F.
-Navarro* and
-Vidal. *Phytopathology
Phytopathology Program-Colegio de
-Campus Montecillo,
Franco
Godinez
**Phytopathology
Program
Postgraduados
F. FrancoFranco-Navarro*
and D.
D. GodinezGodinez-Vidal.
Program-Colegio
de PostgraduadosPostgraduados-Campus
Montecillo, Montecillo
Montecillo 56230,
56230, Mexico
Mexico
State,
-mail: [email protected].
State
Mexico
*E
[email protected]
State,, Mexico.
Mexico.. *E*E-mail:
[email protected]..
Project: Conservation and Sustainable Management of BelowBelow-Ground Biodiversity [PROJECT FUNDED BY GEF]
In
Conservation and
-Ground
Below
In the
the context
context ff the
the Multinational
Multinational Project
Project ““Conservation
and Sustainable
Sustainable Management
Management of
of the
the BelowBelow-Ground
Biodiversity”
” (CSM/BGBD),
", Mexico,
Biodiversity
Tuxtlas
Biodiversity”
(CSM/BGBD), aa study
study at
at the
the Biosphere
Biosphere Reserve
Reserve "Los
"Los Tuxtlas",
Tuxtlas",
Mexico, to
to determinate
determinate the
the effect
effect of
of
different
ed. Three
conduct
different land
land use
use intensities
intensities on
on the
the soil
soil nematodes
nematodes was
was conducted.
conducted.
Three localities
localities into
into the
the Reserve
Reserve were
were chosen
chosen
as
replications
and
from
each
of
them,
different
fields
belonging
g
to
four
land
use
intensities
(Natural
forest,
belongin
as replications and from each of them, different fields belonging to four land use intensities (Natural forest,
Secondary
selected
Secondary forest,
forest, Pasture
Pasture fields
fields and
and Maize
Maize fields)
fields) were
were selected.
selected.. Ecological
Ecological measures
measures of
of the
the structure
structure of
of soil
soil
nematodes
nd compared
aand
nematodes fauna,
fauna, diversity,
diversity, and
and maturity
maturity indices
indiceswere
wereassessed
assessedand
comparedamong
among land
land uses.
uses.Fifty
Fiftythree
threefamilies
families
and
and one
one hundred
hundred twenty
twenty four
four genera
genera were
were identified.
identified. The
The highest
highest nematode
nematode abundance,
abundance, richness
richness of
of genera
genera and
and
diversity
condary forest.
Se
diversity corresponded
corresponded to
to Natural
Natural forest,
forest, closely
closely followed
followed by
by Secondary
Secondary
forest. Intensive
Intensive agricultural
agricultural systems
systems like
like
Maize
-disturbed
non
Maize fields
fields and
and Pasture
Pasture fields
fields presented
presented low
low richness
richness of
of genera
genera and
and significant
significant lower
lower diversity
diversity than
than nonnon-disturbed
systems.
-parasitic nematodes
plant
systems. In
In general,
general, plantplant-parasitic
nematodes and
and bacterial
bacterial feeders
feeders were
were the
the most
most dominant
dominant and
and abundant
abundant in
in the
the
study
edators. The
pr
study area,
area, followed
followed by
by fungal
fungal feeders,
feeders, omnivores
omnivores and
and finally
finally predators.
predators.
The higher
higher number
number of
of bacterial
bacterial feeders
feeders
was
was collected
collected in
in Pasture
Pasture fields
fields and
and Maize
Maize fields;
fields; fungal
fungal feeders
feeders were
were more
more abundant
abundant in
in Maize
Maize fields,
fields, omnivores
omnivores and
and
predators
-parasitic in
plant
predators in
in Natural
Natural forest
forest and
and Secondary
Secondary forest,
forest, and
and plantplant-parasitic
in Secondary
Secondary forest.
forest. Some
Some disturbance
disturbance indices
indices
(Maturity
(Maturity index,
index, Plant
Plant parasite
parasite index,
index, modified
modified Maturity
Maturity index,
index, and
and plant
plant parasite
parasite index/maturity
index/maturity index
index ratio)
ratio)
showed
differences
among
land
uses,
corresponding
most
of
the
highest
ghest
values
to
nondisturbed
systems
hi
non
showed differences among land uses, corresponding most of the highest values to non-disturbed systems
(Natural
e food
th
(Natural and
and Secondary
Secondary forest).
forest). In
In general,
general, the
the conditions
conditions of
of the
the
food chain
chain in
in the
the study
study area
area correspond
correspond to
to aa low
low
to
-enriched, with
eria, low
non
bact
to moderate
moderate disturbance,
disturbance, nonnon-enriched,
with canal
canal of
of decomposition
decomposition balanced
balanced by
by fungi
fungi and
and bacteria,
bacteria,
low C/N
C/N
ratio
and
food
chain
in
maturation.
Most
of
the
ecological
indices
es were
ratio and food chain in maturation. Most of the ecological indic
indices
were useful
useful to
to establish
establish significant
significant effects
effects of
of
different
different land
landuses
uses on
onsoil
soil nematodes
nematodes fauna
fauna in
in the
the study
study area.
area.
