earthworm ecology, annelida ecology, ecologia lombriz de tierra

SECOND EDITION

EarthwormEcology

2004 by CRC Press LLC

SECOND EDITION

Clive A. Edwards

EarthwormEcology

CRC PR ESSBoca Raton London New York Washington, D.C.

Edited by


Preface


About the Editor


Contributors


Table of Contents

Part I

Introduction ......................................................................................................................................1

Part II

Earthworm Taxonomy, Diversity, and Biogeography.................................................................51

Part III

Earthworm Biology, Ecology, Behavior, and Physiology............................................................89


Part IV

Influence of Earthworms on Soil Organic Matter Dynamics, Nutrient Dynamics, and Microbial Ecology .................................................................................................................143

Part V

Effects of Earthworms on Soil Physical Properties and Function..........................................181

Part VI

Interactions of Earthworms with Microorganisms, Invertebrates, and Plants......................211

Part VII

Earthworms in Agroecosystems..................................................................................................261


Part VIII

Earthworms and Environmental Pollution ...............................................................................297

Part IX

Earthworms in Waste Management ...........................................................................................343


Part I

Introduction


3

1

The Importance of Earthworms as Key Representatives of the Soil Fauna

Clive A. Edwards

Soil Ecology Laboratory, The Ohio State University, Columbus, Ohio, U.S.A.

CONTENTS

HISTORY


4

Earthworm Ecology, Second Edition

EARTHWORM TAXONOMY

EARTHWORM ECOLOGY



5

EARTHWORMS AND SOIL FERTILITY

S

OIL

F

ORMATION


6


T

URNOVER

OF

S

OIL

S

OIL

A

ERATION

AND

D

RAINAGE

O

RGANIC

M

ATTER

B

REAKDOWN

AND

I

NCORPORATION

INTO

S

OIL



7

N

UTRIENT

A

VAILABILITY

EFFECTS OF AGRICULTURE ON EARTHWORMS


8


EARTHWORMS AS INDICATORS OF SOIL QUALITY AND HEALTH

EARTHWORMS AND SOIL POLLUTION



9

EARTHWORM IMMIGRATIONS

NEED FOR EARTHWORM RESEARCH

CONCLUSIONS

REFERENCES


10


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11

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13

2

How Earthworms Affect Plant Growth: Burrowing into the Mechanisms

George G. Brown

Embrapa Soja, Londrina, Brazil

Clive A. Edwards

Soil Ecology Laboratory, The Ohio State University, Columbus, OH, U.S.A.

Lijbert Brussaard

Soil Quality Section, Wageningen University, Wageningen, The Netherlands


CONTENTS

14


EFFECTS OF EARTHWORM ON PLANTS: THE HISTORY



15

E

ARTHWORMS

AND

P

LANT

P

RODUCTION

IN

THE

T

ROPICS


16


FIGURE 2.1

In 75% of cases, earthworms affected plant biomass positively

In 43% of cases,increase was >20%

100 to 200%(9%)

60 to 100%(6%)

20 to 60%(21%)

0 to 20%(33%)

200 to 300%(5%)

>300%(2%)

100 to 60%(0.4%)

60 to 20%(4%)

20 to 0%(20%)

Region ofgenerally non-significanteffects (withlittle short-termimportance butwith possiblecumulativeimportance)



17

THE MECHANISMS BY WHICH EARTHWORMS AFFECT PLANT GROWTH: A CONCEPTUAL BACKGROUND

T

YPES

AND

M

ODES

OF

I

NTERACTION

S

PATIAL

AND

T

EMPORAL

S

CALES

OF

E

ARTHWORM

A

CTION


18


W

HY

F

OCUS

ON

E

FFECTS

OF

E

ARTHWORMS

ON

P

LANT

R

OOTS

?

THE SEVEN MAIN MECHANISMS BY WHICH EARTHWORMS AFFECT PLANTS



19

1. D

ISPERSAL

AND

C

HANGES

IN

P

OPULATIONS

AND

A

CTIVITIES

OF

B

ENEFICIAL

M

ICROORGANISMS

FIGURE 2.2

OTHER ORGANIC MATTERSOURCES

ORGANICMATTER

CASTINGSEARTHWORMS

Nutrientabsorption

Rhizo-deposition

Excretions,secretions,dead tissue

MICROBIALPOPULATIONSand ACTIVITY

H2O and aircirculation

Better rootpenetration

BURROWS

SOIL

PLANT


20


TABLE 2.1The Seven Main Mechanisms by Which Earthworms Affect Plant (Mostly Root) Growth either Directly or Indirectly through Physicochemical or Biological Changes to the Soil Environment

Mechanism Category (Type)

Mechanism Mode Biological Physical Chemical

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21

FIGURE 2.3

Earthwormfeeding

Beneficial plant-growth promoting (PGP), facultative, or obligatorypathogenic rhizosphere microorganisms

Time

Root growthand development

Soil/rootingenvironment

Earthworm burrowingand casting


22


FIGURE 2.4


How Earthworms Affect Plant Growth: Burrowing into the Mechanisms 23

2. CHANGES IN POPULATIONS AND IMPACTS OF PLANT PESTS, PARASITES, AND PATHOGENS

Potential Role of Earthworms in the Reduction of Plant Disease and Pest Problems

fi


24 Earthworm Ecology, Second Edition



Potential Role of Earthworms in Increasing Plant Disease or Pest Problems

3. EARTHWORMS AND PLANT GROWTH-REGULATING AND GROWTH-INFLUENCING SUBSTANCES



4. ROOT ABRASION AND INGESTION OF LIVING PLANT PARTS BY EARTHWORMS



5. INTERACTIONS OF EARTHWORMS WITH SEEDS

6. CHANGES IN SOIL STRUCTURE CAUSED BY EARTHWORMS



Earthworm Casts

FIGURE 2.5

Earthworms

Root penetration and growth

Micropores< 0.2 m

Mesopores0.2 to 30 m

Water-holdingcapacity

Infiltrability,aeration

Macropores>30 m

Soil structure(pore size distribution

and aggregate stability)

Soil physical functions

Casting Burrowing



FIGURE 2.6



Earthworm Burrows




7. CHANGES IN NUTRIENT SPATIOTEMPORAL AVAILABILITY CAUSED BY EARTHWORMS


FIGURE 2.7

Mineral soil+

OM (food) inputs

comminution

(Bio)chemicalbreakdown

Physicalbreakdown

Mucus, enzymeproduction,pH changes

GAPs(grinding ingizzard,microbialactivity)

CAPs(microbialactivity andsoil chemicalchanges)

Fresh casts

Aging casts

Plant nutrient spatio-temporal availability

Root growth anddevelopment

Nutrientprotection

NutrientreleaseBreakdown

Compact Decompact



Nutrients from Earthworms (Death, Excretion)

CRAWLING FORWARD: THE CHALLENGE OF IDENTIFYING AND QUANTIFYING THE POTENTIAL OF EARTHWORMS TO

INCREASE PLANT GROWTH



ALL-MINUS-ONE TESTS AND FIELD TRIALS

f



THE EARTHWORM THRESHOLD CONCEPT

FUTURE NEEDS IN EARTHWORM RESEARCH



ACKNOWLEDGMENTS

REFERENCES



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Part II

Earthworm Taxonomy, Diversity, and Biogeography


53

3

Planetary Processes and Their

Distributions and Ecology

Samuel W. James

Department of Life Sciences, Maharishi University of Management, Fairfield, Iowa, U.S.A.

