57 research outputs found
Using the Landsat data archive to assess long-term regional forest dynamics assessment in Eastern Europe, 1985-2012
Abstract. Dramatic political and economic changes in Eastern European countries following the dissolution of the “Eastern Bloc” and the collapse of the Soviet Union greatly affected land-cover and land-use trends. In particular, changes in forest cover dynamics may be attributed to the collapse of the planned economy, agricultural land abandonment, economy liberalization, and market conditions. However, changes in forest cover are hard to quantify given inconsistent forest statistics collected by different countries over the last 30 years. The objective of our research was to consistently quantify forest cover change across Eastern Europe from 1985 until 2012 using the complete Landsat data archive. We developed an algorithm for processing imagery from different Landsat platforms and sensors (TM and ETM+), aggregating these images into a common set of multi-temporal metrics, and mapping annual gross forest cover loss and decadal gross forest cover gain. Our results show that forest cover area increased from 1985 to 2012 by 4.7% across the region. Average annual gross forest cover loss was 0.41% of total forest cover area, with a statistically significant increase from 1985 to 2012. Most forest disturbance recovered fast, with only 12% of the areas of forest loss prior to 1995 not being recovered by 2012. Timber harvesting was the main cause of forest loss. Logging area declined after the collapse of socialism in the late 1980s, increased in the early 2000s, and decreased in most countries after 2007 due to the global economic crisis. By 2012, Central and Baltic Eastern European countries showed higher logging rates compared to their Western neighbours. Comparing our results with official forest cover and change estimates showed agreement in total forest area for year 2010, but with substantial disagreement between Landsat-based and official net forest cover area change. Landsat-based logging areas exhibit strong relationship with reported roundwood production at national scale. Our results allow national and sub-national level analysis of forest cover extent, change, and logging intensity and are available on-line as a baseline for further analyses of forest dynamics and its drivers
Monitoring conterminous United States (CONUS) land cover change with Web-Enabled Landsat Data (WELD)
Forest cover loss and bare ground gain from 2006 to 2010 for the conterminous United States (CONUS) were quantified at a 30 m spatial resolution using Web-Enabled Landsat Data available from the USGS Center for Earth Resources Observation and Science (EROS) (http://landsat.usgs.gov/WELD.php). The approach related multi-temporal WELD metrics and expert-derived training data for forest cover loss and bare ground gain through a decision tree classification algorithm. Forest cover loss was reported at state and ecoregional scales, and the identification of core forests\u27 absent of change was made and verified using LiDAR data from the GLAS (Geoscience Laser Altimetry System) instrument. Bare ground gain correlated with population change for large metropolitan statistical areas (MSAs) outside of desert or semi-desert environments. Google Earth™ time series images were used to validate the products. Mapped forest cover loss totaled 53,084 km2 and was found to be depicted conservatively, with a user\u27s accuracy of 78% and a producer\u27s accuracy of 68%. Excluding errors of adjacency, user\u27s and producer\u27s accuracies rose to 93% and 89%, respectively. Mapped bare ground gain equaled 5974 km2 and nearly matched the estimated area from the reference (Google Earth™) classification; however, user\u27s (42%) and producer\u27s (49%) accuracies were much less than those of the forest cover loss product. Excluding errors of adjacency, user\u27s and producer\u27s accuracies rose to 62% and 75%, respectively. Compared to recent 2001–2006 USGS National Land Cover Database validation data for forest loss (82% and 30% for respective user\u27s and producer\u27s accuracies) and urban gain (72% and 18% for respective user\u27s and producer\u27s accuracies), results using a single CONUS-scale model with WELD data are promising and point to the potential for national scale operational mapping of key land cover transitions. However, validation results highlighted limitations, some of which can be addressed by improving training data, creating a more robust image feature space, adding contemporaneous Landsat 5 data to the inputs, and modifying definition sets to account for differences in temporal and spatial observational scales. The presented land cover extent and change data are available via the official WELD website (ftp://weldftp.cr.usgs.gov/CONUS_5Y_LandCover/ftp://weldftp.cr.usgs. gov/CONUS_5Y_LandCover/)
Contrasting tree-cover loss and subsequent land cover in two neotropical forest regions: sample-based assessment of the Mexican Yucatán and Argentine Chaco
