Automated sampling of dew water to identify hidden nutrient inputs to ecosystems

The terrestrial water and nutrient cycle is of crucial importance, influencing the climate, ecosystems, and related services. In many climates, non-rainfall water inputs (NRWIs) play a significant role in the water cycle. These inputs stem from various processes, including dew, fog, and soil water vapour adsorption. Weighable lysimeters are ideal tools for quantifying such water inputs to ecosystems, as their surfaces are either plant- or soil-covered, which is relevant for their formation processes, compared to devices with artificial surfaces. However, the nutrient inputs from dew and fog, apart from wet and dry deposition, are yet to be overlooked, as it is difficult to monitor these hidden nutrient inputs to ecosystems without adequate sampling devices.

We present a newly developed dew collector for the regular collection and analysis of dew samples, for example for stable isotopes, nutrients, and other substances. The lack of automated methods for collecting dew samples represents a significant bottleneck to account for these hidden nutrient inputs. Using a comprehensive measurement setup with weighable lysimeters, wet and dry deposition, and dew and fog water collectors, we show how NRWIs introduce nutrients into ecosystems with different land uses (grassland and cropland) in a temperate climate.