19 research outputs found
Historic emissions from deforestation and forest degradation in Mato Grosso, Brazil: 1) source data uncertainties
<p>Abstract</p> <p>Background</p> <p>Historic carbon emissions are an important foundation for proposed efforts to Reduce Emissions from Deforestation and forest Degradation and enhance forest carbon stocks through conservation and sustainable forest management (REDD+). The level of uncertainty in historic carbon emissions estimates is also critical for REDD+, since high uncertainties could limit climate benefits from credited mitigation actions. Here, we analyzed source data uncertainties based on the range of available deforestation, forest degradation, and forest carbon stock estimates for the Brazilian state of Mato Grosso during 1990-2008.</p> <p>Results</p> <p>Deforestation estimates showed good agreement for multi-year periods of increasing and decreasing deforestation during the study period. However, annual deforestation rates differed by > 20% in more than half of the years between 1997-2008, even for products based on similar input data. Tier 2 estimates of average forest carbon stocks varied between 99-192 Mg C ha<sup>-1</sup>, with greatest differences in northwest Mato Grosso. Carbon stocks in deforested areas increased over the study period, yet this increasing trend in deforested biomass was smaller than the difference among carbon stock datasets for these areas.</p> <p>Conclusions</p> <p>Estimates of source data uncertainties are essential for REDD+. Patterns of spatial and temporal disagreement among available data products provide a roadmap for future efforts to reduce source data uncertainties for estimates of historic forest carbon emissions. Specifically, regions with large discrepancies in available estimates of both deforestation and forest carbon stocks are priority areas for evaluating and improving existing estimates. Full carbon accounting for REDD+ will also require filling data gaps, including forest degradation and secondary forest, with annual data on all forest transitions.</p
Contrasting Patterns of Damage and Recovery in Logged Amazon Forests From Small Footprint LiDAR Data
Tropical forests ecosystems respond dynamically to climate variability and disturbances on time scales of minutes to millennia. To date, our knowledge of disturbance and recovery processes in tropical forests is derived almost exclusively from networks of forest inventory plots. These plots typically sample small areas (less than or equal to 1 ha) in conservation units that are protected from logging and fire. Amazon forests with frequent disturbances from human activity remain under-studied. Ongoing negotiations on REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus enhancing forest carbon stocks) have placed additional emphasis on identifying degraded forests and quantifying changing carbon stocks in both degraded and intact tropical forests. We evaluated patterns of forest disturbance and recovery at four -1000 ha sites in the Brazilian Amazon using small footprint LiDAR data and coincident field measurements. Large area coverage with airborne LiDAR data in 2011-2012 included logged and unmanaged areas in Cotriguacu (Mato Grosso), Fiona do Jamari (Rondonia), and Floresta Estadual do Antimary (Acre), and unmanaged forest within Reserva Ducke (Amazonas). Logging infrastructure (skid trails, log decks, and roads) was identified using LiDAR returns from understory vegetation and validated based on field data. At each logged site, canopy gaps from logging activity and LiDAR metrics of canopy heights were used to quantify differences in forest structure between logged and unlogged areas. Contrasting patterns of harvesting operations and canopy damages at the three logged sites reflect different levels of pre-harvest planning (i.e., informal logging compared to state or national logging concessions), harvest intensity, and site conditions. Finally, we used multi-temporal LiDAR data from two sites, Reserva Ducke (2009, 2012) and Antimary (2010, 2011), to evaluate gap phase dynamics in unmanaged forest areas. The rates and patterns of canopy gap formation at these sites illustrate potential issues for separating logging damages from natural forest disturbances over longer time scales. Multi-temporal airborne LiDAR data and coincident field measurements provide complementary perspectives on disturbance and recovery processes in intact and degraded Amazon forests. Compared to forest inventory plots, the large size of each individual site permitted analyses of landscape-scale processes that would require extremely high investments to study using traditional forest inventory methods
Reconstructing Three Decades of Land Use and Land Cover Changes in Brazilian Biomes with Landsat Archive and Earth Engine
Variabilidade genética de populações de fava d'anta (Dimorphandra mollis) da região norte do Estado de Minas Gerais
Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial
Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
Improving spatial distribution estimation of forest biomass with geostatistics: A case study for Rondonia, Brazil
Mapping aboveground forest biomass is of fundamental importance for estimating CO2
emissions due to land use and land cover changes in the Brazilian Amazon. However,
existing biomass maps for this region diverge in terms of the total biomass estimates
derived, as well as in the spatial patterns of mapped biomass. In addition, no regional
or location-specific measure of reliability accompanies most of these maps. In this study,
330 one-hectare plots from the RADAMBRASIL survey, acquired over and along areas adjacent
to the state of Rondonia, were used to generate a biomass map over the entire region ˆ
using geostatistics. The RADAMBRASIL samples were used to generate a biomass map, along
with a measure of reliability for each biomass estimate at each location, using kriging with
external drift with elevation, vegetation type and soil texture considered as biomass predictor
variables. Cross-validation was performed using the sample plots to compare the
performance of kriging against a simple biomass estimation using the sample mean. Overall,
biomass varied from 225 to 486 Mg ha−1, with a local standard deviation ranging from
62 to 202 Mg ha−1. Large uncertainty values were obtained for regions with low sampling
density, in particular in savanna areas. The geostatistical method adopted in this paper
has the potential to be applied over the entire Brazilian Amazon region to provide more
accurate local estimates of biomass, which would aid carbon flux estimation, along with
measures of their reliability, and to identify areas where more sampling efforts should be
concentrated
Biomass collapse and carbon emissions from forest fragmentation in the Brazilian Amazon
Forest fragmentation due to deforestation is one of the major causes of forest degradation in the Amazon. Biomass collapse near forest edges, especially within 100 m, alters aboveground biomass and has potentially important implications for carbon emissions in the region. This phenomenon is tightly linked to spatial and temporal dynamics of forest edges in a landscape. However, the potential biomass loss and carbon emissions from forest edges and these spatiotemporal changes have never been estimated for actual landscapes in the Amazon. We conducted a deep temporal analysis of Rondonia, southwestern Brazilian Amazonia, using six Landsat path-row scenes covering the 1985-2008 time period to estimate annual biomass loss and associated carbon emissions within 100 m of forest edges. Annual edge biomass loss averaged 9.1% of the biomass loss from deforestation during the study period, whereas average annual edge-related carbon emissions from biomass loss were 6.0% of deforestation-derived carbon emissions. However, because many edges were subsequently deforested during the 24 year study period, actual unaccounted for edge-related carbon emissions during the 1985-2008 period, calculated from edges of all ages extant on the landscape in 2008, amounted to 3.6% of that attributed to all deforestation-derived carbon fluxes for this time interval. Biomass loss and carbon emissions are highly influenced by the extent and age of edge-affected forests. Large annual contributions of biomass loss and carbon emissions were found from active deforestation regions with young edges, whereas regions dominated by older edges had lower biomass loss and carbon emissions from edges.Pages: G0302