Estimating nonlinear mixing effects for arid vegetation scenes with MISR channels and observation directions

A Monte-Carlo ray-trace model has been applied to simulated sparse vegetation desert canopies in an effort to quantify the spectral mixing (both linear and nonlinear) occurring as a result of radiative interactions between vegetation and soil. This work is of interest as NASA is preparing to launch new instruments such as MISR and MODIS. MISR will observe each ground pixel from nine different directions in three visible channels and one near-infrared channel. It is desired to study angular variations in spectral mixing by quantifying the amount of nonlinear spectral mixing occurring in the MISR observing directions

Active Amplification of the Terrestrial Albedo to Mitigate Climate Change: An Exploratory Study

This study explores the potential to enhance the reflectance of solar insolation by the human settlement and grassland components of the Earth's terrestrial surface as a climate change mitigation measure. Preliminary estimates derived using a static radiative transfer model indicate that such efforts could amplify the planetary albedo enough to offset the current global annual average level of radiative forcing caused by anthropogenic greenhouse gases by as much as 30 percent or 0.76 W/m2. Terrestrial albedo amplification may thus extend, by about 25 years, the time available to advance the development and use of low-emission energy conversion technologies which ultimately remain essential to mitigate long-term climate change. However, additional study is needed to confirm the estimates reported here and to assess the economic and environmental impacts of active land-surface albedo amplification as a climate change mitigation measure.Comment: 21 pages, 3 figures. In press with Mitigation and Adaptation Strategies for Global Change, Springer, N

A review of methods to measure and monitor historical carbon emissions from forest degradation

In the absence of historical field data, developing countries can rely on consistent current ground data and remote sensing assessments

What lies beneath : detecting sub-canopy changes in savanna woodlands using a three-dimensional classification method

QUESTION : Increasing population pressure, socio-economic development and associated natural resource use in savannas are resulting in large-scale land cover changes, which can be mapped using remote sensing. Is a three-dimensional (3D) woody vegetation structural classification applied to LiDAR (Light Detection and Ranging) data better than a 2D analysis to investigate change in fine-scale woody vegetation structure over 2 yrs in a protected area (PA) and a communal rangeland (CR)? LOCATION : Bushbuckridge Municipality and Sabi Sand Wildtuin, NE South Africa. METHODS : Airborne LiDAR data were collected over 3 300 ha in April 2008 and 2010. Individual tree canopies were identified using object-based image analysis and classified into four height classes: 1–3, 3–6, 6–10 and >10 m. Four structural metrics were calculated for 0.25-ha grid cells: canopy cover, number of canopy layers present, cohesion and number of height classes present. The relationship between top-of-canopy cover and sub-canopy cover was investigated using regression. Gains, losses and persistence (GLP) of cover at each height class and the four structural metrics were calculated. GLP of clusters of each structural metric (calculated using LISA – Local Indicators of Spatial Association – statistics) were used to assess the changes in clusters of eachmetric over time. RESULTS : Top-of-canopy cover was not a good predictor of sub-canopy cover. The number of canopy layers present and cohesion showed gains and losseswith persistence in canopy cover over time, necessitating the use of a 3D classification to detect fine-scale changes, especially in structurally heterogeneous savannas. Trees >3 min height showed recruitment and gains up to 2.2 times higher in the CR where they are likely to be protected for cultural reasons, but losses of up to 3.2-foldmore in the PA, possibly due to treefall caused by elephant and/or fire. CONCLUSION : Land use has affected sub-canopy structure in the adjacent sites, with the low intensity use CR showing higher structural diversity. A 3D classification approach was successful in detecting fine-scale, short-term changes between land uses, and can thus be used as amonitoring tool for savannawoody vegetation structure. Remove selectedThe Carnegie Airborne Observatory is made possible by the Avatar Alliance Foundation, Margaret A. Cargill Foundation, John D. and Catherine T. MacArthur Foundation, Grantham Foundation for the Protection of the Environment, W.M. Keck Foundation, Gordon and Betty Moore Foundation, Mary Anne Nyburg Baker and G. Leonard Baker Jr. and William R. Hearst III. Application of the CAO data in South Africa is made possible by the Andrew Mellon Foundation and the endowment of the Carnegie Institution for Science.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1654-109X2016-07-31hb201

