2025 Aggregation ESU

Vegetation parameters

Fractional Vegetation Cover (FVC)

FVC refers to estimating the proportion of an area that is covered by vegetation, whereby it is not distinguished between vital, senescent and dry vegetation. The fractional vegetation cover value is estimated in percent.

Proportion of senescent material (PSM)

Vegetation components are classified in two categories: (1) living biomass and (2) senescent material. The senescent material includes all dry vegetation components at the designated area, whereby dry vegetation of the standing plants and components lying on the ground are included. PSM is defined as the proportion of senescent vegetation, which is the dry vegetation cover, related to the overall vegetation coverage as covered by the reference frame. Only the estimated value of the senescent material will be recorded.

Canopy height

Canopy height is the mean height of the highest vegetation component above the soil surface of several plants (Nakai et al., 2010).

Content of Leaf Chlorophyll (Chl)

Chl is defined as the mass of chlorophyll (in μg) per leaf area (in cm²) and will be derived from nondestructive absorbance measurements with a SPAD-502Plus (Konica Minolta, Inc.) chlorophyll meter.

Soil parameters

Soil Moisture

Soil moisture is the water that is held in the spaces between soil particles. Surface soil moisture is the water that is in the upper 10 cm of soil.

Leaf Area Index

The plant area index (PAI), i.e., the leaf area index (LAI) including ears and cornstalks (Neumann et al., 1989), is an important canopy structural parameter in radiative transfer models and retrieval models in general (Gobron, 2008). The LAI is defined as the one-sided leaf area in relation to the ground area (m3/m3). With non-destructive sampling, photosynthetic activity (e.g. Sun Scan) or the GAP fraction expressed by transmitted light in the ultraviolet spectra (e.g. LAI-2200) are measured. With the destructive vegetation sampling, more specific measurements are possible, because all plant parts (leafs, ears, cornstalks) can be measured separately in a scanner (e.g. LA3100). Here, GAP fraction in the ultraviolet spectra is measured that includes ears and cornstalks is measured (PAI). For a more accurate estimation of the LAI, laboratory values are required in order to calibrate the field measurements.