Earthworms Gaia's Best Friends

GAIA

Hipotesis : EARTH is a super organism able to perform homeostasis

Cell

Tissue

Órgan

Organism

Population

Community

Ecosystem

Landscape

Biome

Biosphere

The highest level of organisation of life

Ecosphere = GAIA

Organite

Life on Earth

• Regulates atmospheric composition

• Regulates temperature

• Renew old soils

CO2: 350ppmO2 : 21%T° : 13°C

CO2: 96%O2 : tracesT° : 350°C

LIVING EARTH NO LIFE

Accumulates C in skeleton(CaCO3)

Skeletons accumulatein sediments

Decrease in CO2;Accumulation of 02Decreased pressure

ATMOSPHERICREGULATION

Sediment weight moves continental platesVolcanism

Material for new soil formation

Marine plancton

SOIL

What we owe to plancton!!

Earthworms and GAIA

José Miguel Flores

Earthworms said to have appeared on EARTH500M years ago

They have experienced considerable changes in climate conditions

… different vegetations and organic input qualities…

ANGIOSPERM

GYMNOSPERM

PTERIDOPHYTES

Earthworms have evolved and diversified

EPIGEIC

ANECIC

ENDOGEICS

Source: Bouché, 1977; Lavelle , 1983; Lavelle et al., 1998

Earthworm communities at Lamto (Ivory Coast)

The Lamto earthworm community0

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1. Millsonia lamtoiana (anecic)

2. Dichogaster baeri (epigeic)

3. Dichogaster agilis (epigeic)

4. Millsonia anomala(mesohumic)

5. Chuniodrilus zielae6. Stuhlmannia porifera (polyhumic)

7. Dichogaster terrae nigrae (oligohumic

8. Millsonia ghanensis (oligohumic

9. Agastrodrilus opisthogynus (carnivorous)10. Agastrodrilus multivesiculatus(oligohumic+11. Dichogaster baeri12. Dichogaster bolaui13. Eudrilus eugeniae14. Hyperiàdrilus africanus15. Chuniodrilus vuattouxi16. Chuniodrilus palustris

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9. Agastrodrilus opisthogynus (carnivorous)

10. Agastrodrilus multivesiculatus(oligohumic+11. Dichogaster baeri12. Dichogaster bolaui13. Eudrilus eugeniae14. Hyperiàdrilus africanus15. Chuniodrilus vuattouxi16. Chuniodrilus palustris

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Ingest 800-1250 Mg soil per ha per year

after Lavelle et al., 2004, in D.Wall (ed)Lavelle et al., 2006 Eur.J Soil Biol..

Soil Physicalstructure

ActivationSelection

Water Infiltration+ storage

SOM dynamics

Nutr CyclingClimate Reg.

EWMPop

EWMComm

Drilosphere in a self organized SOIL

lavelle

garder??

« En el suelo quedaron unos

turriculos, fieles testigos de una vida de

trabajo »Lavelle & Fragoso

Casts and galleries……

……. As homologous to plancton skeletons ???

SOM dynamics

Nutrient cycling

C sequestration

Aggregatedstructures

BIODIVERSITY

HYDRICSERVICES CASTS

CLIMATEREGULATION

Plant protection

PRIMARYPRODUCTION

Habitats

InfiltrationWater storage

In the long term, earthworms conserve C in soilYurimaguas 6 yr experiment

Source : Pashanasi et al., 1996; Lavelle and Spain, 2001

Earthworm energy budget at Lamto:a precarious balance

A=9%

NA=91%

R=95%A

Pc=95%P

R=5%P

Source: Lavelle, 1978

P/I = 0.045% energy mostly spent in mechanical activities

Primary forest in MadagascarHIGEST SENSITIVITY OF SOILS TO EROSION

What Earthworms do : Hydraulic Engineers

in Madagascar

Upper humic horizon with high root density (1km

per m²)

Absorbs 20-100 mm rain

In the A1 horizon, giant worms build networks of galleries that allow drainage

Erosion

Deforestation and removal of surface horizons trigger a catastrophic process of erosion

Water flow

Road built for illegal timber exploitaion

B prismatic horizon

Massive soil erosionlavakas

Earthworms have a « green thumb »

Plants: Earthworms have a « green hand »

(Blouin et al…)

• Nutrient release in the rhizosphere

• Hormone like effects (gene expression)

• Stimulation of mutualistic microflora

• Hydric services

+ ++-

+ PONTOSCOLEX

Sources: Pashanasi et al., 1996; Blouin et al., 2006; Brown et al., 1999; Scheu et al., 2003

NO Worm

Earthworms in the anthropocene(Paul Crutzen, Nobel price)

Servicios Ecosistemicos UNALPalmira 2010

GAIA is sick!!!

