Jake F. Weltzin Mark D. Schwartz In-situ validation of land- surface phenology A framework for involvement with USA National Phenology Network
A national biological science and monitoring program Agencies, NGOs, academia, the public Standard protocols for plants, animals & landscapes Facilitate scaling from 'leaf to globe' Integrate with other monitoring networks Business to Business and Business to Customer USA-NPN in a nutshell
Remote sensing of phenology 2005 Start of Season (SOS) Standardization Parameterization Validation Integration across products and scales Research into utility and accuracy of products
The temporal nature of phenology stages v. curves
Phenology reference stages - note parallel to LAI Start End Peak Amplitude Length Base: (NDVI start + NDVI end ) / 2 Green-up: (NDVI start / NDVI 80% ) / t Senescence: (NDVI 80% / NDVI end ) / t Large integral Small Integral Season modality The whole curve!
Event Leaf-outFloweringFruiting Day of year Ground-based phenology monitoring methods Status & Abundance Status
Event –When did you see the first leaf? (date) Status –Do you see leaves? (Y N ?) Status & Abundance –Do you see leaves? (Y N ?) –If Y, canopy is: –0 - 5% full –>5 - 25% full –> % full –> % full –> % full –> % full Phenology Monitoring Protocols e.g., canopy development Similar categories for leaf color
Event Day of year Event vs Status Monitoring e.g., flowering Y Status NNNN??NNNYNNNYYYYYNN
Advantages of Methods Event Onset Status Termination, duration, vagrants, multiple Estimates of error Sequence & overlap of phenophases Within individual Among species
Status & Abundance Abundance or intensity Shape of distribution Biologically meaningful information Remote sensing of canopy development C source > sink; CUP; NEE C Probability of interactions (intra- & interspecific) Resource & habitat availability Efficacy of management activities Set harvest dates & take limits Advantages of Methods
Building a suite of direct validation sites and datasets
White et al GCB Estimating start of season (SOS)
Go to ∙225+ plant species ∙58+ animal species ∙Core protocols User profiles –Intensive protocols Any species Abundance reporting a project of USA-NPN Coming soon
Preliminary Results 2009 growing season 2,522 registrants 911 data contributors 160,000 observations 2009
We collect other ground data useful for LPV Site condition reporting (optional) –Site characteristics Slope Aspect Habitat type Development –Date of each observation Snow on the ground? ( Y N ? ) If yes, % snow cover = ____% Snow in canopy? ( Y N ? ) –Comments Stress Mortality
Other datasets useful for LPV Dataset registry (create, view, search) Access historical datasets Standardized methodologies (design, protocols) Landing pages (regional efforts, special projects) Soon: data mgmt tools (upload, download, analyze)
Scaling from ground to satellite
PHENOCAM
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