Barbara Koch

University of Freiburg | Albert-Ludwigs-Universität Freiburg · Chair of Remote Sensing and Landscape Information Systems

Detailed information on spatial patterns of tree species diversity (TSD) is essential for biodiversity assessment, forest disturbance monitoring, and the management and conservation of forest resources. TSD mapping approaches based on the Spectral Variability Hypothesis (SVH) could provide a reliable alternative to image classification methods. How...

Unoccupied aerial vehicles (UAV) with RGB-cameras are affordable and versatile devices for the generation of a series of remote sensing products that can be used for forest inventory tasks, such as creating high-resolution orthomosaics and canopy height models. The latter may serve purposes including tree species identification, forest damage asses...

Concerted use of CNN + UAV can close the gap in reference data scarcity Multitemporal, large-scale maps of standing deadwood with high spatial resolution (10 m) Best model with all S1 + S2 bands R² = 0.38 after 5-fold CV Model slope: y = 0.45x + 0.26 Error equally distributed across range Optimization of co-registration improved results Robust acro...

Information about the distribution of standing dead trees (SDT) is essential for forest biodiversity estimation, forest disturbances monitoring, and forest management strategy planning. Although remote sensing techniques offer unique capabilities to map SDT over large areas, three major hurdles exist: (1) the sporadic distribution of SDT in the stu...

Spartina alterniflora (S. alterniflora) is one of the worst plant invaders in the coastal wetlands of China. Accurate and repeatable mapping of S. alterniflora invasion is essential to develop cost-effective management strategies for conserving native biodiversity. Traditional remote-sensing-based mapping methods require a lot of fieldwork for samp...

The use of unmanned aerial vehicles (UAVs) in vegetation remote sensing allows a time-flexible and cost-effective acquisition of very high-resolution imagery. Still, current methods for the mapping of forest tree species do not exploit the respective, rich spatial information. Here, we assessed the potential of convolutional neural networks (CNNs)...

Land Surface Temperature (LST) plays a significant role with respect to drought, vegetation covers and climate change. Therefore, the main objective of this paper is to evaluate the effect of LST in some parameters and to carry out mapping using Remote Sensing Data and Geographic Information System (GIS) techniques. Remote sensing techniques were u...

Deadwood mapping is of high relevance for studies on forest biodiversity, forest disturbance, and dynamics. As deadwood predominantly occurs in forests characterized by a high structural complexity and rugged terrain, the use of remote sensing offers numerous advantages over terrestrial inventory. However, deadwood misclassifications can occur in t...

Airborne laser scanning (ALS) is generally known as the most accurate and primary source providing the 3D structure of forest canopy model (CHM) information; however, in many countries, it is not updated as needed for continuous forest management planning due to its high costs. Image-based point clouds derived from airborne stereo aerial photograph...

Retention forestry, which retains a portion of the original stand at the time of harvesting to maintain continuity of structural and compositional diversity, has been originally developed to mitigate the impacts of clear‐cutting. Retention of habitat trees and deadwood has since become common practice also in continuous‐cover forests of Central Eur...

The concept of sustainability takes different meanings, depending on the discipline, and on research and social practices. It can be associated with new technologies, with societal changes and innovations, and with new modes of governance. Sustainability has increasingly integrated both individual and social group lifestyles and values. There is th...

Forests are one of the most important terrestrial ecosystems for the protection of biodiversity, but at the same time they are under heavy production pressures. In many cases, management optimized for timber production leads to a simplification of forest structures, which is associated with species loss. In recent decades, the concept of retention...

Spatially explicit information on tree species composition of any forest provides valuable information to forest managers as well as to nature conservationists. In this study, the potential of three spaceborne sensors: (1) Landsat-8, (2) Sentinel-2, and (3) IRS-Pansharpened were compared by applying Random Forest (RF) classification algorithms to c...

Digital stereo aerial photographs are periodically updated in many countries and offer a viable option for the regular update of information on forest variables. We compared the potential of image-based point clouds derived from three different sets of aerial photographs with airborne laser scanning (ALS) to assess plot-level forest attributes in a...

- Terrestrial and UAV scans in combination lead to more accurate representation of forest structures due to occlusion effects. - While exact matching or georeferencing is hardly possible in unstructured terrain, aggregating summary statistics is a sufficient workaround. - "Trust vectors" can represent the strength of the different viewpoints to descri...

Land-cover mapping (LCM) at a fine scale would be useful for forest management across heterogeneous natural landscapes. However, the heterogeneity of land covers at such scales results in complex spectral and textural properties that hinder the applicability of LCM. Besides, the method suffers from, e.g. inconsistent representation of different lan...

Structural analysis of forests by UAV is currently growing in popularity. Given the reduction in platform costs, and the number of algorithms available to analyze data output, the number of applications has grown rapidly. Forest structures are not only linked to economic value in forestry, but also to biodiversity and vulnerability issues. LiDAR re...

