In some 
ancy. In 
:S not 
icity. One 
serpentine 
11., 1954). 
[hese 
't, rank as 
nearly 
(| soils are 
Walker, 
1-serpentine 
lon of 
2getation. 
result in 
ant of 
ht be 
iral vegeta- 
loration. 
several 
'ombining 
he use of 
> the 
to detect 
ince. This 
-pentine 
ciyou 
and 
1 is known 
ion types 
'radients 
study area 
jy maritime 
'ature is 
: 200.-cm 
ees C). 
2getation 
js). This 
511) 
jalocedrus 
    
  
  
  
Serpentine vegetation ofcuws within all of these zones. At the 
lowest elevations, it differs from the surrounding vegetation by having 
virtually no broadleaved evergreen tree species. The vegetation often consists 
of a very open Jeffrey pine (Pinus jeffreyi) mixed grassland type often with 
scattered manzanita (Arctostaphylos sp.). This contrasts with the much denser 
surrounding vegetation which usually has an important broadleaf tree component. 
At somewhat higher elevations (approximately 600m), other coniferous tree 
species are present in the serpentine flora. The understory often has an open 
cover of broadleaf tree species which are highly stunted. At this elevation, 
non-serpentinized peridotite becomes an important associated ultramafic rock 
type. This parent material can be vegetationally differentiated from the 
serpentine vegetation by the much denser sclerophyll shrub and stunted broad- 
leaf evergreen tree understory (Figure 1 illustrates this difference). At high- 
er elevations (approximately 1,000m) the serpentine flora is distinct from the 
surrounding flora by certain indicator species, many of which are stunted, and 
a scattered shrub-grass understory. The broadleaf tree component, which is so 
typical of the surrounding non-ultramafic rocks is virtually absent. Trees 
which typically grow upon the higher elevation serpentine rocks include Port 
Orford cedar (Chamaecyparis lawsoniana), Jeffrey pine, incense cedar, western 
white pine (P. monticola), sugar pine (P. lambertiana), and Douglas fir. 
Image Analysis 
The primary imagery used in the analysis consisted of color and 
color infrared aerial photography at scales varying between 1:15,840 and 
1:130,000, and high altitude multispectral scanner imagery. The latter was 
acquired by the NASA Ames Research Center over the study area on September 11, 
1981. It was made with a modified Daedalus DEI-1260 scanner with ten operating 
channels in the visible, near IR and thermal infrared (Table I). The imagery 
was acquired at an altitude of 20,000m and , with a 1.25mrad IFOV, has a ground 
resolution of approximately 25m X 25m. 
The aerial photography was useful for separating the serpentine- 
bearing rock types from the non-ultramafic rock types. A simulated false 
color composite (FCC) made from the airborne scanner imagery was also useful 
for separating those rock types. However, it required a ratio color composite 
(made from ratioing the near IR to the red band, the red to a green band, and 
the green to a blue band) and an enhanced 2.05 - 2.35 channel to separate 
the serpentine from the non-serpentinized peridotite. A modified unsupervised 
classification employing extensive ground data has been successful in a limited 
area in separating those rock types. Attempts at using principal components 
analysis techniques have so far not been successful for separating the 
serpentine from the non-serpentinized peridotite. Further attempts will be made 
with this technique. 
JASPER RIDGE STUDY AREA 
The Jasper Ridge Biological Preserve of Stanford University is 
located 50km south of San Francisco and is situated on a low lying ridge on the 
eastern flank of the Santa Cruz Mountains. It is bounded on the west by the 
San Andreas Fault.  Elevations within the study area range from 70m to 190m. 
The study area receives most of its precipitation (approximately 70cm annually) 
in the winter. Temperatures rarely reach freezing. Geologically, the ridge 
consists of greenstone, chert, graywacke, and serpentine of the Jurassic- 
Cretaceous Franciscan Formation and the Eocene Butano sandstone (Page and 
Tabor, 1967). 
The top of the ridge is a broad gently roll-ng plateau covered with 
grassland. The surrounding north and east facing slopes are covered with