Joan E Luther

Natural Resources Canada | NRCan · Canadian Forest Service

Assessing trade-offs among ecosystem services (ESs) that are provided by forests is necessary to support decision-making and to minimize negative effects of timber harvesting. In this study, we examined how spatial data, forest operational rules, ESs, and probabilistic statistics can be combined into a practical tool for trade-off analysis that cou...

Airborne laser scanning (ALS) has emerged as a technology capable of generating descriptors of vegetation structure and best available terrain information. Research and operational implementations of ALS data have highlighted their value for characterizing forest structure and generating spatially explicit and objective spatial coverages and mappin...

Light detection and ranging (lidar) data acquired from airborne or spaceborne platforms have revolutionized measurement and mapping of forest attributes. Airborne data are often either acquired using multiple overlapped flight lines to provide complete coverage of an area of interest, or using transects to sample a given population. Spaceborne lida...

In this study, we assessed the effect of airborne laser scanning (ALS) scan angle on point cloud metrics and the estimation of forest attributes in balsam fir (Abies balsamea (L.) Mill.) dominated forests of western Newfoundland, Canada. We collected calibration data from ground plot locations representing varying scan angles from two flight lines:...

Le secteur forestier canadien a besoin d’information détaillée au sujet de la quantité et des caractéristiques des ressources forestières. Pour répondre à de tels besoins, des systèmes d’inventaire exacts, complets et opportuns qui quantifient spatialement le bois d’œuvre et les autres services écosystémiques liés aux forêts sont nécessaires. Le pr...

The Canadian forest sector requires detailed information regarding the amount and characteristics of the forest resource. To address these needs, inventory systems that spatially quantify timber and other forest related ecosystem services are required, that are accurate, comprehensive and timely. The Assessment of Wood properties using Remote Sensi...

Maps of ecosystem services are becoming increasingly useful for reporting on the potential impacts of human activity on the environment. However, interactions in watersheds are complex, and mapping hydrological ecosystem services (HES) requires indicators which accurately measure underlying processes. The main objective of this study was to take ad...

Mapping the supply of ecosystem services (ESs) is essential for communicating the importance of ESs to policy makers and to demonstrate that sustainable development is being applied with due diligence by forest managers. ES mapping facilitates the integration of ES assessments into the decision-making process. To that end, the main objective of thi...

Information about wood fibre attributes (WFA) is important for optimizing forest resource management and increasing the competitiveness of the sector. Many factors influence WFA at both the plot (e.g., age, stand density, climate, and disturbance) and tree (e.g., crown development, stem shape, branchiness) levels. Recently, the use of terrestrial l...

We developed a methodology for extending estimates of the presence-absence of trees and several tree species contained in the Canadian National Forest Inventory using nationally consistent Landsat data products. For a prototype boreal forest region of Newfoundland and Labrador, Canada, we modeled and assessed changes in the presence-absence of tree...

Avian species are often highlighted as key indicator species as they are easily and reliably studied, are sensitive to environmental change, and occupy a wide range of ecological niches. A link between structural vegetation indices and avian diversity has been widely established. Remote sensing technologies such as airborne laser scanning (ALS) can...

The value of combining Landsat time series and airborne laser scanning (ALS) data to produce regional maps of forest structure has been well documented. However, studies are often performed over single study areas or forest types, preventing a robust assessment of the approaches that produce the most accurate estimates. Here, we use Landsat time se...

Airborne laser scanner (ALS) data are used to map a range of forest inventory attributes at operational scales. However, when wall-to-wall ALS coverage is cost prohibitive or logistically challenging, alternative approaches are needed for forest mapping. We evaluated an indirect approach for extending ALS-based maps of forest attributes using mediu...

Improving the quality of information that can be obtained from forest inventories can enhance planning for the best use of forest resources. In this study, we demonstrate the capability to improve the characterization of forest inventory attributes using terrestrial laser scanner (TLS) data, a fine-scale architectural model (L-Architect), and airbo...

