Albedo estimated from remote sensing correlates with ecosystem multifunctionality in global drylands

Area of Science:

• Ecology
• Remote Sensing
• Environmental Science

Background:

• Dryland ecosystems face degradation and desertification, necessitating effective monitoring tools.
• Remote sensing-based vegetation indices (VIs) and land surface albedo are key indicators of ecosystem status.
• Previous research has not explored the link between remote sensing-measured albedo and ecosystem multifunctionality in global drylands.

Purpose of the Study:

• To evaluate the correlation between six albedo metrics and two VIs with multifunctionality indices in global drylands.
• To determine if albedo can serve as an indicator for monitoring dryland ecosystem functioning and desertification.

Main Methods:

• Analyzed correlations between albedo metrics (shortwave, visible, near-infrared black-sky and white-sky) and VIs (NDVI, EVI) with multifunctionality indices (carbon, nitrogen, phosphorus cycling).
• Utilized data from 61 dryland ecosystems across all continents except Antarctica.
• Compared the strength of correlations between albedo, VIs, and multifunctionality.

Main Results:

• A negative relationship was found between land surface albedo and multifunctionality.
• Black-sky albedo metrics, particularly visible black-sky albedo, showed stronger correlations with multifunctionality and nutrient cycling than white-sky albedo.
• Vegetation indices correlated positively with multifunctionality but not with phosphorus cycling, which was linked to albedo.

Conclusions:

• Remotely sensed albedo correlates with dryland ecosystem multifunctionality, suggesting its potential for monitoring desertification.
• Albedo provides unique insights into phosphorus cycling, complementing VIs which are better indicators for carbon and nitrogen cycling.
• Albedo's relationship with multifunctionality can inform about ecosystem shifts and the onset of desertification in drylands.