Title: Investigation of rapid white oak (Quercus alba) decline within the Ozark plateau and adjacent ForestPrairie Transition ecoregion
Location: Missouri, Iowa, Arkansas
Date: September 28, 2012
Duration: 12 months
Funding Source: Base EM
Project Leaders: Rose-Marie Muzika, Forest Ecology Professor, Forestry Dept. and James English, Plant
Pathology Professor, Division of Plant Sciences, University of Missouri (MU), Columbia, MO
Cooperators: Simeon Wright, State Forest Pathologist, Missouri Department of Conservation (MDC),
Columbia, MO. John Kabrick, Forest Ecologist, USDA-Forest Service, Columbia, MO. Tivon Feeley, State
Forest Project Leader, Iowa Department of Natural Resources, Des Moines, IA. Marty Spetich, Forest
Ecologist, USDA-Forest Service, Southern Research Station, Hot Springs AR.
FHP Sponsor/ Contact: Joseph O’Brien, Plant Pathologist, USDA-Forest Service, Northeastern Area,
Project Objectives
1) Develop a database of white oak decline distribution with associated site characteristics
2) Characterize insect and fungal pathogens associated with declining white oak, including emphasis on
Phytophthora cinnamomi, a possible new oomycetous pathogen in the Ozark Plateau region.
Justification
a. Linkage: Oak species are declining in their importance relative to other species within the central
hardwood region and nearby southern-pine hardwood and forest-prairie ecoregions (FIA data). In
particular, white oak (Quercus alba) has declined significantly within its native western range during
the past 30 years (Fei et al. 2011). Since 2011, unexpected white oak decline has been reported from 37
Missouri counties and southeast Iowa.
b. Significance/ Impact: White oak is a critical component of forests in the Ozark Plateau and portions of
nearby ecoregions such as the Forest-Prairie Transition. White oak is important in Missouri due to its
longevity, mast production for wildlife and its saw timber value (2 billion dollars). White oak is used in
Missouri’s cooperage industry, the largest in the nation; and white oak staves are the second most
harvested product from Missouri forests. This research will provide data 1) to improve models
predicting white oak tree mortality due to insects and pathogens 2) contribute to general management
guidelines.
c. Scientific basis/ Feasibility: Project leaders and cooperators have diverse expertise required to
perform this work. In particular, participants have experience with oak decline research and
Phytophthora detection and management. MU researchers have permission from state and federal
agencies to perform research in Missouri and the cooperation of Iowa and Arkansas to develop a report
database (see letters of support).
d. Cost/Economic efficiency: Half of the research will be performed on federal lands and half on state
lands. Federal funds will cover costs of study on federal lands and half of costs for studies on state
lands. MDC and MU are leveraging funds for the state’s cost-share responsibilities.
e. Priority Issues: This research project addresses white oak decline in multiple states. We expect the
project to fill data gaps regarding decline of white oak in its western range and to contribute to models
of decline incorporating associated insect pests and pathogens. Emphasis will also be placed on the
possible occurrence of Phytophthora cinnamomi in decline areas. This exotic pathogen has been
reported recently as a cause of white oak decline in the eastern US. P. cinnamomi has been detected in
Iowa and Missouri, but its distribution and association with white oaks has yet to be investigated.
Description
a. Background: Pockets of white oak decline in mixed oak stands located on slope bottoms and bottomland
have been reported in Missouri and Iowa in the past two years. Oak decline on these sites occurs rapidly,
often within one growing season. In contrast, decline of red oak occurs mostly on ridge tops and upper slopes
and is attributed to the combined effects of advanced tree age, high stem density, drought, opportunistic
pathogens (e.g. Armillaria spp. and Biscogniauxia spp.) and insects (e.g red oak borer) (Muzika and Guyette
2004; Bruhn et al. 2008).
