Floral Availability (FA) quantifies the presence and spatial distribution of floral resources available to pollinators in a given area. It is a normalised index ranging from 0 to 100 (scaled from raw 0--1), computed via the InVEST Pollinator Abundance model developed by the Natural Capital Project.
A high FA indicates a landscape rich in flowering vegetation capable of supporting pollinator populations -- including honeybees (Apis mellifera) and wild bee species -- by providing adequate nectar and pollen throughout the active season. This matters because floral resources are the primary nutritional driver for pollinator health, honey production, and the delivery of pollination ecosystem services.
Recent studies document an alarming decline of pollinators across Europe, closely correlated with the reduction in floral availability caused by agricultural intensification, habitat loss, and landscape fragmentation (Potts et al., 2010).
FA is computed from the InVEST Pollinator Abundance model (Integrated Valuation of Ecosystem Services and Trade-offs), developed by the Natural Capital Project. The calculation involves four main steps:
where the area-weighted mean is computed over all land cover classes within the site polygon, and the raw model output [0, 1] is scaled to [0, 100] for display.
Data are sourced from the InVEST Pollinator Model (Natural Capital Project) at CLC class-level resolution, using ESA WorldCover (10 m), CORINE Land Cover (100 m), or CLC Backbone (100 m) as land cover inputs.
Gauge. A semicircular arc gauge showing the site's floral availability index (ROI) alongside the control area value (CA), with a delta badge indicating the difference.
Purpose: To show at a glance whether the site has sufficient floral resources to sustain pollinator populations, relative to a control area.
Description: The gauge displays two overlapping arcs -- one for the site (ROI) and one for the control area (CA) -- along a 0--100 scale divided into five quality segments from E (critical, 0--20) on the left to A (excellent, 80--100) on the right. A coloured delta badge (green when site exceeds control, red otherwise) appears beneath the gauge. The section also displays the ESRS sub-topic label and a compliance badge.
65Floral Availability
How it's calculated: The displayed value is the area-weighted mean of seasonal floral supply indices across all land cover classes within the site polygon, normalised to [0, 1] and scaled to 0--100. The site value (ROI) and control area value (CA) are computed independently over their respective polygons.
Note: This indicator is not inverted -- higher values indicate better ecological conditions for pollinators.
Legend:
| Level | Range | Color | Meaning |
|---|---|---|---|
| A | 80 -- 100 | ■ #00A67A | Very rich floral supply; ideal habitat for pollinators and honey production |
| B | 60 -- 80 | ■ #00DF80 | Good floral availability; favourable conditions for bees |
| C | 40 -- 60 | ■ #FFD21E | Moderate availability; possible seasonal resource shortfalls |
| D | 20 -- 40 | ■ #FF8B16 | Low floral availability; pressure on pollinator populations |
| E | 0 -- 20 | ■ #FF367F | Floral resources nearly absent; inadequate habitat for pollinators |
Interpretation example:
If the gauge shows ROI = 65 (grade B) and CA = 42 (grade C), it means the site has good floral resources -- diverse flowering vegetation supports pollinators throughout the season -- outperforming its surrounding control area.
Assessment Sidebar Row. A compact row in the left sidebar showing the FA indicator name and A--E grade badges for site (ROI) and control area (CA).
Purpose: To provide a persistent, page-wide reference to the site's FA grade across all seven assessment pages without requiring navigation back to the biodiversity section.
Description: The row is labelled "Floral Availability" in the E4 Biodiversity group of the sidebar. Two small coloured badges display the current grade for Site and Control respectively. The sidebar row appears on all seven assessment pages: Biodiversity, Land Use, Microclimate, Urbanization, Risks, Sensors, and Double Materiality.
How it's calculated: Same as the gauge -- area-weighted FA index, displayed as an A--E grade derived from the [0, 20, 40, 60, 80, 100] range thresholds.
Interpretation example:
If the sidebar row shows Site = B and Control = C, the site's floral resources are above the regional benchmark -- a positive signal for pollinator habitat quality.
Highlights Table Row. A column in the multi-site KPI comparison table on the Highlights page, showing FA site and control values side by side for each monitored site.
Purpose: To allow direct comparison of floral availability across multiple sites in a single tabular view.