Global forest ecosystems provide multiple merchantable and non-merchantable ecosystem services, and are highly required to be monitored and protected. One major ecosystem service is theminimization and mitigation of the negative effects of climate change. Depending on various spatial scales, different planning actions are required for forest manage...

The globally emerging concepts and strategies for a “bioeconomy” rely on the vision of a sustainable bio-based substitution process. Fossil fuels are scarce and their use contributes to global warming. To replace them in the value chains, it is essential to gain knowledge about quantities and spatial distributions of renewable resources. Decision m...

Information pertaining to forest timber volume is crucial for sustainable forest management. Remotely-sensed data have been incorporated into operational forest inventories to serve the need for ever more diverse and detailed forest statistics and to produce spatially explicit data products. In this study, data derived from airborne laser scanning...

The estimation of various forest inventory attributes from high spatial resolution airborne remote sensing data has been widely examined and proved to be successful at the experimental level. Nevertheless, the operational use of these data in automated procedures to support forest inventories and forest management is still limited to a small number...

Supplementary data for "Estimating stand density, biomass and tree species from very high resolution stereo-imagery – towards an all-in-one sensor for forestry applications?"

Accurate and updated knowledge of forest tree heights is fundamental in the context of forest management. However, measuring canopy height over large forest areas using traditional inventory techniques is laborious, timeconsuming and excessively expensive. In this study, image-based point clouds produced from stereo aerial photographs (AP) were use...

Das Reallabor „Wissensdialog Nordschwarzwald“ ist eng an den Nationalpark Schwarzwald gekoppelt: Wie lassen sich Chancen nutzen, die der Nationalpark für die nachhaltige Entwicklung der Region bietet? Was lässt sich aus den im Nationalparkgebiet stattfindenden ökologischen Prozessen lernen? Dies sind die zentralen Forschungsfragen des Projekts. Der...

The use of remote sensing for the quantification of forest resources, viz. above ground biomass and growing stock volume has been a topic of research as well as has been in practice for monitoring to support decision making. There have been continuous efforts to apply improved methodologies and tools to ever improving remote sensing datasets in ord...

Monitoring the impacts of land-use practices is of particular importance with regard to biodiversity hotspots in developing countries. Here, conserving the high level of unique biodiversity is challenged by limited possibilities for data collection on site. Especially for such scenarios, assisting biodiversity assessments by remote sensing has prov...

Das Reallabor Wissensdialog Nordschwarzwald ist mit dem neuen Nationalpark Schwarzwald eng verknüpft. Das Reallaborteam erarbeitet mit den Akteuren vor Ort Chancen, die der Nationalpark für die nachhaltige Entwicklung der Region bietet, und berichtet hier von den Erkenntnisgewinnen während des ersten Jahrs ,,im Labor“.

Remote sensing-based timber volume estimation is key for modelling the regional potential, accessibility and price of lignocellulosic raw material for an emerging bioeconomy. We used a unique wall-to-wall air- borne LiDAR dataset and Landsat 7 satellite images in combination with terrestrial inventory data derived from the National Forest Inventory...

Highlights: Tree top detection using laser scanner data is very important when tree modeling and measurement are concerned. However, software used for this purpose are expensive and scarce. This project aimed to assess Scikit-image for tree local maxima detection. Scikit-image is a Python based package using Numpy and Scipy.

Digital elevation models (DEMs) and height measurements are broadly used in environmental studies. Two common elevation sources are the Ice Cloud and land elevation Satellite (ICESat), which acquired laser range measurements with the Geoscience Laser Altimeter System (GLAS) across the globe and elevation data from the Shuttle Radar Topography Missi...

We used spectral, textural and photogrammetric information from very-high resolution (VHR) stereo satellite data (Pléiades and WorldView-2) to estimate forest biomass across two test sites located in Chile and Germany. We compared Random Forest model performances of different predictor sets (spectral, textural, and photogrammetric), forest inventor...

Groundwater is the main source of water supply in Jordan. Due to lower precipitation rates in recent years, the surface water is increasingly limited. Research on groundwater vulnerability helps protect this main source of water supply and assists in the development of plans to confront the deterioration and contamination of aquifers from wastewate...

Remote sensing-assisted estimates of aboveground forest biomass are essential for modeling carbon budget on various scales. For these estimates, multiple factors such as sensor type, statistical prediction method, sampling design for the reference inventory data or the splitting of prediction models into species- strata-specific submodels affect th...

Spaceborne sensors allow for wide-scale assessments of forest ecosystems. Combining the products of multiple sensors is hypothesized to improve the estimation of forest biomass. We applied interferometric (Tandem-X) and photogrammetric (WorldView-2) based predictors, e.g. canopy height models, in combination with hyperspectral predictors (EO1-Hyper...

