The PA – Aerial Cavities (Wetland) component measures the Pollinator Abundance (PA) specifically associated with pollinators that nest in cavities of marsh and wetland vegetation. It is expressed on a normalised scale from 0 to 1 and is one of the sub-indicators of the InVEST Pollinator Model.
This group includes pollinators adapted to wetland environments: solitary bees and wasps that use hollow stems of reeds (Phragmites), rushes and other marsh plants, as well as dead-wood cavities in riparian zones. Wetlands, although covering limited areas, host unique communities of specialised pollinators and serve as ecological corridors between terrestrial habitats.
In the overall Nesting Sites (NS) formula, wetland aerial cavities carry weight 1.
Calculated using the InVEST methodology (Sharp et al., 2020). For each land cover pixel, a suitability value for wetland aerial cavities (0–1) is assigned. The PA value integrates nesting suitability with accessible floral resources (FA), weighted by foraging distance.
Weight in overall NS calculation: 1/13
Scale: 0 (unsuitable habitat) – 1 (maximum suitability)
| Code | Name | Provider | Resolution | Availability |
|---|---|---|---|---|
WRD_INVST_99 | InVEST Pollinator Model | Natural Capital Project, Stanford University | — | — |
| Indicator | Unit | Range | Inverted |
|---|---|---|---|
pa_ns_aboveground_cavities_wetland | — | [0, 8, 16, 24, 32, 40] | No |
| Level | Value | Interpretation |
|---|---|---|
| A (Excellent) | > 32 | Extensive wetlands with cavity-rich marsh vegetation |
| B (Good) | 24 – 32 | Good availability; reed beds and riparian zones present |
| C (Moderate) | 16 – 24 | Average availability; fragmented or limited wetlands |
| D (Poor) | 8 – 16 | Low availability; few residual wetland areas |
| E (Critical) | 0 – 8 | Near absence of wetlands; drained or reclaimed environments |
PA component for aerial cavities in wetlands. Calculated using InVEST methodology (Sharp et al., 2020). For each land cover pixel, a suitability value for wetland aerial cavities (0–1) is assigned. The PA value integrates nesting suitability with accessible floral resources (FA), weighted by foraging distance. Weight in overall NS calculation: 1/13. Scale: 0–1.