•Some 1.1 billion ha are covered by all of the SFM tools investigated in FRA 2015.•Policies, laws and regulations supporting SFM cover 98% of permanent forest land.•Forest inventories have recently ...been conducted in 112 countries.•Some 52% of the total forest area was under Forest Management Plan (FMP) in 2010.•International forest certification was most extensive in high income countries.•There are positive increases in most SFM indicators globally.
Sustainable forest management (SFM) is many things to many people – yet a common thread is the production of forest goods and services for the present and future generations. The promise of sustainability is rooted in the two premises; first that ecosystems have the potential to renew themselves and second that economic activities and social perceptions or values that define human interaction with the environment are choices that can be modified to ensure the long term productivity and health of the ecosystem. SFM addresses a great challenge in matching the increasing demands of a growing human population while maintaining ecological functions of healthy forest ecosystems. This paper does not seek to define SFM, but rather provides analyses of key indicators for the national-scale enabling environment to gain a global insight into progress in implementing enabling and implementing SFM at the national and operational levels. Analyses of the Global Forest Resources Assessment 2015 (FRA) country report data are used to provide insights into the current state of progress in implementing the enabling conditions for SFM. Over 2.17 billion ha of the world’s forest area are predicted by governments to remain in permanent forest land use, of which some 1.1 billion ha are covered by all of the SFM tools investigated in FRA 2015. At the global scale, SFM-related policies and regulations are reported to be in place on 97% of global forest area. While the number of countries with national forest inventories has increased over that past ten years from 48 to 112, only 37% of forests in low income countries are covered by forest inventories. Forest management planning and monitoring of plans has increased substantially as has forest management certification, which exceeded a total of over 430 million ha in 2014. However, 90% of internationally verified certification is in the boreal and temperate climatic domains – only 6% of permanent forests in the tropical domain have been certified as of 2014. Results show that more work is needed to expand the extent and depth of work on establishing the enabling conditions that support SFM over the long term and suggests where those needs are greatest.
The study objective is to investigate the feasibility and the technical specifications required to develop an operational system in order to detect and monitor the selective logging activities in ...tropical forests. The research relies on a detailed understanding of the remotely sensed signal of natural and logged tropical forests. The experimental study is based on a 100,000
ha semi-deciduous forest located in the south-western part of the Central African Republic. This forest includes a protected area and an area allocated to timber production. Two Landsat Thematic Mapper (TM) images, six SPOT multi-spectral (XS) images and field information were used for the analysis. The 5-year interval between the two Landsat-TM images made it possible to study the forest regeneration dynamics. The SPOT XS time series was used to assess the respective influence of the season, the spatial resolution and the geometry of acquisition. While recent impact of tree fall can be detected, there is no way to identify the cause of a single tree fall, i.e. whether it was due to the natural forest dynamics, storm damage or logging. Nevertheless, logging activities were identified due to the local concentration of large gaps and the linear features of the skid trail. The logging trails are clearly detected but with different degrees of success depending on the image geometry. The seasonality and hazy atmospheric conditions did not significantly affect the detectability of the trails. The geometry of observation, i.e. the sensor viewing and sun illumination angles, appeared to be a key factor. More than 40% of the trail network can be missed when the geometry of acquisition is not suitable. Despite rapid canopy closure over the logging roads and skid trail surface, more than 50% of the network was still visible 5 years after the last timber extraction. However, the spatial resolution of the images became critical as soon as the contrast between trails and the forest vanished. On a 120
m regularised image recorded right after the logging, more than 95% of the logging trail network was still visible, but only 34% was detected on a 5-year post-harvest image. These results led to the definition of the main specifications for a remote sensing-based system for monitoring and controlling the logging activities in tropical forests.
One of the main land administration challenges in Namibia concerns urban growth. It is a fast process which is only partly done formally. The aim of this work is to identify and present an optimal ...prototypical workflow to be used by planning authorities to monitor spatial growth of informal settlements in Namibia. This workflow involves the access to satellite image data sources, processing services for object identification and change detection. Very high spatial resolution images have been proven as the most suitable data source. Other sources such as the use of aerial images derived from drones or cadastral data have been looked at but are not applicable to perform informal settlement monitoring on a larger scale and on a regular basis. The current detection practice, from visual interpretation and point location is used as baseline for improvement. Automatic object base detection is promising, but still requires a visual validation and is sensitive to image pair quality. The improved system proposed to the planning authorities includes visual interpretation of image difference and computer aided delineation.