CONTENTS


Interactions with Earthworm

54


PLATE TECTONICS AND EARTHWORM PHYLOGENY


Planetary Processes and Their Interactions with Earthworm Distributions and Ecology

55

FIGURE 3.1


Meg

asco

leci

dae

Aca

ntho

drili

dae

Ocn

erod

rilid

ae

othe

r Lum

bric

oida

e

Hor

mog

astri

dae

Lum

bric

idae

Mic

roch

aetid

ae

Eud

rilid

ae

Glo

ssos

cole

cida

e

other Clitellata*

56


APPLICATIONS OF EARTHWORM BIOGEOGRAPHY TO THE EARTHS HISTORY



57


58


HOW THE EARTHS HISTORY AFFECTS EARTHWORM DISTRIBUTIONS



59


60




61

REFERENCES


62



63

4

The Status of Earthworm Biogeography, Diversity, and Taxonomy in North America Revisited with Glimpses into the Future

John W. Reynolds

Oligochaetology Laboratory, Kitchener, Ontario, Canada

CONTENTS

INTRODUCTION

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64



The Status of Earthworm Biogeography, Diversity, and Taxonomy in North America

65

EARTHWORM BIOGEOGRAPHY, DIVERSITY, AND TAXONOMY

B

IOGEOGRAPHY

North America

Canada

United States


66


TABLE 4.1Regional Earthworm Surveys in North America

RegionNumber of

Species

Number of Units (%) Surveyed Ref.



67

Other Countries

D

IVERSITY

T

AXONOMY


68


PRESENTATIONS AT THE INTERNATIONAL EARTHWORM ECOLOGY SYMPOSIA



69

FUTURE TRENDS AND RESEARCH IMPERATIVES IN EARTHWORM TAXONOMY

T

RAINING

OF

E

ARTHWORM

T

AXONOMISTS

E

ARTHWORM

P

ARTHENOGENESIS

AND

E

FFECTS

ON

T

AXONOMY

E

ARTHWORM

S

URVEYS


70


E

ARTHWORM

L

IFE

H

ISTORIES

M

ODERN

E

ARTHWORM

T

ECHNIQUES

E

ARTHWORMS

FOR

E

NVIRONMENTAL

M

ONITORING

P

LAIN

L

ANGUAGE

AND

L

ESS

E

SOTERY


USE OF EARTHWORMS FOR WASTE MANAGEMENT

The Status of Earthworm Biogeography, Diversity, and Taxonomy in North America 71

REFERENCES


The Status of Earthworm Biogeography, Diversity, and Taxonomy in North America 73


75

5

Invasion of Exotic Earthworms into North America and Other Regions

Samuel W. James

Department of Life Sciences, Maharishi University of Management, Fairfield, Iowa, U.S.A.

Paul F. Hendrix

Institute of Ecology and Department of Crop and Soil Sciences, University of Georgia, Athens, Georgia, U.S.A.

CONTENTS

INTRODUCTION


76




77

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CRITERIA OF EXOTIC EARTHWORM


78


CHARACTERISTICS OF EARTHWORMS THATMAKE THEM INVASIVE



79

MECHANISMS OF EARTHWORM INVASION AND THE DYNAMICS OF INVADING POPULATIONS


80


fi

HOW DO INVASIVE EARTHWORMS INTERACT WITH NATIVE EARTHWORMS?



81

HOW DO INVASIVE EARTHWORMS INTERACT WITH OTHER ORGANISMS?


82


EFFECTS OF EXOTIC EARTHWORMS INVASIONS ONECOSYSTEM PROCESSES



83

WHAT CAN BE DONE ABOUT EXOTIC EARTHWORM INVASIONS?


84


FIGURE 5.1

INITIALSTATE

"Pristine" System(Native Earthworms

Exclusively)ModerateB

Severe

MinimalC

A

Disturbance

Native EarthwormsEliminated

Native EarthwormsDiminished

Native EarthwormsExclusively

INTERMEDIATESTATE

Successful

Successful

Successful?

Successful?

Unsuccessful

2

1

1

2

Exotic InvasionCURRENT

STATE

ExoticEarthwormsExclusively

Native and ExoticEarthwormsCoexisting

NativeEarthwormsExclusively



85


86


ACKNOWLEDGMENTS

REFERENCES



87


Part III

Earthworm Biology, Ecology, Behavior, and Physiology


91

6

Factors Affecting the Abundance of Earthworms in Soils

James P. Curry

Department of Environmental Resource Management, University College, Belfield, Dublin, Ireland

CONTENTS

INTRODUCTION


92


CLIMATE



93

SOIL PROPERTIES


94


FOOD



95

TABLE 6.1Earthworm Tissue Production in Relation to Food (mg fresh mass g

1

dry mass)

Lumbricus terrestris

Aporrectodea caliginosa

Mixed spp.

TABLE 6.2Earthworm Growth Rates in Peat/Mineral Soil Cultures under Different Feeding Regimes (mg ind

1

d

1

SE)

Lumbricus terrestris n

Aporrectodea caliginosa n


96


TABLE 6.3Tissue Production and Nitrogen Requirements of an Earthworm Population in a Winter Cereal Field

1988 1989 1990



97

TABLE 6.4Food Requirement and Supply for the Earthworm Population in a Winter Cereal Field

g DM m

2

g N m

2a


98


COMPETITION



99

PREDATION



PARASITISM AND DISEASE

LAND MANAGEMENT


Factors Affecting the Abundance of Earthworms in Soils 101

MINING AND INDUSTRIAL WASTES



DEFORESTATION

AFFORESTATION



GRASSLAND MANAGEMENT

ARABLE CROPPING



FIGURE 6.1

A B

C D

200

150

100

50

0

200

150

100

50

0

120

100

80

60

40

20

0

120

100

80

60

40

20

0

0 0.5 1.0 1.5 2.0 2.5 3.0

0 0.5 1.0 1.5 2.0 2.5 3.0

0 100 200 300 400

0 100 200 300 400

Stocking rate (LU ha1) Mineral nitrogen input (kg N ha1)

Mineral nitrogen input (kg N ha1)

Ane

cic

eart

hwor

m b

iom

ass

(g m

2)

