Transpiration Rate Measurement Using Miniature Temperature/Humidity Sensors

A novel method for the evaluating the transpiration rate (TR) has been proposed. Miniature temperature/humidity loggers were attached onto the leaf surface of a mangrove plant, Bruguiera gymnorrhiza, via a spacer. TR values were calculated using the mass-balance equation; the results showed good agreement with those measured using a conventional porometer when the plant root was surrounded by water. In a saline environment, on the other hand, the correlation became poor. The method was shown to require not only minimal invasion, but also a very short time for attaching leaves.