Unsustainable fuelwood extraction from South African savannas

Wood and charcoal supply the majority of sub-Saharan Africa’s rural energy needs. The long-term supply of fuelwood is in jeopardy given high consumption rates. Using airborne light detection and ranging (LiDAR), we mapped and investigated savanna aboveground biomass across contrasting land uses, ranging from densely populated communal areas to highly protected areas in the Lowveld savannas of South Africa. We combined the LiDAR observations with socio-economic data, biomass production rates and fuelwood consumption rates in a supply–demand model to predict future fuelwood availability. LiDAR-based biomass maps revealed disturbance gradients around settlements up to 1.5 km, corresponding to the maximum distance walked to collect fuelwood. At current levels of fuelwood consumption (67% of households use fuelwood exclusively, with a 2% annual reduction), we calculate that biomass in the study area will be exhausted within thirteen years. We also show that it will require a 15% annual reduction in consumption for eight years to a level of 20% of households using fuelwood before the reduction in biomass appears to stabilize to sustainable levels. The severity of dwindling fuelwood reserves in African savannas underscores the importance of providing affordable energy for rural economic development.The CSIR researchers were funded by the CSIR Strategic Research Panel and the Department of Science and Technology’s Earth Observation Unit. SUCSES study (Sustainability in Communal Socio-Ecological Systems) which provided data on fuelwood use in Justicia was funded by the South African National Research Foundation. The airborne campaign and analysis was funded by the Andrew Mellon Foundation.http://iopscience.iop.org/1748-9326am201

Biomass increases go under cover : woody vegetation dynamics in South African rangelands

Woody biomass dynamics are an expression of ecosystem function, yet biomass estimates do not provide information on the spatial distribution of woody vegetation within the vertical vegetation subcanopy. We demonstrate the ability of airborne light detection and ranging (LiDAR) to measure aboveground biomass and subcanopy structure, as an explanatory tool to unravel vegetation dynamics in structurally heterogeneous landscapes. We sampled three communal rangelands in Bushbuckridge, South Africa, utilised by rural communities for fuelwood harvesting. Woody biomass estimates ranged between 9 Mg ha-1 on gabbro geology sites to 27 Mg ha-1 on granitic geology sites. Despite predictions of woodland depletion due to unsustainable fuelwood extraction in previous studies, biomass in all the communal rangelands increased between 2008 and 2012. Annual biomass productivity estimates (10–14% p.a.) were higher than previous estimates of 4% and likely a significant contributor to the previous underestimations of modelled biomass supply. We show that biomass increases are attributable to growth of vegetation <5 m in height, and that, in the high wood extraction rangeland, 79% of the changes in the vertical vegetation subcanopy are gains in the 1-3m height class. The higher the wood extraction pressure on the rangelands, the greater the biomass increases in the low height classes within the subcanopy, likely a strong resprouting response to intensive harvesting. Yet, fuelwood shortages are still occurring, as evidenced by the losses in the tall tree height class in the high extraction rangeland. Loss of large trees and gain in subcanopy shrubs could result in a structurally simple landscape with reduced functional capacity. This research demonstrates that intensive harvesting can, paradoxically, increase biomass and this has implications for the sustainability of ecosystem service provision. The structural implications of biomass increases in communal rangelands could be misinterpreted as woodland recovery in the absence of three-dimensional, subcanopy information.S1 Dataset. Biomass model data. Data include 2012 LiDAR-derived average height and canopy cover extraction metrics, as well as field-work based allometry. Each line item is per 25 m x 25 m grid cell. Metadata are included in the dataset.S2 Dataset. Biomass and subcanopy data. Data include 2008 and 2012 biomass estimates derived from biomass models as well as % subcanopy returns for voxel data for the height class categories: 1-3m, 3-5m, 5-10m and >10m. Each line item is per 25 m x 25 m grid cell. Data are organized per land extraction category into separate worksheets. Metadata are included in the dataset.S3 Dataset. Biomass changes (Mg ha-1) in relation to relative height and canopy cover change. Data include biomass change estimates (2008–2012), percentage height and canopy cover changes for each 25 m x 25 m grid cell. Each height class (relative to height in 2008) are shown on separate worksheets. Metadata are included in the dataset.S1 Fig. Site-specific biomass model residuals. The residual spread demonstrates heteroskedasticity with increasing biomass fitted values for rangelands with a) high, b) intermediate and c) low extraction pressure.S2 Fig. Biomass changes (%) relative to height-specific change in subcanopy returns (%). Height categories are: 1–3 m, 3–5 m, 5–10 m and >10 m.The Carnegie Airborne Observatory (CAO) is made possible by the Avatar Alliance Foundation, Margaret A. Cargill Foundation, John D. and Catherine T. MacArthur Foundation, Grantham Foundation for the Protection of the Environment, W. M. Keck Foundation, Gordon and Betty Moore Foundation, Mary Anne Nyburg Baker and G. Leonard Baker, Jr., and William R. Hearst III. Application of the CAO data in South Africa is made possible through the Andrew Mellon Foundation and the endowment of the Carnegie Institution for Science, the Council for Scientific and Industrial Research (CSIR), and the South African Department of Science and Technology (grant agreement DST/ CON 0119/2010, Earth Observation Application Development in Support of SAEOS). CSIR coauthors are supported by the European Union’s Seventh Framework Programme (FP7/2007-2013, grant agreement n°282621, AGRICAB). PJM acknowledges funding from the National Research Foundation (NRF: SFH1207203615). Additionally, PJM and ETFW acknowledge the DST-NRF Centre of Excellence in Tree Health Biotechnology (CTHB) and, PJM and BFNE, the Applied Centre for Climate and Earth Systems Science (ACCESS). BFNE acknowledges financial support from Exxaro.http://www.plosone.orgam201