A model comparison approach, based on the Akaike’s information criterion, was used to evaluate the contribution of terrestrial laser scanning (TLS) to the estimation of wood fiber attributes at the tree level for black spruce (Picea mariana (Mill.) B.S.P.) trees growing in Newfoundland, Canada. Substantial efforts were made to acquire, process, and...

Knowledge of wood fiber attributes (WFA) is important for evaluating forest resources and optimizing efficiency in the forest industry. To improve our ability to estimate WFA in the forest, we analyzed the relationships between structural metrics derived from terrestrial laser scanner (TLS) data and four key attributes of industrial significance: w...

We used a hierarchical approach to examine patterns of black spruce and balsam fir wood density across Newfoundland. Wood density measurements were aggregated at ring, tree, and plot levels. Portions of the variance in wood density at the different levels were explained by predictor variables at multiple levels of a forest structural hierarchy (rin...

Adaptive management of social-ecological systems requires integration and collaboration among scientists, policy makers, practitioners, and stakeholders across multiple disciplines and organizations. Challenges associated with such integration have been attributed to gaps between how human systems are organized and how ecosystems function. To addre...

Free and open access to the more than 40 years of data captured in the Landsat archive, combined with improvements in standardized image products and increasing computer processing and storage capabilities, have enabled the production of large-area, cloud-free, surface reflectance pixel-based image composites. Best-available-pixel (BAP) composites...

The objective of this study was to determine whether a suite of wood quantity and quality attributes of balsam fir and black spruce forests could be predicted using airborne laser scanner data. In situ estimates of stand structure and wood fibre attributes were derived from measurements at sample plots covering a wide range of forest conditions of...

We explore the possibility of predicting wood fiber attributes across Newfoundland for two commercial species: black spruce (Picea mariana (Mill.) B.S.P.) and balsam fir (Abies balsamea (L.) Mill.). Estimates of key fiber attributes (including wood density, coarseness, fiber length, and modulus of elasticity) were derived from measurements of wood...

The fine reconstruction of tree structure provides important information that is relevant to forest ecological processes and may be linked to wood quality attributes. Terrestrial laser scanners (TLS) provide detailed and accurate 3-D data and have the potential to enhance forest inventories with fine-scale information on structure. However, in fore...

As airborne laser scanning (ALS) gains wider adoption to support forest operations in Canada, the consistency and quality of derivative products that support long-term monitoring and planning are becoming a key issues for managers. The Canadian Consortium for Lidar Environmental Applications Research (C-CLEAR) has supported almost 200 projects acro...

LiDAR data and architecture models have potential to enhance forest inventories with fine-scale information on forest structure. At the individual tree scale, terrestrial laser scanners (TLS) provide detailed and accurate 3-D data. However, in dense forest canopies, TLS data is limited by the occlusion of the laser beam from opaque objects and move...

A shadow fraction method was developed previously for mapping forest attributes of northern black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) forests. This paper evaluates application of the method for (i) balsam fir stands (Abies balsamea (L.) Mill.), (ii) stands with higher volume and biomass than those of previous studies, and (iii...

This study demonstrates a method to map forest stand polygons based on four forest attributes (volume, basal area, height, and crown closure) using shadow fraction values estimated from high spatial resolution QuickBird panchromatic images. The method was tested over three test sites in northeastern Canada that were largely dominated by black spruc...

Monitoring ecological indicators is important for assessing impacts of human activities on ecosystems. A means of identifying and applying appropriate indicators is a prerequisite for: environmental assessment; better assessment and understanding of ecosystem health; elucidation of biogeochemical trends; and more accurate predictions of future resp...

Important and complex spatial decisions, such as allocating land to development or conservation-oriented goals, require information and tools to aid in understanding the inherent tradeoffs. They also require mechanisms for incorporating and documenting the value judgements of interest groups and decision makers. Multiple-criteria decision analysis...

The use of sapwood cross-sectional area at breast height (S) was compared with the use of diameter at breast height (D) and total height (H) for predicting branch weight per tree (B). Data obtained by destructive sampling of 58 balsam fir (Abiesbalsamea (L.) Mill.) trees growing in western and northern Newfoundland were used to fit a simple linear...

