Browsing by Autor "Liana O. Anderson"

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An alert system for Seasonal Fire probability forecast for South American Protected Areas
(Wiley, 2021) Liana O. Anderson; Chantelle Burton; João Reis; Ana Carolina Moreira Pessôa; Philip E. Bett; Nathália S. Carvalho; Celso H. L. Silva; Karina Williams; Galia Selaya; Dolors Armenteras
Abstract Timely spatially explicit warning of areas with high fire occurrence probability is an important component of strategic plans to prevent and monitor fires within South American (SA) Protected Areas (PAs). In this study, we present a five‐level alert system, which combines both climatological and anthropogenic factors, the two main drivers of fires in SA. The alert levels are: High Alert, Alert, Attention, Observation and Low Probability. The trend in the number of active fires over the past three years and the accumulated number of active fires over the same period were used as indicators of intensification of human use of fire in that region, possibly associated with ongoing land use/land cover change (LULCC). An ensemble of temperature and precipitation gridded output from the GloSea5 Seasonal Forecast System was used to indicate an enhanced probability of hot and dry weather conditions that combined with LULCC favour fire occurrences. Alerts from this system were first issued in August 2020, for the period ranging from August to October (ASO) 2020. Overall, 50% of all fires observed during the ASO 2017–2019 period and 40% of the ASO 2020 fires occurred in only 29 PAs were all categorized in the top two alert levels. In categories mapped as High Alert level, 34% of the PAs experienced an increase in fires compared with the 2017–2019 reference period, and 81% of the High Alert false alarm registered fire occurrence above the median. Initial feedback from stakeholders indicates that these alerts were used to inform resource management in some PAs. We expect that these forecasts can provide continuous information aiming at changing societal perceptions of fire use and consequently subsidize strategic planning and mitigatory actions, focusing on timely responses to a disaster risk management strategy. Further research must focus on the model improvement and knowledge translation to stakeholders.
An alert system for Seasonal Fire probability forecast for South American Protected Areas
(Harvard University, 2022) Liana O. Anderson; Chantelle Burton; João Reis; Ana Carolina Moreira Pessôa; Philip E. Bett; Nathália S. Carvalho; Celso Silva Júnior; Karina Williams; Galiaa Selaya; Dolors Armenteras
Timely spatially explicit warning of areas with high fire occurrence probability is an important component of strategic plans to prevent and monitor fires within South American (SA) Protected Areas (PAs). In this study, we present a five-level alert system, which combines both climatological and anthropogenic factors, the two main drivers of fires in SA. The alert levels are: High Alert, Alert, Attention, Observation and Low Probability. The trend in the number of active fires over the past three years and the accumulated number of active fires over the same period were used as indicators of intensification of human use of fire in that region, possibly associated with ongoing land use/land cover change (LULCC). An ensemble of temperature and precipitation gridded output from the GloSea5 Seasonal Forecast System was used to indicate an enhanced probability of hot and dry weather conditions that combined with LULCC favour fire occurrences. Alerts from this system were first issued in August 2020, for the period ranging from August to October (ASO) 2020. Overall, 50% of all fires observed during the ASO 2017–2019 period and 40% of the ASO 2020 fires occurred in only 29 PAs were all categorized in the top two alert levels. In categories mapped as High Alert level, 34% of the PAs experienced an increase in fires compared with the 2017–2019 reference period, and 81% of the High Alert false alarm registered fire occurrence above the median. Initial feedback from stakeholders indicates that these alerts were used to inform resource management in some PAs. We expect that these forecasts can provide continuous information aiming at changing societal perceptions of fire use and consequently subsidize strategic planning and mitigatory actions, focusing on timely responses to a disaster risk management strategy. Further research must focus on the model improvement and knowledge translation to stakeholders.
