AMF diversity in grassland ecosystems · • Non‐linear relations between plant diversity and AMF...

Relationship between plant diversity andRelationship between plant diversity and AMF diversity in grassland ecosystems

Liang, Yug,Institute of Botany, Chinese Academy of Sciences

coolrain@ibcas ac cncoolrain@ibcas.ac.cn

Case study 1: The effects of PFG removal on yAMF diversity: intermediate disturbance 

hypothesishypothesis

Liang Y, SUN XF, Shahid Naeem, BAI YF,MA KPg , , , ,

Experimental Experimental designdesign 4 4 Plant Function Groups (PFG)Plant Function Groups (PFG)

PR(PR(perennial rhizome grass), ), PB(PB(perennial bunchgrasses), ), PF(PF( i l f b ))PF(PF(perennial forbs), ), AB(AB(annuals and biennials))

16 16 PFG combinations PFG combinations 5PFG diversity level5PFG diversity level: CK,1,2,3,4: CK,1,2,3,4 Two removal way, Complete removal Two removal way, Complete removal

and partial removal(equal disturbance and partial removal(equal disturbance p ( qp ( qremoval ) removal )

3 3 replicates (96 plots)replicates (96 plots) A i i (A i i ( AMF community in plant roots (TAMF community in plant roots (T--

RFLP)RFLP)BEF‐experimental plots established in 2005

AMF OTUs found in the BEF experimentsAMF OTUs found in the BEF experiments

• 110 sequences, 30 AMF OTUsS i h• Some species have not been found in any other sites orany other sites or studies

Species richness of AMF （complete removal）

CV （complete removal）

AMF i i h N f d PFGAMF species richness vs. No. of removed PFG16 a

8

10

12

14

ness

of A

M fu

ngi

abab ab

b

2

4

6

8

Spec

ies R

ichn

00 1 2 3 4

The number of PFGs removed (completely)

Partial removal– equal disturbance removal

S i i hSpecies richness

Species richness of AMF （Partial removal）

AMF species richness vs. No. of removed PFG

Indicator species for different PFGs‐Complete removal

Total                25.9%

Indicator species for different PFGs‐Partial removalIndicator species for different PFGs Partial removal 

Total                65.8%

Relationship between dissimilarity of plant communities andRelationship between dissimilarity of plant communities and dissimilarity of AMF community

0 1623 + 0 4944

0.75

mun

ities

y = 0.1623x + 0.4944

R2 = 0.6899

0.65

AMF comm

0.55

betw

een A

0.45

0 0.2 0.4 0.6 0.8 1 1.2milarity b

Dissimilarity between plant communitiesDissi

Effects of PFG removal on composition of AMF community

Relationship between plant richness and AMF diversity         ‐complete removal

1618

f AMF

complete removal

8101214

ichn

ess o

f

y = -0.2733x2 + 3.3946x + 0.9879R2 = 0.60550

246

Species ri

2

2.5

0 2 4 6 8 10 12 14

ex

1

1.5

2

ersity inde

y = -0.025x2 + 0.2604x + 1.201R2 = 0.759

0

0.5

0 2 4 6 8 10 12 14anno

n dive

0 2 4 6 8 10 12 14

Plant species richness

Sha

Relationship between plant richness and AMF diversity         ‐

18AMF

partial removal

10121416

hness o

f A

02468

pecies rich

2.5

00 2 4 6 8 10 12

xSp

1.5

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rsity

 index

0

0.5

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non diver

00 2 4 6 8 10 12

Plant species richness

Shan

intermediate dist rbance h pothesis is helpf lintermediate disturbance hypothesis is helpful to explain plant‐AMF relations

Complete removal Partial removal

versity

versity

AMF div

AMF di

Plant diversity Plant diversity

• The relations between AMF and plant diversity were different under two removal methods, why?

• intermediate disturbance will enhance the AMF diversity?intermediate disturbance will enhance the AMF diversity?

ConclusionsConclusionsR l f PFG ill i CV f AMF i i h• Removal of PFGs will increase CV of AMF species richness (increased beta diversity?)

• Five AMF species could act as indicator species for PFG p pcomplete removal, 10 AMF species were indicators for PFG partial removal;

• Biomass of PR and PB were important determinants of AMFBiomass of PR and PB were important determinants of AMF community composition;

• Non‐linear relations between plant diversity and AMF diversity were found in complete removal treatments but notdiversity were found in complete removal treatments, but not in partial removal treatment, indicating intermediate disturbances will enhance the AMF diversity in grassland 

tecosystems. 

Case study 2: Effects of climate changes on AMF y gdiversity in a semiarid steppe: precipitation as a 

key regulator in plant‐AMF relationskey regulator in plant AMF relations 

LIANG Y, SUN X, SU Y, et al.LIANG Y, SUN X, SU Y, et al.

EXPERIMENTAL DESIGNEXPERIMENTAL DESIGN

• Study site: grassland in north of China• Treatments:

– Warming: +2C (infrared radiator)– Increased Precipitation: +120 mm (ca 30% MAP, 15 / k i J l d A )15mm/week in July and August) 

– 3*4m plots, 6 replicatesl f d l• Sampling: in August from 2005 to 2008, roots and soil cores

• Measurements:( ) d l (– AMF Spore community (2005‐2006), intra‐radical community (2007‐

2008)– Plant community (2005‐2008)y ( )

R ltResults 

P‐

P+

P‐

P+

red, xerophytic plants (X); yellow, xeromesophytic or mesoxerophytic plants (XM‐MX); green, mesophytic plants (M)

ConclusionsConclusions • (a) increased precipitation had significant but contrary effects on• (a) increased precipitation had significant but contrary effects on 

plant‐spore and plant‐intra‐radical AMF species richness relationships;

• (b) relative coverage of grass and forb showed significantly positive and negative correlations with AMF species richness under ambient precipitation respectively while no significantunder ambient precipitation, respectively, while no significant correlations were found under increased precipitation; 

• (c) compared with grasses, forbs showed significant preferences(c) compared with grasses, forbs showed significant preferences to plots with high AMF species richness, and for plants in different water ecological types, plants with lower drought 

i t h d f t l t ith hi h AMFresistances showed more preferences to plots with high AMF species richness.