The Humber River Basin (HBR) responds to critical issues facing decision-makers concerning climate change and the sustainability of the HRB and its environments. The basin and its component watersheds represent an excellent platform from which to develop and integrate science and policy. The research presented herein is considered an important prer...

The Humber River Basin (HBR) responds to critical issues facing decision-makers concerning climate change and the sustainability of the HRB and its environments. The basin and its component watersheds represent an excellent platform from which to develop and integrate science and policy. The research presented herein is considered an important prer...

The increasing importance and complexity of land and natural resource management are creating a need for ecosystem-based management (EBM). Multiple criteria decision analysis (MCDA) combined with geographic information systems (GIS) can integrate factors related to the triple bottom line of ecological, economic, and social perspectives required by...

Forest structure influences a variety of biophysical and ecological processes. Consequently, the development of technologies to measure forest structure has become a highly active research area. However, the physical complexity of forest environments has limited characterization of structure at a scale where the complex spatial arrangement of folia...

Knowledge of forest biomass is necessary for reporting on the state of Canada's forests. It is also an indicator of carbon that enables insights on the interaction between forests and the atmosphere. Forest biomass information has largely been aspatial and derived using plot estimates from Canada's National Forest Inventory. Provincial and territor...

Quantifying spatial forest change information is important for assessing impacts of human activities and environmental changes on ecosystem sustainability. As part of an interdisciplinary research project aimed at ensuring sustainability of the Humber River Basin in western Newfoundland, we monitored land cover and forest transitions using satellit...

Capture of land cover information is a key requirement for supporting forest monitoring and management. In Canada, provincial and territorial forest stewards use land cover information to aid in management and planning activities. At the federal level, land cover information is required to aid in meeting national and international reporting obligat...

Forest inventory data often provide the required base data to enable the largearea mapping of biomass over a range of scales. However, spatially explicit estimates ofabove-ground biomass (AGB) over large areas may be limited by the spatial extent of theforest inventory relative to the area of interest (i.e., inventories not spatially exhaustive), o...

We have developed and tested a method for mapping above-ground forest biomass of black spruce (Picea mariana (Mill.) B.S.P.) stands in northern boreal forests of eastern Canada. The method uses QuickBird images and applies image processing algorithms to extract tree shadow fraction (SF) as a predictive variable for estimating biomass. Three QuickBi...

Identifying appropriate validation sources for large-area land cover products is a challenge, with logistical constraints frequently necessitating the use of preexisting data sources. Several issues exist when comparing polygon (vector-based) datasets to raster imagery: geolocational mismatches, differences in features or classes mapped, disparity...

A method for mapping forest biomass was developed and tested on a study area in western Newfoundland, Canada. The method, BIOmass from Cluster Labeling Using Structure and Type (BioCLUST), involves: (i) hyperclustering a Landsat TM image, (ii) automatically labeling the clusters with information about forest type and structure, and (iii) applying s...

Spatial measures of forest biomass are important to implement sustainable forest management, monitor global change, and model forest productivity. Several methods for estimating forest biomass by remote sensing have been developed, but their comparative advantages have not been evaluated for large areas in Canada. This study compares four methods t...

Forest mapping from satellite remote sensing images is a convenient approach for regions with limited or absent forest inventories. We developed and tested a method to map above-ground biomass of black spruce (Picea mariana) stands in northeastern boreal regions of Canada using high resolution satellite images. Development of the method involved: 1...

The limited availability of ground sample plots (GSP) in huge and remote regions requires mapping methods with greater dependence on modeling and remote sensing. We developed and tested a method to map the biomass of black spruce (Picea mariana) stands of Canadian subarctic forest using a k-NN approach applied to Landsat Thematic Mapper imagery wit...

Analysis of vegetation spectra is often characterized by an adverse ratio of sample size to number of wavelengths. A reduction in the dimensionality of the spectra is needed to ensure consistent estimates. We propose a reduction based on a non-linear mixed modeling of power spectra transforms of truncated Fourier series representations of vegetatio...