Framing the concept of satellite remote sensing essential biodiversity variables: challenges and future directions

Although satellite-based variables have for long been expected to be key components to a unified and global biodiversity monitoring strategy, a definitive and agreed list of these variables still remains elusive. The growth of interest in biodiversity variables observable from space has been partly underpinned by the development of the essential biodiversity variable (EBV) framework by the Group on Earth Observations – Biodiversity Observation Network, which itself was guided by the process of identifying essential climate variables. This contribution aims to advance the development of a global biodiversity monitoring strategy by updating the previously published definition of EBV, providing a definition of satellite remote sensing (SRS) EBVs and introducing a set of principles that are believed to be necessary if ecologists and space agencies are to agree on a list of EBVs that can be routinely monitored from space. Progress toward the identification of SRS-EBVs will require a clear understanding of what makes a biodiversity variable essential, as well as agreement on who the users of the SRS-EBVs are. Technological and algorithmic developments are rapidly expanding the set of opportunities for SRS in monitoring biodiversity, and so the list of SRS-EBVs is likely to evolve over time. This means that a clear and common platform for data providers, ecologists, environmental managers, policy makers and remote sensing experts to interact and share ideas needs to be identified to support long-term coordinated actions

Search for CP Violation in D^0--> K_S^0 pi^+pi^-

We report on a search for CP violation in the decay of D0 and D0B to Kshort pi+pi-. The data come from an integrated luminosity of 9.0 1/fb of e+e- collisions at sqrt(s) ~ 10 GeV recorded with the CLEO II.V detector. The resonance substructure of this decay is well described by ten quasi-two-body decay channels (K*-pi+, K*0(1430)-pi+, K*2(1430)-pi+, K*(1680)-pi+, Kshort rho, Kshort omega, Kshort f0(980), Kshort f2(1270), Kshort f0(1370), and the ``wrong sign'' K*+ pi-) plus a small non-resonant component. We observe no evidence for CP violation in the amplitudes and phases that describe the decay D0 to K_S^0 pi+pi-.Comment: 10 pages, 3 figures, also available at http://w4.lns.cornell.edu/public/CLNS/, submitted to PR