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Harvard Forest REU Symposium Abstract 2022
- Title: Artificial Soil Warming Negatively Affects Mycorrhizal Colonization Rates and Root Respiration
- Author: Gabriela Martinez (Xavier University)
- Abstract:
As climate change increases atmospheric temperature, it is unclear whether soils will continue to act as a carbon (C) sink due to an increase in soil respiration and carbon (C) inputs. Fine roots and their associated mycorrhizal fungi are important drivers of soil C cycling. Mycorrhizal fungi aid roots in attaining nutrients by increasing root tip surface area. This is done either by extending their hyphae into the soil or forming a dense hyphal net on root tips. Once the fungi provide nutrients to the roots, they receive glucose from the plant. Earlier studies have asserted the existence of a mycorrhizal-associated nutrient economy for soils, but do not address the extent to which roots themselves can attain nutrients from soil, as not all root tips are colonized by mycorrhizal fungi. Here, we question how fine root structure and mycorrhizal fungi will respond to simulated soil warming and thereby control root respiration and exudation rates, two important factors of forest C cycling. Samples were collected from Barre Woods Soil Warming Experiment at Harvard Forest LTER. We hypothesize that soil warming will increase root respiration and exudation, but the amount will be managed by mycorrhizal fungi. We therefore predict that the regulators and mechanisms of root respiration and exudation under warming will be mycorrhizal specific. Results show a negative correlation (R2 = -0.1907) between average percent of mycorrhizal-fungi colonized root tips and respiration rates (?mol CO2 / g*s).
- Research Category: Ecological Informatics and Modelling; Forest-Atmosphere Exchange; Large Experiments and Permanent Plot Studies
