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| Titel |
Small-scale soil water repellency in pine rizhosphere associated with ectomycorrhiza is affected by nutrient patchiness: a soil microcosms study |
| VerfasserIn |
Elena Lozano, Paul Hallett, David Johnson, Lucy Moore, Jorge Mataix-Solera, Patricia Jiménez-Pinilla, Victoria Arcenegui |
| 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 |
250092580
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| Publikation (Nr.) |
 EGU/EGU2014-6935.pdf |
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| Zusammenfassung |
| Soil water repellency (SWR) or hydrophobicity has been commonly related to organic
compounds released from the roots or decomposition of different plant species (Doerr et al.,
2000). In addition, fungi and microorganisms that are associated with specific plants, could
also influence SWR through the production of exudates or cellular material that form
hydrophobic coatings on soil surfaces (Feeney et al., 2004; Hallett and Young, 1999) or act as
surfactants. Nutrient availability, microbial biomass, organic matter and specific exudates
have all been associated with the development of SWR. In terms of plant productivity,
these impacts can be significant as their interaction with pore structure changes at
the root-soil interface regulates both water transport and storage (Sperry et al.,
1998).
In boreal forests, basidiomycetous fungi are known to have a large impact on the
development of SWR. These fungi are important degraders of organic material and symbionts
forming ectomycorrhizal fungi (EF) associations with trees. Although many researchers have
suggested a strong positive impact of EF on the ability of plants to capture water from soils,
their impact on SWR at the root-soil interface and spatially within soil with a patchy nutrient
distribution has not yet been investigated. This study used microcosms with mycelia systems
of the EF extending from Pinus sylvestris host plants. Each microcosm was incubated
during 15 days and contained plastic cup with 33P under the roots. The transfer of P
from the mycelium to the host plant was monitored using a radioactive tracers and
a non-destructive electronic autoradiography system in another study (data not
published). SWR was measured using different approaches; as repellency index, R
using a microinfiltrometer with a contact radius of 0.1 mm (modified from Hallet et
al., 2002) and with the water drop penetration time test (WDPT). Sorptivity and
SWR were measured between 40-50 points/microcosms. Results obtained with both
approaches were correlated (Spearmans’ rho correlation coefficient = 0.698*). Most of
the points measured along the microcosms showed hydrophobicity. Preliminary
results indicate that the presence/absence in each point of visual roots along the
microcosms was not related with a higher hydrophobicity (P>0.05). However, the
distance from each point to the cups of 33P was significant (P |
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