In contrast to this red oak decline syndrome, recent white oak decline patterns in Missouri fit those described
for the root pathogen, Phytophthora cinnamomi. This pathogen has recently been associated with white oak
decline in the Alleghany Plateau (Balci 2009; Nagle et al. 2010). Additional Phytophthora species are wellknown pathogens of oak species globally (Balci et al. 2010 and references therein). Similar to Missouri,
declining white oaks in Appalachia were located on slope bottoms or bottomland soils that had experienced
unusually wet weather followed by drought (Balci et al. 2010). Attack by insects and Biscogniauxia canker
contributed to P. cinnamomi-associated oak decline. Similar insect pests and Biscogniauxia canker are also
observed frequently with declining white oak in Missouri and Iowa.
P. cinnamomi population density has been assessed in relation to site and soil characteristics including soil
pH, moisture levels, percent clay and soil nutrient content (Balci et al. 2010; Nagle et al. 2010). Moist soils
or soils undergoing wet-dry cycles favor P. cinnamomi (Balci et al. 2010). Warmer, wetter weather is
predicted to increase the impact of P. cinnamomi (Sturrock et al. 2011). Based on climate change prediction
of more frequent, abnormally dry and wet years, oak decline associated with P. cinnamomi is likely to
increase. Management recommendations addressing the interaction between P. cinnamomi, oaks, and site are
needed to reduce loss of white oak resources.
b. Method:
Development of white oak decline database: A database of the distribution of decline will be created for
Missouri, Iowa, and Arkansas. Data will be gathered from federal forests in Arkansas, state and federal
forests in Missouri (50/50% distribution) representing the Ozark Plateau, and a minor component from Iowa
state lands representing the northern forest-prairie transition. Arkansas and Iowa database entries will be the
products of reports, not site visits and the respective institutions will incur the cost. The database will include
information on locations of oak decline pockets, estimation of decline severity, site characteristics including
soil characteristics from soil survey maps and slope position, and historical pathogen and insect pest
occurrence. The information for inclusion will come from white oak decline reports received over the past
two years by state and federal cooperators. Requests will be issued for additional reports from state and
federal foresters during the project period. The database will serve as the basis for a more complete survey of
white oak decline in the region to be submitted for the 2014 EM FHM competition.
Characterization of associated pathogens and insects: Plot Location and Characterization: Half of the study
will be located on federal and half on state land. Two study areas (10- 20 ha) will be established for detailed
characterization of pathogens and insect pests associated with declining oaks in northern and southern
regions of Missouri’s Ozark Plateau. MDC and USFS cooperators will help locate one plot in each region.
Thirty-five 0.08-ha plots will be created along transects established at each site. Each plot will be labeled as
declining or healthy after averaging canopy vigor ratings for oak trees in each plot (Nagle et al. 2010). In
addition, within each healthy and declining plot, the number of dead stems will be counted for each tree
species and a subset of trees will be used to determine age of mortality. In each healthy and declining oak
plot, general site characteristics will be recorded, including soil type and texture, soil pH, and moisture
holding capacity. Landform type and slope-aspect will be determined as a measure of soil water
characteristics.
Isolation of beetles and pathogens: Within each plot labeled healthy or declining, three white oak trees will
be selected along randomly placed transects. Each tree will be assessed for signs and symptoms of oak
pathogens, including Biscogniauxia spp. (formerly Hypoxylon) (canker disease), Ceratocystis fagacearum
(oak wilt), and Armillaria spp. (root rot). Molecular diagnostic tools will be applied to a subset of trees to
confirm the presence of these or other important pathogens in symptomatic tissues (Sánchez-Ballesteros et al.
2000).
Soils at the base of each surveyed tree will be sampled for the occurrence of P. cinnamomi. A wellestablished soil baiting technique will be used to recover Phytophthora . Molecular diagnostic tools will be
used to sort recovered Phytophthora isolates into two classes, P. cinnamomi or “other” Phytophthora species
(Balci et al. 2007; 2010).
To collect beetles associated with declining oaks, wood sections will be collected from the main stem of one
declining tree in each healthy and declining oak plot. Wood sections will be waxed and placed into
emergence containers for nine months. Emerged beetles will be identified. A subset of collected beetles
from abundant species will be sampled to determine occurrence of known Ceratocystis spp. and other
pathogenic fungi (Hayslett et al. 2008).
