Gas exchange, leaf trait, pigment, and spectral measurements were collected from white spruce trees at the northern and southern edges of the species' distribution. Data includes light response curves, Kok curves, ACi curves, leaf carbon and nitrogen content, specific leaf area, chlorophyll levels, carotenoids, and photochemical reflectance index. Measurements were taken during the 2017 growing season by researchers using a portable photosynthesis system, spectroradiometer, and digital camera.
Use Cases
- Modeling photosynthetic light response curves using gas exchange data from the LI-6800 system.
- Analyzing vertical canopy gradients in physiology by comparing data from high and low canopy positions.
- Investigating geographic adaptation by correlating leaf pigment data (Chlorophyll a, b, Carotenoids) with site location (Alaska vs. New York).
- Studying leaf economics via relationships between specific leaf area and leaf nitrogen/carbon content.
- Calibrating remote sensing indices by linking the photochemical reflectance index (PRI) with direct photosynthetic measurements.
Strengths
- Measurements cover two distinct geographic extremes of the species' range (Alaska and New York).
- Data includes multiple physiological measurement types (gas exchange curves, leaf traits, pigments, spectral indices).
- Measurements were taken at two vertical canopy positions (high and low) on each tree.
Limitations
- Data is from a single growing season (June-July 2017), limiting temporal analysis.
- Sample size is constrained to trees at only two sites, reducing geographic generalizability.
- The dataset focuses on a single tree species (Picea glauca).
Provenance
- Source
- ORNL_CLOUD via NASA EarthData.
- Collection Method
- Field measurements using a LI-6800 portable photosynthesis system, a spectroradiometer for PRI, and a digital camera for hemispherical photographs.
- Time Range
- 2017-06-19 to 2017-07-20.
- Freshness
- Data collection ended in July 2017.
- Geography
- Alaska (northern range edge) and Black Rock Forest, New York (southern range edge).