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@InProceedings{MouraSVSGVNC:2019:NeEcEx,
               author = "Moura, Magna and Silva, Thieres and Von Randow, Celso and Souza, 
                         Luciana and Galvincio, Josicleda and Verhoef, Anne and Nobrega, 
                         Rodolfo and Carvalho, Herica",
          affiliation = "{Empresa Brasileira de Pesquisa Agropecu{\'a}ria (EMBRAPA)} and 
                         {Universidade Federal Rural de Pernambuco (UFRPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Universidade Federal 
                         Rural de Pernambuco (UFRPE)} and {Universidade Federal de 
                         Pernambuco (UFPE)} and {University of Reading} and {University of 
                         Reading} and {Empresa Brasileira de Pesquisa Agropecu{\'a}ria 
                         (EMBRAPA)}",
                title = "Net ecosystem exchange and evapotranspiration in a contrasting 
                         climate and land-use conditions in a tropical deciduous dry forest 
                         in Brazil",
                 year = "2019",
         organization = "EGU General Assembly",
             abstract = "The largest single block of seasonally dry forest in the world is 
                         the Caatinga biome found in northeastern Brazil. It covers 844,453 
                         km2 and houses a high level of endemic plant species adapted to 
                         the low precipitation (400-800 mm year-1), high mean air 
                         temperature (26-28 oC), and elevated potential evapotranspiration 
                         (over 2,500 mm year-1). The Caatinga biome has about 55% of its 
                         original area preserved, and 45% with some degree of degradation 
                         related to anthropogenic impacts such as unsustainable natural 
                         resources management and land cover clearing for agricultural and 
                         grazing activities. Since 2012 the region has been experiencing 
                         the most severe drought of the last 50 years. Under this scenario, 
                         the caatinga vegetation performs a crucial role due to its 
                         capacity to fix atmosphere carbon dioxide even when water is 
                         scarce. Quantifying radiation, energy, CO2 and evapotranspiration 
                         in different caatinga areas is essential for a better 
                         understanding of their functioning and for evaluating possible 
                         changes in their interaction with the atmosphere due to dynamic 
                         climate and environmental change. Eddy covariance is a widely 
                         accepted method to evaluate energy and carbon fluxes over 
                         ecosystem scale, and was used to study two sites in the Pernambuco 
                         state of Brazil within the Caatinga biome. The first study site is 
                         a pristine caatinga (PC) located in Petrolina municipality, Brazil 
                         (09.03S, 40.32W). This site has an area of 600 ha and has been 
                         preserved for over 40 years. Its vegetation comprises a mix of 
                         shrubby-arboreal hyperxerophilic species plants with average 
                         height of 5 m. The second study site, characterized by 5 ha of 
                         degraded caatinga (DC), is located in Araripina (07.45S, 40.42W), 
                         about 176 km north from PC. It was used as a rainfed agricultural 
                         area during the 1980s and 1990s and has slowly been reclaimed by 
                         caatinga species since the beginning of the last decade. 
                         Micrometeorological measurements were conducted at both sites for 
                         an average rainfall year (2011) and an unusually extremely dry 
                         year (2012). The towers monitor turbulent fluxes by measuring 
                         three-dimensional wind velocity and temperature with an ultrasonic 
                         anemometer, and CO2 and H2O concentrations with an open path 
                         infrared gas analyzer at a frequency of 10 Hz. The collected 
                         high-frequency data were filtered, despiked, rotated, and 
                         corrected using standard eddy covariance (EC) processing methods. 
                         In addition, air temperature, air humidity, net radiation, soil 
                         heat flux, soil temperature, and photosynthetically active 
                         radiation were measured. Data were processed and analysed on daily 
                         and seasonal time scales. The dynamics of net ecosystem exchange 
                         and of latent heat flux (evapotranspiration) over these two 
                         contrasting land use of caatinga were compared for the two years 
                         with very different water availability, revealing the importance 
                         of long term ecosystem studies across the Caatinga biome and its 
                         various physiognomies.",
  conference-location = "Vienna, Austria",
      conference-year = "07-12 apr.",
             language = "en",
           targetfile = "moura_net.pdf",
        urlaccessdate = "16 abr. 2021"
}


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