For reasons of documentation, management and certification there is a high interest in efficient inventories of palm plantations on the single plant level. Recent developments in unmanned aerial vehicle (UAV) technology facilitate spatial and temporal flexible acquisition of high resolution 3D data. Common single tree detection approaches are based...

This paper focuses on accuracy assessment of canopy top elevation, ground elevation and vegetation height (VH) derived from space borne full-waveform LiDAR (Light Detection And Ranging) data across forested areas. Computed height metrics from LiDAR data which were acquired by the GLAS sensor aboard the ICESat (Ice Cloud and land Elevation Satellite...

Tree species information is a basic variable for forest inventories. Knowledge on tree species is relevant for biomass estimation, habitat quality assessment, and biodiversity characterization. Hyperspectral data have been proven to have a high potential for the mapping of tree species composition. However, open questions remain concerning the robu...

The variety of different remote sensing sensors and thus the types of data specifications which are available is increasing continuously. Especially the differences in geometric, radiometric and temporal resolutions of different platforms affect their ability for the mapping of forests. These differences hinder the comparability and application of...

The role of remote sensing in forest biomass assessment is well defined and has been used to make assessments that range from local, regional to global scales. For large area biomass assessments, the limitations using remote sensing tools can be generally categorized into: 1. data availability and costs, 2. temporal coverage, 3. complexity of analy...

Species-specific information is important for many tasks related to forest management. We review the use of airborne laser scanning (ALS) and complementary data for providing this information. The main ALS-based information is related to structural features, intensity of the echoes, and waveform parameters, whereas spectral information may be provi...

This chapter reviews the use of airborne LiDAR data for the segmentation of forest to tree objects. The benefit obtained by LiDAR data is typically related to the use of the third dimension, i.e. the height data. Forest and stand objects may be segmented based on physical criteria, for example height and density information, while a further delinea...

The measurement of geometric tree attributes is a major part of forest inventories. In practice respective attributes are mostly measured by terrestrial surveys, less often by laser scanning. These methods are relatively time consuming or costly. The presented study was conducted in order to evaluate photogrammetric point clouds, based on Unmanned...

Knowledge of tree species distribution is important worldwide for sustainable forest management and resource evaluation. The accuracy and information content of species maps produced using remote sensing images vary with scale, sensor (optical, microwave, LiDAR), classification algorithm, verification design and natural conditions like tree age, fo...

Biomass estimation models retrieved from the combination of field measurements and discrete return lidar and spaceborne Imaging Spectroscopy data (IS) collected by EO1-Hyperion are presented. The study site Monte Oscuro is located in Central Chile close to the "Valle del Estero Upeo" and is dominated by a natural second growth forest with complex f...

In both ecology and forestry, there is a high demand for structural information of forest stands. Forest structures, due to their heterogeneity and density, are often difficult to assess. Hence, a variety of technologies are being applied to account for this "difficult to come by" information. Common techniques are aerial images or ground- and airb...

We report the results from modelling standing volume, above-ground biomass and stem count with the aim of exploring the potential of two non-parametric approaches to estimate forest attributes. The models were built based on spectral and 3D information extracted from airborne optical and laser scanner data. The survey was completed across two geogr...

This paper presents the potential of remote sensing data for modeling different forest eco-system services. In future the estimation of forest ecosystem services will become more and more important for the management of forests. Dependent on the management objectives alternatives for different decisions are possible. With the support of remote sens...

This is a review of forestry related multi-angular remote sensing which is a recent technology making use of optical remote sensing datasets collected from differing viewing-angles during a short period of time. A particular advantage of these datasets lies in their capability to capture structural information. Since forests can be considered to be...

Despite numerous studies existing for tree species classification the difficult situation in dense and mixed temperate forest is still a challenging task. This study attempts to extend the existing limitations by investigating comprehensive sets of different types of features derived from multiple data sources. These sets include features from full...

Results from biomass potential assessments vary considerably, both on global and European level. On the other hand reliable figures on biomass potentials are an important basis for energy policy and for strategies that aim at an increase of use of biomass for energy both on EU-Level as well as e. g. on national level in the National Renewable Energ...

The interest in the joint use of remote sensing data from multiple sensors has been remarkably increased for environmental applications. This is because a combined use is supposed to improve the results of e.g. forest modeling tasks compared to single-data use. To explore the ability of combined airborne 2D and 3D information to describe the forest...

The movements of the sand dunes are considered as a threat for roads, irrigation networks, water resources, urban areas, agriculture and infrastructures. The main objectives of this study are to develop a new GIS-based model for automated extraction of sand dune encroachment using remote sensing data and to assess the rate of sand dune movement. To...

A vegetation index (VI) is presented which is calculated as the inner angles of a triangle. The triangle is spanned between three distinct points (on a spectral curve of imaging spectroscopy data) which are defined for each individual pixel by the wavelength (x-axis) and the reflection value (y-axis). The ideal wavelengths of the three points are d...