Birch sap extraction and short-term physiological responses in Betula celtiberica forests of north-western Spain

Abstract

In recent years, birch sap has been investigated due to its applications in various sectors. However, it is necessary to explore the ecological impact of its extraction and how it affects the sustainability of the ecosystem. Therefore, this study focuses on the sustainable management of Betula celtiberica (Rothm. and Vasc.) extraction in the Reserva de la Biosfera de los Valles de Omaña y Luna (RBVOyL), evaluating the effects of this process on tree physiology and studying the biocompounds in the sap and their possible commercial uses. Recommended practices for sustainable and responsible sap collection are also proposed. The results obtained show that sap extraction does not negatively affect either the water potential or the chlorophyll fluorescence of the birch trees studied one month after extraction. Moreover, the levels of extracted sap and the concentrations of biocompounds seem to corroborate its potential as a food and cosmetic product. Therefore, birch sap could be a viable, sustainable and natural alternative to be produced on a small scale in the study region, which would diversify commercial activities. However, further studies on the long-term effects of sap extraction and its potential as a forest product would be necessary.