CAREER: The effects of non-rainfall moisture inputs on dryland ecosystem functions

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Drylands, broadly defined as areas where mean annual precipitation is less than two-thirds of evaporative demand, account for nearly 40% of the global land surface and represent the largest terrestrial biome on the planet. Globally, ~2.5 billion people reside in drylands, and therefore drylands are socioeconomically important. The effect of non-rainfall precipitation components (e.g., fog and dew) on dryland ecosystems is one of the least studied aspects in hydrology. Quantifying and identifying the various sources of non-rainfall moisture to dryland systems are integral to predict how non-rainfall components will change under future climate change and how dryland ecosystems will respond accordingly. Through the use of emerging technology, comprehensive field observations and process-based modeling, this project will provide a key step toward understanding the origins and effects of non-rainfall inputs in dryland ecosystems. This project will include broad community outreach, and educate students at all levels (K-12, undergraduate and graduate), including those underrepresented in the STEM fields. These outreach and educational activities include education module development for third through ninth grade students, authentic research experiences for high school students, a summer teacher-training program for high school teachers, research abroad experience for undergraduate students, and professional development for graduate students. Despite the importance of non-rainfall precipitation, it remains unclear as to the amount of non-rainfall input that is needed to sustain dryland ecosystems. Furthermore the specific sources of non-rainfall water (e.g., ocean water vs. local groundwater), and the relative contribution of fog and dew, are not known for dryland systems. Quantifying and identifying the various sources of non-rainfall moisture to dryland systems are integral to predict how non-rainfall components will change under future climate change and how dryland ecosystems will respond accordingly. The overarching goal of this proposed research is to evaluate the effects of non-rainfall inputs on dryland ecosystem functions through stable isotope (2H, 17O and 18O) and modeling analyses. The field research will be conducted at a long-standing international station in Namibia (Gobabeb Research and Training Center) due to its unique ecological location, prior research and existing logistics for conducting field research at the proposed site.