Tot

al e

arth

wor

m b

iom

ass

(g m

2)

Tot

al e

arth

wor

m b

iom

ass

(g m

2)

Ane

cic

eart

hwor

m b

iom

ass

(g m

2)

Stocking rate (LU ha1)



MANURES AND FERTILIZERS

FIGURE 6.2


Conventional wheat

Direct-drilled wheat

Direct-drilled wheat with white clover

Conventional wheat

Direct-drilled wheat

Direct-drilled wheat with white clover

Autumn 1995 Spring 1996 Autumn 1997

Ear

thw

orm

num

bers

(indi

vidu

als

m2

)E

arth

wor

m b

iom

ass

(g m

2)

800

600

400

200

0

300

200

100

0


PESTICIDES AND POLLUTANTS

SOIL WATER MANAGEMENT



CONCLUSIONS



REFERENCES



fl

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115

7

A Comprehensive Study of the Taxonomy and Ecology of the Lumbricid Earthworm Genus

Octodrilus

from the Carpathians

Victor V. Pop and Adriana A. Pop

Institute of Biological Research, Cluj-Napoca, Romania

CONTENTS


116



A Comprehensive Study of the Taxonomy and Ecology of the Lumbricid Earthworm

117

TABL

E 7.

1Th

e

Oct

odri

lus

Spec

ies

from

the

Sou

thea

ster

n an

d Ea

ster

n C

arpa

thia

ns

Oct

odri

lus

(

Om

odeo

195

6)M

ale

Pore

sSp

erm

athe

cae

Tube

rcul

a pu

bert

atis

Clit

ellu

mSe

gmen

tsTy

phlo

sole

en

dig

Leng

th

(mm

)D

iam

eter

(m

m)

2

004

by C

RC

Pre

ss L

LC

118


THE CARPATHIANS

TAXONOMY OF THE LUMBRICID GENUS

OCTODRILUS

FIGURE 7.1



119

V

ARIABILITY

OF

C

HARACTERS


FIGURE 7.2

120


T

AXA

D

ISCRIMINATION

AND

I

DENTIFICATION

OF

O

CTODRILUS

S

PECIES

BY

N

UMERICAL

T

AXONOMY

FIGURE 7.3



121

FIGURE 7.4


Tubercula pubertatis

30

38

39

39

29

37

40

90111

116136

72120

88118

125158

125152

140162

122


MOLECULAR TAXONOMY AND PHYLOGENY OF THE OCTODRILUS SPECIES

RESULTS

16S rDNA Sequences


A Comprehensive Study of the Taxonomy and Ecology of the Lumbricid Earthworm 123

COI Gene Sequences

TABLE 7.2Nucleotide Structure of 16S rDNA and Cytochrome c Oxidase Sequences in Octodrilus Species

16S COI

Octodrilus Species GC% AT% GC/AT bp GC% AT% GC/AT

FIGURE 7.5

Biomphalaria

O. exacystis

O. compromissus

O. aporus

O. permagnus

O. frivaldszkyi

O. b. bihariensis

O. b. rendzinicola



Discussion

FIGURE 7.6

Biomphalaria

O. frivaldszkyi

O. compromissus

O. b. bihariensis

O. b. rendzinicola

O. exacystis

O. aporus

O. permagnus



INSULARLIKE ACCELERATED SPECIATION IN OCTODRILUS IN THE CARPATHIANS

ECOLOGY OF THE GENUS OCTODRILUS

EARTHWORM COMMUNITIES DOMINATED BY OCTODRILUS SPECIES



FIGURE 7.7

1 2 3 4 5 6 7 8 9 10

0 010 10.120 20.140 40.160 60.1100

Dominance %

B.P., Brown podzolic soil; B.E., Brown earth; A.B., Acid brown soil; B.F., Brown forest soil.

VegetationSoilSiteS p e c i e s

Oak

Bee

ch

Hor

nbea

m

Bee

ch

Fir +

bee

chFi

r

B.P. B.E. A.B. B.F. B.P.

Allolobophora caliginosa (Savigny, 1826)Allolobophora dacica (Pop, 1938)Allolobophora georgii Michaelsen, 1890Allolobophora mehadiensis Rosa, 1895Allolobophora rosea (Savigny, 1826)Dendrobaena alpina (Rosa, 1884)Dendrobaena byblica (Rosa, 1893)Dendrobaena clujensis Pop, 1938Dendrobaena octaedra (Savigny, 1826)Dendrobaenarubida (Savigny, 1826)Fitzingeria platyura Fitzinger, 1833Lumbricus polyphemus (Fitzinger, 1883)Lumbricus rubellus Hoffmeister, 1843Octolasion lacteum rley, 1885Octodrilus c. compromissus Zicsi & V. V. Pop, 1984Octodrilus exacystis exacystis (Rosa, 1896)Octodrilus e. oresbius V. V. Pop, 1989



fl

FIGURE 7.8

Allolobophora dacica (Pop, 1938)Allolobophora georgii Michaelsen, 1895Allolobophora rosea (Savigny, 1826)Dendrobaena alpina (Rosa, 1884)Dendrobaena byblica (Rosa, 1893)Dendrobaena clujensis Pop, 1938Dendrobaena rubida (Savigny, 1826)Lumbricus polyphemus (Fitzinger, 1883)Lumbricus rubellus Hoffmeister, 1843Octolasion lacteum (rley, 1885)Octodrilus aporus V. V. Pop, 1989Octodrilus bihariensis V. V. Pop, 1989Octodrilus compromissus Zicsi & V. V. Pop, 1984Octodrilus exacystis (Rosa, 1896)Octodrilus frivaldszkyi (rley, 1880)Octodrilus ophiomorphus V. V. Pop, 1989Octodrilus permagnus V. V. Pop, 1989

S p e c i e sSoilSite 1 2 3 4 5 6 7 8 9 10

R T.R. B.E. P.B.


SEASONAL DYNAMICS OF EARTHWORM COMMUNITIES WITH OCTODRILUS FRIVALDSZKYI


Site

Methods

FIGURE 7.9

0 010 10.120 20.140 40.160 60.1100

Dominance %

T.R., Terra rossa. E.B.E., Brown earth. C.A., Colluvialalluvial.

S p e c i e s

Soil

Site 1 2 3 4 5

T.R. E.B.E. C.A.

Allolobophora caliginosa (Savigny, 1826)Allolobophora dacica (Pop, 1938)Allolobophorarosea (Savigny, 1826)Dendrobaena byblica (Rosa, 1893)Dendrobaena clujensis Pop, 1938Dendrobaena rubida (Savigny, 1826)Lumbricus polyphemus (Fitzinger, 1883)Lumbricus rubellus Hoffmeister, 1843Octolasion lacteum rley, 1885Octodrilus b. bihariensis V. V. Pop, 1989Octodrilus b. rendzinicola V. V. Pop, 1989Octodrilus c. compromissus Zicsi & V. V. Pop, 1984Octodrilus e. exacystis Rosa, 1896Octodrilus e. oresbius V. V. Pop, 1989



Microclimatic Dynamics

Seasonal Dynamics of the Earthworm Community

FIGURE 7.10

AIRA 05 cmA 510 cmA 1015 cm

OLHFA 05 cmA 510 cmA 1015 cm

May June July Aug. Sept. Oct. 1979

May June July Aug. Sept. Oct.

