Soil fungal diversity follows plant diversity across the alpine grassland ecosystems of the Tibetan Plateau

Transcription

1 LOGO Soil fungal diversity follows plant diversity across the alpine grassland ecosystems of the Tibetan Plateau Jonathan ADAMS Ex-Cranfield University, soon to be based in China!

2 With CHU Haiyan, YANG Teng, SHI Yu, et al. Yang T, Adams J, Shi Y, He JS, Jing X, Chen L, Tedersoo L, Chu H, (2017): Soil fungal diversity in natural grasslands of the Tibetan Plateau: associations with plant diversity and productivity. New Phytologist. 215(2) DOI: /nph Company Logo

3 Background Dimensions of biodiversity in the Earth mycobiome Peay et al. 2016, Nat Rev Microbiol

4 vhypothesis: More plant species should allow more fungal diversity to coexist v(more types of substrate for decay, hosts for pathogens, hosts for mutualists) vis it true? Expect to see patterns of correlation in nature Company Logo

5 Background Tedersoo et al. 2014, Science

6 v Tedersoo et al (2014) found no global scale relation between fungal and plant diversity (after removing climate, NPP) Company Logo

7 vtedersoo et al. found correlation between predicted plant productivity and fungal diversity vbut not between plant diversity and fungal diversity vbut if they had looked on a more localized scale, maybe they would have found it? Company Logo

8 Background Amazonian rainforests (alpha) Global temperate grasslands (beta) Peay et al. 2013, ISME J Prober et al. 2015, Ecol Lett

9 vwe decided to look at the relationship on Tibetan Plateau vbig enough to show significant climate and plant species diversity gradients vbut small enough not to be complicated by biogeographical barriers or distinct seasonal patterns Company Logo

10 Background China Temperature Map (Tibetan Plateau has fairly uniform temperature) Map of Tibetan Plateau Tibetan Plateau is very cold and dry.

11 Mean Annual Precip Map: Tibetan Plateau has strong aridity gradient Background

12

13 Background Hotter, drier weather and progressive urbanization are turning grasslands into sand near the headwaters of the Yellow, Yangtze and Mekong rivers. Qiu 2014, Nature The Tibetan Plateau is suffering from climate change and human activity, with a major biodiversity crisis.

14 Methods Soil sampling m 5 1m 1m 6 10m m 180 samples in 60 sites across the Plateau; within sites, three quadrats 1, 5, 9 were for soil sampling, and 2, 6,10 were for vegetation survey.

15 Methods Vegetation survey One quadrat for vegetation survey in alpine meadow (Photo from Peking University) Desert steppe ( 荒漠草原 ) Alpine steppe( 高寒草原 ) Alpine meadow ( 高寒草甸 ) The plant species table contains 172 vascular plant species, with most belonging to Grasses (45.33%) and Forbs (44.07%).

16 Methods Metadata collection as the proxy of plant productivity

17 Methods Seqs for ITS2 region Miseq PE300 platform Resulted in 11,576,489 fungal sequences covering 14,207 OTUs.

18 Results Basic fungal diversity information Taxonomic classification Functional classification Ascomycota (90.87%) was the most abundant phyla, while saprobes (30.51%) and pathogens (13.58%) were the most dominant functional guilds (FUNGUILD).

19 Results Fungal diversity trend Alpha diversity 1) Alpha diversity was significantly higher in the moister climate-vegetation zones; 2) Also Beta diversity was different between climate-vegetation zones (ADONIS P<0.05).

20 Results The diversity relationship between fungi and plants Total fungal diversity both alpha and beta diversity was related to plant species diversity of the sample quadrats.

21 Results Alpha diversity: Different functional guilds Fungal diversity Plant richness Productivity In the relationship among productivity, fungal and plant diversity for fungal guilds. Relationship to productivity is stronger, and after removing it there s no significant relation to diversity.

22 Results Structural Equation Model

23 Results SEM Integrated model a) The diversity coupling between fungi and plants is partly due to the shared environmental drivers rather than direct interactions; b) Plant richness also directly drove soil fungal richness; c) Productivity also drives fungal richness, and fungal richness also drives plant richness.

24 Overall fungal alpha and beta diversities were partly explained by plant alpha and beta diversities, respectively, (after accounting for environmental drivers and geographic distance). The best ordinary least squares (OLS) multiple regression models, partial least squares regression (PLSR) and variation partitioning analysis (VPA) indicated that plant richness was positively correlated with fungal richness. Company Logo

25 Conclusion On the Tibetan Plateau, fungal alpha and beta diversity both correlate with plant alpha and beta diversity, respectively. However, various other environmental factors correlate with similar strength with alpha/beta diversity of BOTH plants and fungi Primary productivity emerges as the strongest single predictor of diversity of both plants and fungi, but their diversity closely covaries - suggesting an additional causal link between them. Primary productivity AND plant diversity seem to be affecting fungal diversity In the relationships among productivity, fungal and plant diversity, the effect on symbiotic fungi is stronger than that of saprobes, and the weakest for that of pathogens.

26 Further possibilities: v Concentrate on the root microbiome rather than the bulk soil v Look at diversity of the microbiome of aboveground plant parts in context of plant diversity v Use experimental plots to manipulate conditions (diversity, climate) v Additional studies needed in other regions! Company Logo

27 LOGO