Leaf wettability and plant surface water storage for common wetland species of the Biebrza peatlands (northeast Poland)

Abstract

Wetlands play a crucial role in buffering the effects of climate change. At the same time, they are one of the most endangered ecosystems on the globe. The knowledge of the water cycle and energy exchange is crucial for the practical preservation and exploiting their capabilities. Leaf wettability is an important parameter characterising the plant's ability to retain water on its surface, and is linked to the ecosystems' hydrological and ecological functioning. This research investigates the relationship between leaves' wettability based on contact angle measurements and water storage capacity (interception) for wetland vegetation. We performed the study for ten common plant species collected from Biebrza peatlands (Poland). We used CAM100 goniometer for the wetting contact angle measurements on the leaves' surface, and the weighing method for the plant surface water storage determination. The wetland plants' initial contact angle values ranged from 64.7° to 139.5° and 62.4° to 134.0° for the leaves' adaxial and abaxial parts, respectively. The average plant surface water storage was equal to 0.31 g·g-1, and values ranged from 0.09 to 0.76 g·g-1. The leaf hydrophobicity contributes to the amount of retained water. With increasing average contact angle, the amount of water retained on the plant decreased.