Former Northwest Climate Adaptation Science Center (NW CASC) Fellow Hamid Dashti is the lead author of a new paper that evaluates methods for measuring nitrogen in dryland ecosystems. As the climate warms, dryland ecosystems in the western United States are already experiencing change and becoming more susceptible to fire-prone, invasive species such as cheatgrass. However, the long-term ecological impacts of climate change and short-term impacts of restoration activities are still poorly understood. The goal of this research was to develop more reliable estimates of nitrogen to better understand the relationship between nitrogen, vegetation and climate change in dryland ecosystems.
Nitrogen plays an important role in many dryland ecosystem processes and has been linked to climate change and nutrient limitation. This NW CASC-funded research tested methods for measuring nitrogen in dryland ecosystems using hyperspectral remote sensing. Because soil and vegetation canopy structure can complicate estimates of nitrogen obtained through remote sensing, this study tested the assumption that removing the impact of canopy structure and soil would result in more reliable nitrogen estimates. However, after removing the influence of soil and canopy structure, the study’s empirical methods failed to predict nitrogen. This suggests that using empirical methods to estimate vegetation’s nitrogen content might be unreliable and requires careful consideration of scale and analysis. This research contributes to our understanding of how to study dryland ecosystems to help land management agencies tasked with protecting them as our climate changes.
(If you have trouble accessing Hamid’s new paper, please email firstname.lastname@example.org)