Leaching effects of rainfall on particulate matter of plant leaf surface

ObjectiveRainfall could wash away the particulate matter on leaf surface, therefore the leaf surface could retain particulate matter repeatedly. Understanding the influences of different rainfall durations and rainfall intensities on particulate matter removing has guiding significance to acknowledge the mechanism of particulate matter removing on plant leaf surface.

MethodBy simulating rainfall with different rainfall durations (5, 10 and 15 min) and varied rainfall intensities (15, 30 and 45 mm/h), we quantified the elution volume of particulate matter on the plant leaf surface and the effects of rainfall on particulate matter with different sizes.

Result(1) The elution volume of plant leaf surface increased with increasing precipitation. (2) Under different rainfall intensities, the elution volume of particulate matter on plant leaf surface was extremely correlated with plant species (P < 0.05), with the average elution volume on plant leaf surface decreasing from Jasminum nudiflorum to Eucommia ulmoides(Jasminum nudiflorum> Ginkgo biloba > Euonymus alatus> Eucommia ulmoides). (3) The elution volume on plant leaf surface of 4 plant species increased with the extension of rainfall duration. The elution volume was basically same for the four plant species when the rainfall duration was 5 minutes. When the rainfall durations were 10 and 15 min, the elution volume increased significantly (P < 0.05) on plant leaf surface of Euonymus alatus, Ginkgo biloba and Jasminum nudiflorum, but there was no significant difference for Eucommia ulmoides (P>0.05). (4) Elution volume proportions of particulate matter with 3 different sizes were different (0.45-2.5 μm < 2.5-10 μm < 10-100 μm), and the elution volume of 10-100 μm was significantly higher than 0.45-2.5 μm and 2.5-10 μm (P < 0.05), but the elution volume of 0.45-2.5 μm showed no significant difference with 2.5-10 μm. The percentage of particulate matter elution was not significantly correlated with rainfall intensity (P>0.05).

ConclusionDifferent precipitation, rainfall durations and rainfall intensities have different leaching effects on different plant species and varied particulate matter with different sizes.