Perennial crop and biodiversity

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Rubber plantapon impact on biodiversity is undeniable when tree plantapon ... The impact of this land use change on soil biodiversity remains unknown.
Brauman  Alain1,  Perawatchara  Monrawee2,  Lafaye  De  Micheaux  Marin1,  Robain  H1,  Alonso  Pascal1,  Nopmanee  Suvannang2  ,  Choosai  ChuEnan3,  Sebag  David4,  Chevallier   Tiphaine5,  Trap  Jean5,  Gay  Frederic6   1  IRD,  UMR  ECO&SOLS,  Thailand,  2  Land  Development  Department,  Thailand,  3  Khon  Kaen  University,  Thailand,  4  IRD,  UMR  M2C,  France,  5  IRD–  UMR  ECO&SOLS,  France,  6  CIRAD,  UMR  

ECO&SOLS,  Kasetsart  University,  Thailand,  

Context: Perennial crop and biodiversity: a debate •  Tree  plantaEons  are  oOen  denigrated  for  their  negaEve  impact  on  natural  resources  parEcularly  loss  of  biodiversity.   •  Rubber   plantaEons   represent   the   second   world   perennial   crop   and   most   of   natural   rubber   is     produced   in   Asia   (94%   of   world   producEon).   •  Rubber  plantaEon  impact  on  biodiversity  is  undeniable  when  tree  plantaEon  encroached  natural  forests.     •  However  in  Thailand  (first  world  natural  rubber  producer),  rubber  plantaEon  oOen  replaced  intensively  managed  annual  crops   such  as  cassava.   •  The  impact  of  this    land  use  change  on  soil  biodiversity  remains  unknown.  

Objective and question of the study Ques,on  of  the  study:  What  is  the  most  important  driver  of  soil  biodiversity  

Objec,ve   Impact  of  land  use  change  (cassava-­‐>rubber  trees)  on  soil  biodiversity  

PlantaEon  age    

Land  use  changes  

Soil  type    

Methodologies A   chronosequence   containing   four   classes   of   plantaEon   ages   and   cassava   field   (the  previous  crop)  have  been  selected.     Sampling   and   field   measurements   were   realised   at   the   same   Eme   in   3   blocks   contains  a  full  sequence  of  four  age-­‐classes  of  rubber.    

•  • 

Cassava   field

cassava  

• 

Group  IV

Group  III

4-­‐6  y.  old  

1-­‐3  y.  old  

Research   site:   Thailand,   Rubber   Research   Center   (CRRC)   Chachoengsao   Province.   Tropical   climate,   1200  mm  annual  rainfall,  4  months  dry  seasons,  T°=28°C,  sandy  clay  type  soil.   Parameters   measured:   soils   physico-­‐chemical   parameters,   soil   fauna   diversity   using   TSBF   methodology   (Anderson   &   Ingham   (1993);   soil   microbial   physiological   profiles   (15   substrats)   using   MicrorespTM   techniques   (Campbell   et   al.,   2003),   microbial   diversity   using   barcoded   pyrosequencing   analysis   (454)   using   universal   primer   27F   and   518R   for   bacterial   ,   and   ITS   1F   and   ITS2   for   fungal   diversity.  

• 

Group  II

Group  I

>  23  y.  old  

6-­‐10  y.  old  

AcEvity  (µresp)   Diversity  (454)   Soil  analysis  

Soil  fauna  diversity  

Soil  microbial  diversity  

Results 7%   5%   5%  

9%   4%  

3%  

11%  

18%  

1%   4%  

2%  

2%   3%  

5%  

1%  

Canopy  closure  

14%  

4%  

64%  

57%  

49%  

18%  

59%  

5%  

9%  

5%  

7%  

3%   1%  

19%   56%  

35%  

13%  

Biomass

Cassava Legend

1-3 y

Biomass (g/m²)

35

55

75

4-6 y

8-12 y

23-25 y

Earthworms

Dipt.

Dermapt.

Isopt.

Coleopt.

Lepidopt.

Form.

Hemipt.

Diplo.

Young  planta,ons:  High   decrease  of  density  but   slight  structural  change   Old  planta,ons:  increase  of   fauna’s  biomass  and  change   of  soil  fauna  structure  at   the  canopy  closure  

Fungi  

b

Cassava

PlantaEon  age  

Cass  

60.2  

10.8      35.4            

1-3 y

Soil  proper,es  and  age  of   planta,on  are  the  main   driver  of  soil  fauna   diversity  

23y  

cellulose   2,0   1,5  

b

b

4-6 y

8-12 y

eau  

0,5   0,0  

Cassava  

7  

b

6   5  

a

4  

a

a

a

3   2   1   0  

Cassava   RP  1-­‐3   Cassava 1-3 y years  

23-2520-­‐25   y

RP  4-­‐6   4-6 y years  

RP  8-­‐12   RP  23-­‐25   8-12 y 23-25 years   years   y

PCA  analysis   R20-25y

ferr  acid  

   

glucosamine  

R8-12y R4-6y

C R1-3y

glucose  

glycine  

glutamine  

1-­‐3  y  

 23-­‐25  y  

49  %  

V-­‐Bacterial  diversity  

PCA  analysis  

100"

d=1

18%  

80"

R20-25y

C R1-3y

60"

R8-12y 40" R4-6y

20"

0"

58  %   Cassava"

1;3y"

4;6y"

8;12y"

20;25y"

"""Proteobacteria" """Firmicutes" """Ac6nobacteria" """Acidobacteria"

10y  

Biplot  of  redondancy  analysis   (RDA)  

b

malic  acid  

RelaEve  abundance  of  phyla  %    

Old  planta,ons   dominated  by  termites   and    earthworms  

II-­‐What  are  the  main  driver  of  soil  fauna  diversity  

1-­‐3y  

b

1,0  

oxalic  acid  

Young  planta,ons   dominated  by  ants    

Soil  Parameters  

a

IV-­‐Microbial  metabolic  profiles  

Soil  engineers    

5-­‐6y  

a

ab

urea  

Cass 1-3 4-6 8-12 >23

Resilience ?

ab

vanil  acid  

Cass 1-3 4-6 8-12 >23

Bacteria  

perturbation

Arach.

Cass 1-3 4-6 8-12 >23

Fields  measurements  

In  vivo  measurements  (substrate  induce  respira?on  )   Soil CO2 efflux (µmol.m-2.s-1)  

 intercropping    

11%  

1%   1%  

III-­‐  Microbial  biomass  dynamic   µg C-Co2 g-1 Soil h-1

Total density (ind/m²)

I-­‐Soil  fauna  dynamic  

Only  old  rubber  plantaEons  differs  significantly  from  cassava  fields  In  terms   of  microbial  parameters  (density,  acEvity,  structure  and  diversity)  

Variance  parEEoning  (Venn  Diagram  )  by   soil  properEes  and  age  of  plantaEon  

Conclusions

 Land  management  (pineapple  intercropping)  rather  than  land  use  changes    (cassava  to  rubber)  affects  the  density  and  acEvity  of  the  soil  fauna.   u   PlantaEon  age  and  soil  type  are  the  main  drivers  of  soil  fauna  diversity  in  rubber  plantaEons.     u   Old  rubber  plantaEons  represent  a  specific  environment  in  terms  of  soil  biodiversity  characterized  by  the  dominance  of  earthworms  and    Firmicutes.     u 

This  research  was  funded  by  the  TICA  project,  the  LMI  LUSES  and  the  French  Ins?tute  for  Natural  Rubber  (IFC)  and  the  companies  SIPH,  SOCFIN  and  MICHELIN