Description: The table displays one row per site and one column per KPI. The FA column header reads "Floral Availability", with two sub-columns "SITE" and "CONTROL" showing the numeric values on the 0--100 scale.
How it's calculated: The displayed values are the FA site and control indices as returned by the monitoring API.
Interpretation example:
If Site A shows FA = 72 (SITE) / 48 (CONTROL) and Site B shows FA = 35 (SITE) / 40 (CONTROL), Site A has substantially richer floral resources than its surrounding landscape, while Site B is slightly below its control area.
Highlights Table Row. An axis selector option in the multi-site scatter matrix on the Highlights page, allowing FA to be selected as the X or Y axis.
Purpose: To enable cross-site benchmarking with FA as one of the comparison dimensions.
Description: When selected, the scatter matrix plots each site's FA value along the chosen axis, enabling visual clustering and outlier detection.
How it's calculated: Same FA site value as used in the gauge and table.
Interpretation example:
Selecting FA on one axis and PA on the other reveals whether sites with high floral availability also tend to have high pollinator abundance -- a positive correlation expected in ecologically healthy landscapes.
Data Table. A column in the historical scenario data table, showing paired FA site and control values across successive polygon versions and years.
Purpose: To track how the site's floral availability has changed over time as land use evolves.
Description: The scenarios table includes columns for key biodiversity and land use KPIs. The FA column displays the site and control values side by side for each historical snapshot.
How it's calculated: Each row corresponds to one polygon version and year, using the same InVEST model applied to the land cover data valid for that period.
Interpretation example:
If FA increases from 32 to 58 across three years, it likely reflects land use change such as agricultural extensification or the addition of wildflower margins -- both increasing floral supply.
Map Layer. An interactive raster map layer in the CLC & Pollinator Analysis layer group, visualising the spatial distribution of floral availability across the site and surroundings.
Purpose: To show which parts of the landscape contribute most to floral supply, helping identify hotspots and deficiency zones for pollinators.
Description: When activated, the layer overlays a colour-coded raster on the basemap. Each pixel is coloured according to its raw FA value using a continuous gradient palette. This layer uses a gradient colourmap distinct from the gauge's A--E palette.
How it's calculated: The raster is generated pixel-by-pixel from the InVEST model output, using the land cover class FA value for each pixel. The displayed palette is the raw [0, 1] output before area-aggregation.
Legend: Continuous gradient from dark red (no floral resources) to dark green (maximum floral supply):
Floral Availability
01No floral resourcesMaximum floral supply
Interpretation example:
If the map shows a bright green band along the site perimeter with darker red tones in the centre, it indicates floral resources are concentrated at habitat edges -- typical of agricultural sites with hedgerows or buffer strips.
Detail Card. A structured data variable fed into the AI-generated pollinator commentary in the Risks & Opportunities section.
Purpose: To contextualise the FA index within a holistic pollinator status analysis comparing site vs control area conditions.
Description: The AI report receives FA site and FA control values as labelled input variables, alongside PA, NS, and NP. The generated commentary discusses floral availability in the context of bottlenecking pollinator activity, seasonal resource gaps, and landscape composition. FA does not render as a standalone chart on this page.
How it's calculated: Same FA site and control values as displayed elsewhere; the AI model receives the numeric values and the reference ranges to generate qualitative text.
Interpretation example:
If FA site = 28 and FA control = 45, the AI report will note that the site has below-average floral supply relative to its control area -- a likely driver of reduced pollinator abundance.
| Source | Provider | Coverage | Resolution | Period |
|---|---|---|---|---|
| InVEST Pollinator Model | Natural Capital Project | Global | CLC class-level | On request |
| ESA WorldCover | ESA / Impact Observatory | Global | 10 m | 2020, 2021 |
| CORINE Land Cover | EEA | Europe | 100 m | 1990--2018 |
| CLC Backbone | EEA | Europe | 100 m | 2012, 2018 |
The InVEST Pollinator Abundance model computes floral availability through a multi-step pipeline:
The seasonal floral supply values per land cover class are derived from the ecological literature and calibrated for the relevant biogeographic region. Semi-natural habitats (meadows, hedgerows, field margins) contribute disproportionately to the index compared to arable land.
For the map layer, the raster is generated pixel-by-pixel from the InVEST model output, using the raw [0, 1] values before area-aggregation.