5
Q1BE6
Q1BW1
Q1BW2
Q1BW3
Q1BW4
Q1BW6
Q1BW7
Q1BW8
Q1BW9
Q1BW10
Q1BW11
Q1BW12
Q1BW13
Q1C1
Q1C2
Q1C3
Q1C4
Q1C5
Q1C6
Q2A1
Q2A2
Q2A3
Q2A4
Q2B1
Q2B2
Q2B3
Q2B4
Q3A1
Q3A2
Q3A3
Q3A4
Q3A5
Q3A6
Q3B1
Q3B2
Q3B3
Q3B4
Q3B5
Q3B6
Q3C1
Q3C2
Q3C3
Q3C4
Q3C5
Q3C6
Distribution and Abundance of Northern Coastal Scrubs
Axis 1
Axis2
GAP
1
2

11. Axis 2
• Eriophyllum staechadifolium ( seaside wooly), Anagallis arvensis (scarlet pimpernel), Galium
aparine ( goose grass), Angelica hendersonii ( wild celery), Carex opnupta ( sedge), Scrophularia
californica ( Ca. Figwort), Erigeron glaucus ( beach aster), and Baccharus pularis ( coyote brush)
were all correlated with Axis 2
• ESF- -.82
• AAB- -.343
• GAP - -.243
• AHE- -.255
• COB- +.235
• EGL- +.495
• SCA- +.30
• BPL- +.74

12. Axis 2
• Similar to Axis 1, a high abundance of BPL seems to be a factor in axis 2.
• ESF ( seaside wooly), is negatively correlated with BPL abundance (r value=-.82), although both
these plants are native shrubs.
• ESF grows up to 5 ft. tall and requires full sunlight. Thus this plant likely does not grow in the understory vegetation
characteristic of canopy gaps of BPL.
• Furthermore this species is also responsible for a small percentage of canopy gaps
• Coexistence at the local scale may not be possible
• An analysis of the abundances between sites show that Axis 2 distinguishes ESF for site 3, and EGL
and SCA for Sites 1 and 2.
• Both EGL and SCA are absent in abundance for the majority of all plots in site 3, and both are in relative abundance
in plots of Site 1 and 2.
• ESF is most abundant in the plots of site 3.

13. Q1AE1
Q1AE2
Q1AE3
Q1AE5
Q1AW1
Q1AW2
Q1AW3
Q1AW4
Q1BE1
Q1BE2
Q1BE3
Q1BE4
Q1BE5
Q1BE6
Q1BW1
Q1BW2
Q1BW3
Q1BW4
Q1BW6
Q1BW7
Q1BW8
Q1BW9
Q1BW10
Q1BW11
Q1BW12
Q1BW13
Q1C1
Q1C2
Q1C3
Q1C4
Q1C5
Q1C6
Q2A1
Q2A2
Q2A3
Q2A4
Q2B1
Q2B2
Q2B3
Q2B4
Q3A1
Q3A2
Q3A3
Q3A4
Q3A5
Q3A6
Q3B1
Q3B2
Q3B3
Q3B4
Q3B5
Q3B6
Q3C1
Q3C2
Q3C3
Q3C4
Q3C5
Q3C6
Distribution and Abundance of Northern Coastal Scrubs
Axis 1
Axis2
SITE
1
2
3

14. Axis 2
• Differences in topography and zonation of plant species may also be driving the axis 2 gradient.
• All of the negatively correlated species of axis, except ESF, are annual herbs or non-rhizomatous.
• AAV ( Scarlet pimpernel) is a invasive annual herb
• Can grow in elevations up to 3,300 ft.
• Generally occur on coastal terraces near disturbed habitats
• AHE ( wild celery) - is a cosmopolitan species of the Western U.S region, this plant is not shade
tolerant, displays erect growth of up to 5 ft tall, and grows via a deep taproot.
• GAP- ( Galium)- is also a non-native annual herb, also common in disturbed habitats
Where as….
• COB ( sedge), SCA ( Ca. Figwort), and EGL ( beach aster) are all positively correlated with Axis 2, and are
all native prostrate herbs and sedges of the Northern Coastal Scrub community. These species likely
are able to survive in the understory of Coyote Brush canopy gaps.
• Thus, Axis 2 may represent a zonation and topography gradient because non-native species may
occupy higher elevation topographic regions which contain annual grasslands, as well as different
zones within a coastal terrace.

15. Axis 2 cont.
• As you increase up axis 2, a possible gradient towards a lower elevation containing native plants
that are adapted to exposure to environmental stresses.
• it may be possible that other environmental gradients which may also follow a topographic or
zonal influence are present along axis 2
• These may be the impact of salt spray and strong coastal winds.
• salt spray- the deposition of sea salts onto coastal plants influences coastal scrub communities
• Ex. Coyote Brush is highly salt tolerant, accumulates salt on foliage and roots which eventually deposit
into soil and increase concentrations ( Clayton 1972)
• Wind- strong coastal winds affect all species in the northern coastal scrub, however it is likely to
most affect species closest to the coastal bluff or cliff. Faster winds are correlated with more salt
deposition, thus this gradient may differ from site to site depending on site exposure
• Environmental stresses experienced towards the edge of cliffs or bluffs, are countered by coastal
scrub adaptations such as prostrate growth. These adaptations are seen in the native plant
species of scrub communities.

16. Conclusions
• Coyote brush is a dominant species in this study.
• The overall dominant abundance of coyote brush may be due to its strong ability to colonize after
disturbance ( ex. Fire) .
• Coyote brush is a pioneer species, which colonizes quickly after a disturbance.
• Historical FRI of coastal scrub are estimated at 10-20 years, thus the cosmopolitan distribution of this species in this
study site may not only be due to coyote brush’s overall hardiness as plant, but also due to disturbances such as fire
which allow them to proliferate quickly.
Baxter, J. W., & Parker, V. T.. (1999). CANOPY GAPS, ZONATION
AND TOPOGRAPHY STRUCTURE: A NORTHERN COASTAL SCRUB
COMMUNITY ON CALIFORNIA COASTAL BLUFFS. Madroño,
46(2), 69–79. Retrieved from
http://www.jstor.org/stable/41425302