U.S

. Bu

rea

u o

f the

Ce

ns

us

NOAA

NASA

Ma

ck

en

zie e

t al (2

00

2)

Ric

ha

rds

(19

91

), WR

I (19

90

)

Go

lde

wijk

an

d B

attje

s (1

99

7)

IPCC

FAO


GAIA has fever +0.8°C


Infections Green algae in Bretagne


Skin diseasesDeforestation in Amazonia

Disappearance of many species, especially large earthworms

AMAZ projectlandscape intensification

Fig.2. Study sites

ABCD

Landscape intensification in Eastern Amazonia

LargeWorms> 15 cm

Source: Marichal et al., ISEE 9

Why?Demographic constraints

Habitat requirements

F=3.1Ad:12

F=10.7Ad=6

F= 6.2Ad=10

F= 13.0Ad=8

F= 1.9Ad=14

F= 1.3Ad=30

F= 1.3Ad=14

Demography

Size

Pontoscolex

Large worms

Exceptional rates of endemismin earthworms

% regional pool

Lavelle, P. and E. Lapied (2004). Pedobiologia. 47: 419-427.

EWM

..and very high rates of cryptic speciation

Source: Novo et al., 2008, Zoologica scripta, 38, 5.

7 localities, 82 ind

at least 4 species of Hormogaster elisae

Hormogaster elisae

,38 haplotypes

Invasives!!!!

• Formerly called Peregrine !!! (Lee, 1987)

• European Lumbricidae (the ones that recolonized land after glaciations)

• A few tropical generalists with high demographic profiles

C. Fragoso

A. caliginosa

P. corethrurus

High density ofPontoscolex corethrurus

Other decompactorsdepleted

Intense earthworm activityin the upper 10 cm of soil

Chauvel et al., 1999; Nature

Continuous crustof compact earthworm casts

6 t C mineralised

Forest soil exposed tothe community of the pasturewas compacted in one year

Source: Barros et al., 2001, Geoderma

Compacted soil exposedto the diverse fauna of the Primary forest recoveredOriginal conditions in one year

European Lumbricidae in Northern Minnesota

http://www.nrri.umn.edu/worms/forest/plants.html

BEFORE AFTER

“But I thought earthworms were good for plants !”

In the Amazonian arc of deforestation

Pontoscolex corethrurus occupies a newly formed niche that natives are unable to use

Invasion of Pontoscolex corethrurus (Glossoscolecidae, Oligochaeta) in landscapes of the Amazonian deforestation arc

Marichal R1,3, Feijoo Martinez A2, Praxedes C3, Ruiz D2, Carvajal A F 2, Oszwald J4, Hurtado M P5, Brown G G6, Grimaldi M1,8, Desjardins T1, Sarrazin M1, Decaëns T7 , Velasquez Eç, and Lavelle P1,5

See Raphaël Marichal’s poster

Earthworms still do a lot inanthropised systems

Soil aggregation and GISQ improved in a gradient of landscape intensification in the Amazonian arc of deforestation

PontoscolexIs there

Aggregation

LANDSCAPE INTENSIFICATION

The GAIA theoryPontoscolex was there

Not here

Peregrines as bandages on GAIAS’s wounds???

Bixa orelana

Source: Pashanasi et al. 1996

Speciation is surely at hand

If H. elisae has 3-7 species

how many species in Pontoscolex corethrurus

or A. caliginosa??

Photo: C. Fragoso

Conclusions

• Earthworms have a profound, still not evaluated, role in GAIAS’s homeostasis

EVALUATE AT APPROPRIATE SCALES

• Many species will disappear during the AnthropoceneCrisis:

NEED FOR SPECIFIC CONSERVATION SCHEMES

• Peregrines with very special adaptive strategies act as bandages on Gaia’s wounds:

USE IN RESTORATION AND CONSTRUCTIONOF ECOEFFICIENT LANDSCAPES?

Special to:

Isabelle y CarlosJose Miguel FloresAna CaleroRaphaël MarichalElena Velasquez…….

Many Thanks

Drilosphere: the earthworm functional domain

Earthworms

Microflora Soil fauna

Macro aggregates

GalleriesMacropores

PLANTSGrowth; Protection

Communities

ORGANIC MATTERDynamics; Accumulation

++

+

WATERInfiltration; Storage

DRILOSPHERE

The mutualist digestion system(sleeping Beauty paradoxe)

Source : Barois and Lavelle, 1986

Mucus (10%) and water (100%)Mixing

Digestion ofMO in the median part of the gut

Education

Earthworms Gaia's Best Friends