Nectar Potential (NP) quantifies the amount of nectar produced in vegetated areas of a polygon, expressed in kg of nectar per hectare per year (kg/ha/yr). It is one of the three core indicators of the InVEST Pollinator Model (Natural Capital Project), together with the Nesting Sites index (NS) and Pollinator Abundance (PA).
Nectar is the primary carbohydrate source for adult pollinators and represents an essential floral resource for sustaining populations of bees, butterflies and other insect pollinators. High NP values indicate landscapes rich in floral resources, capable of supporting abundant and diverse pollinator populations, with positive effects on agricultural production and natural ecosystem functioning (Ricketts et al., 2008; Klein et al., 2007).
NP integrates with NS and PA in the InVEST model: an area with high nectar potential but few nesting sites (low NS) will not reach optimal pollinator abundance (PA); conversely, excellent nesting sites without adequate floral resources equally limit pollinator populations.
Nectar Potential is calculated using the InVEST methodology (Sharp et al., 2020), involving the following steps:
Unit: kg/ha/yr Visualisation scale: 0 – 250 kg/ha/yr
| Code | Name | Provider | Resolution | Availability |
|---|---|---|---|---|
WRD_INVST_99 | InVEST Pollinator Model | Natural Capital Project, Stanford University | — | — |
| Indicator | Unit | Range | Inverted |
|---|---|---|---|
np | kg/ha/yr | [0, 35, 70, 110, 200, 250] | No |
Inverted = No: a higher value indicates greater nectar potential and better conditions for pollinators.
| Level | NP (kg/ha/yr) | Interpretation |
|---|---|---|
| A (Excellent) | > 200 | Florally very rich landscape; abundant nectar resources throughout the year |
| B (Good) | 110 – 200 | Good nectar availability; landscape favourable to pollinators |
| C (Moderate) | 70 – 110 | Average availability; some seasonal gaps in floral resources |
| D (Poor) | 35 – 70 | Low availability; landscape with limited floral cover |
| E (Critical) | 0 – 35 | Minimal nectar resources; degraded or intensively farmed environments |
| Indicator | Code | Description | Relationship with NP |
|---|---|---|---|
| Nectar Potential | np | Nectar produced in the area (kg/ha/yr) | — |
| Nesting Sites | ns | Suitability of areas for nesting (0–1) | NP and NS jointly determine PA |
| Pollinator Abundance | pa | Habitat suitability index for pollinators (0–1) | PA depends on NP and NS |
np
(kg/ha/y)Calculated using the InVEST methodology (Sharp et al., 2020). Requires Land Cover processing and Element-e module (NP component). Steps: land cover classification → nectar contribution assignment per vegetation class (weighted by seasonality and density) → weighted sum normalised per ha/yr → feeds into Aggregated Floral Resources (FA) for the PA calculation. Unit: kg/ha/yr. Visualisation scale: 0–250 kg/ha/yr.