Tree allometric models, essential for monitoring and predicting terrestrial carbon stocks, are traditionally built on global databases with forest inventory measurements of stem diameter (D) and tree height (H). However, these databases often combine H measurements obtained through various measurement methods, each with distinct error patterns, affecting the resulting H:D allometries. In recent decades, terrestrial laser scanning (TLS) has emerged as a widely accepted method for accurate, non‐destructive tree structural measurements. This study used TLS data to evaluate the prediction accuracy of forest inventory‐based H:D allometries and to develop more accurate pantropical allometries. We considered 19 tropical rainforest plots across four continents. Eleven plots had forest inventory and RIEGL VZ‐400(i) TLS‐based D and H data, allowing accuracy assessment of local forest inventory‐based H:D allometries. Additionally, TLS‐based data from 1951 trees from all 19 plots were used to create new pantropical H:D allometries for tropical rainforests. Our findings reveal that in most plots, forest inventory‐based H:D allometries underestimated H compared with TLS‐based allometries. For 30‐metre‐tall trees, these underestimations varied from −1.6 m (−5.3%) to −7.5 m (−25.4%). In the Malaysian plot with trees reaching up to 77 m in height, the underestimation was as much as −31.7 m (−41.3%). We propose a TLS‐based pantropical H:D allometry, incorporating maximum climatological water deficit for site effects, with a mean uncertainty of 19.1% and a mean bias of −4.8%. While the mean uncertainty is roughly 2.3% greater than that of the Chave2014 model, this model demonstrates more consistent uncertainties across tree size and delivers less biased estimates of H (with a reduction of 8.23%). In summary, recognizing the errors in H measurements from forest inventory methods is vital, as they can propagate into the allometries they inform. This study underscores the potential of TLS for accurate H and D measurements in tropical rainforests, essential for refining tree allometries.

Most species experience microclimate temperatures, that is, variable and fine‐grained thermal conditions determined by atmospheric conditions interacting with biotic and abiotic components of the earth's surface. Unfortunately, measuring microclimates at biologically meaningful grain sizes is challenging. We showcase the potential of fibre‐optic distributed temperature sensing (DTS) to quantify diurnal variation in microclimatic air temperatures during the growing season along a 135‐m forest edge‐to‐interior transect at 25‐cm horizontal resolution. We benchmark DTS measurements against the microclimate quantified with ultrafine wire thermocouples and more conventional sensors at 15‐m intervals along the transect. Diurnal measurements from DTS indicate maximal cooling of forest floor temperatures (up to −6°C) in the morning (around 8:00 AM) and well away from the forest edge. Negative offset values gradually increased during the day reaching zero (0°C) in the evening (around 21:00 PM). Synthesis . While both DTS and discrete point sampling with microclimate loggers allow to quantify diurnal cycles of microclimate gradients with unified spatial and temporal patterns, DTS provides accurate temperature measurements at a spatial detail nearly impossible to achieve with discrete point sampling. When applied over transects of several hundreds of meters—up to kilometres—fibre‐optic DTS is a cost‐efficient alternative offering substantial potential to advancing microclimate research.

Terrestrial laser scanning (TLS) provides highly detailed 3D information of forest environments but is limited to small spatial scales, as data collection is time consuming compared to other remote sensing techniques. Furthermore, TLS data collection is heavily dependent on wind conditions, as the movement of trees negatively impacts the acquired data. Hardware advancements resulting in faster data acquisition times have the potential to be valuable in upscaling efforts but might impact overall data quality. In this study, we investigated the impact of the pulse repetition rate (PRR), or pulse frequency, which is the number of laser pulses emitted per second by the scanner. Increasing the PRR reduces the scan time required for a single scan but decreases the power (amplitude) of the emitted laser pulses commensurately. This trade-off could potentially impact the quality of the acquired data. We used a RIEGL VZ400i laser scanner to test the impact of different PRR settings on the point cloud quality and derived tree structural metrics from individual tree point clouds (diameter, tree height, crown projected area) as well as quantitative structure models (total branch length, tree volume). We investigated this impact across five field plots of different forest complexity and canopy density for three different PRR settings (300, 600 and 1200 kHz). The scan time for a single scan was 180, 90 and 45 s for 300, 600 and 1200 kHz, respectively. Differences among the raw acquired scans from different PRR replicates were largely removed by several necessary data processing steps, notably the removal of uncertain points with a low reflectance attribute. We found strong agreement between the individual tree structural metrics derived from each of the PRR replicates, independent of the forest complexity. This was the case for both point cloud-based metrics and those derived from quantitative structural models (QSMs). The results demonstrate that the PRR in high-end TLS instruments can be increased for data collection with negligible impact on a selection of derived structural metrics that are commonly used in the context of aboveground biomass estimation.

Forest edges can be important strongholds for biodiversity and play a crucial role in the protection of forest interiors against edge effects. However, their potential to host biodiversity is dependent on the structure of the forest: Abrupt edges often fail to realise this potential. Yet, methods to accurately characterise and quantify forest edge abruptness are currently lacking. Here, we combine three‐dimensional forest structural data with biodiversity monitoring to assess the influence of forest edge structure on habitat suitability. We derived several structural metrics to determine forest edge abruptness using terrestrial laser scanning and applied these to six forest edge transects in Belgium. The local soundscapes were captured using audio recording devices (Audiomoths) and quantified using acoustic indices (AIs) (metrics on the soundscape characteristics). In each transect, the dawn choruses were recorded over a period of a week, both at the edge and the interior of the forest. No correlation between the AIs and bird species richness was found. There were clear differences between transects in the structural metrics and the recorded soundscapes. Some possible relations between both were found. In this proof of concept, we demonstrated innovative techniques to semi‐automatically classify forest structure and rapidly quantify soundscape characteristics and found a weak effect of forest edge structure on bird biophony.

It is widely acknowledged that elected representatives have often benefited from a variety of steppingstones in their passage to power. This article comparatively studies a selection of such steppingstones amongst local councillors in Europe. More specifically, it takes account of family ties, ambition, the entrenchment in the locality and the political party as elements of activation and apprenticeship in the process of political recruitment. In doing so, it sets out ideal-typical laymen from their professionalized counterparts. The article shows that at this early stage of recruitment, local councillors still generally tend towards the layman archetype. Furthermore, some assets, such as the inclusion in the local community and the enrolment in a political party, seem necessary to enter on a political career. Others are more provisional (e.g. family, motivations, social background, municipal size, ideology and function) or dependent upon the institutional provisions in place (e.g. quota, electoral system). Finally, professionalization patterns do not depend directly from traditional country types, but rather from the specific combination of factors in each country.