Satellite observed positive impacts of fog on vegetation

Fog is an important water source for many ecosystems, especially in drylands. Most fog-vegetation studies focus on individual plant scale; the relationship between fog and vegetation function at larger spatial scales remains unclear. This hinders an accurate prediction of climate change impacts on dryland ecosystems. To this end, we examined the effect of fog on vegetation utilizing both optical and microwave remote sensing-derived vegetation proxies and fog observations from two locations at Gobabeb and Marble Koppie within the fog-dominated zone of the Namib Desert. Significantly positive relationships were found between fog and vegetation attributes from optical data at both locations. The positive relationship was also observed for microwave data at Gobabeb. Fog can explain about 10%-30% of variability in vegetation proxies. These findings suggested that fog impacts on vegetation can be quantitatively evaluated from space using remote sensing data, opening a new window for research on fog-vegetation interactions. Plain Language Summary This study presents the first observed relationships between fog and vegetation function using satellite remote sensing data. Significant correlations were found between fog and satellite-derived vegetation indices at two study sites within the Namib Desert. These findings suggested that satellite data can be used to assess and quantify the impacts of fog on vegetation at large spatial scales.