GlobalIssuesEcolMangmntcompact4a

8/2/2019 GlobalIssuesEcolMangmntcompact4a

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Planet Earth has always been in a State of Change;

the rate of change has never been constant

Global Issues in Nematode Ecology and Management

Commonalities and Differences in Nematode Issues across the Globe

Howard Ferris

Department of Nematology

University of California Davis


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Big Issues in World Agriculture,Economy and Ecology

1. Global climate change and mitigation measures

2. Fossil fuel depletion and costs

3. Global trade agreements

4. Land ownership and land tenure

Context: the need to provide food, fiber,water, and shelter for 6.7 billion people

and their interlinkages


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Adaptation:Shifts in land-use patternsand management practices

Climate Change

Land TenureTrade Agreements

Energy Costs

Big Issues in World Agriculture,Economy and Ecology

Mitigation-slowing the process

Adaptation-minimizing the effecton services


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How are different nematode functional groups affected by climateand land-use change?

Provide Services Provide Disservices

Mitigation tradeoffs?


5/27

A simplistic analysis of climatechange effects on soil

nematodes

But.the same factors affect growth and tolerance of hosts, prey and naturalenemies of the nematodes..And management decisions of the environmental steward.

So, the net outcome is unpredictable, at least by me.

Temperature

Higher Lower

Higher +++ -+

Rainfall

Lower +- ---

Nematode winners and losers?


6/27

Thermal amplitude of bacterivores

Ferris et al., 1995We have some of the necessary information

Physiological Ecology


7/27Foley et al., Science 309, 570 -574 (2005)

A conceptual framework for comparing trade-offs on ecosystem services

But we need to think at a larger scale


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Professor Shenglei Fu, Chinese Academy of Sciences:

Mitigation - reforestation altering climateAdaptation - vegetation mixes to maximize functions and services

Services:

pulp production

wildlife habitat

pollination

refugia

erosion control

groundwater quality

carbon sequestration

decomposition

nutrient cycling

nutrient retention

mineralization

soil quality

esthetics

public education

Total area 50 ha.Each plot 1 ha.Treatments 14Replications 3

China, 2007

Landscape Ecology


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Mitigation/Adaptation: Coffee under tree shadeCosta Rica, 2008

Temperature effects

Rhizosphere interactions

Host effects

Farmscape Ecology


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Winter cover crop bell beansCalifornia, 2006

No-till soybeans, Brazil, 2006

Soil fertilityOrganic matterFood web activitySoil structure

Fossil fuel reductionHabitat conservationFood web activitySoil structure

Adaptations


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Adapted from:Meine van NoordwijkWorld Agroforestry Centre

Bogor, Indonesia

Current crops/animals

Newcrops/animals

Newcropping system

Newfarming system

Non-farminglivelihoods

Is life still possibleon this planet?

Sustainagility:Change

crops/animals

Sustainagility:Change

cropping system

Sustainagility:Changefarming system

Sustainagility:Shift to non-farming

livelihood

Sustainagility:Migration to another

region of planet

Sustainability of . . .

Soil Fauna


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Consistent N-yieldover 75 yearswithout inputN-yield similar tothat of high inputwheat

StructureIndex

BasalIndex

From Glover et al., subm.

Land-use change in Kansas:Soil food web effects

Community Ecology


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Soil Food Web: Functions and Servicesin relation to punctuated and continuous resource supply

O Pr

B

F

P

Mineralization

Reverting to prairie?

Need to understand invasion biology ofomnivores and predators

RegulationEasierto

go

in

this

direction


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Some Global Issues in Nematode Management

Nematicide tradeoffs production enhancement vs. economics, environmentalhazards and food web simplification (pesticide treadmill)

Zimbabwe, 1961

California, 1999


15/27

Ten Years After Cu Application

0

10

20

30

40

50

60

0 200 400 600 800

Cu Concentration (Kg/ha)

PredatorNe

matodes

Korthals et al., 1998

Impact on Higher Trophic Levels

California, 1973

An ideal:

Biodiversity-friendly nematicides that protect roots without killing non-target soil organisms:

immunogenic nematicides


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Global Issues in Nematode Management

Management practices in industrializedagriculture result in food websimplification cp1 and cp2

bacterivores and fungivorespredominate

Reduction in cp3, 4, 5 higher trophiclevels

Costa Rica, 2008

Farmscape Ecology


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Global Issues in Nematode Management

Nematode biomass in soil food web

Conventional

Organic

Bacterivore Biomass

Bacterivore Biomass

Herbivore Biomass

0

1

2

3

4

5

6

7

8

2 3 4 5 6 7 8 9

Ln Biomass Prey

LnBioma

ssPredators

y=-3.18+1.34x; r2=0.59, p


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What is the rhizosphereeffect of Theobromaon Musa?

molecular signals

border cells

nematodesHawes et al., 1998

Farrar et al., 2003 Hirsch et al., 2003

Molecular Ecology


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Other Nematode Services enhancing soil fertility

bacteria and bacterivore nematodes

with twenty nematodes

0 nematodes with five nematodes

Fu et al. 2005

0

20

40

60

80

100

0 5 10 20 40 80 160

Nematode Abundance

Bac

terialCells

Positive feedback Overgrazing

0

20

40

60

80

100

0 5 10 20 40 80 160

Nematode Abundance

Bac

terialCells

0

20

40

60

80

100

0 5 10 20 40 80 160

Nematode Abundance

Bac

terialCells

Positive feedback Overgrazing

An example of positive and negative feedback

Behavioral Ecology


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The Service - N mineralization

