| dc.contributor.advisor | Polle, Andrea Prof. Dr. | |
| dc.contributor.author | Valtanen, Kerttu | |
| dc.date.accessioned | 2013-11-11T10:19:00Z | |
| dc.date.available | 2013-11-11T10:19:00Z | |
| dc.date.issued | 2013-11-11 | |
| dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-0001-BC3D-6 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-4142 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | |
| dc.subject.ddc | 333 | de |
| dc.subject.ddc | 577 | de |
| dc.title | Functional diversity of mycorrhizal fungi with regard to nutrient transfer | de |
| dc.type | doctoralThesis | de |
| dc.contributor.referee | Polle, Andrea Prof. Dr. | |
| dc.date.examination | 2012-12-18 | |
| dc.description.abstracteng | Mycorrhizal associations of tree species are important drivers of plant belowground interactions. The main objective of this study was to investigate the contribution of mycorrhizal fungi on plant competition for nutrients. Another goal of the present study was to determine nutrient and carbon fluxes between trees, and soil food web via mycorrhizal fungi.
The influence of interspecific interactions on N and P acquisition of ash (Fraxinus excelsior) and beech was analysed in nutrient limited conditions. Beech and ash saplings were grown in conspecific and heterospecific pairs and labelled with nutrient solution containing 6.27 ng ³³PH333PO4 (3.7 MBq) and 4 mM 15NH415NO3. The growth of beech was not influenced by the species identity of the neighbouring tree, whereas the height growth of ash decreased in the presence of beech. Beech was also neutral to interspecific competition for nutrients, whereas ash shifted to increased deprivation of N and P in the presence of beech.
The N and P accumulation was higher in EM root tips than in vital ash roots and non-mycorrhizal beech roots. Non-mycorrhizal beech root tips accumulated 1.2 times less N and 4.2 times less P than mycorrhizal root tips. Vital ash fine root tips accumulated 2.3 times less N and 6.7 times less P than mycorrhizal beech root tips. The N and P concentrations of beech fine roots and mycorrhizal root tips were positively correlated.
Differences in N and P accumulation of EM species demonstrated the functional diversity within beech roots colonizing EM community. The most abundant EM species Tomentella castanea and Sebacina sp. (81.7 % mono; 89.2% mix) had high P and N accumulation.
The ability of tree species to use organic N and carbon (C) was examined using 15N and 13C enriched litter in double-split-root rhizotrons planted with ash and beech saplings (Chapter 4). Nitrogen uptake from litter was documented in both ash and beech. No C from organic origin was detected in fine roots or other plant tissues after 475 days of incubation. Although beech root biomass was significantly lower than that of ash only beech decreased soil carbon and nitrogen concentrations significantly. These results suggest that trees, which are colonized by mycorrhizal fungi, use organic nutrient sources. However, the allocation of C is presumably unidirectional, namely from plant to fungus.
In another experiment we demonstrated that when the allocation carbon from photoassimilates was inhibited through girdling, EM was supplied from root carbon storages (Appendix, Chapter 6).
The path of plant derived C via EM fungi to soil food web was analyzed using 15NO315NH4 and 13CO2 labelling. Beech saplings from Hainich national park were removed with intact soil cores in order to maintain intact soil community and labelled for five months in a green house. The highest concentrations of 13C and 15N were found in mycorrhizal root tips. The strong relation of 15N in EM root tips and adjacent fine root demonstrated that 15N taken up by the EM fungus was mainly transported to host plant. The results demonstrated that mycorrhizal structures are an important nutrient source for soil animals and a considerable channel of plant C into soil food web.
Based on the present results, the interactions between beech and ash are suggested to be driven mainly by effects of beech and associated EM fungi. It can be concluded that abundant root colonizing EM fungi significantly contribute to N and P nutrition of beech.
| de |
| dc.contributor.coReferee | Leuschner, Christoph Prof. Dr. | |
| dc.subject.eng | Mycorrhizal fungi, nutrient transfer, Fagus sylvatica, Fraxinus excelsior, nitrogen, phosphorus, isotope labelling | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-11858/00-1735-0000-0001-BC3D-6-9 | |
| dc.affiliation.institute | Göttinger Zentrum für Biodiversitätsforschung und Ökologie (GZBÖ) | de |
| dc.subject.gokfull | Ökologie {Biologie} (PPN619463619) | de |
| dc.identifier.ppn | 771123671 | |