The Effect of Parent Material on Ectomycorrhizal Community Composition and Diversity

Abstract: Abstract Nutrient availability is one of the most important components of soil chemistry, and has Been shown to strongly impact ectomycorrhizal community composition and diversity. Phosphorous, magnesium, and potassium are important macronutrients for plant growth. Tree growth in the boreal and temperate forests is immensely dependent on their fungal mutualistic partners for their nutrition, particularly nitrogen and phosphorous. Studies have found that prolonged additions of nitrogen, sulfur and liming have altered the ectomycorrhizal community composition and diversity. In this thesis, I examined the effects of different nutrients’ availability on the ectomycorrhizal community composition and diversity by comparing the communities on three different soil types which are derived from three contrasting parent materials. The granite bedrock is poor in magnesium and rich in potassium, the serpentinite is highly rich inmagnesium and poor in potassium, and the amphibolite is fairly moderate in magnesium and rich in calcium. 798 sequences were successfully identified from 1392 ectomycorrhizal root--‐tips which were collected from soil cores. 37 OTU’s were successfully identified from the 798 successful sequences.Non--‐parametric multi--‐dimensional scaling (NMDS) demonstrated that the ectomycorrhizal community composition were not appreciably different between the granite and amphibolite but was significantly different in the serpentinite. The ectomycorrhizal community composition was slightly different between the organic and mineral horizons in the granite and amphibolite, but was markedly different in the serpentinite. Rarefaction analysis demonstrated that the granite ectomycorrhizal diversity was significantly less than serpentinite and amphibolite ectomycorrhizal diversity. In this study the distinct difference in magnesium, calcium, and potassium availability between the granite and amphibolite was not associated with any significicant difference in ectomycorrhizal community composition while the distinct difference in potassium, magnesium and phosphorous availability between the serpentinite and the other catchments was associtated with a strong effect on the ectomycorrhizal community composition in both horizons. Popular science summary: Ectomycorrhizal Fungi in the Forest Ecosystem Trees in the boreal and temperate forests are limited by nitrogen and phosphorous, in part due to the slow decomposition of organic matter. The vast majority of trees in the boreal and temperate forest form symbiotic relationships with fungi called ectomycorrhizae. Trees are dependant on fungi to colonize their roots and form this mutualistic association; they supply the fungi with carbon and the fungi supply the trees with nitrogen, phosphorous, and other nutrients. Ectomycorrhizae are a diverse group of soil fungi; they are widely distributed in soils of temperate and boreal forests and the reasons for their diversity (hundreds of fungal species can colonize the roots of one tree) are poorly understood. Three different small catchments in the Slavkov forest in the Czech republic with extremely different soil types (podzol, strangnsol, and cambisol ) were chosen to study the effect of differing nutrient availability on ectomycorrhizal community composition and diversity. These soils vary greatly in the availability of magnesium, phosphorous, potassium, and calcium. We hypothesized that these three different soils will have different ectomycorrhizal community composition and diversity. Ectomycorrhizal root-tips were taken from soil samples that were collected in the organic and mineral soil from each catchment. All the ectomycorrhizal species were identified by amplifying and sequencing the ITS1f region of the fungal DNA. The communities were compared with ordination methods, and the abundance of the most common fungi was compared with analysis of variance. Rarefaction analysis and different diversity indices were used to analyze the ectomycorrhizal diversity. The podzolic and cambisol soils had similar ectomycorrhizal community composition despite big differences in magnesium, potassium, and calcium. The strangnsol soil had a distinct community composition from the other two soils, and we believe this may be due to the much lower phosphorus availability in this soil, but it may also be due to the higher pH. Ectomycorrhizal diversity was significantly lower in the podzolic soil than in the strangnsol and cambisol soils. Adivisor: Nicholas Rosenstock Master´s Degree project 45 credits in Molecular Ecology Department of Biology, Lund University