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| Titel |
Application experiments to trace N-P interactions in forest ecosystems |
| VerfasserIn |
Jaane Krüger, Jörg Niederberger, Stefanie Schulz, Friederike Lang |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250152103
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| Publikation (Nr.) |
 EGU/EGU2017-16898.pdf |
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| Zusammenfassung |
| Phosphorus is a limited resource and there is increasing debate regarding the principles of
tight P recycling. Forest ecosystems show commonly high P use efficiencies but the processes
behind this phenomenon are still unresolved. In frame of the priority program “SPP 1685
Ecosystem nutrition - Forest strategies for limited phosphorus resources” around 70
researchers from different disciplines collaborate to unravel these processes. The
overall hypothesis to be tested is that the P nutrition strategy of forest ecosystems
at sites rich in mineral P is characterized by high P uptake efficiency (acquiring
systems). In contrast, the P strategy of forest ecosystems facing low soil P stocks is
characterized by highly efficient mechanisms of P recycling. To test this hypothesis,
we analyzed five beech forest ecosystems on silicate rock with different parent
materials representing a gradient of total P stocks (160 – 900 g P m−2, down to 1m soil
depth). In fact, we found evidence confirming our hypothesis, but controls and
drivers of P strategies are still unknown as other environmental variables differ. One
of those might be the N content, as organisms strive to reach a specific internal
N:P ratio. Thus, an additional application of N might also alter P nutrition. To test
this, we established a factorial P x N application experiment at three of the study
sites. With our presentation we will introduce this experiment and give a review on
published P x N experiments discussing different advantages and disadvantages
of different basic conditions (e.g. amount and application form, doses, sampling
and statistical design, monitoring periods, budget calculation, isotopic tracing).
Finally, we want to initiate a common discussion on the standardization of P x N
field experiments to enable interdisciplinary and across-compartment comparisons
(e.g. different land use, different climate zones, terrestrial and aquatic ecosystems). |
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