Sap Is Clever? Sap Ascent for Undergraduates Investigated with an Artificial Tree

摘要

Water is the essential component in living and its role is particularly important in plants. In fact, the crucial photosynthesis process involves a huge loss of sap by transpiration (around 99% from the total amount recovered from the soil through the plant roots) from the stomas on the leaves. Therefore, a question arises: How could trees raise the sap to heights up to 100 m? In this article we present a simple experimental setup that provides a direct visualization and quantification of the water ascent process against gravity. Moreover, the artificial tree offers analogies with "real" ones that will help undergraduate science students from different areas to investigate the influence of environmental and morphological parameters on the variety of physics phenomena underlying the ascension mechanism.