Tem

pera

ture

C

02468

1012141618

Moi

stur

e %

0

50

100

150

200

250

300



THE ROLE OF GIANT OCTODRILUS SPECIES IN BUILDING UP VERMIC (EARTHWORM-BASED) CHARACTERS IN

MOUNTAIN SOILS

TABLE 7.3Characters of the Lumbricid Species in the Beech Forest from Padis (the Apuseni Mountains) with Ecological Significance

Character Species PigmentLength (mm)

Diameter (mm)

Fresh Weight (g)

Ecologic Category



FIGURE 7.11

0

20

40

60

80

100

% 120

N*m2

g*m2

01020304050607080





Total density

% 100

0102030405060708090

O. bihariensisO. frivaldszkyi

Octodrilus unident. juv.D. alpina

D. byblica

D. clujensis

0

50

100

150

200

250

300

Total biomass

O. bihariensis

O. frivaldszkyi

Octodrilus unident. juv.D. alpinaD. byblicaD. clujensis



FIGURE 7.12

N*m2


D. clujensis

O. frivaldszkyi

Octodrilus unident. juv.

D. alpina

D. byblica

O. bihariensis

Total density

0

20

40

60

80

100

0

2

4

6

8

0

5

10

15

05

1015202530

0

5

10

15

0

5

10

15

20

0

5

10

15

20



FIGURE 7.13

0

100

200

300

400

0

10

20

30

40

050

100150200250300

0

10

20

30

40

0

0.1

0.2

0.3

0.4

0

1

2

3

4

05

10152025


Total biomass

g*m 2

O. bihariensis

O. frivaldszkyi

Octodrilus unident. juv.

D. alpina

D. byblica

D. clujensis



THE EARTHWORM COMMUNITIES

TABLE 7.4Yearly Mean Biomass and Monthly Mean Range of Earthworm Communities in Three Forest Ecosystems from the Apuseni Mountains (MayOctober 1979) (g m2 earthworms preserved in formalin)

Ecosystem Species Mean Minimum Maximum



MORPHOLOGY AND MICROMORPHOLOGY OF SOIL PROFILES

TABLE 7.5Proportion of Total Density (D%) and Biomass (B%) of Lumbricid Species in Three Soil Types with Vermic Characters from the Carpathians

Cambic Rendzina, Padis, August 16, 1979

Brown Earth, Buces Vulcan,June 6, 1972

Podzolic Brown, Abrud, June 12, 1992

Species D% B% D% B% D% B%



PHYSICAL AND CHEMICAL PROPERTIES OF VERMIC SOILS

FIGURE 7.14



FIGURE 7.15



EXPERIMENTAL STUDY OF THE INFLUENCE OF CALCOPHILOUS OCTODRILUS SPECIES ON SOIL

Material and Methods



Results

CONSERVATION OF THE ENDEMIC OCTODRILUS SPECIES IN THE CARPATHIANS

EFFECTS OF AIR POLLUTION ON EARTHWORMS



EFFECTS OF SYLVICULTURAL CUTTING ON ENDEMIC EARTHWORMS

ACKNOWLEDGMENTS

REFERENCES



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Part IV

Influence of Earthworms on Soil Organic Matter Dynamics, Nutrient Dynamics, and Microbial Ecology


145

8

Effects of Earthworms on Soil Organic Matter and Nutrient Dynamics at a Landscape Scale over Decades

Patrick Lavelle,

1

Fabienne Charpentier,

1

Ccile Villenave,

1

Jean-Pierre Rossi,

1

Laurent Derouard,

1

Beto Pashanasi,

2

Jean Andre,

3

Jean-Franois Ponge,

4

and Nicolas Bernier

4

1

Laboratoire dEcologie des Sols Tropicaux,

Bondy Cedex, France;

2

Estacion Experimental San Ramon, INIAA, Yurimaguas, Loreto, Peru;

3

Universit de Savoie, France;

4

MNHN, Brunoy, France

CONTENTS


146


EARTHWORMS AND SOIL FUNCTION: THE DRILOSPHERE CONCEPT


Effects of Earthworms on Soil Organic Matter and Nurient Dynamics

147

FIGURE 8.1

FIGURE 8.2

Interactionswith microflora for digestionof complex organic molecules

MICROFLORA

LITTER TRANSFORMERS

ECOSYSTEM ENGINEERS

MICROPREDATORS

Formation of biogenic structures

PEDOGENESIS

SOIL STRUCTURE

SOM DYNAMICS

AGGREGATION

HUMIFICATION

MINERALIZATIONEARTHWORM

MICROBIALACTIVITY

DIGESTION

MYCORRHIZALINFECTION

CASTINGBURROWING


148


EARTHWORM BEHAVIOR

S

ELECTION

OF

S

OIL

P

ARTICLES

FIGURE 8.3

TimeStructure

HOURSGUT CONTENT

Effect onSOM

DAYS/WEEKSFRESH CASTS

MONTHSAGING CASTS

YEARS: DECADESSOIL PROFILE

ASSIMILATIONCOMMINUTION

NUTRIENTRELEASE

PHYSICALPROTECTION

ACCELERATIONOF TURNOVER

ConservationActivationof mineralizationTransfers

Functional Groups Spatial Distribution



149

S

PATIAL

P

ATTERNS

OF

H

ORIZONTAL

D

ISTRIBUTION

OF

E

ARTHWORMS

C

OMPACTING

VS

. D

ECOMPACTING

S

PECIES


150


TABLE 8.1Effects of Inoculation of the Earthworm

Millsonia anomala

into Cropping Systems on Bulk Density and Aggregation of Soil

Bulk Density

% Aggregates Larger than 2 mm

Maize 010 cm

Maize 010 cm

Yam Mounds, Sieved Soil

Maize 010 cm, Undisturbed Soil

Maize 010 cm, Sieved Soil



151

MEDIUM-TERM EFFECTS: EXPERIMENTS INOCULATING EARTHWORMS INTO CROPPING SYSTEMS OF THE

HUMID TROPICS

LONG-TERM EFFECTS OF EARTHWORMS: MODELING AND OBSERVATION OF SUCCESSIONAL PROCESSES


152


M

ODELING

FIGURE 8.4

C content in the 0- to 10-cm layer

N content in the 0- to 10-cm layer

C %

N %

Number of Crops

Number of Crops

Earthworm +Earthworm

a

a

a

aa a

a

a

aa

a

a

a

b

0.14

0.13

0.12

0.11

0.10

0.09

1.9

1.8

1.7

1.6

1.5

1.4

1.3

1.20 1 2 3 4 5 6

0 1 2 3 4 5 6



153

E

ARTHWORM

A

CTIVITIES

AND

S

UCCESSIONAL

P

ROCESSES

FIGURE 8.5

Time (yr)

