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| Titel |
Fate of increased nitrogen deposition in humid sub-tropical forests in Southern China |
| VerfasserIn |
Geshere Abdisa Gurmesa, Per Gundersen, Xiankai Lu, Jiangming Mo |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250104178
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| Publikation (Nr.) |
 EGU/EGU2015-3602.pdf |
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| Zusammenfassung |
| Increased nitrogen (N) emissions from anthropogenic activities have dramatically increased
N deposition to forest ecosystems particularly in the warm and humid south-east of China.
Elevated N input may lead to eutrophication, nutrient imbalances, N leaching and soil
acidification. The effects of deposited N depend greatly on the initial status of the forest and
the fate of deposited N. However, the fate of increased N deposition is not well
understood.
In this study the objective was to quantify the retention of atmospheric N deposition in
different ecosystem compartments as well as the leaching loss from a N-rich subtropical
forest ecosystem. To this end, we investigate the fate of simulated increased N-deposition in
an old growth forest using isotopic labelling (15N). We used an on-going long-term
N-addition experiment in Dinghushan Biosphere Reserve in South China. Stable
15N-tracer in the form of 15NH415NO3was mixed with fertilizer (NH4NO3)and
sprayed to the forest floor under two different N deposition levels over one year.
Following application, the recovery of added 15N in major ecosystem pools (trees,
ground vegetation, forest floor and mineral soil) and in water fluxes was determined.
Samples were collected in June-July 2014 about three months after the last monthly
addition.
We hypothesize less recovery of 15N and lower N assimilation by trees in this N-rich
subtropical forest compared to the high recovery and retention usually observed in such
experiments performed in N-limited boreal and temperate forests. Due to the high N status
we expect the N cycle to be relatively open in this forest and that most of the deposited N to
be lost from the forest ecosystem. |
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