![Hier klicken, um den Treffer aus der Auswahl zu entfernen](images/unchecked.gif) |
Titel |
Greenhouse gas exchange in tropical mountain ecosystems in Tanzania |
VerfasserIn |
Friederike Gerschlauer, Imani Kikoti, Ralf Kiese |
Konferenz |
EGU General Assembly 2014
|
Medientyp |
Artikel
|
Sprache |
Englisch
|
Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 16 (2014) |
Datensatznummer |
250095371
|
Publikation (Nr.) |
EGU/EGU2014-10821.pdf |
|
|
|
Zusammenfassung |
Tropical mountain ecosystems with their mostly immense biodiversity are important regions
for natural resources but also for agricultural production. Their supportive ecosystem
processes are particularly vulnerable to the combined impacts of global warming and the
conversion of natural to human-modified landscapes. Data of impacts of climate and land use
change on soil-atmosphere interactions due to GHG (CO2, CH4, and N2O) exchange from
these ecosystems are still scarce, in particular for Africa. Tropical forest soils are
underestimated as sinks for atmospheric CH4 with regard to worldwide GHG budgets
(Werner et al. 2007, J GEOPHYS RES Vol. 112). Even though these soils are an
important source for the atmospheric N2O budget, N2O emissions from tropical
forest ecosystems are still poorly characterized (Castaldi et al. 2013, Biogeosciences
10).
To obtain an insight of GHG balances of selected ecosystems soil-atmosphere
exchange of N2O, CH4 and CO2 was investigated along the southern slope of Mt.
Kilimanjaro, Tanzania. We will present results for tropical forests in three different
altitudes (lower montane, Ocotea, and Podocarpus forest), home garden (extensive
agro-forestry), and coffee plantation (intensive agro-forestry). Therefore we used a combined
approach consisting of a laboratory parameterization experiment (3 temperature and
2 moisture levels) and in situ static chamber measurements for GHG exchange.
Field measurements were conducted during different hygric seasons throughout two
years.
Seasonal variation of temperature and especially of soil moisture across the different
ecosystems resulted in distinct differences in GHG exchange. In addition environmental
parameters like soil bulk density and substrate availability varying in space strongly
influenced the GHG fluxes within sites. The results from parameterization experiments
and in situ measurements show that natural forest ecosystems and extensive land
use had higher uptakes of CH4. For the investigated forest ecosystems we found
considerable differences in soil sink strength for CH4. N2O emissions were highest in
natural forest ecosystems even though N input in the intensively managed system
was considerably higher. Highest N2O efflux rates were identified in the region of
highest mean annual precipitation. CO2 emissions reduced from managed to natural
ecosystems. In general an increase in temperature as well as in soil moisture caused
higher GHG fluxes throughout all investigated natural and managed ecosystems.
With increasing altitude of the investigated forests GHG emissions reduced overall. |
|
|
|
|
|