TY  - JOUR
A1  - Buendía, Corina
A1  - Arens, Susanne
A1  - Hickler, Thomas
A1  - Higgins, Steven Ian
A1  - Porada, Philipp
A1  - Kleidon, Axel
T1  - On the potential vegetation feedbacks that enhance phosphorus availability : insights from a process-based model linking geological and ecological time scales [Discussion paper]
T2  - Biogeosciences discussions
N2  - In old and heavily weathered soils, the availability of P might be so small that the primary production of plants is limited. However, plants have evolved several mechanisms to actively take up P from the soil or mine it to overcome this limitation. These mechanisms involve the active uptake of P mediated by mycorrhiza, biotic de-occlusion through root clusters, and the biotic enhancement of weathering through root exudation. The objective of this paper is to investigate how and where these processes contribute to alleviate P limitation on primary productivity. To do so, we propose a process-based model accounting for the major processes of the carbon, water, and P cycle including chemical weathering at the global scale. We use simulation experiments to assess the relative importance of the different uptake mechanisms to alleviate P limitation on biomass production. Implementing P limitation on biomass synthesis allows the assessment of the efficiencies of biomass production across different ecosystems.
We find that active P-uptake is an essential mechanism for sustaining P availability on long time scales, whereas biotic de-occlusion might serve as a buffer on time scales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modeling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth), and that vegetation on older soils becomes P-limited leading to a smaller biomass production efficiency.
With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological time scales under different environmental settings.
Y1  - 2013
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/32975
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-329759
SN  - 1810-6277
N1  - © Author(s) 2013. This work is distributed under the Creative Commons Attribution 3.0 License.
VL  - 10
SP  - 19347
EP  - 19407
PB  - European Geosciences Union
CY  - Katlenburg-Lindau
ER  -