Publication Details |
Category | Text Publication |
Reference Category | Journals |
DOI | 10.3112/erdkunde.2017.03.03 |
Title (Primary) | Missing hot moments of greenhouse gases in Southern Amazonia |
Author | Meurer, K.H.E.; Franko, U.; Spott, O.; Schützenmeister, K.; Niehaus, E.; Stange, C.F.; Jungkunst, H.F. |
Source Titel | Erdkunde |
Year | 2017 |
Department | BOPHY |
Volume | 71 |
Issue | 3 |
Page From | 195 |
Page To | 211 |
Language | englisch |
Keywords | Brazil; CO2; N2O; land use; soil science; CH4 |
UFZ wide themes | RU1 |
Abstract | The superlative environmental conditions in Southern Amazonia, i.e.
high temperatures and annual rainfall, create ideal conditions for high
soil organic matter turnover rates and therewith the soil-atmosphere
exchanges of greenhouse gases. In this study, we present daily
observations of soil-related carbon dioxide (CO2), nitrous oxide (N2O),
and methane (CH4) emissions from the dominant land use types in Mato
Grosso (cerrado, gallery forest, cattle pasture, and cropland under
soybean) and Pará (rainforest and cattle pastures) during the early rain
season. We followed the hypothesis that precipitation events provoke
hot moments for CO2 and N2O, and lead to alternating uptake and emission
for CH4, respectively. Observed fluxes differed significantly between
land use types and underlying soil type. CO2 fluxes from soils under
natural vegetation ranged from 101 mg m-2 h-1 in the cerrado to 160 mg C
m-2 h-1 in the rainforest. Fluxes from cattle pastures varied between
locations and were 79 mg C m-2 h-1 from the pasture in Mato Grosso and
between 120 and 180 mg C m-2 h-1 from pastures in Pará. For N2O, fluxes
were highest from rainforest (16 µg N m-2 h-1) and lowest from cerrado
soil (-0.05 µg N m-2 h-1). Similar to CO2, the pastures in Pará emitted
higher fluxes of N2O (2–8 µg N m-2 h-1) compared to the pasture in Mato
Grosso (0.09 µg N m-2 h-1). CH4 fluxes were negative on all sites,
except for two pasture sites in Pará, where recorded fluxes amounted to
10 and 53 µg C m-2 h-1, respectively. The dynamic behavior during the
measurement period, as determined by an indicator function, was moderate
for N2O, low for CO2 and CH4, and depended on the site and measurement
chamber, respectively. Nevertheless, N2O fluxes from the cropland
increased during the end of the vegetation period of soybean, likely as a
result of increased nitrogen availability due to ceasing plant roots.
At the same time cattle pastures showed an age-related decrease of N2O
emissions, whereas they turned out to being considerable sources for
CH4. Generally, the low dynamics and missing reactions to precipitation
events demonstrate poor process understanding and need to be further
investigated. |
Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=19262 |
Meurer, K.H.E., Franko, U., Spott, O., Schützenmeister, K., Niehaus, E., Stange, C.F., Jungkunst, H.F. (2017): Missing hot moments of greenhouse gases in Southern Amazonia Erdkunde 71 (3), 195 - 211 10.3112/erdkunde.2017.03.03 |