Search

Forest understory complexity is important for many species, from large herbivores such as deer to small mammals such as mice and voles. For species that utilize the forest understory on a very small scale, it is often impractical to conduct correspondingly fine‐grained manual surveys of the understory, and thus few studies consider this small‐scale variation in understory complexity and instead work with average values on a larger scale. We explored the use of a mobile laser scanning derived understory complexity measure—understory roughness—to predict the capture probability of two representative small mammal species, the yellow‐necked mouse (Apodemus flavicollis) and the bank vole (Clethrionomys glareolus). We found a positive relationship between capture probability and understory roughness for both bank voles and yellow‐necked mice. Our results suggest that mobile laser scanning is a promising technology for measuring understory complexity in an ecologically meaningful way. [ABSTRACT FROM AUTHOR]

The provision of ecosystem functions and services in forests is closely linked to the presence of complex structures. One such service is the ability to store carbon. It has recently become possible to quantify both structural complexity and biomass of forests (as proxy of carbon storage) using light detection and ranging (LiDAR). The objective of this study was to analyze how the community-level complexity of a forest stand relates to structural characteristics, and biomass in particular, of the trees comprising the stand. To do so, we virtually assembled 30 forests (3D models), all representing different versions of a beech-pine forest in Germany, based on real world 3D LiDAR scan data of all trees in the forest. At the individual tree level, various structural characteristics, including wood volume and biomass were derived using both voxel models and quantitative structure models (QSM). Basal area and biomass, as well as to a lower degree also the mean height of maximum crown projection area, significantly affected the structural complexity at stand level. Among the different forest models, the variation in complexity could best be described using a combination of basal area, mean height of the maximum crown projection area, and the coefficient of variation of total tree height. Biomass alone explained 54% of the variation in stand-level complexity, while the multivariate model based on measures addressing the amount and vertical distribution of plant material explained 86% of the variability in complexity. Using a laser-based and holistic approach of assessing the structural complexity, namely the box-dimension, allowed identifying key structural attributes that promote aboveground structural complexity of the forest studied here. [ABSTRACT FROM AUTHOR]

Accurate information on the timber quality of hardwoods is often lacking, in particular for standing trees. In situ measurements of timber quality have the potential to improve the economic yield of a stand and may contribute to the optimal timing of a harvest and, in general, to improving forest management. Here, we used terrestrial laser scanning (TLS) to assess external timber quality metrics nondestructively. We investigated how competition intensity affected the metrics of 118 European beech (Fagus sylvatica L.) trees. We found that two newly developed TLS-based measures of external stem characteristics (number of bark anomalies per metre and stem non-circularity) were affected by competition intensity, suggesting that regulating competition levels may improve timber quality. Our study confirms empirical findings indicating a positive relationship between competition intensity and timber quality of European beech and offers a new methodology to assess external timber quality measures in the field objectively and nondestructively. Key words: bark anomalies, competition index, European beech, terrestrial laser scanning, timber quality. On manque souvent d'information precise sur la qualite du bois des feuillus, particulierement dans le cas des arbres sur pied. L'evaluation in situ de la qualite du bois pourrait ameliorer le rendement economique d'un peuplement, contribuer a determiner le moment optimal de la recolte et, de facon generale, ameliorer l'amenagement forestier. Nous avons utilise un scanneur laser terrestre (SLT) pour evaluer de facon non destructive les mesures externes de la qualite du bois. Nous avons etudie de quelle facon l'intensite de la competition a affecte les metriques de 118 hetres communs (Fagus sylvatica L.). Nous avons trouve que deux mesures recemment developpees basees sur le SLT (nombre d'anomalies de l'ecorce par metre et excentricite du tronc) sont influencees par l'intensite de la competition, ce qui indique que le controle du niveau de competition pourrait ameliorer la qualite du bois. Notre etude confirme des resultats empiriques selon lesquels il y a une relation positive entre l'intensite de la competition et la qualite du bois du hetre commun et offre une nouvelle methode pour evaluer objectivement et de facon non destructive les mesures externes de la qualite du bois sur le terrain. [Traduit par la Redaction] Mots-cles: anomalies de l'ecorce, indice de competition, hetre commun, scanneur laser terrestre, qualite du bois., 1. Introduction The conversion of pure forest stands to mixed stands is a major objective of forest management in several countries around the world (Food and Agriculture Organization of the [...]