NEMATODE COMMUNITIES AS NEMATODE COMMUNITIES AS BIOINDICATORS OF BIOINDICATORS OF ANTROPOGENIC INFLUENCE IN ANTROPOGENIC INFLUENCE IN AGROECOSYSTEMSAGROECOSYSTEMS

Mirjana BRMEZ, Marija IVEZIC, Emilija RASPUDIC, Vesna TRIPAR, Renata BALICEVIC

University of J.J. Strossmayer in Osijek, Faculty of Agriculture in Osijek, Croatia

Nematodes as Nematodes as bioindicatorsbioindicators

– they occur in almost every habitat (terrestrial, aquatic and marine),

– they occure with many species per sample or habitat,

– they respond quickly to environmental changes,

– they show specific respond to various types of pollution or disturbances,

– they are in close contact with dissolved compounds in free soil water,

Nematodes as Nematodes as bioindicatorsbioindicators

– they are easily sampled and extacted from the soil,

– the sampling can be done in any time of the year,

– storage of the samples requires little space– Analyses of nematode community

structure can be related to feeding types (trophic group), c-p groups from 1-5, absolute abundances, number of genera, Maturity index, Plant parasitic index etc.

““PersistersPersisters””- long life-cyclelong life-cycle- sensitive to sensitive to

disturbancesdisturbances- low reproduction ratelow reproduction rate- they hardly fluctuate they hardly fluctuate

in number over the in number over the yearyear

- never belong to never belong to dominant species in dominant species in the samplethe sample

- have few small have few small gonads, and produced gonads, and produced large eggslarge eggs

““ColonizersColonizers””- short life cycleshort life cycle- tolerance to tolerance to

disturbancesdisturbances- high reproductive ratehigh reproductive rate- high colonization high colonization

abilityability- have voluminous have voluminous

gonads, gonads, - release large numbers release large numbers

of small eggs, and of small eggs, and are often viviparousare often viviparous

C-p groups (1-5)C-p groups (1-5)

http://www.microscopyu.com/smallworld/gallery/contests/2003/honorablelarge14.html

Maturity index Maturity index (Bongers, 1990)(Bongers, 1990)

v(i) – (c-p) v(i) – (c-p) value assigned to familyvalue assigned to family ((i) f(i) - f(i) - the frequency of family (the frequency of family (i) in a in a

samplesample

Lower index reflect disturbanceLower index reflect disturbance

if

ifivMI

AimAim

The objective of this investigation The objective of this investigation was to determine if the nematode was to determine if the nematode communities in the soil could communities in the soil could serve as bioindicators of serve as bioindicators of anthropogenic activities in anthropogenic activities in agroecosystems. agroecosystems.

MATERIAL AND METHODSMATERIAL AND METHODS

TREATMENTS:TREATMENTS:– Poplar forest,– Arable land with standard tillage

regimes – wheat, – Arable land with standard tillage

regimes – corn. Sampling: in spring period 2001, in Sampling: in spring period 2001, in

the 4 replicates, using sonda the 4 replicates, using sonda ØØ 2 2 cm, on the depth of 20 cmcm, on the depth of 20 cm

MATERIAL AND METHODSMATERIAL AND METHODS

• Extaction of of nematodes – 100 nematodes – 100 g of soil - g of soil - Seinhorst method Seinhorst method (1956)(1956)

• Identification – genus level

RESULTSRESULTSTotal number of nematodes and number of genera

0

500

1000

1500

2000

2500

3000

poplar wheat corn

No.

of n

emat

odes

in

100

ml o

f soi

l

0

5

10

15

20

25

num

ber

of g

ener

a

total no. of nematodes number of genera

Trophic structure

0

10

20

30

40

50

60

poplar wheat corn

Bacterial feeders Fungal feeders Omnivorous Predators Plant feeders

%

RESULTS

Tretments

AverageMI

Average PPI

Average PPI/MI

AverageTotal no.

nematodes

Average no.

genera

poplar 1,95 2,40 1,27 1386 20,25

wheat 1,72 2,58 1,50 1922 17,25

corn 1,57 2,83 1,83 2456 14,50

Lsd 0,05 n.s. n.s. 0,3751 n.s. 3,4758

Lsd 0,01 n.s. n.s. n.s. n.s. n.s.

RESULTS

On the base of this investigations we can conclude that nematode communities could serve as a very bood bioindicator of antropogenic influence in agroecosystem.

CONCLUSIONCONCLUSION

AcknowledgAcknowledgeementment

The investigations are suported The investigations are suported by the Ministry of Science and by the Ministry of Science and Technology in Croatia (Project- Technology in Croatia (Project- 079024).079024).