SOD Monitoring in
Monitoring Strategy for
determining presence of SOD in
Strategy
includes:
1
Spatial
Analysis:
1.1
Risk Assessment and Mapping;
1.2
Remote Sensing;
1.3
Aerial survey to detect mortality areas;
2
Ground-based
surveys:
2.1
2.2
Systematic ground-based surveys for distribution of P. ramorum on leaf
spot or twig dieback hosts;
2.3
Nursery Survey;
2.4
Statewide Urban Areas Survey;
2.5
Early Detection in the
3
Diagnostic, GIS database and map support:
3.1
Field and laboratory diagnostic support;
3.2
GIS database and map support;
3.3
Host maps.
The entire document is available
at: http://www.suddenoakdeath.org
1.
SPATIAL ANALYSIS
(From
Completed:
Preliminary SOD risk model for areas of
§
Relational
database of species presence and abundance for each CALVEG vegetation alliance,
compiled from text descriptions of the alliances; species which are known SOD
hosts are coded as such and assigned a risk ranking score in the database;
§
SOD
host vegetation scores for each CALVEG alliance, calculated as the sum of host
species abundance score times host risk ranking score for all SOD hosts within
each alliance;
§
Distribution
map of SOD CALVEG host vegetation scores; maps show relative risk of SOD due to
presence, abundance, and importance of SOD host species in the landscape
§
Climate
maps of 30 year averages of total annual precipitation, July maximum
temperature, January minimum temperature, spring relative humidity, and total
annual snowfall;
§
Climate
variables scored and weighted to map environmental suitability for the SOD
pathogen;
1.2 Remote Sensing (from
Completed:
1.
Mapping
of stressed trees using ADAR imagery
a. Research
has been completed, and a paper has been submitted for review in GeoCarto.
b.
Achieved
50% accuracy with automated methods, and 75% with additional field information.
c.
Summary: We investigated the ability of high
spatial-resolution 4-band imagery (Airborne Digital Acquisition and
Registration - ADAR) to discern moisture stress in trees affected by Sudden Oak
Death (SOD). We wanted to test if the imagery could be used to distinguish
between green oak trees with advanced SOD trunk symptoms, and green oaks with
no SOD trunk symptoms. ADAR imagery of China Camp State Park in Marin County,
California was flown in spring 2000 and 2001. Training samples from the
field consisting of the locations green healthy oaks and green symptomatic oaks
were used to derive spectral signatures for the two classes. Both hierarchical
unsupervised classification (HUC) and maximum likelihood classification (MLC)
were used to classify the imagery. Accuracy assessment and other spectral
measurements were performed to analyze the separability of the two
signatures. Poor overall accuracy 55.17% was obtained by the HUC method.
A better overall accuracy 74.19% was obtained by MLC method, but the low
transformed divergence (1448) indicated poor separability of the training
samples. The poor accuracy results can be explained by the fact that ADAR image
has relatively broad spectral bands that combine narrow moisture-
stress-sensitive regions with broader stress-insensitive regions; such
combination could decrease the capability of ADAR to detect moisture stress. In
addition, healthy oaks in the area display a marked variability in canopy
condition, making it difficult to separate healthy trees from those
experiencing some stress. In conclusion, this research indicated the inability
to automate mapping of moisture stress in oaks using ADAR imagery, and limited
success in using methods that require extensive field data. From Kelly and Liu,
in Review.
2. Mapping of dead and dying oaks in
Marin Co.
a.
Papers
published: Oak symposium, and PE&RS.
b.
Imagery
(2000, 2001) classified using standard methods.
c.
New
classifiers evaluated for 2000, 2001, and 2002 imagery
d. Summary:
Sudden Oak Death is caused by a newly discovered virulent pathogen
(Phytophthora ramorum) that is killing thousands of native oak trees in
California. We present a landscape-scale study on the spatio-temporal
dynamics of the disease. Second order spatial point pattern analysis techniques
(Ripley's K) were applied to the distribution of dead tree crowns (derived from
high-resolution imagery) in Marin County, CA to determine the existence and
scale of mortality clustering in two years (2000 and 2001). Both years showed
clustering patterns between 100 and 300 m. A classification tree model was
developed to predict spatial patterns in disease risk based on several
landscape-scale variables. Proximity to forest edge was the most
important explanatory factor, followed by topographic moisture index, proximity
to trails, abundance of Umbellularia californica,
and potential summer solar radiation. This research demonstrates the utility of
integrating remotely sensed imagery analysis with geographic information
systems and spatial modeling for understanding the dynamics of exotic species
invasions. From Kelly and Meentemeyer, 2001.
