Stewardship of Soil Ecosystem Services (2010)

Stewardship of Soil Ecosystem Services

Howard Ferris Department of Nematology University of California, Davis November, 2010

The soil ecosystem is strongly affected by type and frequency of Carbon and Energy input

CO2

carbohydrates and proteins carbohydratesC and amino acids N

CO2

CO2

bacteria

protozoa nematodes

nematodes

nematodes other arthropods organisms fungi

fungi

NO3

Carbon and energy transfer

CO2

arthropods nematodes •Carbon is respired by all organisms in the food web Carbon and NH3 •The amounts NHof NH3 3 Energy available limit the size and activity of the web

Carbon and Energy Subsidy Effects

Prey resources

800

Input Biomass

700

Predators

600 500 400 300 200 100 0 0

50

100

150

200 Time

Infrequent (Punctuated) Resource Input

250

300

350

400

Carbon and Energy Subsidy Effects

Prey resources

800

Input Biomass

700

Predators

600 500 400 300 200 100 0 0

50

100

150

200 Time

Frequent (Continuous) Resource Input

250

300

350

400

Land-use change in Kansas

Resource Inputs: Bottom up effects on Soil Ecosystem Structure and Function Community Ecology

Structure Index From Glover et al., 2010

Basal Index

•Consistent N-yield over 75 years without input •N-yield similar to that of high input wheat

Soil Ecosystem Functions - metabolic and behavioral activities of organisms that impact the biotic or abiotic components of the ecosystem Feeding: Behavior:

Ingestion, assimilation, defecation and excretion Movement, activity, migration

Functions may be classified, subjectively, as Services, Disservices (or Neutral) Disservices: Damage plants of agricultural or ornamental significance Injure humans and vertebrate animals

Services: Sequester and redistribute minerals Individual species Mineralize organic molecules services Accelerate turnover Regulate and suppress pests Alter substrate to provide access to other organisms Redistribute organisms in space Biodegrade toxins Aggregate Reduce soil erosion Increase agricultural production ecosystem services

Management of Soil Organisms…. to enhance services and reduce disservices Provide Services

Provide Disservices

Management tradeoffs?

Soil Ecosystem – environmental effects on Structure

Standardized Counts

Nematode Sensitivity to Mineral Fertilizer

Ammonium sulfate 200

Nematode guild

150

c-p 1 c-p 2 c-p 3 c-p 4 X c-p 5

100 X 50

X X

0

0 0.02 0.05 0.1

X X 0.5

1

Concentration (mM-N)

Tenuta and Ferris, 2004

Some Ecosystem Functions

Feeding and Redistributing Organisms

Fungi exploit nematodes through:

1. traps and networks that remain attached to the hyphae. 2. spores that detach from hyphae

Behavioral Ecology

Distribution of organisms to new resources bacteria and bacterivore nematodes

0 nematodes

Bacterial Cells

100

5 nematodes Positive feedback Overgrazing

20 nematodes

80 60 40 20 0 0

5

10

20

40

Nematode Abundance Fu et al. 2005

80

160

Exploiting Ecosystem Services: The N-Mineralization Service of Bacterivore Nematodes

Taking it to the field…… Soil Ecosystem Management – an experiment

Cover crop

Cover crop

Irrigation

temperature moisture

T0 activity M0 Aug

Ferris et al., 2004

Sep

Oct

Nov

Dec

Jan

Feb

Mar

Apr

May

Complementarity NitrogenFunctional mineralization

14

N- mineralization

N (µg/g Soil)

12 10

Cruznema

6 500

2 0

A diverse functional guild of bacterivores supports….

Mesorhabditis

8 600

4

+Cephalobus -Cephalobus

Rhabditis

400

Total N

300

200 5 100

10

15

20

25

30

35

40

45

Organic Matter C:N Ratio 29-Jul

22-Jul

15-Jul

8-Jul

1-Jul

24-Jun

17-Jun

10-Jun

3-Jun

27-May

20-May

13-May

6-May

29-Apr

22-Apr

15-Apr

8-Apr

1-Apr

0

Functional Continuity N-mineralization Mesorhabditis

900 800 700 600 500 400 300 200 100 0

Acrobeloides bod

Ferris et al., 2004

29-Jul

22-Jul

15-Jul

8-Jul

1-Jul

24-Jun

17-Jun

10-Jun

3-Jun

27-May

20-May

13-May

6-May

29-Apr

22-Apr

15-Apr

8-Apr

1-Apr

Total N

Another Ecosystem Service: Regulation of Opportunistic Species Density-dependent predation

Soil Suppressiveness

100

95

90

85

80 0

0.1

0.2

Predator: Prey Ratio Predator:Prey Ratio (Density Class Averages)

Sánchez-Moreno and Ferris, 2007

0.3

Predators and prey Target Prey

Amplifiable Prey

Generalist and Specialist Predators

Soil Ecosystem Complexity and the Regulation Function Management practices in industrialized agriculture result in: Soil ecosystem simplification Reduction in higher trophic levels

We tested nematode predator:prey hypotheses with data from banana plantations in four Central American countries……….

Costa Rica, 2008

Banana Plantations - Panama

The relationships are fuzzy because…………….

Ln Predator-Target Prey Ratio

B

0 -0.5 -1 -1.5 -2 -2.5 y=-4.97+0.852 x; R2=0.33; p