This viewpoint paper presents a reaction to the article by Brandt et al. (2016). It highlights the complexities inherent to the attribution of deforestation impacts to policy interventions when using ...remote-sensing data. This critique argues that in the context of the Congo a suite of factors (i.e., population density in particular) other than those considered by Brandt et al. (e.g., type of forest, distance from roads and markets) play essential roles in determining the fates of forests. It also contends that care is needed when making decisions regarding which units will be included in the comparison group so that contextual factors and on-the-ground information are properly considered (e.g., when logging operations are inactive or when a concession is used for 'conservation' purposes). Finally, it proposes that a focus on an analysis of deforestation rates for a given level of timber production might be a metric that more accurately represents one aspect of the consequences of forest management, which should also consider the appraisal of trade-offs associated with a larger set of social, financial and ecological objectives.
The natural tropical rain forest is an irregular mosaic of ever-changing developmental phases of vegetation. Its structure is a key information for forest monitoring and sustainable management. This ...experimental study aims to improve the understanding of the relationships between the forest structure and the anisotropic behaviour of the remotely sensed forest reflectance. It relies on intensive field-based measurements and synchronous remote sensing data collection. Three different tropical rain forests have been observed using six different SPOT–HRVIR images. Texture information is related to forest structure by means of geostatistical analysis based on directional variograms for the NIR channel. The results demonstrate a strong interaction between the elements contributing to the forest structure, i.e. the tree crowns and the gaps, and the viewing and illumination conditions of each observation. The concept of the Bi-directional Standard deviation Distribution Function (BSDF) is introduced to discriminate the forest structures. A simple geometric-optical gap model explains more than 80% of the variability of the NIR reflectance standard deviation. Finally, a cross-thresholding approach using the NIR reflectance and the Local Directional Contrast (LDC) is proposed and successfully applied to discriminate the canopy roughness of the different forest sites.
This viewpoint paper presents a reaction to the article by Brandt et al. (2016). It highlights the complexitiesinherent to the attribution of deforestation impacts to policy interventions when using ...remote-sensingdata. This critique argues that in the context of the Congo a suite of factors (i.e., population density inparticular) other than those considered by Brandt et al. (e.g., type of forest, distance from roads and mar-kets) play essential roles in determining the fates of forests. It also contends that care is needed whenmaking decisions regarding which units will be included in the comparison group so that contextual fac-tors and on-the-ground information are properly considered (e.g., when logging operations are inactiveor when a concession is used for ‘conservation’ purposes). Finally, it proposes that a focus on an analysisof deforestation rates for a given level of timber production might be a metric that more accurately rep-resents one aspect of the consequences of forest management, which should also consider the appraisalof trade-offs associated with a larger set of social, financial and ecological objectives.
Muons produced in atmospheric cosmic ray showers account for the by far dominant part of the event yield in large-volume underground particle detectors. The IceCube detector, with an instrumented ...volume of about a cubic kilometer, has the potential to conduct unique investigations on atmospheric muons by exploiting the large collection area and the possibility to track particles over a long distance. Through detailed reconstruction of energy deposition along the tracks, the characteristics of muon bundles can be quantified, and individual particles of exceptionally high energy identified. The data can then be used to constrain the cosmic ray primary flux and the contribution to atmospheric lepton fluxes from prompt decays of short-lived hadrons.
In this paper, techniques for the extraction of physical measurements from atmospheric muon events are described and first results are presented. The multiplicity spectrum of TeV muons in cosmic ray air showers for primaries in the energy range from the knee to the ankle is derived and found to be consistent with recent results from surface detectors. The single muon energy spectrum is determined up to PeV energies and shows a clear indication for the emergence of a distinct spectral component from prompt decays of short-lived hadrons. The magnitude of the prompt flux, which should include a substantial contribution from light vector meson di-muon decays, is consistent with current theoretical predictions.
The variety of measurements and high event statistics can also be exploited for the evaluation of systematic effects. In the course of this study, internal inconsistencies in the zenith angle distribution of events were found which indicate the presence of an unexplained effect outside the currently applied range of detector systematics. The underlying cause could be related to the hadronic interaction models used to describe muon production in air showers.
ABSTRACT We present the results of a search for astrophysical sources of brief transient neutrino emission using IceCube and DeepCore data acquired between 2012 May 15 and 2013 April 30. While the ...search methods employed in this analysis are similar to those used in previous IceCube point source searches, the data set being examined consists of a sample of predominantly sub-TeV muon-neutrinos from the Northern Sky (−5 ) obtained through a novel event selection method. This search represents a first attempt by IceCube to identify astrophysical neutrino sources in this relatively unexplored energy range. The reconstructed direction and time of arrival of neutrino events are used to search for any significant self-correlation in the data set. The data revealed no significant source of transient neutrino emission. This result has been used to construct limits at timescales ranging from roughly 1 s to 10 days for generic soft-spectra transients. We also present limits on a specific model of neutrino emission from soft jets in core-collapse supernovae.
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