3. Use of hyperspectral imagery to
map oaks with SOD
a. Paper in press in IJRS
b. Water content of leaves correlated
with portions of spectrum.
c. Discrimination
between healthy and stressed not found, work continues.
d. Summary:
A total of 139 reflectance spectra (between 350 and 2500 nm) from coast live
oak (Quercus Agrifolia) leaves were measured in the laboratory with a
spectrometer FieldSpec®Pro FR. Correlation analysis
was conducted between absorption features, three-band ratio indices derived
from the spectra and corresponding relative water content (RWC, %) of oak
leaves. The experimental results indicate that there exist linear
relationships between the RWC of oak leaves and absorption feature parameters:
wavelength position (WAVE), absorption feature depth (DEP), width (WID) and the
multiplication of DEP and WID (AREA) at the 975 nm, 1200 nm and 1750 nm
positions and two three-band ratio indices: RATIO975 and RATIO1200, derived at
975 nm and 1200 nm. AREA has a higher and more stable correlation with RWC
compared to other features. It is worthy of noting that the two
three-band ratio indices, RATIO975 and RATIO1200, may have potential
application in assessing water status in vegetation. From Pu et al. in Press. Discrimination between healthy
and stressed not found, work continues.
4.
Other
imagery analysis
a.
CASI,
ETM, IKONOS being evaluated.
1.3
Aerial Survey.
·
USFS, Cal Poly SLO, & UC Berkeley
collectively involved in planning/implementing aerial surveys to detect/monitor
SOD May-July 2002;
·
Survey area included 12 infested & 31 uninfested counties totaling 60 M acres, within which 20 M
acres of potential host habitat prioritized for survey
·
Over 14,500 miles flown, mapping approx
150,000 acres (gross polygon area) hardwood mortality, over 450 polygons
recorded using Digital Aerial Sketch-mapping System.
·
Ground visits just completed by USFS
contract crews/near completion or completed by Cal
Poly crews for approximately 100 priority polygons (some additional sites are
being visited by counties interested in participating on ground effort).
·
Information received to date by USFS has
been summarized (as of
o
Total sites visited (polygons, multiple points
within, or points outside) = 103
o
Total number of samples submitted for testing = 52
o
Total number of results positive = 5 (2 contra costa, 2
o
Total number of results pending = 15
·
Paper Presentation accepted for upcoming
SOD Science Symposium in
2. GROUND BASED SURVEYS
2.1
·
In progress, but no report submitted.
2.2 Systematic ground-based surveys for
distribution of P. ramorum on
leaf spot or twig dieback hosts;
·
In progress, but no report submitted.
2.3 Nursery Survey
·
Completed for 2002. See attached report.
2.4 Statewide Urban Areas Survey
·
In progress, but no report submitted.
2.5
Early detection survey for the
·
We risk rated areas in the
·
Four contractors drove over 9000 miles and
checked P. ramorum hosts for infection.
The lab results are still pending from Rizzo/Garbelotto.
·
It was difficult to tell maple scorch from
possible P. ramorum infection.
·
The survey covered the Sierra, Sequoia, Stanislaus, Eldorado, Tahoe,
·
The results will be presented at a future
meeting, still to be decided.
·
The project was a collaboration
between
The other accomplishment was with
3.
DIAGNOSTIC, GIS DATABASE AND MAP SUPPORT:
3.1 Field and laboratory diagnostic
support
·
In progress, but no report submitted.
3.2 GIS database and map support
Maintain up-to-date
spatial database of SOD
Database completed, and updated as new confirmations come
in from CDFA and UC labs
·
22
batches of data have been sent out to cooperators statewide (14 collaborators,
from PG&E, private organization, county regulators, forest service, CDF,
research).
·
Confirmations
have gone from 196 on
o
Up-to-date
maintenance of GIS database of SOD distribution (from all sources: hand-drawn
maps, field notes, GPS data, etc.)
o
Maintained
metadata and projection for all data.
