Effects of drying on lowland tropical root biomass in Panamanian rainforests
Category: Research Poster
Author(s): Maya McCain, Ally Lewis, Hailey Tharp, Olivia Aaron, Grace McLaughlin, Daniela Cusack
Presenter(s): Maya McCain
Mentors(s): Daniela Cusack
Ecosystems worldwide are being affected by disturbances brought on by global change, such as drought and chronic drying. The effects of drying on tropical rainforests remain poorly understood, despite the importance of these ecosystems in the global carbon (C) budget, in particular because of their large root biomass and transfers of C into soil long-term C pools. Drought and chronic drying are predicted to increase in tropical regions due to global change, motivating the Panama Rainforest Changes with Experimental Drying (PARCHED) project across four distinct lowland, seasonal forests across the Isthmus of Panama. The project simulates chronic drying by excluding ~70% of throughfall from forest plots, paired with control plots (32 plots total). We addressed the uncertainty in rainforest root responses to chronic drying by processing root samples from the four PARCHED forest sites. We assessed how root dynamics differ between drying treatment versus control plots during the wet season. Results to date indicate that the four forests have different baseline root biomass stocks, related to local moisture and soil fertility. Root biomass has also generally declined in the drying treatment. Our results have implications for the future of C storage in tropical forests under a changing climate.