Current Trends in Forest Ecological Applications of Three-Dimensional Remote Sensing: Transition from Experimental to Operational Solutions?

The alarming increase in the magnitude and spatiotemporal patterns of changes in composition, structure and function of forest ecosystems during recent years calls for enhanced cross-border mitigation and adaption measures, which strongly entail intensified research to understand the underlying processes in the ecosystems as well as their dynamics. Remote sensing data and methods are nowadays the main complementary sources of synoptic, up-to-date and objective information to support field observations in forest ecology. In particular, analysis of three-dimensional (3D) remote sensing data is regarded as an appropriate complement, since they are hypothesized to resemble the 3D character of most forest attributes. Following their use in various small-scale forest structural analyses over the past two decades, these sources of data are now on their way to be integrated in novel applications in fields like citizen science, environmental impact assessment, forest fire analysis, and biodiversity assessment in remote areas. These and a number of other novel applications provide valuable material for the Forests special issue “3D Remote Sensing Applications in Forest Ecology: Composition, Structure and Function”, which shows the promising future of these technologies and improves our understanding of the potentials and challenges of 3D remote sensing in practical forest ecology worldwide

3D Remote Sensing Applications in Forest Ecology: Composition, Structure and Function

Dear Colleagues, The composition, structure and function of forest ecosystems are the key features characterizing their ecological properties, and can thus be crucially shaped and changed by various biotic and abiotic factors on multiple spatial scales. The magnitude and extent of these changes in recent decades calls for enhanced mitigation and adaption measures. Remote sensing data and methods are the main complementary sources of up-to-date synoptic and objective information of forest ecology. Due to the inherent 3D nature of forest ecosystems, the analysis of 3D sources of remote sensing data is considered to be most appropriate for recreating the forest’s compositional, structural and functional dynamics. In this Special Issue of Forests, we published a set of state-of-the-art scientific works including experimental studies, methodological developments and model validations, all dealing with the general topic of 3D remote sensing-assisted applications in forest ecology. We showed applications in forest ecology from a broad collection of method and sensor combinations, including fusion schemes. All in all, the studies and their focuses are as broad as a forest’s ecology or the field of remote sensing and, thus, reflect the very diverse usages and directions toward which future research and practice will be directed

Canonical Correlation Analysis for Interpreting Airborne Laser Scanning Metrics along the Lorenz Curve of Tree Size Inequality

Canonical Correlation Analysis for Interpreting Airborne Laser Scanning Metrics along the Lorenz Curve of Tree Size Inequalit

Diversity and Equitability Ordering Profiles Applied to the Study of Forest Structure

Diversity and Equitability Ordering Profiles Applied to the Study of Forest Structur

Optimizing the airborne laser scanning estimation of basal area larger than mean (BALM): An indicator of cohort balance in forests

Airborne laser scanning (ALS) assisted basal area larger than mean (BALM) estimation measures the cohort balance in forests and provides adequate opportunities to describe forest structure. However, a problem still exists that how the plot size, sample size (number of trees), and ALS point density affect the BALM estimation. We tackled this question by using both field and ALS data from a typical managed boreal forest area in Finland. Various concentric circular plots (1-15 m radii) were simulated within the actual field plots (squared) and the optimal plot size and sample size were selected by observing changes in the absolute correlation between BALM estimates and various ALS metrics. Instability in the correlation was found at the smaller concentric circular plots (1-5 m radii) and sample sizes (less than 6 trees) but as the plot size and sample size increased, the correlation followed a convex curve. The maximum correlation was found between a concentric circular plot size 11-14 m radii (380-615 m2 area) and sample size 50-80 trees which could be the optimal plot size and sample size for a reliable BALM estimation. With regards to the ALS point density, no major effects were observed on the relationship between BALM estimates and various ALS metrics unless the point density is less than at least 5 points m 2. The point density of the current nationwide ALS survey is matching the minimum point density requirement obtained in this study and thus it is suitable for a reliable forest structural assessment

Cartography of uncertainty of predicted forest variables estimated from ALS data

cartografía de incertidumbre

Efecto del choque de temperatura y tiempo sobre la fertilización y sobrevivencia de larvas de bocachico (Prochilodus magdalenae) sometidos a tratamientos de triploidización

La inducción a la poliploidía en organismos acuáticos, permite mejorar su desempeño en cultivo, debido a que no alcanzan la madurez sexual, por lo que existe un control sobre la población; además en el ámbito ambiental, específicamente aplicado a programas de repoblamiento con individuos estériles, se atenúan o eliminan riesgos ligados a la interacción reproductiva con poblaciones naturales residentes en el medio, lo que posibilita conservar la diversidad genética y evitar endogamia.  El objetivo de este trabajo fue evaluar el efecto de dos rangos de temperatura (0-4 y 4-8°C) y tres tiempos de choque térmico (5, 10 y 15 min) sobre los porcentajes de fertilización y sobrevivencia larvaria en bocachico (Prochilodus magdalenae). Para esto se realizó reproducción inducida mediante tratamiento hormonal con Extracto de Hipófisis de Carpa (EHC) a machos y hembras que presentaran signos de madurez avanzada. Una vez obtenido el desove, se utilizaron muestras de 1g aproximadamente para realizar los diferentes tratamientos (5 min post fertilización). Una vez realizado el choque térmico, las muestras fueron incubadas en contenedores de flujo ascendente de 2L de capacidad, a las 6 Horas Post Fertilización (HPF) se cuantificó el porcentaje de fertilización y a las 10 HPE el porcentaje de sobrevivencia larvaria. Se observó para el control los mayores valores con relación a los porcentajes de fertilización y sobrevivencia. Solo en el tratamiento 6 se observó triploidía en los organismos evaluados por medio de la cuantificación de los cromosomas. La obtención de un método práctico y efectivo para la inducción a la triploidía es necesario para poder considerar  la triploidía como una tecnología de aplicación comercial, por lo que se deben considerar la realización de más investigaciones relacionadas con el manejo de ovocitos y efecto de los choques térmicos en las larvas de especies de interés para cultivo y programas de repoblamiento (malformaciones)

A Simple Approach of Groundwater Quality Analysis, Classification, and Mapping in Peshawar, Pakistan

Groundwater is an important source of water for drinking, agriculture, and other household purposes, but high population growth, industrialization, and lack of oversight on environmental policies and implementation have not only degraded the quality but also stressed the quantity of this precious source of water. Many options existed, but this study evaluated, classified, and mapped the quality of groundwater used for potable consumption with a simple approach in an urban area (Peshawar valley) of Pakistan. More than 100 groundwater samples were collected and analyzed for physio-chemical parameters in a laboratory. Hierarchal clustering analysis (HCA) and classification and regression tree (CART) analysis were sequentially applied to produce potential clusters/groups (groundwater quality classes), extract the threshold values of the clusters, classify and map the groundwater quality data into meaningful classes, and identify the most critical parameters in the classification. The HCA produced six distinct potential clusters. We found a high correlation of electrical conductivity with total hardness ( R2= 0.72 ), alkalinity ( R2= 0.59 ) and chloride (R2= 0.64) , and, total hardness with chloride ( R2 = 0.62), and alkalinity ( R2 = 0.51). The CART analysis conclusively identified the threshold values of the six classes and showed that total hardness was the most critical parameter in the classification. The majority of the groundwater was either with worse quality or good quality, and only a few areas had the worst groundwater quality. This study presents a simple tool for the classification of groundwater quality based on several aesthetic constituents and can assist decision makers develop and support policies and/or regulations to manage groundwater resources.published versionpeerReviewe