Provide access to
up-to-date spatial database via:
-
Maps
o
Created
on-demand customized user-specified county and zoomed-in maps, both page poster
size. Delivered
via email, FTP downloading, or by burned CD through mail. Used for variety of purposes: personal use,
presentation, reference, etc.
o
Created
database to track map and data requests, with person and use of maps and data.
o
Maps
(~150) distributed to public (60%), government agencies (30%), private
organizations affiliated with SOD project (5%) and non-profit/regional groups
(5%).
-
Web (OakMapper site)
·
Total
hits to OakMapper website since
·
Updated
the interactive OakMapper webGIS application to make
it faster, more user-friendly, and more useful for users from every discipline
(public, researchers, regulator). Added capabilities include customized
printouts, find-address function to locate specific address or intersection of
anywhere in
·
Created
a separate OakMapper webGIS application for Aerial
Survey work, to be used by CDF and other specialists for ground-truthing of areas of mortality as found through aerial
survey.
·
Created
a separate OakMapper webGIS application for
researchers to communicate the location, purpose, and progress of individual
SOD research projects, to be used by UC Berkeley, UC Davis, CalPoly,
independent contractors and researchers, and others.
·
Kept
each OakMapper website up-to-date as needed (as new data arrived).
·
Kept
all metadata up-to-date, and created new table of contents to allow easy access
to metadata.
-
Text reports
o
Available
via the web.
3.3 Host maps (from RM)
In Progress:
·
Mapping SOD host species based on California GAP
Project vegetation coverage; integration of GAP data into risk mapping for
areas not covered by CALVEG;
·
Using USFS FIA plot data to validate the
application of CALVEG and GAP Analysis vegetation data in mapping distribution
and abundance of SOD host species;
·
Developing a statistical model of SOD risk based on
relationships
between predictor variables and confirmed infection sites (incorporating FIA
data, ground surveys, and COMTF reports).
·
Developing a dynamic model of SOD spread through
time and
simulations of potential habitat loss as consequence of disease.
Nursery Survey.
Please see
document below submitted by
Memorandum
|
To: |
Aurelio
Posadas, Chief Pest Exclusion |
Date: Place: Phone: |
January
21, 2003 916-654-0435 |
From: Department of Food and Agriculture Umesh Kodira, Program Supervisor
Subject:
Sudden Oak Death (SOD) Statewide Nursery Survey
A statewide survey for Phytophthora ramorum, the
causal agent for Sudden Oak Death (SOD) has been completed. Host plants in 99 nurseries (approximately
8,500 acres) and a quarter-mile buffer area around them were inspected for
symptoms of Phytophthora ramorum, between February 25 and
The survey was risk-based and biologically biased in that
it focused on nurseries 1) located in areas where known SOD host plants
naturally occur and 2) that ship known hosts of Phytophthora ramorum. Additional focus was placed on nurseries
shipping to
The closed-circles on the vegetation map (Attachment A)
show the locations of the 99 nurseries surveyed. Attachment B contains information on
nurseries and counties surveyed to date, 17 of which ship nursery stock to
Fifty-seven samples were collected during the survey and
submitted to the California Department of Food and Agriculture’s
The process for the selection of nurseries to be surveyed
was as follows:
·
A
list of candidate nurseries was prepared based on two criteria:
1) Nurseries that ship or were
planning to ship nursery stock to
2)
Nurseries
producing any of the plants listed by Canada as host of SOD including all
species in the following a) genera: Acer,
Arctostaphylos, Quercus, Viburnum, Aesculus,
Lithocarpus, Rhamnus, Arbutus, Lonicera, Rhododendron and b) species: Vaccinium ovatum, Heteromeles arbutifolia, and Umbellularia californica).
·
The list of nurseries meeting the foregoing criteria was
then pared down to those geographically located in areas of naturally occurring
SOD host plants. Using a vegetation map
of naturally occurring SOD host plants, nurseries were selected to provide a
wide distribution of nurseries in the natural SOD host vegetation zone.
·
A training session for CDFA Nursery biologists was held on
February 22 to go over the survey plans, information on host plants, Phytophthora
ramorum symptomatology, data recording, sample
collection and submission, completion of