Earthworm removal

0 10 20 30 40 50 60 70 80 90 100

1500

1000

500

0


154


FIGURE 8.6

FIGURE 8.7

Endogeic

Anecic

Epigeic

Years10 20 30 50 60 16

0

190

120100806040200

n m

2

% minmaterials

60

50

40

30

20

10

010 20 30 50 60 160 190

BoundedOM

Years

UnboundedOM



155

DISCUSSION


156



Effects of Earthworms on Soil Organic Matter and Nurient Dynamics 157

REFERENCES


Effects of Earthworms on Soil Organic Matter and Nurient Dynamics 159



fl


161

9

Integrating the Effects of Earthworms on Nutrient Cycling across Spatial and Temporal Scales

Patrick J. Bohlen

Archbold Biological Station, Lake Placid, Florida, U.S.A.

Robert W. Parmelee

Yucca Valley, California, U.S.A.

John M. Blair

Division of Biology, Kansas State University, Manhattan, Kansas, U.S.A.

CONTENTS


162


OVERVIEW


Integrating the Effects of Earthworms on Nutrient Cycling

163


164




165

CONCEPTUAL MODELS

M

ECHANISTIC

M

ODELS

fi fi

fi


166


FIGURE 9.1

Soil OrganicMatter

AggregateFormation

MicrobialTurnover

LitterProcessing

Respirationand Mucus

+

+

+

+

CO2 Loss



167


168


E

COSYSTEM

B

UDGET

M

ODELS

FIGURE 9.2

Soil OrganicMatter

+

+

+

+

Excretionand Mucus

MicrobialTurnover

LitterProcessing

AggregateFormation

AvailableNitrogen

Leaching

Uptake

Runoff

Denitrification



169

FIGURE 9.3

Matrix and Bypass

StableAggregates

RunoffFertilizer

GaseousLoss

Crop

Root

Litter

Plant Uptake

MicrobialBiomass

Earthworm

Burrow

AvailableC and N

Soil OrganicC and N


170


F

UTURE

E

XPERIMENTS

FIGURE 9.4

SoilOrganicC and N

MicrobialBiomass Available

C and N

StableAggregates

GaseousLoss

Matrix and Bypass

Fertilizer

Litter

Crop

Root

Plant Uptake

Runoff



171

A HIERARCHICAL APPROACH

I

NDIVIDUAL

E

ARTHWORMS

FIGURE 9.5

Assimilation and ExcretionGut Microbiology

Biomass and GrowthReproduction and Mortality

Spatial PatternsSource-Sink Relationships

Storage vs. Loss of C and N

C and N FluxEcological Groups

Landscape

Ecosystem

Community

Population

Individual


172




173

E

ARTHWORM

P

OPULATIONS


174


E

ARTHWORM

C

OMMUNITIES

EARTHWORMS IN ECOSYSTEMS


Integrating the Effects of Earthworms on Nutrient Cycling 175

EARTHWORMS IN LANDSCAPES



CONCLUSIONS

ACKNOWLEDGMENTS

REFERENCES



fi


Part V

Effects of Earthworms on Soil Physical Properties and Function


183

10

Quantifying the Effects of Earthworms on Soil Aggregation and Porosity

Martin J. Shipitalo

North Appalachian Experimental Watershed, U.S. Department of Agriculture, Agricultural Research Service, Coshocton, Ohio, U.S.A.

Rene-Claire Le Bayon

Department of Plant Ecology, Neuchtel University, Neuchtel, Switzerland

CONTENTS

INTRODUCTION


184


ECOLOGICAL CLASSIFICATION OF EARTHWORMS

AGGREGATION

I

NGESTION

R

ATES

AND

P

ROPERTIES

OF

C

ASTS



185

R

EMOLDING

OF

S

OIL

A

GGREGATES

BY

E

ARTHWORMS


186


M

EASUREMENT

OF

THE

S

TABILIZATION

OF

A

GGREGATES

IN

C

ASTS

S

TABILIZATION

OF

A

GGREGATES

IN

C

ASTS

: P

HYSICAL

, C

HEMICAL

,

AND

B

IOLOGICAL

P

ROCESSES



187

fi

fi

fi

R

OLE

OF

O

RGANIC

M

ATTER

fi


188


fi

fi

S

URFACE

C

ASTING

, S

OIL

E

ROSION

,

AND

N

UTRIENT

T

RANSPORT

fi fi



189

fifi

fififi

FIGURE 10.1

fi

raindropsintensity

runoff

percolation

physical brakefeedback

rainfall impactphysical processes

hypodermicinfiltration

4.5% slope

deposition/suspensionof particles

breakdowndispersion


190


POROSITY AND INFILTRATION

C

HARACTERIZATION

OF

B

URROW

M

ORPHOLOGY

fi

fi fi

fifi

fi

E

FFECTS

OF

E

ARTHWORM

B

URROWS

ON

I

NFILTRATION

fifi


fi fi


191

fi

FIGURE 10.2

fi


192


fifi

fi

fi fi

fi fi fifi fi fi fi fi

fi fifi fifi


Quantifying the Effects of Earthworms on Soil Aggregation and Porosity 193

EFFECTS OF EARTHWORM BURROWS ON WATER QUALITY



CONCLUSIONS

fifi

fifi

fi fi fi

REFERENCES



fi fi

fi

fi



fi

fifi

fi

fi

fi

fi

fi

fi

fi



fifi

fi

fi



fi

fi

fi

fi

fi



fifl

fi

fi

fi


201

11

Effects of Earthworms on Soil Organization

Andr Kretzschmar

INRA-Biometri, Avignon, France

CONTENTS

fi

THE EFFECTS OF EARTHWORMS ON SOIL ORGANIZATION: INTERACTIONS BETWEEN EARTHWORMS AND SOIL STRUCTURE

S

OIL

P

OROSITY

C

AUSED

BY

E

ARTHWORMS


202


fi fi fi

T

HE

R

OLES

OF

E

ARTHWORM

-O

RIGINATED

S

OIL

S

TRUCTURES

fi fifi

fifi

D

O

E

ARTHWORM

B

URROWS

A

FFECT

S

PECIFIC

S

OIL

F

UNCTIONS

OR

S

TRUCTURES

?



