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| Titel |
Contribution of aboveground plant respiration to carbon cycling in a Bornean tropical rainforet |
| VerfasserIn |
Ayumi Katayama, Kenzo Tanaka, Tomoaki Ichie, Tomonori Kume, Kazuho Matsumoto, Mizue Ohashi, Tomo'omi Kumagai |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250088998
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| Publikation (Nr.) |
 EGU/EGU2014-3179.pdf |
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| Zusammenfassung |
| Bornean tropical rainforests have a different characteristic from Amazonian tropical
rainforests, that is, larger aboveground biomass caused by higher stand density of large trees.
Larger biomass may cause different carbon cycling and allocation pattern. However, there are
fewer studies on carbon allocation and each component in Bornean tropical rainforests,
especially for aboveground plant respiration, compared to Amazonian forests. In this study,
we measured woody tissue respiration and leaf respiration, and estimated those in ecosystem
scale in a Bornean tropical rainforest. Then, we examined carbon allocation using the data of
soil respiration and aboveground net primary production obtained from our previous studies.
Woody tissue respiration rate was positively correlated with diameter at breast height (dbh)
and stem growth rate. Using the relationships and biomass data, we estimated woody tissue
respiration in ecosystem scale though methods of scaling resulted in different estimates
values (4.52 – 9.33 MgC ha-1 yr-1). Woody tissue respiration based on surface
area (8.88 MgC ha-1 yr-1) was larger than those in Amazon because of large
aboveground biomass (563.0 Mg ha-1). Leaf respiration rate was positively correlated
with height. Using the relationship and leaf area density data at each 5-m height,
leaf respiration in ecosystem scale was estimated (9.46 MgC ha-1 yr-1), which
was similar to those in Amazon because of comparable LAI (5.8 m2 m-2). Gross
primary production estimated from biometric measurements (44.81 MgC ha-1 yr-1)
was much higher than those in Amazon, and more carbon was allocated to woody
tissue respiration and total belowground carbon flux. Large tree with dbh > 60cm
accounted for about half of aboveground biomass and aboveground biomass increment.
Soil respiration was also related to position of large trees, resulting in high soil
respiration rate in this study site. Photosynthesis ability of top canopy for large trees
was high and leaves for the large trees accounted for 30% of total, which can lead
high GPP. These results suggest that large trees play considerable role in carbon
cycling and make a distinctive carbon allocation in the Bornean tropical rainforest. |
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