Salinity and Sediment Contaminants and the Reflectance & Green-up of Phragmites australis Ildiko Pechmann & Francisco Artigas New Jersey Meadowlands Commission – Meadowlands Research Institute 9th Wetlands & Watersheds Workshop Atlantic City, NJ Oct. 23-26 2006

Project Overview Background: Relationship between pigment concentration and light reflectance from leaves Light reflectance from leaves is modulated by stressor factors

Hypothesis: The light reflected from plants can be used as a surrogate variable to determine salinity and metal concentration in the sediments.

Objectives Overall: Specific: - Find if metal toxicity alters or modifies chlorophyll content in a way that plants under metal stress show differences in reflectance Specific: - Measure salinity and metals at seven distinct study sites - Measure metal uptake by leaves over the growing season - Measure light reflectance from leaves and canopies over the growing season - Find if there is a relationship between metal content in leaves and light reflectance

Field Work DA,DB BA,BB CT KP, KG Sampling (May 2 – July 20) Leaf samples Sediment samples Leaf reflectance (field data) Canopy reflectance (field data) DA,DB BA,BB CT KP, KG

Parameters measured Test plant: Phragmites australis Leaves: metal concentration (Cd, Cr, Cu, Fe, Hg, Ni, Pb, Zn) reflectance Canopy: reflectance Sediment: metal concentration (Cd, Cr, Cu, Fe, Hg, Ni, Pb, Zn) Salinity [ppt]

Contaminants in the sediment in May and August

Metal-metal relationship in the sediment Cd Cr Cu Fe Hg Ni Pb Zn Correlation 1 0.869 0.387 0.085 0.816 0.833 -0.298 0.991 Sig. . 0.011 0.391 0.856 0.025 0.020 0.517 0.000   0.131 -0.039 0.964 0.861 -0.369 0.880 0.779 0.934 0.013 0.416 0.009 0.915 0.175 0.492 -0.168 0.446 0.004 0.707 0.262 0.718 0.316 0.005 0.322 -0.171 0.162 0.482 0.714 0.729 0.924 -0.318 0.852 0.003 0.487 0.015 -0.332 0.889 0.467 0.007 -0.259 0.575 Cr, Cd, Hg and Zn tend to coexist in the sediment

Calculating Toxic Units - Metal concentrations in sediment were transformed in toxic units (TU) according to the E-RM (Effect Range Median) values (Long&Morgan, 1990) - Toxicity ranged between 0 and 80 TU depending on how much the metal concentrations exceeded the E-RM criteria. - Summary of TUs were calculated for each sampling site and related to reflectance parameters

Spectral data analysis Vegetation Indices PeakFit v.4.12 -NDVI: ρNIR – ρRED ρNIR + ρRED -Greenness Ratio: ρGREEN ρRED -Red Edge Inflection Point (REIP)

Metal in the leaves

Leaf Red Edge Inflection Point versus sediment toxicity

Canopy Red Edge Inflection Point versus metal toxicity

Conclusion The most saline site – CT - showed a delayed green-up The most contaminated sites – DA; DB - showed an early flowering Our results indicated that there were no changes in the leaf reflectance due to the metal toxicity However the canopy reflectance measurements showed relationship with sediment toxicity.

Future Research Continue to use remote sensors to classify stress levels in Phragmites communities. Focus on differences in light reflectance due to the plant architecture and canopy texture as they relate to bio-geological conditions in the sediment. Also use remote sensors to look at phenology (i.e. flowering and green-up timing) to identify Phragmites stands under heavy metal stress

Acknowledgements The Meadowlands Environmental Research Institute Dr. Jin Young Shin Yefim Levinsky So Yeon

Acknowledgements The Meadowlands Environmental Research Institute Dr. Jin Young Shin Yefim Levinsky So Yeon