The neotropical-forest’s northern and southern extremes, covering the Mexican Yucatán and the Argentine Chaco, have among the highest rates of recent tree-cover loss in the biome. This study contrasts the character of loss in these regions, estimating proportions of types of loss and subsequent land cover. It is based on two-stage probability sampling design and field and satellite-image surveys. All estimates include uncertainties, which could be further reduced via model-assisted estimation or additional sampling. This approach can be replicated in other regions to estimate types of loss and associated land cover from a definitive, in-situ perspective. The character of loss in the two areas differed greatly. That in the Yucatán was 54% temporary, mostly under fallow or selectively logged, while that in the Chaco was 85% permanent, split nearly equally between crops and pasture. These data contribute to a quantitative basis for studies of socio-economic drivers of neotropical deforestation.Fil: Krylov, Alexander. University of Maryland; Estados UnidosFil: Steininger, Marc K.. University of Maryland; Estados UnidosFil: Hansen, Matthew C.. University of Maryland; Estados UnidosFil: Potapov, Peter V.. University of Maryland; Estados UnidosFil: Stehman, Stephen V.. State University of New York; Estados UnidosFil: Gost, Allison. University of Maryland; Estados UnidosFil: Noel, Jacob. University of Maryland; Estados UnidosFil: Talero Ramirez, Yamile. University of Maryland; Estados UnidosFil: Tyukavina, Alexandra. University of Maryland; Estados UnidosFil: Di Bella, Carlos Marcelo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ellis, Edward A.. Universidad Veracruzana; MéxicoFil: Ellis, Peter. The Nature Conservancy. Global Lands; Estados Unido
Peculiarities of the Accumulation of Mineral Elements and Nitrogen in the Assimilation Apparatus of Scots Pine
The research has been carried out in the Arkhangelsk forestry of the Arkhangelsk Region in a drained shrub-sphagnum pine forest. Census trees of medium diameter and height for the stand have been selected, from which samples of needles, both living and dying yellow ones, and shoots of different ages have been taken on model branches. Soil samples have also been taken from the 3 upper horizons. It has been established that most of all nitrogen and mineral elements accumulate in the living needles – 4.4 % on average, in the dying needles and shoots there are 37–40 % less. Among all the elements, nitrogen, potassium and calcium make up the largest proportion; while the rest of the chemical elements are several time less. In descending order of the share, they are arranged in the following sequence: magnesium, sulfur, phosphorus, manganese, silicon, iron and aluminum. The most important mineral elements are derived in significant quantities from the dying yellow needles. The content of sulfur, magnesium, phosphorus, manganese and iron decreases in them by 3.3, 2.1, 8.0, 1.5 and 1.4 times, respectively, compared to the living needles. Data on the presence of nitrogen and mineral elements in the soil horizons A0, T1 and T2 have been obtained. It has been established that some of the essential elements for the life of a tree are concentrated in the living needles in much larger quantities than in the soil: potassium, phosphorus, manganese and calcium – by 12.0, 4.0, 6.0 and 1.9, respectively. The yellow falling needles create a biological cycle of substances. The amount of nitrogen and ash constituents in these needles is proportional to their presence in the soil. In turn, the content of mineral elements in the shoots is close to their amount in the yellow falling needles, on the one hand, and on the other, depends on the age of the shoots. There is a steady trend of decreasing the content of nitrogen, potassium, phosphorus and sulfur with the age of the shoots
Comparative validation of recent 10 m-resolution global land cover maps
Accurate and high-resolution land cover (LC) information is vital for addressing contemporary environmental challenges. With the advancement of satellite data acquisition, cloud-based processing, and deep learning technology, high-resolution Global Land Cover (GLC) map production has become increasingly feasible. With a growing number of available GLC maps, a comprehensive evaluation and comparison is necessary to assess their accuracy and suitability for diverse uses. This particularly applies to maps lacking statistically robust accuracy assessment or sufficient reported detail on the validation procedures. This study conducts a comparative independent validation of recent 10 m GLC maps, namely ESRI Land Use/Land Cover (LULC), ESA WorldCover, and Google and World Resources Institute (WRI)’s Dynamic World, examining their spatial detail representation and thematic accuracy at global, continental, and national (for 47 larger countries) levels. Since high-resolution map validation is impacted by reference data uncertainty owing to geolocation and labelling errors, five validation approaches dealing with reference data uncertainty were evaluated. Of the considered approaches, validation using the sample label supplemented by majority label within the neighborhood is found to produce more reasonable accuracy estimates compared to the overly optimistic approach of using any label within the neighborhood and the overly pessimistic