203

fi

fi

S

OIL

-S

TRUCTURE

D

EPENDENT

E

FFECTS

OF

E

ARTHWORM

B

URROWS

fi

fififi fi fifi

fifi


204


E

ARTHWORM

B

EHAVIOR

I

S

N

OT

S

TABLE

fifi

fi

fi fi

INTERACTIONS BETWEEN EARTHWORM BURROWS AND SOIL PROPERTIES

I

NTERACTIONS

OF

E

ARTHWORM

B

URROWS

WITH

O

THER

S

OIL

P

ORES

fi



205

fi

fi

fi fi

I

NTERACTIONS

BETWEEN

E

ARTHWORM

B

URROWS

AND

M

ASS

T

RANSFER

P

ROCESSES

fi

fi


206


fi fi fi

I

NTERACTIONS

BETWEEN

E

ARTHWORM

B

URROWS

AND

O

THER

S

OIL

B

IOLOGICAL

C

OMPONENTS

fififi fi fi

fi



207

OBSERVATION OF EARTHWORM INTERACTIONS WITH SOILS: METHODOLOGICAL CONSIDERATIONS

F

ROM

T

WO

TO

T

HREE

D

IMENSIONS

fi

T

OPOLOGY

AND

F

UNCTIONAL PROBLEMS IN COMPARING EARTHWORM BURROW PATTERNS

fifi fi

fi fi fi fi



PROBLEMS OF SCALE

fi fi fi

CONCLUSIONS

INTERACTIONS BETWEEN EARTHWORMS AND SOIL FORMATION

fififi fi

fi fi

MONITORING INTRODUCTIONS OF EARTHWORMS TO NEW SITES

fi fi


Effects of Earthworms on Soil Organization 209

REFERENCES



fifi

fi


Part VI

Interactions of Earthworms with Microorganisms, Invertebrates, and Plants


213

12

Functional Interactions between Earthworms, Microorganisms, Organic Matter, and Plants

George G. Brown

Embrapa Soya, Londrina, Brazil

Bernard M. Doube

Wood Duck Cellars, Bridgewater, South Australia, Australia

CONTENTS

INTRODUCTION

fi


214


Figure 12.1

fi

Intimate mixing of mineraland organic particlesLitter comminution and decompositionMicrobial and faunal proliferationExternal rumen

MIDDEN

Mucus and other secretionsRespiration

Nutrientabsorption, leaching

Aestivation/diapause chamber

Walls(Changes in C, N, microbial

populations and activity)

Open burrows/macro- porosity

Closed burrows (cast-filled)

Roots growing in burrow and into cast

Burrows open to soil surface Gases, water

BURROW SYSTEM

EARTHWORMSURFACE

FOREGUT MIDGUT HINDGUT

Mostly below groundChanges in microbial biomass, activity, diversity and successional processesChanges in the concentration of nutrients (C, N, some macro and micro)MicroporosityAggregation (C protection)

CO2

CO2

N2O

N2

Soil surface

CASTS

DRILOSPHERE COMPONENTS

Fecesegestion(casts)Metabolic

wastes

Reassimilation of C

C

Assoc. N2 fixation(e.g., Chlostridia?)

Antifungal andantibacterialsecretions

(antibiotics?)

External mucussecretion (alongwhole bodysurface)

Changes in P & Ksolubility,

ammonification(Org. N NH3)

Bacterial stimulation,enzyme production,digestion of organic

compounds

EnteronephridialN excretion

(into the gut)

Tissue production(nutrient

immobilization)

Gizzard(grinding)

Calciferous glands(CaCO3 secretion,

pH increase)

Food selection/ingestion Crop

EARTHWORMINTERNALPROCESSES Exonephridial(external) N

excretion

Digestion of fungal hyphae,bacteria, trophozoites, algae

Intestinal mucus(assimilable C and N)



215

fi

fifi

fi

ORGANIC MATTER AND MICROBIAL COMMUNITIES

fi

A

NNUAL

O

RGANIC

I

NPUTS

AND

D

ECOMPOSITION

P

ROCESSES

fi

fi


216


fi

FIGURE 12.2

Root biomass515%

Faunal biomass510%

Microbial biomass7590%

Macro-organic matter1030%

Humus7085%

Inert carbon520%

Living15%

Nonliving85%

Soil

Mineral content>90%

Soil organic matter0.110%



217

V

ERTICAL

C

ARBON

G

RADIENTS

, P

ATCHINESS

,

AND

Q

UALITY

OF

R

ESIDUES

IN

S

OIL

fififi fi fi

fi

S

UCCESSIONS

OF

M

ICROORGANISMS

DURING

THE

D

ECOMPOSITION

P

ROCESSES

fi


218


F

EEDING

B

EHAVIOR

OF

E

ARTHWORMS

INTERACTIONS BETWEEN EARTHWORMS AND MICROBIAL COMMUNITIES

fi

fi fi

T

HE

E

ARTHWORM

D

RILOSPHERE

: M

ICROSCALE

I

NTERACTIONS

fi

Food Preferences and Dietary Requirements



219

fi

FIGURE 12.3

fi

% C

arbo

n

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

02.5 2.55.0 1020

Soil Depth (cm)

Parent soil Casts (no dung) Casts (plus dung)


220


fi



221

fi

fi

f l

The Fate of Microorganisms in the Intestines of Earthworms



fi

fi fi

fi

Microbiological Composition and Activity in Earthworm Burrows and Casts

fififi


Functional Interactions between Earthworms, Microorganisms, Organic Matter, and Plants 223

fififififi fi fi

fi

Successional Processes within Casts



fi

MESOSCALE INTERACTIONS BETWEEN EARTHWORMS AND MICROORGANISMS

fi



fi

fi

fi



fifi fi fi

fi

fififi fi

fi



fi fi

FIGURE 12.4 fifi

POTENTIAL DECREASE IN PLANT YIELDS

POTENTIAL INCREASE IN PLANT YIELDS

EARTHWORMS

Increased potential forplant damage

Dispersal of plant pathogenicfungi, bacteria, andparasitic nematodes

Increase in activity andpopulations of

plant pathogens and parasites

Litter and organic matterbreakdown, consumption,

and digestion ofmicroorganisms

Decrease in activityand populations of

plant pathogensand parasites

Increased activity anddispersal of litter decomposing

fungi and bacteria,microbivores, mycorrhizal fungi,N2 fixers, and biocontrol agents

Nutrient release and availability Reduced potential for plant damage



FIGURE 12.5



MACROSCALE INTERACTIONS BETWEEN EARTHWORMS AND MICROORGANISMS

fi fififi

fi

fi

fi fi fifi fi



fi

fifififi

fifi fi

SUMMARY AND CONCLUSIONS



fi

fi

REFERENCES

fl



fi

fifi

fi

fi fi

fi



fi

fi

fi

fi



fi

fi

fifi

fi

fi



fi



fi

fi



fi

fi

fi

fi

fi


241

13

Impacts of Earthworms on Other Biota in Forest Soils, with Some Emphasis on Cool Temperate Montane Forests

Dennis Parkinson

Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada

Mary Ann McLean

Department of Biology, Indiana State University, Terre Haute, Indiana, U.S.A.

