Tropical montane cloud forests (TMCF) make up only 2.5% of all tropical forests, yet de- spite their rarity they make a tremendous contribution to global biodiversity with large numbers of endemic species. Cloud forests also capture airborne cloud-water and play a crucial role in regulating the steady release of water downstream throughout the year. Studies have shown that cloud-water interception contributes a significant portion of annual inputs into TMCF. This regulatory function is closely tied to plant diversity, physiology, and structure. Changes in climate—such as increased temperature and a rising cloud base—can affect plant function and could therefore have major impacts on TMCF ecosystem services.
Using cloud-capturing infrastructure, we are conducting research within the first ever “cloud reduction” experiment to directly create the predicted future climate conditions of reduced cloud cover on a patch of TMCF in the Andes-Amazon transition zone of Peru. The design of this cloud-capturing infrastructure provides a unique opportunity to examine the degree to which plant species might change their water sourcing under reduced cloud conditions.
Results/Conclusions
Recent data shows distinct isotopic signatures of “cloud-water” versus rainwater, making it possible to discover what proportions of these differing water sources plants are accessing in the control and experimental exclusion plot. While this experiment will run over a period of five years, we present here preliminary findings of plant-water sourcing, pre-cloud exclusion. Initial results indicate that there are diverse water-use strategies in this TMFC. We will continue to monitor potential plant-water sourcing shifts both pre- and post-cloud exclusion.