Assessment of fire hazard in Southwestern Amazon
(Frontiers Media, 2023) Igor José Malfetoni Ferreira; Wesley A. Campanharo; Maria Lucia Ferreira Barbosa; Sonaira Souza da Silva; Galia Selaya; Luiz E. O. C. Aragão; Liana O. Anderson
Fires are among the main drivers of forest degradation in Amazonia, causing multiple socioeconomic and environmental damages. Although human-ignited sources account for most of the fire events in Amazonia, extended droughts may magnify their occurrence and propagation. The southwestern Amazonia, a transnational region shared by Brazil, Peru, and Bolivia and known as the MAP region, has been articulating coordinated actions to prevent disasters, including fire, to reduce their negative impacts. Therefore, to understand the fire patterns in the MAP region, we investigated their main drivers and the changes in the suitability of fire occurrence for the years 2005, 2010, 2016, and 2020. We used a maximum entropy (MaxEnt) model approach based on active fire data from satellites, climatic data, and land use and land cover mapping to spatially quantify the suitability of fire occurrence and its drivers. We used the year 2015 to calibrate the models. For climatic data and active fire count, we only considered grid cells with active fire count over the third quartile. All our models had a satisfactory performance, with values of the area under the curve (AUC) above 0.75 and p &lt; 0.05. Additionally, all models showed sensitivity rates higher than 0.8 and false positive rates below 0.25. We estimated that, on average, 38.5% of the study region had suitable conditions for fire occurrence during the study period. Most of the fire-prone areas belong to Acre, representing approximately 74% of the entire MAP region. The percentage of deforested areas, productive lands, forest edges, and high temperatures were the main drivers of fire occurrence in southwestern Amazonia, indicating the high vulnerability of fragmented landscapes extreme climatic conditions to fire occurrence. We observed that the modeling approach based on Maxint is useful for useful for evaluating the implications of climatic and anthropogenic variables on fire distribution. Furthermore, because the model can be easily employed to predict suitable and non-suitable locations for fire occurrence, it can to prevent potential impacts associated with large-scale wildfire in the future at regional levels.
Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests
(Copernicus Publications, 2016) Fabien Wagner; Bruno Hérault; Damien Bonal; Clément Stahl; Liana O. Anderson; Timothy R. Baker; Gabriel Sebastian Becker; Hans Beeckman; Danilo Boanerges Souza; Paulo César Botosso
Abstract. The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is < 2000 mm yr−1 (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000 mm yr−1.
Mapping landscape scale variations of forest structure, biomass, and productivity in Amazonia
(2009) Sassan Saatchi; Yadvinder Malhi; Brian R. Zutta; Wolfgang Buermann; Liana O. Anderson; Alejandro Araújo; Oliver L. Phillips; J. Peacock; Hans ter Steege; G. Lopez Gonzalez
Abstract. Landscape and environmental variables such as topography, geomorphology, soil types, and climate are important factors affecting forest composition, structure, productivity, and biomass. Here, we combine a network of forest inventories with recently developed global data products from satellite observations in modeling the potential distributions of forest structure and productivity in Amazonia and examine how geomorphology, soil, and precipitation control these distributions. We use the RAINFOR network of forest plots distributed in lowland forests across Amazonia, and satellite observations of tree cover, leaf area index, phenology, moisture, and topographical variations. A maximum entropy estimation (Maxent) model is employed to predict the spatial distribution of several key forest structure parameters: basal area, fraction of large trees, fraction of palms, wood density, productivity, and above-ground biomass at 5 km spatial resolution. A series of statistical tests at selected thresholds as well as across all thresholds and jackknife analysis are used to examine the accuracy of distribution maps and the relative contributions of environmental variables. The final maps were interpreted using soil, precipitation, and geomorphological features of Amazonia and it was found that the length of dry season played a key role in impacting the distribution of all forest variables except the wood density. Soil type had a significant impact on the wood productivity. Most high productivity forests were distributed either on less infertile soils of western Amazonia and Andean foothills, on crystalline shields, and younger alluvial deposits. Areas of low elevation and high density of small rivers of Central Amazonia showed distinct features, hosting mainly forests with low productivity and smaller trees.
