12 research outputs found
An integrative environmental pollen diversity assessment and its importance for the Sustainable Development Goals
Pollen is at once intimately part of the reproductive cycle of seed plants and simultaneously highly relevant for the environment (pollinators, vector for nutrients, or organisms), people (food safety and health), and climate (cloud condensation nuclei and climate reconstruction). We provide an interdisciplinary perspective on the many and connected roles of pollen to foster a better integration of the currently disparate fields of pollen research, which would benefit from the sharing of general knowledge, technical advancements, or data processing solutions. We propose a more interdisciplinary and holistic research approach that encompasses total environmental pollen diversity (ePD) (wind and animal and occasionally water distributed pollen) at multiple levels of diversity (genotypic, phenotypic, physiological, chemical, and functional) across space and time. This interdisciplinary approach holds the potential to contribute to pressing human issues, including addressing United Nations Sustainable Development Goals, fostering social and political awareness of these tiny yet important and fascinating particles
WATCHING GRASS GROW- A PILOT STUDY ON THE SUITABILITY OF PHOTOGRAMMETRIC TECHNIQUES FOR QUANTIFYING CHANGE IN ABOVEGROUND BIOMASS IN GRASSLAND EXPERIMENTS
Grassland ecology experiments in remote locations requiring quantitative analysis of the biomass in defined plots are becoming increasingly widespread, but are still limited by manual sampling methodologies. To provide a cost-effective automated solution for biomass determination, several photogrammetric techniques are examined to generate 3D point cloud representations of plots as a basis, to estimate aboveground biomass on grassland plots, which is a key ecosystem variable used in many experiments. Methods investigated include Structure from Motion (SfM) techniques for camera pose estimation with posterior dense matching as well as the usage of a Time of Flight (TOF) 3D camera, a laser light sheet triangulation system and a coded light projection system. In this context, plants of small scales (herbage) and medium scales are observed. In the first pilot study presented here, the best results are obtained by applying dense matching after SfM, ideal for integration into distributed experiment networks
Intercomparison of cosmic-ray neutron sensors and water balance monitoring in an urban environment
Sensor-to-sensor variability is a source of error common to all
geoscientific instruments that needs to be assessed before comparative and
applied research can be performed with multiple sensors. Consistency among
sensor systems is especially critical when subtle features of the surrounding
terrain are to be identified. Cosmic-ray neutron sensors (CRNSs) are a recent
technology used to monitor hectometre-scale environmental water
storages, for which a rigorous comparison study of numerous co-located
sensors has not yet been performed. In this work, nine stationary CRNS probes
of type CRS1000 were installed in relative proximity on a grass patch
surrounded by trees, buildings, and sealed areas. While the dynamics of the
neutron count rates were found to be similar, offsets of a few percent from
the absolute average neutron count rates were found. Technical adjustments of
the individual detection parameters brought all instruments into good
agreement. Furthermore, we found a critical integration time of 6 h above
which all sensors showed consistent dynamics in the data and their RMSE fell
below 1 % of gravimetric water content. The residual differences between
the nine signals indicated local effects of the complex urban terrain on the
scale of several metres. Mobile CRNS measurements and spatial simulations
with the URANOS neutron transport code in the surrounding area (25 ha)
have revealed substantial sub-footprint heterogeneity to which CRNS detectors
are sensitive despite their large averaging volume. The sealed and constantly
dry structures in the footprint furthermore damped the dynamics of the CRNS-derived soil moisture. We developed strategies to correct for the sealed-area
effect based on theoretical insights about the spatial sensitivity of the
sensor. This procedure not only led to reliable soil moisture estimation
during dry-out periods, it further revealed a strong signal of intercepted
water that emerged over the sealed surfaces during rain events. The presented
arrangement offered a unique opportunity to demonstrate the CRNS performance
in complex terrain, and the results indicated great potential for further
applications in urban climate research