Transcript Nematode Faunal Indicators of Soil Food Web Condition

Bioindicators of the Soil Food Web
•maturity
•structure
•function
•resources
•stress
•recovery
•management
•assessment
Howard Ferris
Department of Nematology
University of California, Davis
[email protected]
Soil food web structure - disturbance and recovery
Effects of minor disturbance
Effects of greater disturbance
Stress
Basal condition
Basal condition - what’s missing?
Effects of Enrichment
Recovery
Maturity
Structure
Evaluation of the Soil Food Web
Structural Analysis
Complete biotic analysis: sample,
extract, identify, enumerate bacteria,
fungi, protozoa, nematodes, arthropods,
annelids, rodents…….., etc..
Indicator guilds, faunal analysis
Functional Analysis
Rates of decomposition, mineralization,
respiration, suppressiveness…….., etc..
Nematode Faunal Structure as a Soil Food Web Indicator
Herbivores
Bacterivores
Fungivores
Omnivores
Predators
Why nematodes?
•
•
•
•
•
The most abundant of the metazoa
Occupy key positions in soil food webs
Standard extraction procedures
Identification based on morphology
Clear relationship between structure and
function
• Each sample has high intrinsic information
value
Enrichment Indicators
Rhabditidae
Panagrolaimidae
etc.
Short lifecycle
Small/ Mod. body size
High fecundity
Small eggs
Dauer stages
Wide amplitude
Opportunists
Disturbed conditions
Structure Indicators
Aporcelaimidae
Nygolaimidae
etc.
Basal Fauna
Cephalobidae
Aphelenchidae,
etc.
Moderate lifecycle
Small body size
Stress tolerant
Feeding adaptations
Present in all soils
Long lifecycle
Large body size
Low fecundity
Large eggs
Stress intolerant
Narrow amplitude
Undisturbed conditions
Nematode
Guild Analysis
Structured
Basal
B
M
E
Ba1
Om4
Om5
3.2
5.0
Ca2
Ca3
Ca4
Ca5
0.8
1.8
3.2
5.0
Fu2
Fu3
Fu4
Fu5
0.8
1.8
3.2
5.0
Ba2
Ba3
Ba4
Ba5
omnivores
carnivores
3.2
cp-1
fungivores
Fu2
0.8
cp-2
bacterivores
0.8
1.8
3.2
5.0
cp-2
cp-3
cp-4
cp-5
Structure trajectory
Testable Hypotheses of Foodweb Structure and Function
•Disturbed
•N-enriched
•Low C:N
•Bacterial
•Conducive
Ba1
Enriched
Structured
Fu2
Fu2
Basal
condition
Ba2
•Maturing
•N-enriched
•Low C:N
•Bacterial
•Regulated
•Degraded
•Depleted
•High C:N
•Fungal
Basal
•Conducive
Ca3
Fu3
Ba3
Om4
Ca4
Fu4
Ba4
Structure trajectory
•Matured
•Fertile
•Mod. C:N
•Bact./Fungal
•Suppressive
Om5
Ca5
Fu5
Ba5
Basal Component:
BI = 100 x S Guild(B) x Weight(B) / S Guild(B,ES) x Weight(B,ES)
Enrichment Component:
EI =100 x S Guild(E) x Weight(E) / S Guild(B,E.) x Weight(B,E)
Structure Component:
SI = 100 x S Guild(S) x Weight(S) / S Guild(B,S) x Weight(B,S)
CON
HIGH
% Enrichment
100
LOW
ORG
50
Annual System Averages
0
0
50
% Structure
100
100
Con 1988
Con 1991
Con 1992
Con 1993
% Enrichment
Con 1994
Con 1995
Con 2000
Low 1988
Low 1991
50
Low 1992
Low 1993
Low 1994
Safflower
Low 1995
Low 2000
Org 1988
Org 1991
Org 1992
0
Org 1993
0
50
% Structure
100
Org 1994
Org 1995
Org 2000
% Enrichment
100
50
Beans
0
0
50
% Structure
100
% Enrichment
100
50
Tomatoes
0
0
50
% Structure
100
Annual crop agriculture
Cover crops and Tomatoes, California
100
Y1+C+I
Y1-C+I
Y1+W-I
Enrichment Index
Y1-C-I
Y2+C+I
Y2-C+I
50
Y2+W-I
Y2-C-I
Y3+C+I
Y3+W-I
Y3-C-I
0
0
50
Structure Index
Data from Ferris, et al
100
Annual crop agriculture
Organic Amendments, North Carolina
Enrichment Index
100
Fert
CGT
HW
50
RV
0
0
50
Data from Bulluck, et al.
Structure Index
100
Perennial tree and vine crops
California Prune Orchards
Enrichment Index
100
50
0
0
50
Structure Index
100
Forests
New Zealand Forest and Pasture
Enrichment Index
100
50
0
0
50
Structure Index
100
100
Forest soils, France
Enrichment index
Data from Armendariz and Arpin. 1996. Biol Fert. Soils
50
Fo rest clearing
Clearing with Ruscus aculeatus
Regeneratio n
Regeneratio n with Ruscus aculeatus
0
Senescent
0 with Ruscus aculeatus
Senescent
M ature
M ature with Ruscus aculeatus
50
100
Structure Index
Stressed environments
Mojave Desert, California
Enrichment Index
100
50
Rabbit Brush
Bare Soil
Creosote Bush
0
0
50
Structure Index
100
Soil contamination
Grassland/Acid Rain, Poland
Enrichment Index
100
pH 6.1
pH 4.7
50
pH 3.9
0
0
50
100
Structure Index
Dmowska (1998) in De Goede and Bongers, Nematode communities of northern
temperate grasslands
Soil contamination
Zinc Smelter, Netherlands
Enrichment Index
100
50
0
0
50
Structure Index
100
Higher resolution
Zinc smelter, Netherlands
Index Value
100
75
SI
50
CI
25
0
0
500
1000
Metals (mg/kg)
1500
2000
Primary Production System
Grassland and Pasture
Natural
Managed
Forest and Woodland
Natural
Managed
Annual Crop Agriculture
Conventional
Low-input
Organic
Perennial Crop Agriculture
Conventional
Low-input
Organic
Quadrat
Normal Food Web Condition
C
A-B
Structured
Disturbed-Structured
C
C
Structured-Stable
Structured
D-A-B
B
A-B
Degraded-Disturbed-Structured
Structured
Disturbed-Structured
B-C
C
B-C
Structured-Stable
Stable
Structured-Stable
References
Bongers, T., M. Bongers. 1998. Functional diversity of nematodes. Applied Soil
Ecology 10:239-251.
Bongers, T., H. Ferris. 1999. Nematode community structure as a bioindicator in
environmental monitoring. Trends in Ecology and Evolution 14:224-228.
Ferris, H., T. Bongers, R. G. M. de Goede. 2001. A framework for soil food web
diagnostics: extension of the nematode faunal analysis concept. Applied Soil
Ecology 18:3-29.
Ferris, H. and Bongers, T. 2009. Indices for analysis of nematode assemblages.
Chapter 5 in: "Nematodes as Environmental Bioindicators". Editors: M.J. Wilson
and T. Kakouli-Duarte. CAB International, Wallingford, UK, pp 124-145.
Ferris H. 2010. Form and function: metabolic footprints of nematodes in the soil food
web. European Journal of Soil Biology 46:97-104.
More information:
http://plpnemweb.ucdavis.edu/nemaplex