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The High Plains Initiative for Integrated Phenology: Where we are today. Sherri Harms Jose Martinez University of Nebraska – Kearney June 16, 2005. Objectives for 2004/2005. Gather information & communicate with each other What do we already know? What do we want to know?

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The high plains initiative for integrated phenology where we are today

The High Plains Initiative for Integrated Phenology: Where we are today

Sherri Harms

Jose Martinez

University of Nebraska – Kearney

June 16, 2005


Objectives for 2004 2005
Objectives for 2004/2005 we are today

  • Gather information & communicate with each other

    • What do we already know?

    • What do we want to know?

  • Gather data – what is available?

  • Study the data – what does it tell us?


Issues we would like to address
Issues We Would Like to Address we are today

The break-out sessions will address these issues & the related discussion questions.


What data is available
What data is available? we are today

  • Wheat flowering data for several sites since 1935 (Stephen Baenziger/Len Nelson)

  • Temperature & precipitation data by site for entire US (time lengths vary) (NOAA; NDMC; & see NADSS)

  • Horticultural flowering dates for 4 species, 1978-2004 (Lincoln, NE) (Richard Sutton) (many gaps)

  • Soybean yield data (2000-2004 from several NE sites) (L. Nelson)

  • Sorghum bloom data 1987-2004 (Lincoln, NE) (Jeff Perdersen)

  • Wheat stem rust data 1922-1992 several sites (USDA Cereal Disease Lab)

  • Oceanic climatic data (NOAA)

  • Other?


Preliminary studies what does our data tell us
Preliminary Studies: we are todayWhat does our data tell us?

  • Trends

    • Temperature trends

    • Wheat flowering date trends

    • Horticultural date trends

    • Sorghum Blooming date trends

  • Associations/Correlations

    • Wheat flowering dates & temperature

    • Wheat flowering dates & horticultural flowering dates

    • Wheat flowering dates & sorghum flowering dates

    • Precipitation (Local) & Oceanic (Global) Conditions

  • Climatic change verification

    • Have wheat horticultural varieties, and sorghum dates been occurring earlier?

    • If so, can this be attributed to climatic change?


Trends

Trends we are today


Temperature trends
Temperature Trends we are today

High Plains Regional Climate Center (1905-2004)


Temperature trends1
Temperature Trends we are today

  • Lincoln Data (from CALMIT) 1887-1998

  • March 1- May 30 weekly data

  • Minimum temperatures showed a slight negative trend

  • For example:


Temperature trends2
Temperature Trends we are today

  • Lincoln Data (from CALMIT) 1887-1998

  • March 1- May 30 weekly data

  • Maximum temperatures showed a slight positive trend

  • For example:







Associations of wheat flowering dates to temperature
Associations of wheat flowering dates to temperature we are today

  • Initial Study

  • UNL Agronomy Farm (East Campus) & Mead NE Research Farm

  • Wheat flowering dates from 1935 - 1998

  • Two wheat varieties: Kharkov & Scout

  • Lincoln daily minimum temperature 1935 – 1998

  • Decision Trees & Neural Networks Data mining methods


Association of wheat flowering dates to temperature
Association of wheat flowering dates to temperature we are today

  • Standardize all data into 7 categories (based on standard deviations)

  • Use minimum temperatures for a pre-defined number of weeks that precede the approximate flowering date

  • Experiment I: Ten weeks prior to the average flowering date.

  • Experiment II: Twenty four weeks prior to the average flowering date.

  • Build a model based on these temperatures

  • Performance measure: percentage of time the model arrived at the actual value on test data (using cross validation)


Experiment 1 results
Experiment 1 Results we are today




Wheat vs sorghum
Wheat vs. Sorghum dataset

Correlation Coefficent .33


Relationships between horticultural wheat sorghum flowering dates
Relationships between Horticultural, Wheat & Sorghum Flowering Dates

Confidence = examples covered by the premise / covered by the consequence

Lift =confidence/ the proportion of all examples covered by the consequence


The high plains initiative for integrated phenology where we are today

Index Flowering Dates

type

Brief meaning & calculation

Sign of index value

Other names/

Conditions

Possible impacts on Nebraska

SOI

Standardized pressure difference between Tahiti and Darwin

Positive

La Niña

Drier than normal

Negative

El Niño

Wetter than normal

MEI

Calculated as the first unrotated principal component of six observed fields* (i.e., SLP, U, V, SST, A, and C) combined

Positive

El Niño

Wetter than normal

Negative

La Niña

Drier than normal

NAO

Normalized pressure difference between a station on the Azores and one on Iceland

Positive

Strong mid-latitude westerly flow

Undetermined

Negative

Weak mid-latitude westerly flow

Undetermined

PDO

Leading principal component of North Pacific monthly sea surface temperature variability (poleward of 20N)

Positive

Warm phase

Wetter than normal

Negative

Cold phase

Drier than normal

PNA

PNA = 0.25 * [ Z(20N,160W) - Z(45N,165W) + Z(55N,115W) - Z(30N,85W) ]where Z are standardized 500 hPa geopotential height values

Positive

Positive phase

Undetermined

Negative

Negative phase

Undetermined

Climatic Associations to Precipitation in Nebraska

T. Tadesse, 2002


Sample relationships

Global Flowering DatesOcean Conditions

Local Drought Conditions

Sample Relationships

ed = extremely dry; sd = severely dry; md = moderately dry

Tadesse & Harms


Predicting phenological development in winter wheat
Predicting Phenological Development in Winter Wheat Flowering Dates

  • Xue, Wiess, Baenziger, 2004

  • Streck, Weiss, Xue, Baenziger, 2003

  • Calculate daily development rate based on

    • Temperature

    • Vernalization response function

    • Photoperiod

  • Used to predict flowering dates with good accuracy (RMSE 5-6 days)



An interesting problem
An interesting problem Flowering Dates

  • Are there statistical or computer science analysis tools that can tie temporal data to singular events?

  • In other words, how do we tie climate data to phenological data?


Wheat flowering date trends1

Kharkov Flowering Dates

Scout

Wheat Flowering Date Trends


Wheat flowering dates temperature

Kharkov Flowering Dates

Scout

Wheat Flowering Dates & Temperature


Summary of 2004 2005 activities
Summary of 2004/2005 Activities Flowering Dates

  • Gathered information & communicated with each other

  • Gathered data – limited and with holes

  • Studied the data

    • Several data sets indicate trends toward earlier maturation in plants – why?

    • Worth further exploring – global warming?


Where do we go from here
Where do we go from here? Flowering Dates

  • What other data do we want to tie together?

  • Repository for data (Tied to the National Phenology Network)

  • Decision Support System

    • Such as the National Agricultural Decision Support System (NADSS) for USDA Risk Management Association

    • Built-in analysis tools

    • Data access tools that can be used by researchers, policy makers, educators