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Harvard Forest REU Symposium Abstract 2013
- Title: The effects of soil warming and nitrogen fertilization on root phenology
- Author: Johanna M Recalde Quishpe (Pomona College)
- Abstract:
Soils of northeastern forests serve as vital carbon (C) sinks, which are especially important in a time of rapid climate change. Driving the process of C accumulation and allocation in soils are roots, which are usually ignored in C estimates of forest soils. Due to climate change, soil warming and nitrogen fertilization may alter root processes such as growth, mortality, and mycorrhizal activity that drive C accumulation in soils. Changing root processes can result in changes in the timing and magnitude of C accumulation in the soil, such as earlier root growth in warmer soils that result in larger flux of C belowground. Thus, the purpose of this study is to gain better understanding of the effects of soil warming and nitrogen fertilization on root allocation and phenology by using a minirhizotron camera to take underground photos of roots in four different treatments: control, heated, nitrogen addition, and heated + nitrogen. In March through early July of 2013, there was no difference in root production between treatments (RM-ANOVA, F=0.7365, p=0.6416), suggesting that roots may have become acclimated to long-term soil treatments. While there was no significant effect of day of year on root production values, it is interesting to note that in the heated treatment, root growth began earlier, possibly due to earlier temperature cues. This suggests that as the climate warms carbon allocation to roots may increase, resulting in larger carbon storage in the absence of higher decomposition rates.
- Research Category: Soil Carbon and Nitrogen Dynamics
- Figures: DSC05516.JPG
