Linking soil biodiversity to ecosystem functioning Influence of soil macrofauna on soil structure &...
31
Linking soil biodiversity to ecosystem functioning Influence of soil macrofauna on soil structure & erosion Pascal JOUQUET IRD / France - [email protected]
-
Upload
rhoda-griffith -
Category
Documents
-
view
216 -
download
1
Transcript of Linking soil biodiversity to ecosystem functioning Influence of soil macrofauna on soil structure &...
Linking soil biodiversity to ecosystem functioningInfluence of soil
macrofauna onsoil structure & erosion
Pascal JOUQUETIRD / France - [email protected]
Decaëns et al. 2006. EJSB
A large number of unknown speciesA large number of unknown species
A large number of unknown speciesA large number of unknown speciesperforming a large number of functionsperforming a large number of functions
Trophic functions Trophic functions
Trophic functions Trophic functions
Bioturbation functionsBioturbation functions
THE KEY SOIL BIOTURBATORSTHE KEY SOIL BIOTURBATORS
Bioturbation by soil engineers
Formation of biostructures: Biopores & Biogenic aggregates (galeries) (casts, mounds…)
Water infiltration, retention& quality Flood & erosion control
Fertility & productivityGreenhouse gas emission
Modification of soil structureHydrodynamic, SOM decomposition, nutrient cycling
Ecosystem services
Some examples of Biogenic structuresBiogenic structures
Some examples to convince you of the importance of
« SOIL ENGINEERS »
1- Effect on soil properties
C & N content
Hong et al. 2011. SBB
cast
control
Protection of fresh OM
More SOM
Clay content & quality
Jouquet et al. 2002. EJSS
Jouquet et al. 2005. BFS
1- Effect on soil properties
Soil porosity
Bottinelli et al. 2010. Geoderma
1- Effect on soil properties
Jouquet et al. 2008. Geoderma
Soil aggregate scale
Soil matrix scale
vs
Jouquet et al., 2012. Appl. Soil Ecol.
Soil, N and P loss
2- Effect on soil erosion
Jouquet et al., 2010. Catena
Loss of C
2- Effect on soil erosion
Jouquet et al. 2004. Appl. Soil Ecol.
Plant growth & diversity
3- Effect on plants
Choosai et al., 2009. Env. Conserv.
Soil macrofauna diversity
3- Effect on soil macrofauna diversity
Some examples to convince you of the importance of
« SOIL ENGINEERS »
Convinced?
And now?And now?
New research questions in soil ecology?New research questions in soil ecology?
Are soil engineers all the same?
Link between soil fauna strategy and ecosystem functioning?
Earthworms
Are soil engineers all the same?
« Dissipating processes »
RespirationDispersion of ressourcesMineralisationErosion, runoff
solS- S+
FLUXSOIL
« Organizing processes »
SOM protectionAggregation of ressourcesWater diffusionResistance to erosion
STOCK
Can these differences be explained byThe ecology of soil engineers?
Exe
rgie
(«
E »
)
(1) (2) (3)
S+
SOM mineralisationS-
SOM & nutrient protection
Improving ecosystem eco-efficiencythrough soil macrofauna stimulation?
METHODS:- Direct inoculation and/or indirect stimulation.- Externalization (vermicompost)
METHODS:- Direct inoculation and/or indirect stimulation.- Externalization (vermicompost)
Not always an easy job…
METHODS:- Direct inoculation and/or indirect stimulation.- Externalization (vermicompost)
Control Mulch + Dieldrin Mulch
Productivity+ 25 termite sp.
Mando et al., 1999, Rest. Ecol.
25 y. after
METHODS:- Direct inoculation and/or indirect stimulation.- Externalization (vermicompost)
Lepage, pers. com.
Longer but much more impressive…
METHODS:- Direct inoculation and/or indirect stimulation.- Externalization (vermicompost)
A Boom of knowledge !
An alternative to the composting method: The vermicomposting technology
N=789 articles since 1989
METHODS:- Direct inoculation and/or indirect stimulation.- Externalization (vermicompost)
Externalization and Intensification of ecological processes
A new fate for OM:more available N, stabilization, PGPM producing phytohormones
An expl ofEcological Engineering
Very different substrate…
Ngo et al. 2012. SBB
And therefore, very different SOM dynamic
Ngo et al. 2011. Ecol Engineering
Long term effect of this amendment?
Plant development
Jouquet et al. 2010. Compost Sci. Util.
Influence of vermicompost (and biochar) on:(i) Soil fertility,(ii) Exportation of N and microorganisms,(iii) Water quality
M BD C V
0
3
6
9 1st year 2nd year 3th year T
on.h
a -1
M BD C VM BD C V
AbA BCcAB
CDDEEe
Ff GgG GHh
a
cd
e f
h
Corn yield
More a trend than a generality
Doan Thu, in prep.
0
1
2
3
Cc
A Aa
D
Bb
a
M Soil To BM VC
0
4
8
12
16
A
Bc
C
a
Cc
Bb
(a)
(b)
bact
eria
g-1
(× 1
06 )vi
ruse
s g-1
(× 1
06 )
Flow of bacteria and viruses
Doan Thu, in prep.
Bacterial diversity
T0
V+
V-
C
BM
M-
M+
In soil
Fertilization > biochar
V-
BM
C
V+
M-
Ct
T0
M+
In Water
Biochar > Fertilization
Doan Thu, in prep.
Thank you for your attention
Convinced?Convinced?
Join the Soil Ecology!
I WANT YOU!