Stefan Scheu

Institute of Zoology, Darmstadt University of Technology, Darmstadt, Germany

CONTENTS


242


EFFECTS OF CHANNELING, COMMINUTION, AND MIXING

fi fi fi

fi fi fi


Impacts of Earthworms on Other Biota in Forest Soils

243

fi fi

fi

fi

fi

fi

fi

fi

fi fi


244


fi fi fi

EFFECTS OF EARTHWORM GRAZING, GUT TRANSIT, AND CASTS ON SOIL ORGANISMS



245

fi

fi


246


fi

fi fi

fi

fifi



247

fi

fi

fi fi fi fi

fi

fi

fi

fi


248


fi

ROLES OF THE SOIL BIOTA IN DEVELOPMENT OF FOREST HUMUS FORMS

fi fi

fi fi

fi



249

fi fi

EXPERIMENTAL APPROACHES TO INTERACTIONS

fi

L

ABORATORY

S

TUDIES

OF

I

NTERACTIONS

fi fi fi fifififi


250


F

IELD

S

TUDIES

OF

I

NTERACTIONS

fi fi

fi fi fi

fi

fi

fi

fi



251

IMPACTS OF EARTHWORM INVASIONS OF TWO MONTANE FORESTS

M

ODE

OF

I

NVASION

OF

N

ORTH

A

MERICAN

F

OREST

S

OILS

BY

E

UROPEAN

E

ARTHWORMS

CHANGES IN SOIL STRUCTURE BY COLONIZING EARTHWORMS

fi



fi

CHANGES IN SOIL BIOTA CAUSED BY COLONIZING EARTHWORMS

Soil Microorganisms

fifi

fi


Impacts of Earthworms on Other Biota in Forest Soils 253

Soil Fauna

fi fi

fi

fi



CHANGES IN ECOSYSTEM PROCESSES AND PLANT GROWTH CAUSED BY EARTHWORMS

fi

fififi

fi

REFERENCES



fi

fifi

fi fi

fi

fi

fi

fi

fi



fi



fi

fi



fi


Part VII

Earthworms in Agroecosystems


263

14

Managing Earthworms as a Resource in Australian Pastures

Geoff H. Baker

CSIRO Entomology, Canberra, Australia

CONTENTS

INTRODUCTION

fi fi


264


fi fi fifi

fififififi

THE EARTHWORM FAUNA IN AUSTRALIA

fi



265

FIGURE 14.1

Num

bers

of

Ear

thw

orm

s (m

2)

0

100

200

300

400

500

600

700(a)

Num

bers

of E

arth

wor

ms

(m2

)

0

100

200

300

400

500

600

700

800

900(b)

0

50

100

150

200

250

300

350

400

450

Num

bers

of

Ear

thw

orm

s (m

2)

(c)


266


fi



267

EFFECTS OF EARTHWORMS ON SOIL PROPERTIES AND PLANT PRODUCTIVITY IN AUSTRALIA

fi

fi

fi

FIGURE 14.2

fi

Initial Numbers of Worms/Cage

% I

ncre

ase

in P

astu

re P

rodu

ctio

n

8 15 30 450

10

20

30

40

50

60

70

A. caliginosaA. trapezoidesA. longa


268


flflfi

fi

fi

FIGURE 14.3

fi

Whe

at Y

ield

/Pot

(g)

0

2

4

6

8

10

12

Ear

thw

orm

Bio

mas

s/P

ot (

g)

0

2

4

6

8

10

12

0 2 4 6 8 10

Dead Earthworms/Pot

AA

ABB B B

StrawGrainEarthworms



269

fi

fi

fi fi

fi fi fi

fi

fi

fi

fifi


270


fi fi

EFFECTS OF AGRICULTURAL MANAGEMENT PRACTICES ON EARTHWORMS

fi fi

FIGURE 14.4

fi fi

Soil Depth

3.5

4.5

5.5

6.5

Soil

pH

02.5 cm 2.55 cm 510 cm 1015 cm 1520 cm

*

*

* *

*

ControlA. caliginosaA. longaA. trapezoides



271

fi

fi

fi fi

fi

fi

fi


272


fi

fi

fifi

fi fifi

fl



273

FIGURE 14.5

fi

FIGURE 14.6

fi

Dry Biosolids (t/ha)

Num

bers

of

Ear

thw

orm

s (m

2)

0

10

20

30

40

50

60

70Other spp.S. macleayiM. dubiusA. trapezoides

a

bb

b

0 30 60 120

Num

bers

of

Ear

thw

orm

s (m

2)

Bio

mas

s of

Ear

thw

orm

s (m

2)

0

5

10

15

20

25

30

Earthworm PopulationEarthworm Biomass

Clay (t/ha1)

0 10 75 1500

10

20

30

40

50

60

70

80



fi fifi fi

fi fi

FIGURE 14.7 fi

0.13

0.03

0.03

0.14

0.22

0

2

4

6

8

10

12

14

16

18

20

0

10

20

30

40

50

60

70

80

90

100

Num

ber

of C

ocoo

ns/P

ot

% C

litel

late

Adu

lts

Control Fenamiphos Endosulfan Methiocarb Ridomil

Number ofCocoons% ClitellateAdults


Managing Earthworms as a Resource in Australian Pastures 275

INTRODUCTIONS OF EARTHWORM TAXA TO NEW AREAS



fi fi

fi

FIGURE 14.8 fi

Fre

quen

cy

Distance from Release0 m 1 m 2 m 3 m 4 m 5 m 6 m 7 m

0

2

4

6

8

10

12



THE POTENTIAL FOR INTRODUCING NEW EARTHWORM SPECIES INTO AUSTRALIA

fi fi fi

EARTHWORMS IN PASTURES IN NORTHERN AUSTRALIA



EARTHWORMS AS INDICATORS OF THE SUSTAINABILITY OF AGRICULTURE: FROM THE FARMERS PERSPECTIVE

fi

fi

fififi

CONCLUSIONS



fi

fi fi

fi

fi

fi

REFERENCES



fi

fi

fi

fi

fi

fi

fi

fi

fi



fi

fi

fi

fi

fi

fi



fl

fi

fi

fi



fi

fi



fi


287

15

Earthworms in Agroecosystems: Research Approaches

Paul F. Hendrix

Institute of Ecology, University of Georgia, Athens, GA, U.S.A.

Clive A. Edwards

Soil Ecology Program, The Ohio State University, Columbus, OH, U.S.A.

