@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 = "27 abr. 2024"
}