Regeneration of tropical montane cloud forests increases water yield in the Brazilian Atlantic Forest

Tropical montane cloud forests (TMCF) have paramount importance with regards to hydrological and ecological functions. Despite such importance in terms of water provision, they are one of the most endangered ecosystems on the planet. One important topic that is still unclear is related to TMCF regeneration: can it recover the hydrological function of such critical ecosystems? In the present paper, the hydrological effects of the natural regeneration of TMCF were examined. We selected three catchments with different degrees of TMCF, and we examined the relationship between the amount of TMCF over time and hydrological variables such as water yields and baseflow using a time series (1984-2011). Our results suggest that the increase in TMCF cover can contribute to increases in water yield. This pattern was found in a catchment with an increase of approximately 20% of forest cover. In catchments with TMCF increase lower than this threshold, water yield and flow path were influenced by hydroclimatic variables such as air temperature and rainfall. The effect of the reduction in water yield, in accordance with the increase in mean temperature, sheds light on possible consequences of climate change on ecosystem services produced in foggy environments. In light of these findings, aiming to increase the water yield, we recommend that regions frequently affected by fog are prioritized for forest restoration or conservation. To ensure significant effects, regeneration and/or successional development of TMCF has to reach at least 20% of a catchment area.

Automated summary

The study examined the hydrological effects of natural regeneration of Tropical Montane Cloud Forests (TMCF), finding that an increase in TMCF cover can contribute to increases in water yield. However, to ensure significant effects, regeneration and/or successional development of TMCF has to reach at least 20% of a catchment area.