- Functional Complementarity

0

100

200

300

400

500

600

1-

Apr

8-

Apr

15-

Apr

22-

Apr

29-

Apr

6-M

ay

13-M

ay

20-M

ay

27-M

ay

3-

Jun

10-

Jun

17-

Jun

24-

Jun

1

-Jul

8

-Jul

15

-Jul

22

-Jul

29

-Jul

Mesorhabditis

Cruznema

Rhabditis

Total N

The Importanceof Biodiversity

The Service - N mineralization

- Functional Continuity

0

100

200

300

400

500600

700

800

900

1-Apr

8-Apr

15-Apr

22-Apr

29-Apr

6-May

13-May

20-May

27-May

3-Jun

10-Ju

n

17-Ju

n

24-Ju

n1-Jul

8-Jul

15-Ju

l

22-Ju

l

29-Ju

l

Mesorhabditis

Acrobeloides bod

Total N

California, 1996


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Depleted Soils of AfricaCereal Yields

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

1962

1965

1968

1971

1974

1977

1980

1983

1986

1989

1992

1995

1998

2001

2004

Mt/Ha

Developed

Countries

Asia

Developing

Latin America

& Carribean

Sub-Saharan

Africa

FAO - redrawn

Corn, cassava, beans - Congo

A

B

C

D

E

F

Crossover RotationsOostenbrink, 1959

A B C D E F

Netherlands, 1965

California, 1982


22/27

Land-use Change: TheGlobal Spread of Nematodes

Examples:Citrus Tylenchulus semipenetrans worldwideGrapevines and their nematode complexesSoybeans and Heterodera glycinesCereals and grass seeds Anguina spp.Potatoes Globodera and Meloidogyne spp.Bananas and Radopholus, Helicotylenchus, Meloidogyne ,Pratylenchus.

Most major nematode pest problems in California are caused by non-native species.

Effects of global exploration, human migration, modern transportation:Despite regulatory efforts, major crops throughout the world support the same

nematode complexes.

Some nematodeshave attributes ofinvaders:

ArrivalEstablishmentIntegration

SpreadDetection Escape

Invasion Biology


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sugarbeet cyst nematode

Sugarbeet Cyst Nematode - Heterodera schachtii

sugarbeet production


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Sources of resistanceand other control/mitigation measures should apply in newareas of production.

Caveat: consider the local acceptability of new varieties and the availability ofappropriate infrastructure/technology.

But.. Every year, we lose between 17,000 and 100,000 speciesas the result of humanactivities (The Sixth Extinction. Leakey and Lewin, 1995) That represents an enormous loss of functions, services and genes.

The problem is compounded by proprietary ownership of resistance genes andcommercialization of seed sources, reducing local selection of desirable traits.

Adaptation to Nematode Globalization and Land-use Change


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Dr. Vandana Shivas movement concerned with saving

seeds, trading seeds, farming without corporate-derivedseed.

Ghandi: You cannot monopolize this which we need for life.

Genetic diversity is a common legacy it should be conserved, not owned

Svalbard Global Seed Vault willstore three million different cropvarieties in case of a worldwide

catastrophe.

Global Issues in Nematode Ecology and Management:


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Land-use ChangeImpacts Research Activities

Changes in croppingand farming systems

Changes in nematodeassemblages andinteractions

Host status and resistance Crop rotation systems Soil food web management Biodiversity conservation Evaluation of sustainability

Optimizing Ecosystem Services

Information Gaps Research Activities Spatial and temporal diversity Scale: from molecular to

landscape

Alpha taxonomy andfunctional guilds

Functional complementarityand continuity

Intercropping,multicropping

GIS Multidisciplinary

teams Multivariate analysis Modeling

Nematode and System ManagementGoals Research Activities

Exclusion and avoidance

Host status, resistance

Cropping system design

Biological regulation

Conservation of soil

biodiversity

Molecular diagnostics Rotation experiments Food web management Sources of genes Ecological amplitudes Immunogenic

nematicides

Global Issues in Nematode Ecology and Management:Summary and Research Directions

Organismal level:Adapt knowledge frombiological models and microcosmexperiments

Farmscape and Landscape levels:Adapt management to scale ofsystem

Develop a biodiversity-friendlylandscape





Optimizing Ecosystem ServicesInformation Gaps Research Activities

Spatial and temporal diversity Scale: from molecular to

landscape





teams Multivariate analysis ModelingNematode and System Management

Goals Research Activities






biodiversity

Molecular diagnostics Rotation experiments Food web management Sources of genes Ecological amplitudes

Immunogenicnematicides

Global Issues in Nematode Ecology and Management:


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Optimizing Ecosystem Services

Information Gaps Research Activities Spatial and temporal diversity Scale: from molecular to

landscape





teams Multivariate analysis Modeling

Nematode and System ManagementGoals Research Activities






biodiversity

Molecular diagnostics Rotation experiments Food web management Sources of genes Ecological amplitudes Immunogenic

nematicides

Global Issues in Nematode Ecology and Management:Summary and Research Directions

Organismal level:Adapt knowledge frombiological models and microcosmexperiments

Farmscape and Landscape levels:Adapt management to scale ofsystemDevelop a biodiversity-friendly

landscape

Thank you

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