Abstract
Here we test the hypotheses that 19 years of simulated pollutant N deposition increases both losses of carbon (C) and the ability of plants to access P from organic material in upland heathland. The grass, Dactylis glomerata, and the dwarf shrub, Calluna vulgaris, were grown in soil containing microbial-derived organic matter labelled with C-14 and P-33. We found that both soil and root-surface phosphatase activity increased significantly in response to N deposition. We also found a significant positive relationship between root-surface phosphatase activity and P-33 uptake for Calluna, but a negative relationship for Dactylis. Efflux of C-14 from the microbial-derived organic matter was strongly dependent on an interaction among plant presence, plant species and N deposition. Our results show that mineralisation of C and P, and subsequent plant uptake of P from organic sources is decoupled. In our experimental conditions, stimulation of P turnover coupled with subsequent plant uptake through up-regulation of root phosphatases is little affected by N addition. However, our data indicate that root-surface phosphatases are likely to be more important for uptake of P derived from organic sources for Calluna than for Dactylis.
Original language | English |
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Pages (from-to) | 311-319 |
Number of pages | 9 |
Journal | Plant and Soil |
Volume | 326 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - Jan 2010 |
Keywords
- phosphatase
- nitrogen deposition
- heathland
- carbon mineralisation
- organic phosphorus
- P-33
- C-14
- starvation inducible metabolism
- surface phosphatase-activities
- fungus hymenoscyphus ericae
- P-31 NMR-spectroscopy
- lycopersicon-esculentum
- acid-phosphatase
- soil microbes
- biomass
- grasslands
- decomposition