Functional diversity of mycorrhiza in relation to land-use changes and ecosystem functions

Project phase 2017-2020

 

Scientific investigators:

Prof. Dr. Andrea Polle

Dr. Feng Huanying

Silke Ammerschubert

Anis M. Khokon

Bin Song

Prof. Dr. Oliver Gailing (assoc.)

Dr. Markus Müller (assoc.)

(Uni Göttingen)

The project ECTOMYC addresses species richness and ecosystem functions of ectomycorrhizal (EM) fungal assemblages.

In the current project we will analyze:

(i) uptake of nitrate and ammonium by roots of mature host trees in relation to environmental filtering and ectomycorrhizal (EM) fungal community composition

(ii) environmental and host-related factors as drivers of vertical and horizontal variation of root associated fungal (RAF) communities.

We found that soil concentrations of ammonium and nitrate differ among the Exploratories and between beech- and conifer-dominated forests and that EM exhibit differences in uptake and translocation of ammonium and nitrate. Here, we plan to study host effects and seasonality on nitrate and ammonium uptake patterns. Data on the dynamics of nitrate and ammonium in relation to biogeographic and temporal variation of EM assemblages are required for an improved understanding of ecosystem processes and the effect of management of tree composition.

We found differential host-effects on the composition of fungal guilds on conifer and beech roots. We will dissect vertical (organic layer, mineral top soil) and biogeographic variation of fungal guilds to test the hypothesis that EM assemblies show stronger vertical (niche) differentiation than other fungal guilds (saprophytic, pathogenic, endophytic fungi) and that EM diversity, but not that of other fungal guilds, is related to root traits (morphology, nutrients).

Functional diversity of mycorrhiza in relation to land-use changes and ecosystem functions

Project phase 2014-2017

 

Scientific investigators:

Prof. Dr. Andrea Polle

Silke Ammerschubert

(Uni Göttingen)

The project ECTOMYC addresses species richness and ecosystem functions of ectomycorrhizal fungi (EMF) in conjunction with their associated host. The main goal is to establish links between the intraspecific diversity of beech with the interspecific diversity of EMF and to unravel functional links between the microbial community composition and nutrient transfer between soil and plants. The specific questions we will address are:

  • Are there intraspecific differences in the field performance of the progenies from beech populations of the three Exploratories?
  • Do beech progenies from different populations attract different microbial communities?
  • Do microbe and environment x beech interactions in the mycorrhizosphere influence beech N supply via changes in the root transcriptome?

 

To investigate these questions the project ECTOMYC has established a beech transplantation experiment of 12 beech progenies planted in each of 9 forest experimental plots per Exploratory. We plan to determine the performance and beech N uptake by 15N labeling. The root and leaf-associated microbiomes will be analyzed by coordinated metagenome analyses within the Exploratories. Selected root transcriptomes will be determined and identified candidate genes for ecological traits will be validated in the root samples from 150 forest experimental plots.

 

Project phase 2011-2014

Scientific investigators:

Prof. Dr. Andrea Polle

Dr. Rodica Pena

(University Goettingen)

Goals

Model validation

Ecophysiological/mechanistic links between forest utilization and diversity of ectomycorrhizal fungi

 

Research Guiding Questions

1. Do differences in stand structure of managed and unmanaged forests influence belowground carbon allocation, thereby, affecting EMF diversity?

2. Is the taxonomic diversity of soil fungi (= potentially interacting fungi) related to the taxonomic diversity of EMF (= realized interactions)?

3. Does an increased production of root litter/material exchange as a consequence of forest utilization create new niches that foster increased EMF species richness

4. Do beech family structures affect the recruiting behaviour for EMF?

 

Methods

1. Root carbohydrate concentrations in relation to stand structure in all 150 forest EPs (Collaborations with WG Ammer and Kleinn)

2. Analysis of fungal species richness in roots by high-throughput sequencing (Collaborations with workgroups Buscot and Daniel)

3. Experimental disturbance (root detachment) and analysis of EMF in relation soil and litter nutrient composition (NO3-, NH4+, amino acids, carbohydrate)

4. Outplanting of beeches of defined family structures (Continue the collaboration with workgroup Finkeldey)

 

Project phase 2008-2011

Hypotheses

Scientific investigators

Prof. Dr. Andrea Polle

(University Göttingen)

1. EM diversity is not related to management intensity but to the intraspecific genetic structure of the host tree species and the richness of EM-building species present in the soil.

2. Host root production and their nutrient efficiency are correlated with abundance and diversity of ectomycorrhiza.

3. EM community structures affect soil properties.