Functional diversity of mycorrhiza in relation to land-use changes and ecosystem functions Dissertation zur Erlangung des Doktorgrades "Doctor rerum naturalium" (Dr. rer. nat.) der Mathematisch-Naturwissenschaftlichen Fakultät der Georg-August-Universität Göttingen vorgelegt von Kristina Schröter (Master of Science) geboren in Kemnath Juni 2015 Referentin: Prof. Dr. Andrea Polle1 Korreferent: Prof. Dr. Rolf Daniel2 Weiteres Mitglied des Thesis Komitees: Prof. Dr. Christian Ammer3 Weitere Mitglieder des Prüfungsausschusses: PD Dr. Dirk Gansert4 Prof. Dr. Stefan Scheu5 Prof. Dr. Dirk Hölscher6 Tag der mündlichen Prüfung: 14.07.2015 1 Department of Forest Botany and Tree Physiology 2 Genomic and Applied Microbiology, 3 Department of Silviculture and Forest Ecology of the Temperate Zones 4 Göttingen Centre for Biodiversity and Ecology 5 Blumenbach Institute of Zoology and Anthropology 6 Tropical Silviculture and Forest Ecology *all from Georg-August-University Göttingen “The study of plants without their mycorrhizas is the study of artefacts. The majority of plants, strictly speaking, do not have roots; they have mycorrhizas.” BEG Committee, 25th May, 1993 (http://www.i-beg.eu/) Table of contents I Table of contents Table of contents ...................................................................................................................................... I List of abbreviations ................................................................................................................................ V Summary ................................................................................................................................................ IX Zusammenfassung ................................................................................................................................. XII 1 Introduction ..................................................................................................................................... 1 1.1 Influence of humankind on biodiversity.................................................................................. 1 1.2 Ectomycorrhiza – an important plant symbiont in temperate forests ................................... 1 1.3 Carbon supply from the host plant to the mycorrhizal partner .............................................. 3 1.4 Nitrogen as a limiting growth factor in temperate forests ..................................................... 4 1.5 Environmental factors and forest management influence fungal root and soil community .. 5 1.6 Root-associated fungal community ......................................................................................... 6 1.7 Hypothesis and aims of this thesis .......................................................................................... 6 2 Material and Methods ..................................................................................................................... 9 2.1 Study sites................................................................................................................................ 9 2.1.1 Study sites for root sampling on 150 plots .................................................................... 10 2.1.2 Study sites for Root-Trenching-Experiment .................................................................. 10 2.2 Sampling and experimental setup ......................................................................................... 10 2.2.1 Sampling and experimental setup for root sampling on 150 plots ............................... 10 2.2.2 Sampling and experimental setup for Root-Trenching-Experiment ............................. 12 2.3 Sample processing ................................................................................................................. 13 2.3.1 Sample processing for root sampling on 150 plots ....................................................... 13 2.3.2 Sample processing for Root-Trenching-Experiment ..................................................... 13 2.4 Chemical analysis of roots and soil ........................................................................................ 14 2.4.1 Root element concentrations for root sampling on 150 plots ...................................... 14 2.4.2 Carbohydrate analysis for root sampling on 150 plots ................................................. 14 2.4.3 Soil moisture for Root-Trenching-Experiment .............................................................. 14 2.4.4 pH measuerment for Root-Trenching-Experiment ....................................................... 15 2.5 Processing of roots and Morphotyping ................................................................................. 15 2.5.1 Processing of roots for root sampling on 150 plots ...................................................... 15 Table of contents II 2.5.2 Processing of roots for Root-Trenching-Experiment ..................................................... 15 2.5.3 Morphotyping ................................................................................................................ 16 2.5.4 DNA extraction, PCR amplification and ITS sequencing of morphotypes ..................... 16 2.5.5 Species and exploration type assignment ..................................................................... 17 2.6 Pyrosequencing for root sampling on 150 plots ................................................................... 17 2.6.1 DNA Extraction, sample preparation and Pyrosequencing ........................................... 17 2.6.2 Bioinformatical analysis ................................................................................................. 18 2.6.3 Sequence data deposition ............................................................................................. 19 2.7 Statistical data analysis .......................................................................................................... 19 2.7.1 Statistical data analysis for root sampling on 150 plots ................................................ 20 2.7.2 Statistical data analysis for Root-Trenching-Experiment .............................................. 21 2.7.3 Data deposition within the Biodiversity Exploratory database – BexIS ........................ 22 3 Results ........................................................................................................................................... 24 3.1 Results of characterizing the root-associated fungal community in temperate forests ....... 24 3.1.1 Sequence quality control and characterisation ............................................................. 24 3.1.2 OTU clustering and lifestyle annotation ........................................................................ 26 3.1.3 Root-associated fungi within the three Exploratories................................................... 27 3.1.3.1 Overlap of OTUs between the three Exploratories ................................................... 28 3.1.3.2 Taxonomic distribution between the three Exploratories ........................................ 30 3.1.3.3 Richness and Diversity within the three Exploratories ............................................. 39 3.1.3.4 Comparison of the fungal community structure between the three Exploratories . 43 3.1.4 Root-associated fungi on plots, dominated by different tree species .......................... 45 3.1.4.1 Overlap of OTUs between plots, dominated by different tree species..................... 45 3.1.4.2 Taxonomic distribution on plots, dominated by different tree species .................... 47 3.1.4.3 Richness and diversity on plots dominated by different tree species ...................... 57 3.1.4.4 Comparison of the fungal community structure between plots dominated by different tree species ................................................................................................................ 59 3.1.5 Relationship of fungal richness and diversity to different environmental variables .... 62 3.1.6 Relationship of fungal community structure to different environmental variables ..... 69 3.2 Results of the disturbance root trenching experiment ......................................................... 78 3.2.1 Soil properties ............................................................................................................... 78 Table of contents III 3.2.2 Mean fine root biomass ................................................................................................ 81 3.2.3 Percentage of vital tips .................................................................................................. 83 3.2.4 Mycorrhization rate ....................................................................................................... 87 3.2.5 Abundance of single species in the different treatments ............................................. 88 3.2.6 Richness and diversity of ingrowing and undisturbed roots ......................................... 91 3.2.7 EM community structure within different treatments ................................................. 96 3.2.8 Similarity between Ingrowth and Control cores ........................................................... 99 3.2.9 Functional diversity of EM community: exploration types ......................................... 103 4 Discussion .................................................................................................................................... 108 4.1 Evaluation of pyrosequencing and richness calculation method .......................................