Vegetation indices changes in the cloud forest of La Gomera Island (Canary Islands) and their hydrological implications

A key finding from this study is that the laurel forest in Garajonay National Park, La Gomera Island, exhibits peak photosynthetic activity during the dry season (late spring to early summer), contradicting traditional expectations of drought stress. Analysis of vegetation indices—specifically the enhanced vegetation index (EVI)—revealed a strong correlation between EVI values and temperature (p < 0.001), with valley-bottom forests showing the most pronounced seasonal trends. The research used MODIS Aqua data to track EVI changes over two hydrological years (2003–2005) and linked these patterns to climatic factors, including rainfall and fog drip. Notably, fog drip was identified as a critical hydrological factor maintaining soil moisture and forest transpiration, even during warmer periods. This insight is significant for understanding the resilience of subtropical cloud forests and their role in aquifer recharge.

Izquierdo, T., de las Heras, P., & Márquez, A. (2010). Vegetation indices changes in the cloud forest of La Gomera Island (Canary Islands) and their hydrological implications. Hydrological Processes, 25(10), 1531–1541. Portico. https://doi.org/10.1002/hyp.7915