Swiss Federal Institute for Forest, Snow and Landscape Research

About: Swiss Federal Institute for Forest, Snow and Landscape Research is a facility organization based out in Birmensdorf, Switzerland. It is known for research contribution in the topics: Climate change & Soil water. The organization has 1256 authors who have published 3222 publications receiving 161639 citations. The organization is also known as: WSL.

Handbook of standardized protocols for collecting plant modularity traits

Abstract: Plant modularity traits relevant to functions of on-spot persistence, space occupancy, resprouting after disturbance, as well as resource storage, sharing, and foraging have been underrepresented in functional ecology so far. This knowledge gap exists for multiple reasons. First, these functions and related traits have been considered less important than others (e.g., resource economics, organ-based traits). Second, collecting data for modularity traits can be difficult. Third, as a consequence of the previous points, there is a lack of standardized collection protocols. We now feel the time is ripe to provide a solid conceptual and terminological framework together with comparable protocols for plant modularity traits that can be applicable across species, regions and biomes. We identify a suite of 14 key traits, which are assembled into five groups. We discuss the functional relevance of each trait, supplying effective guidelines to assist in the use and selection of the most suitable traits in relation to specific research tasks. Finally, we are convinced that the systematic study and widespread assessment of plant modularity traits could bridge this knowledge gap. As a result, previously overlooked key functions could be incorporated into the functional ecology research-agenda, thus providing a more comprehensive understanding of plant and ecosystem functioning.

Re-analysis of seasonal mass balance at Abramov glacier 1968-2014

Abstract: Abramov glacier, located in the Pamir Alay, Kyrgyzstan, is a reference glacier within the Global Terrestrial Network for Glaciers. Long-term glaciological measurements exist from 1968 to 1998 and a mass-balance monitoring programme was re-established in 2011. In this study we re-analyse existing mass-balance data and use a spatially distributed mass-balance model to provide continuous seasonal time series of glacier mass balance covering the period 1968–2014. The model is calibrated to seasonal mass-balance surveys and then applied to the period with no measurements. Validation and recalibration is carried out using snowline observations derived from satellite imagery and, after 2011, also from automatic terrestrial camera images. We combine direct measurements, remote observations and modelling. The results are compared to geodetic glacier volume change over the past decade and to a ground-penetrating radar survey in the accumulation zone resolving several layers of accumulation. Previously published geodetic mass budget estimates for Abramov glacier suggest a close-to-zero mass balance for the past decade, which contradicts our results. We find a low plausibility for equilibrium conditions over the past 15 years. Instead, we suggest that the glacier’s sensitivity to increased summer air temperature is decisive for the substantial mass loss during the past decade.

Mechanical interactions between neighbouring roots during pullout tests

Abstract: The quantification of root reinforcement function is important for landscape managers and engineers. The estimation of root mechanical reinforcement is often based on models that do not consider the potential interaction between neighbouring roots. Root-soil mechanical interactions related to the root spacing and bundle geometry remain unclear including potential effects on the reliability of the current models. The objective of this study is to quantify the mechanical interactions among neighbouring roots or roots networks using modelling approaches and pullout laboratory experiments. Based on simple geometrical characterization of individual root geometry, we calculated dissipation patterns of frictional root-soil interfacial stresses in radial and longitudinal directions. Considering simple superposition of shear stresses within the soil matrix, we quantified characteristic root densities at which the radial mechanical interactions influence global pullout behaviour of the root bundle both for branched and unbranched roots. Laboratory pullout tests on root bundles were carried out at root spacings of 15, 35 and 105 mm. In addition, we tested effects of non-parallel (crossing) root bundle geometry. We found no significant statistical differences in root pullout force for the different root spacing in parallel alignment of roots. Branches increase pullout force by 1.5 times. Moreover, the mean displacement at the pullout peak-force was 7.2 % of length for unbranched roots and about 4.1 % of length for branched roots. The model shows its potential comparing it with empirical results concerning the holes leaved by roots, according with the branch pattern. The study quantifies the influence of root spacing and arrangement geometry within a root bundle on its mechanical behaviour. The assumption of “non-interacting” neighbouring roots in root reinforcement methods is no longer valid for root spacing less than 15 mm and root reinforcement methods. Moreover crossing roots shown a statistical difference. This information is important for improved understanding root reinforcement mechanisms in steep hill slope and the interplay between anchoring /failure and root bundle pullout vs root breakage.