Hauling field gear up Gothic Mountain…
Field sampling site selection
When selecting individual sampling sites at the day's sampling area, each team chose plots or individuals with high cover of photosynthetically active vegetation and homogeneous characteristics relative to the immediately surrounding area (within ~1.5 m) to decrease confounding impact of neighboring pixel reflectance. Within a sampling area selected a set of sites that represented a range of species and species assemblages.
Quantities: Sites selected within 1.5 m homogeneous areas, representing range of species assemblages per sampling areaDuration: Selection occurred at each day's sampling areaConditions: High cover of photosynthetically active vegetation required, homogeneous characteristics within 1.5 m radius
Equipment: iPads with preliminary AOP imagery
Meadow plot vegetation sampling
For meadow sites, foliar sampling procedures similar to clip strips, 0.1 x 2 m foliar sampling areas, though chose to sample the top 10 cm of green vegetation across the full 1 m² plot rather than the strip orientation. Leaf samples for determining foliar traits and species identities were collected for statistical model development.
Quantities: 1 m² plots, 0.1 x 2 m sampling areas, top 10 cm of vegetation sampledDuration: Sampling occurred during field collection daysConditions: Green vegetation sampled during peak growing season
Equipment: sampling tools for vegetation collection
Tree and shrub sampling
Tree and shrub sampling methods were analogous to those developed and utilized by the Spectranomics group. Outlined the extent of the crown for each individual that was sampled after field work was complete and the spectral data were processed through full orthorectification.
Quantities: Individual trees and shrubs sampled, crown extent outlinedDuration: Sampling during field days, crown delineation after spectral processingConditions: Individual woody plants targeted for sampling
Equipment: tools for crown delineation, spectral processing software
Archive sample collection
Additional samples were collected at each location to develop a sample archive including litter, roots, bulk density sample from 2-7 cm depth, loose soil from 0-10 cm and associated microbial samples. Surface soil samples from the primary 437 sites were split for immediate analysis of microbial biomass, air drying for further chemical analysis, and subsampled and archived at -80°C for rhizosphere and bulk soil microbial DNA analyses.
Quantities: 437 primary sites, soil samples from 0-10 cm and 2-7 cm depths, additional 1660 soil samples from follow-upDuration: During initial field campaign and through October for follow-up subsurface samplingConditions: Samples preserved at -80°C for DNA analysis, air dried for chemical analysis
Equipment: soil sampling tools, sample preservation containers, -80°C freezers
Geophysical data collection
Local scale (~100 m extent) geophysical datasets including soil apparent electrical conductivity and soil moisture were collected at 12 sampling areas using a multi-coil electromagnetic induction (EMI)-based system. Soil electrical conductivity within multiple depth intervals between 0 and 1.8 m was collected, primarily influenced by soil water content, fluid EC, and grain surface conductivity.
Quantities: 12 sampling areas, ~100 m extent per area, depth intervals 0-1.8 mDuration: During field campaign across sampling areasConditions: Multi-depth electromagnetic induction measurements
Equipment: multi-coil electromagnetic induction (EMI)-based system