Multi-Actor adaptation plan to cope with forests under increasing risk of extensive fires (MAP-FIRE)
(2019) Liana O. Anderson; Luiz E. O. C. Aragão; Víctor Marchezini; Sonaira Souza da Silva; Marisa Gesteira Fonseca; Galia Selaya; Foster Brown; Cândida Leite; Guillermo Rioja-Ballivián; Eddy Mendoza
Wildfires, caused by the interaction of social and climate systems, are currently one of the major driver of reduction of Amazonian carbon stocks and biodiversity. This process is also an important threat to the well-being of the ~25 million Amazonian inhabitants, imposing great economic losses in the impacted areas. Most Earth System Models predict increasing occurrence and intensity of droughts in the Amazon which is strongly interlinked with wildfires. The fire-related socio-environmental disaster risks are particularly critical in the tri-national frontier of Madre de Dios (Peru), Acre (Brazil) and Pando (Bolivia), known as MAP, the focal region of this study. For achieving a sustainable future, we propose a conceptual framework, based on four strategic working packages (WP): WP1- to develop a comprehensive understanding of current and future fire probability as well as quantifying the fire impacts; WP2- to produce a diagnostic and identify challenges and bottlenecks of operational and community-based strategies of wildfire risk management in the MAP region; WP3-to contribute towards the increase of risk awareness and capacity building of intergenerational social groups; and WP4- to influence conservation strategies and policies, providing technical reports for governments, improving their terminology, methods of data sharing and streams of information. Our results of a pessimistic climateâ€ landâ€ use projection suggest an increase of more than 100% of the area with high fire probability. Moreover, we have estimated an economic loss of approximately US$ 16 million per year due to fire impacts. Operational strategies for mitigating fire occurrence differ in the three MAP countries: in Acre, governmental actions are aligned among many environmental secretariats, which not being so structured in the two other countries. Community-based strategies will be assessed on high schools' communities. The schools' selection was defined based on their proximity with high concentrated hot pixels areas. Currently the schools' directors are being contacted to be invited for being part of the study. We expect that during the next two years, this project will contribute to identifying bottom-up initiatives and creating participatory methodologies to strengthen the science-police-citizen interface in order to mitigate mega-fires in this region.
RELATOS DE EXPERIÊNCIAS DOS PROJETOS DE PESQUISA MAP-FIRE E ACRE-QUEIMADAS: DIAGNÓSTICO E PERSPECTIVAS DE MITIGAÇÃO ENVOLVENDO A SOCIEDADE PARA REDUÇÃO DO RISCO E DE IMPACTOS ASSOCIADOS A INCÊNDIOS FLORESTAIS
(2020) Liana O. Anderson; Gleiciane Pismel; Yara Araújo Pereira de Paula; Galia Selaya; João Reis; Eddy M. Rojas; Guillermo Rioja-Ballivián; Juan Fernando Reyes; Víctor Marchezini; Foster Brown
Neste relato de experiências trazemos uma breve revisão da literatura, em sua maioria de artigos e relatórios técnicos produzidos pelos projetos de Pesquisa MAP-FIRE e Acre-Queimadas sobre a ocorrência e impactos de incêndios florestais na Amazônia, com detalhamento para a região MAP (Madre de Dios - Peru, Acre – Brasil e Pando-Bolívia). Os incêndios em áreas de agropecuária ou de floresta trazem impactos socioeconômicos e ambientais, e vem aumentando sua ocorrência nos últimos anos, sendo intensificadas em anos em que há seca extrema ou flexibilização da fiscalização. Enquadra-se nesse último caso o ano de 2019, em que se observou no Estado do Acre um aumento de 80% da área queimada em relação ao ano anterior, impactando a qualidade do ar por mais de 30 dias em alguns municípios. Para entendermos como prevenir ou mitigar as consequências a ocorrência de tais eventos, é necessário realizar um diagnóstico da governança, envolvendo as comunidades locais. Estas, uma vez incluídas na elaboração de planos estratégicos para monitorar, mitigar e combater as queimadas e incêndios florestais terão sua vulnerabilidade reduzida e sua capacidade de autoproteção aumentada. Para isso, o diálogo entre ciência e sociedade é imprescindível. Convidamos o leitor interessado em participar do projeto a entrar em contato com os autores.