CONTENTS

INTRODUCTION

fi

fi


288


fi

RECENT TRENDS

fi

fi

TABLE 15.1Number of Contributions within Various Topics Relevant to Agroecosystems Presented at the International Symposia on Earthworm Ecology (ISEE)

Number of Contributions

ISEE4 (Avignon)

ISEE5 (Columbus)

ISEE6 (Vigo)

ISEE7 (Cardiff)

fi



289

fi fi fi

fi fi


fi

290


fi fi

fi

fi

FUTURE RESEARCH NEEDS

fi

fi


fi


291

fi

fi

fi

FIGURE 15.1

INCREASE IN EARTHWORMABUNDANCE AND DIVERSITY

NO TILLAGE ROTATIONS EARTHWORMINOCULATION LIMINGORGANIC

AMENDMENTS

LAND USE PRACTICE

TILLAGE SINGLE CROP TOXICANTS ACIDIFICATION RESIDUEREMOVAL

DECREASE IN EARTHWORMABUNDANCE AND DIVERSITY


292


fi fi

fi fi fi

fi fi

fi

CONCLUSIONS



293

fi fifi

ACKNOWLEDGMENTS

REFERENCES


294


fi



295

fi


Part VIII

Earthworms and Environmental Pollution


299

16

Earthworms as Test Organisms in Ecotoxicological Assessment of Toxicant Impacts on Ecosystems

Adriaan J. Reinecke and Sophi A. Reinecke

Department of Zoology, University of Stellenbosch, Stellenbosch, South Africa

CONTENTS

INTRODUCTION

fi


300


fi

fifi

fi

f i fi fi fi

THE TEST ORGANISMS

fi fi

fi


Earthworms as Test Organisms in Ecotoxicological Assessment of Toxicant Impacts

301

fi

fi

fi fi

fi

fi

fi

fi

fi fi

ACUTE TOXICITY TESTING WITH EARTHWORMS

fi


302


fi

fi

fifi

fi

fi

fi

fi fifi fi fifi



303

CHRONIC TOXICITY TESTS AND SUBLETHAL EFFECTS

fi fi fi


304


EARTHWORM TOXICITY TESTING FOR REGULATORY PURPOSES

fi

fi

fi


fi


305

THE USE OF EARTHWORM BIOMARKERS AND UNDERSTANDING BIOAVAILABILITY

fi

fi

FIGURE 16.1


306


fi

fi

fi fifi fifi

fi



307

fi

fififi fi

fifi

fi

fi

fi

fi


308


fi fi

ESTIMATING ENVIRONMENTAL EXPOSURE OF EARTHWORMS TO TOXICANTS

fi

EARTHWORMS IN BIOASSAYS, MICROCOSMS, AND MODEL ECOSYSTEMS

fi

fi



309

fifi

fi fi

FIELD TOXICITY TESTS USING EARTHWORMS

fi fi fi

fi fi

fi fi

fi

fi


310


fi

fi

fi fi

fi fi fi

fifi

fi

fififi fi

RESIDUES IN EARTHWORMS AND THEIR ROLE AS BIOMONITORS AND BIOINDICATORS

fi



311

fi

fi

fi

fi fi

RISK ASSESSMENT USING EARTHWORMS

fi fi fi fi


312


fi

fi

fi

fi

fi

FIGURE 16.2

fi

fi

RiskAssessment

PAF

Cum

ulat

ive

Prob

abili

ty

Species A

Species bSpecies c

3 2 1 0 1 2 3 4 5

10.90.80.70.60.50.40.30.20.1

0

Log Concentration ( g/l1)

LC50/EC50/NOEC for dif. speciesEQC HC5 SSD



313

fi

fi fi

fi fi

fi

fi

fi fi


fi

314


DECISIONS ON MANAGING ESTIMATED RISK OF CHEMICALS TO EARTHWORMS

fifi

FIGURE 16.3

Hazard Identification

PNEC PEC

Risk characterization

Ris

k as

sess

men

t

Ref

ined

ris

k as

sess

men

t

PEC/PNEC 1?

Current risk minimal(no further testing)

Refined riskcharacterization

No

No

Yes

Riskreductionmeasures

Can ratio PEC/PNEC be lowered by:

1. Refinements of information

2. Further testing?

1. Chronic tests / field tests

2. Bioaccumulation tests

3. Extended representation of trophic levels

and/or

and/or

Refined exposure assessmentincorporating biomarkers andbioavailability levels

Long-term monitoring (includinguse of biomarkers to assesschanging bioavailability)



315

CONCLUSIONS

fifi

fi

fi fifi

fi

fi fi

fi fifi fi fi


316


fi fi fi fi

REFERENCES



317

fi

fi

fi

fi



fi

fi

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Earthworms as Test Organisms in Ecotoxicological Assessment of Toxicant Impacts 319

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Earthworms in Environmental Research

Herman Eijsackers

Alterra, Wageningen University and Research Centre and Institute of Ecological Sciences, Vrije Universiteit, Amsterdam, The Netherlands

CONTENTS

INTRODUCTION

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CURRENT INTEREST IN EARTHWORM ECOTOXICOLOGY

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TOXICOKINETIC BEHAVIOR BY EARTHWORMS (AVAILABILITY, UPTAKE, ELIMINATION, BIOACCUMULATION)

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FIGURE 17.1

FIGURE 17.2

Soil Equilibria Equilibration of Organismswith Their Environment

Redistribution withinOrganisms

Environmental Availability Toxicological BioavailabilityEnvironmental Bioavailability

Solid Phase

Liquid Phase

KP

K1

pH, %Clay, etc.

Toxicokinetic Parameters Toxicodynamic Parameters

time

C(0)

C(eq)

[Me]

mm

ol/k

g Circulation

Target(s)

StorageOrgans(s)

Class A Borderline Class B

Period

2

3

4

5

6

Li

Na

K

Rb

Cs

Be

Mg

Ca

Sr

Cr Mn FeCoNi

Cu Zn Cu

Cd Sn Ag

Pb Au Hg Pb



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TABLE 17.1Multiple Regression of Environmental Availability

k

p

and Bioconcentration Factors (BCFs) in the Earthworm

Eisenia fetida

of Cadmium, Copper, Lead, and Zinc

a


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TESTING CONTAMINANT TOXICITY WITH EARTHWORMS

FIGURE 17.3

FIGURE 17.4

Other Metal Species

Organometal Complexes

Free Metal Ions (Men+)

BCF = f(pH, ion conc., etc.)

LC50 = f(pH, Men+, etc.)

Kp = f(CEC, pH, %OM,%clay, etc.)Adsorbed +

ComplexedMetal Species

Soil Solid Phase Soil Pore Water

Soil Organism

1.5 2.5 3.5 4.5 5.5

3

2

1

0

1

chlorophenolsY = 1.00* + 4.86r2 = 0.93

chlorobenzenesY = 1.85* + 7.62r2 = 0.98

+ chloroanilinesY = 1.04* + 5.00r2 = 0.95

++

++++

++

+

+


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FIGURE 17.5

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time (days)

Cw

orm

/Cse

dim

ent

0

earthworm ecology, annelida ecology, ecologia lombriz de tierra

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