Oomycetes II

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Pollen Forecasting for Juniperus ashei
Estelle Levetin, Peter Van de Water, C.E. Main,
and Thomas Keever
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Mountain cedar (Juniperus ashei)

• Limited Distribution
• Arbuckle Mts of Oklahoma
• Edwards Plateau of Texas
• Scattered areas of Ozarks
• Highly allergenic (cedar fever in Texas)
• Tulsa allergist reported 15 patient sensitivity
• Mid-winter pollination (Dec. and Jan.)
• Tulsa pollen season Feb through early Nov
• Evidence of pollen in Tulsa atmosphere
• Cedar pollen detected since 1980
• In depth study of J. ashei pollen since 1996

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Distribution of Juniperus Ashei
Tulsa
Junction
Austin
Juniperus ashei grows amongst the dissected
slopes of Cretaceous limestone of the Edwards
Plateau. The Species co-occurs with J.
virginiana to the east and J. pinchotii other
Juniperus spp. to the west.
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Burkard Air Samplers

• Tulsa area
• University of Tulsa
• Bixby - Mesonet
• Hectorville - Mesonet
• Additional samplers
• Arbuckle Mts, OK
• Austin, TX
• Junction, TX
• Dripping Springs, TX

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Mountain Cedar Forecasting

• Started in Dec 1998
• Daily forecasts in Dec and Jan
• Forecasts posted on internet at
  http//pollen.utulsa.edu
• During past 4 season 628 forecasts issued
• Three sites in Texas Austin, Junction, San
  Angelo
• One site in Oklahoma Arbuckle Mountains
• One site in Arkansas Ozark Mountains

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Forecast Components

• Release forecast based on meteorological
  conditions and phenology of the plant
• Above 45o F
• Below 50 R.H.
• Sunshine
• No rain in previous 24 hours
• Pollen cone maturity
• Downwind forecast based on model projections
  using
• HY-SPLIT model trajectories
• Meteorological conditions along the path

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Pollen Release Forecasts

• Forecast conditions based on meteorological
  conditions at 1100 am
• Release conditions listed as
• Unfavorable for Release
• Mixed Conditions
• Favorable for Release

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Assessment of Release

• Daily forecast conditions compared to average
  daily pollen concentrations at our Austin and
  Junction, Texas sites
• Grouped by forecast and compared using a
  Kruskal-Wallis test, non-parametric ANOVA

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1998-99 Pollen Season
Austin, TX
Junction, TX
Significant difference among groups using
Kruskal-Wallis ANOVA(p lt0.05)
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1999-2000 Pollen Season
Junction, TX
Austin, TX
Significant difference among groups using
Kruskal-Wallis ANOVA(p lt0.05
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2000-2001 Pollen Season
Significant difference among groups using
Kruskal-Wallis ANOVA(p lt0.05
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All Release Forecasts
Mean 1075
Mean 727
Mean 239
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Qualitative Assessment of Pollen Release
Forecasts for Texas Sites over 3 Years Using
National Allergy Bureau (NAB) Levels
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Downwind Forecasts

• Movement of pollen described for 48 hours using
  HY-SPLIT model trajectories
• Available on-line from NOAA - ARL web site
• Trajectories describe the movement of a
  pollen-laden parcel of air
• Meteorology along the path involved in the
  downwind forecast
• Assessment based on trajectories that passed over
  Tulsa area using data from our 3 Burkard traps in
  Tulsa, Bixby, and Hectorville

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Winter Airborne Cedar Pollen Concentrations in
Tulsa
1998-99
1999-2000
2000-01
2001-2002
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1998-2002 Tulsa Profile

• During Dec and Jan of the 4 years cedar pollen
  present on 173 days
• Most days low levels
• 41 days moderate or high levels
• 12 of these 41 days with high levels
• Trajectories analyzed for these 41 days
• Trajectories crossed Tulsa 131 times with the
  majority of trajectories from the Arbuckle Mts

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Analysis of Dec-Jan Cedar Pollen in Tulsa
All days with moderate or high
concentrations were further analyzed
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Summary of 98-99 Incursions into the Tulsa Area
and Related Sources
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Further Analysis of the 16-Jan Tulsa Incursion
Backward trajectory from Tulsa at 1600 cst on 16
Jan
Forward trajectory from the Arbuckles on 15 Jan
at 1600
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How distant is long distance transport?

• 27 Jan 99, Jim Anderson in London, Ontario
  reported atmospheric Juniperus pollen - 58 pollen
  grains/m3
• Trajectories show that the source of this pollen
  was Texas population of Juniperus ashei

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Forecast on 26 Jan 1999
OUTLOOK Moderate Threat Now that we are
nearing the end of the season, decreasing amounts
of airborne pollen are expected. Mostly favorable
conditions for pollen release, especially from
the west. As on other occasions, airborne pollen
from eastern sections of the Plateau will get
caught up in winds ahead of the low pressure
system and has the potential to travel very long
distances. Pollen released from western sections
of the Plateau will move slower after the first
12 hours as the winds weaken and eventually
change direction.
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Conclusions

• Pollen forecasting requires knowledge of the
  onset of the pollen season and knowledge of the
  effects of weather on pollen release
• Forecasting for mountain cedar pollen has been
  reasonably successful in predicting release
  conditions, but the pollen forecasts are only as
  good as the meteorological forecasts
• Down wind forecasts predicted all but two
  incursions into the Tulsa area during four years
  of forecasting