Phenology Week Talk October 3, 2014 Cynthia Wallace Research Geographer, U.S. Geological Survey, Tucson AZ Buffelgrass Phenology Project: When and Where Buffelgrass is Green

Phenology Days Celebration Thanks to all of our Partners!

The Sonoran Desert Ecosystem Wide spacing between individual plants means that fires that start do not spread Natural fires are infrequent and of low intensity Credit: Caroline Patrick-Birdwell

Buffelgrass (Pennisetum ciliare) invasion in the foothills of the Santa Catalina Mts. north of Tucson Credit: Caroline Patrick-Birdwell

Get it while it’s Green: Using MODIS satellite data to capture dynamics of buffelgrass (Pennisetum ciliare) phenology for eradication and management USGS science and funds directed toward NPS management issue Working with Saguaro National Park Coupling field-based observation of buffelgrass phenology with satellite “land surface phenology” and climate Model when and where buffelgrass is green Alert managers in a timely manner to treat optimally with herbicides

Data MODIS Satellite Data Buffelgrass Phenology Observations SNP Mapping of Buffelgrass Climate Data Preliminary Results Next Steps

Data MODIS Satellite Data Buffelgrass Phenology Observations SNP Mapping of Buffelgrass Climate Data Preliminary Results Next Steps

Passive Sensors A passive sensor records reflected or emitted energy. Usually, the energy source is the sun. Examples include aerial and satellite images. Note: Photographs and image data are different. Photos are recorded on sensitized film whereas images are recorded as electronic data. From: Shane Brandt, Geospatial Extension Agent, U of New Hampshire

Digital Format & Brightness Values Digital format: the subdivision of an image into small equal-sized and shaped areas, called picture elements or pixels, and representing the brightness of each area with a numeric value or digital number. Canada Center for Remote Sensing Pixel: Sensor: 1 mIKONOS 1 m Quickbird 30 mTM, ETM+ 250 mMODIS 1 kmAVHRR

How a Satellite Image is Made  Energy  Data  Display

Energy Blue band Green band Red band NIR band A band of an image is the measurements taken in a specific region of the electromagnetic spectrum.

Data (from 3 bands of energy) In this case, we are creating a “false color” composite, where by convention, green band energy is assigned the color blue, red band energy is assigned the color green, and near infrared energy (which is directly undetectable by the human eye) is assigned the color red,

Display – a “False Color Composite”

Near-IR (band 4)Red (band 3)Green (band 2)Blue (band 1) SATELLITESATELLITE COMPUTERCOMPUTER From: Shane Brandt, U of New Hampshire

Spectral Signature Blue band Green band Red band NIR band The pattern of reflectance characteristic of a surface. Vegetation has a distinctive spectral signature.

Plant Phenology and Spectral Response – One Species Chlorophyll in green leaves absorbs blue and red, reflects green and NIR Senescent leaves reflect more red, less NIR Band ratio can distinguish actively photosynthesizing vegetation from senescent Observing seasonal patterns can identify plant species, guide management decisions (From: Jensen, John R. Remote Sensing of the Environment: An Earth Resource Perspective.)

Vegetation Indices V.I.s are Remote sensing surrogates for estimating certain biophysical parameters of plants (e.g., percent cover, biomass, LAI) From: Paul Pinter,USDA, ARS, US Water Conservation Laboratory For example: Normalized Difference Vegetation Index NDVI = (NIR - Red)/(NIR + Red)

Data MODIS Satellite Data Buffelgrass Phenology Observations SNP Mapping of Buffelgrass Climate Data Preliminary Results Next Steps

Ventana Trail Site Ventana Waterfall Site Ventana Mist Site

Areas in red outline patches of dense buffelgrass from 2008 aerial mapping of the western Santa Catalina foothills area of Tucson AZ.

Data MODIS Satellite Data Buffelgrass Phenology Observations SNP Mapping of Buffelgrass Climate Data Preliminary Results Next Steps

Saguaro National Park

The spatial pattern of rainfall is highly variable in the Sonoran Desert Photo Credit: Zack Guido, CLIMAS, The University of Arizona

Data MODIS Satellite Data Buffelgrass Phenology Observations SNP Mapping of Buffelgrass Climate Data Preliminary Results Next Steps

Get it while it’s Green: Preliminary Results Observed buffelgrass greenness, MODIS-EVI and Precipitation (PPT) data for 16-day periods

Get it while it’s Green: Statistical correlation analysis

Fourier Harmonics of Annual Phenology Fourier Harmonic Analysis of a Waveform Forest Shrubland Grassland Wetland Temporal NDVI profiles for selected SE Arizona landscapes

AZ phenometrics for 1998

Get it while it’s Green: Harmonics analysis of each variable by year 2011 MODIS and Greenness patterns align PPT pattern precedes Greenness

Get it while it’s Green: Harmonics analysis comparing variables Timing of PPT always earlier, Timing of Greenness and MODIS typically coincide

Preliminary Results Buffelgrass greenness observed on the ground is strongly correlated to contemporaneous MODIS-EVI greenness. Buffelgrass greenness observed on the ground is highly correlated to precipitation of the prior time-period and the prior two time periods (prior 16 day total and prior 32 day total). Annual harmonics resonance between greenness-MODIS-PPT show consistent patterns, with PPT peaks preceding others and with greenness and MODIS in synchronicity. Saguaro National Park: so far, we have found lower MODIS-EVI values for some vegetation types with buffelgrass invasion vs. areas without buffelgrass.

Data MODIS Satellite Data Buffelgrass Phenology Observations SNP Mapping of Buffelgrass Climate Data Preliminary Results Next Steps

Precipitation (UA Station) 2005 MODIS NDVI Profiles

1.Join Nature’s Notebook 2.Find a site to monitor buffelgrass – Choose a location that you will visit once every week or two. I can help you select a site or you can have your own site added to the network. 3.Sign up as an observer – Become an official participant with Nature’s Notebook and set your username and password. All you need is an address and Internet access. When you are registering, identify yourself as part of this effort by selecting “Buffelgrass Monitoring Network, Tucson” from the Partner Organization drop-down menu. How to participate…..

Thank you!