A priority of the Canadian Forest Service and Canadian Space Agency joint project, Earth Observation for Sustainable Development of Forests (EOSD), is the production of a land cover map of the forested area of Canada based upon Landsat data. The land cover will be produced through a partnership of federal, provincial and territorial governments, un...

A method of estimating and mapping aboveground tree biomass (AGTB) was developed using provincially available forest inventory databases. More specifically, AGTB conversion tables were devised to estimate biomass for stand attributes that are commonly mapped in provincial inventories over the Canadian landscape, i.e., species composition, projected...

Estimates of forest biomass are needed to meet Canada's international reporting requirements and to provide important inputs for global change, carbon accounting, and forest productivity models. The Canadian Forest Service, in cooperation with the Canadian Space Agency, has developed a strategy for mapping Canada's forest biomass as part of the Ear...

Canada requires a next generation forest measuring and monitoring system that responds to key policy drivers related to climate change and to report upon sustainable forest development of Canada's forest both nationally and internationally. The Canadian Forest Service, in partnership with the Canadian Space Agency, is using space-based Earth observ...

A method has been developed to map forest biomass with Landsat TM and ETM imagery coupled with forest inventory data. The method involves applying an unsupervised classification to a Landsat TM/ETM scene. The unsupervised clusters are labelled according to cover types and forest structure (crown closure and height) using random samples extracted fr...

Forest biomass information is needed for reporting of selected indicators of sustainable forest management and for models that estimate carbon budgets and forest productivity, particularly within the context of a changing climate. In collaboration with the Canadian Space Agency, a strategy for mapping Canada's forest biomass has been developed as p...

Geometric optical canopy reflectance models provide an explicit physical-structural basis to the analysis of satellite imagery and represent an alternative approach to existing classification methods for obtaining forest cover type and structural information (density and height) for biomass estimation. The Multiple-Forward-Mode (MFM) approach appli...

The estimation of forest stand biomass generally involves a conversion of inventory volume to biomass, where the inventory volumes are generated from interpreted values for stand level cover-type and crown closure. Information on land cover and crown closure may be obtained from forest inventory data and/or remotely sensed data. As a result, invent...

In support of Canada’s National Forest Inventory (NFI), methods and techniques to estimate forest stand attributes from remotely sensed data are required. This document provides methods and techniques that may be applied to estimate NFI parameters with Landsat TM data. The approach is based upon the estimation of a suite of basic attributes from wh...

The potential to measure indices of forest vigor from foliar spectral reflectance was assessed in a range of balsam fir conditions achieved through stand manipulations. In order of increasing vigor, treatments consisted of root pruning, control, thinning, and thinning in combination with fertilization. Concentrations of chlorophyll and nitrogen inc...

A group of forested nations agreed upon a set of criteria and indicators to measure the sustainable development of forests. Of the 83 indicators, remote sensing could measure in whole or in part about 25 indicators. Moreover, such measurements could also support elements of Canada's national forest inventory and reporting requirements for the Kyoto...

RÉSUMÉ La réflectance spectrale du feuillage de l'orme a été mesurée avec un spectroradiomètre dans des conditions de laboratoire pour examiner les caractéristiques de réflectance associées avec les différents stades de la maladie hollandaise de l'orme. Des conditions précoces de la maladie résultent en un accroissement rapide de la réflectance dan...

The potential of remote sensing to monitor indices of forest health was tested by examining the spectral separability of plots with different balsam fir, Abies balsamea (L.) Mill, vigor. Four levels of vigor were achieved with controlled experimental manipulations of forest stands. In order of increasing vigor, the treatments were root pruning, con...

The potential of remote sensing to aid in the forecast of insect defoliation and the associated impact on forest stands was tested by examining the relationships between i) preoutbreak forest structure and growth characteristics, ii) multispectral values recorded by the Landsat Thematic Mapper (TM) sensor, and iii) subsequent patterns of defoliatio...

A climate change monitoring site has been established at the northwest margin of the Barnes Ice Cap, in the vicinity of the Lewis Glacier. Three years of climatic data (1989 to 1992) and field observations, supplemented by satellite imagery, provide the basis for updating previous studies of local change at the ice cap margin, including climatology...