The recovery of specific pathogens and beetles will be assessed in relation to oak decline stage and stand
characteristics. This information will direct future studies of the etiology of oak decline.
c. Products
1. Database showing locations of decline sites and associated pathogens in Iowa, Missouri, and Arkansas
2. Characterization of site factors, diseases, and insects associated with declining white oaks
3. Characterization of P. cinnamomi associations with white oak decline
Collected data will be provided to agencies for the purpose of 1) creating management recommendation for
white oaks and 2) submission of follow-up 2014 EM FHM proposal
d. Schedule of activities
Spring 2013: Assemble old and new white oak decline reports, set-up of sampling plots and collection of soil
and wood samples. Summer 2013: Assays for presence of Phytophthora and identification, visual survey for
disease agents and subsequent isolations, collection of insects from emergence buckets. Fall 2013: measure
soil pH, ongoing insect identification, finish white oak decline database.
Costs: One-half of the study will be located on federal lands. Funding requested from EM FHM will pay
partial salary for a post doctoral researcher who will oversee the project and perform research. Funds are also
requested from FHM for student field and lab technicians, site travel, and supplies (PCR-related, fungal isolation
and culture, pH electrode, and tree ring analysis). MDC and MU cost share for work on non-federal lands will
support partial salary for the post-doctoral researcher salary and a doctoral student (0.25 FTE) to perform
Phytophthora isolations and identification.
Requested EM
FHM funding
Administrative
Salaries
Benefits
Indirect (10%)
Travel (fuel, vehicle)
Procurement
Supplies
Totals
Federal land $ request
Non-fed land $ request
Grand total
30640
12000
6665
4000
Other-Source funding
20000
Source
MDC (15000), MU (5000)
6495
39900
19950
59800
19950
19950
Literature cited
Y. Balci, S. Balci, J. Eggers, W. L. MacDonald, J. Juzwik, R. P. Long, K. W. Gottschalk. 2007. Phytophora spp.
associated with forest soils in eastern and north central U.S. oak ecosystems. Plant Disease. 91: 705 – 710.
Y. Balci, R. P. Long, M. Mansfield, D. Balser, W. L. MacDonald. 2010. Involvement of Phytophthora species in white
oak (Quercus alba) decline in southern Ohio. Forest Pathology. 40:430-442.
J.N. Bruhn, J.J. Wetteroff, J.D. Mihail, J.M. Kabrick, J.B. Pickens, J. B. 2000. Distribution of Armillaria species in
upland Ozark Mountain forests with respect to site, overstory species composition and oak decline. Forest Pathology, 30:
43–60.
S. Fei, N.Kong, K.C. Steiner, W. K. Moser, E. B. Steiner. 2011. Change in oak abundance in the eastern United States
from 1980 to 2008. Forest Ecology and Management. 262:1370-1377.
M. Hayslett, J. Juzwik, B. Moltzan. 2008. Three Colopterus beetle species carry the oak
wilt fungus to fresh wounds on red oak in Missouri. Plant Disease. 92:270-275.
R.M. Muzika, R.P Guyette. 2004. A dendrochronological analysis of red oak borer, In. Spetich, Martin A., ed. 2004.
Upland oak ecology symposium: history, current conditions, and sustainability.
Gen. Tech. Rep. SRS–73. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station.311 p.
A.M. Nagle, R.P. Long, L.V. Madden, P. Bonello. 2010. Association of Phytophthora cinnamomi with white oak decline
in southern Ohio. Plant Disease. 94:1026-1034.
J. Sánchez-Ballesteros, V. González, O. Salazar, J. Acero, M. A. Portal, M. Julián, V. Rubio, G. F. Bills, J. D.
Polishook, G. Platas, S. Mochales and F. Peláez. 2000. Phylogenetic study of hypoxylon and related genera based on
ribosomal ITS sequences. Mycologia: 92: 964-977.
R.N. Sturrock, S.J. Frankel, A.V. Brown, P.E. Hennon, J.T. Kliejunas, K.J. Lewis, J.J. Worrall, A.J. Woods. 2011.
Climate change and forest diseases. Plant Pathology, 60: 133–149.