approach of direct comparison between the map and reference labels. Overall global accuracies of the maps range between 73.4% ± 0.7% (95% confidence interval) to 83.8% ± 0.4% with WorldCover having the highest accuracy followed by Dynamic World and ESRI LULC. The quality of the maps varies across different LC classes, continents, and countries. The maps' spatial detail representation was assessed at various homogeneity levels within a 3 × 3 kernel. Although considered as high-resolution maps, this study reveals that ESRI LULC and Dynamic World have less spatial detail than WorldCover. All maps have lower accuracies in heterogenous landscapes and in some countries such as Mozambique, Tanzania, Nigeria, and Spain. To select the most suitable product, users should consider both the map's accuracy over the area of interest and the spatial detail appropriate for their application. For future high-resolution GLC mapping, producers are encouraged to adopt standardized LC class definitions to ensure comparability across maps. Additionally, the spatial detail and accuracy of GLC maps in heterogeneous landscapes and over some countries are the key features that should be improved in future versions of the maps. Independent validation efforts at regional and national levels, as well as for LC changes, should be strengthened to enhance the utility of GLC maps at these scales and for long-term monitoring
Случай использования ингибитора контрольных точек у больной раком шейки матки в реальной клинической практике
The treatment standard for stage IVB cervical cancer is palliative drug therapy combined with cytoreductive surgery used in the presence of resectable lesions. Anticancer therapy is based on two-component regimens that include platinum agents and taxanes. The virus-associated aetiology and pathogenesis of cervical cancer is a predictor of high efficacy of immunotherapy, which made the FDA approve an anti-PD1 agent for use in the treatment of these patients in 2018. The paper presents literature data on the treatment methods for advanced cervical cancer and a case report of indolent disease that was treated with all currently available therapeutic options, including checkpoint inhibitors.Стандартом лечения IVB стадии рака шейки матки является паллиативная лекарственная терапия в комплексе с циторедуктивными операциями при наличии резектабельных очагов. Основа противоопухолевой терапии — двухкомпонентные режимы с включением препаратов платины и таксанового ряда. Вирус-ассоциированный этиопатогенетический механизм развития рака шейки матки является предиктором высокой эффективности иммунотерапии, в связи с чем в 2018 году FDA одобрила применение анти-PD1 препарата в лечении больных данной группы. В статье приведены литературные сведения о методах лечения распространенного рака шейки матки, и представлен клинический случай торпидного течения заболевания, в лечении которого применялись все существующие на сегодняшний день терапевтические опции, в том числе ингибиторы контрольных точек
Will REDD+ safeguards mitigate corruption? Qualitative evidence from Southeast Asia
High levels of faith and finance are being invested in REDD+ as a promising global climate change mitigation policy. Since its inception in 2007, corruption has been viewed as a potential impediment to the achievement of REDD+ goals, partly motivating ‘safeguards’ rolled out as part of national REDD+ readiness activities. We compare corruption mitigation measures adopted as part of REDD+ safeguards, drawing on qualitative case evidence from three Southeast Asian countries that have recently piloted the scheme: Indonesia, the Philippines, and Vietnam. We find that while REDD+ safeguards adopt a conventional principal-agent approach to tackling corruption in the schemes, our case evidence confirms our theoretical expectation that REDD+ corruption risks are perceived to arise not only from principal-agent type problems: they are also linked to embedded pro-corruption social norms. This implies that REDD+ safeguards are likely to be at best partially effective against corruption, and at worst will not mitigate corruption at all
Disentangling the numbers behind agriculture-driven tropical deforestation
Tropical deforestation continues at alarming rates with profound impacts on ecosystems, climate, and livelihoods, prompting renewed commitments to halt its continuation. Although it is well established that agriculture is a dominant driver of deforestation, rates and mechanisms remain disputed and often lack a clear evidence base. We synthesize the best available pantropical evidence to provide clarity on how agriculture drives deforestation. Although most (90 to 99%) deforestation across the tropics 2011 to 2015 was driven by agriculture, only 45 to 65% of deforested land became productive agriculture within a few years. Therefore, ending deforestation likely requires combining measures to create deforestation-free supply chains with landscape governance interventions. We highlight key remaining evidence gaps including deforestation trends, commodity-specific land-use dynamics, and data from tropical dry forests and forests across Africa
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