SAMPLING
SAMPLING
Soil disturbance indices based on soil nematodes fauna from sites
sites with four land use intensities in
the Biosphere Reserve “Los Tuxtlas”
Tuxtlas”, Veracruz,
Veracruz, Mexico.
Index
Natural forest
Secondary forest Pasture fields Maize fields
T
Ff/Bf
WI
MI
PPI
mMI
PPI/MI
PPI/MI
2.57 ns
0.16 b
0.97 b
2.63 a
2.91 a
3.21 a
1.15 ns
2.31 ns
0.18 b
0.95 b
2.60 a
2.85 a
3.15 a
1.13 ns
2.11 ns
0.11 b
1.80 a
2.47 ab
2.68 b
2.93 a
1.18 ns
Means followed by different letters are significantly
different. ns= not significant.
T= Trophic diversity index
Ff/Bf= fungal feeders/bacterial feeders ratio
WI= ratio of microbial feeder nematodes
MI= maturity index
PPI= plant parasite index
mMI=
mMI= modified maturity index
PPI/MI= plant parasite index/maturity index ratio.
BF
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Natural forest
FF
OM
Secondary
forest
2.36 ns
0.45 a
3.49 a
2.37 b
2.68 b
2.87 b
1.18 ns
PR
PP
Pasture fields
Maize fields
In each land use
BIOSPHERE RESERVE
“LOS TUXTLAS”
TUXTLAS”, VERACRUZ, MEXICO
24 sampling points
FOUR LAND USES
BACTERIAL FEEDERS
(distance:
distance: 200 m)
Maize fields
Pasture fields
PREDATORS
Secondary forest
Natural forest
SUBSAMPLING POINT
SAMPLING POINT IN THE GRID
Mononchus
Miconchus
Prionchulus
Mylonchulus
Trypila
Iotonchus
Acrobeles
Aphanolaimus
Plectus
Desmocolex
Prismatolaimus
Rhabditis
Diploscapter
EXTRACTION,
EXTRACTION, COUNTING,
COUNTING, PROCESSING
PROCESSING &
& MOUNTING
MOUNTING
EXTRACTION: Sieving–
Sieving–Sugar flotation method (300 g per sample)
sample)
COUNTING:
Three countings (1 ml)
TOTAL: Average of 3 countings X 10.
PERMANENT MOUNTINGS
Nematodes killed by heat at 60°
60°C for 1
min, and then fixed with cold formalin
4%
MASS DEHYDRATION
OMNIVORES
53 Families & 124 Genera
12
a
SIMPSON’
SIMPSON’S DIVERSITY INDEX
ab
10
ab
b
8
a
3
SHANNON’
SHANNON’S DIVERSITY INDEX
ab
2.5
b
ab
2
6
1.5
4
1
2
0.5
0
NATURAL
FOREST
SECONDARY
FOREST
PASTURE
FIELDS
30
PLANTPLANTPARASITES
a
MAIZE
FIELDS
SECONDARY
FOREST
NATURAL
FOREST
GENERA RICHNESS
b
25
0
b
20
b
PASTURE
FIELDS
MAIZE
FIELDS
Helicotylenchus
Criconema
Ogma
Discocriconemella
Trophorus
Hemicycliophora
Xiphinema
Pratylenchus
Meloidogyne
Trichodorus
Mesodorylaimus
Oriverutus
Belondira
Labronema
Aporcelaimium
FUNGAL FEEDERS
Aphelenchus
15
10
5
0
NATURAL
FOREST
SECONDARY
FOREST
PASTURE
FIELDS
MAIZE
FIELDS
1.1. ESQUIVEL,
-145. 2.
areas
131
ESQUIVEL, A.
A. 2003.
2003. Nematode
Nematode fauna
fauna of
of Costa
Costa Rican
Rican Protected
Protected areas.
areas.. Nematropica
Nematropica 33(2):
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2. NEHER,
NEHER, D.
D. A.
A. 2001.
2001. Role
Role of
of
nematodes
. Journal
-168. 3.3.POWERS,
indicators
161
nematodesin
in soil
soil health
healthand
andtheir
their use
use as
as indicators.
indicators.
Journalof
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Nematology33(4):
33(4): 161161-168.
POWERS, T.
T.O.,
O., NEHER,
NEHER, D.
D.A.,
A., MULLIN,
MULLIN, P.,
P.,
ESQUIVEL,
-DAVIS, R.
-LORIO, L..
GIBLIN
URIBE
diversity
ESQUIVEL,A.,
A., GIBLINGIBLIN-DAVIS,
R. M.,
M., KANSAKI,
KANSAKI, N.,
N., STOCK,
STOCK,S.S. P.,
P.,MORA,
MORA,M.
M.M.
M.&& URIBEURIBE-LORIO,
L..2009.
2009.Tropical
Tropicalnematode
nematodediversity:
diversity::
vertical
-12. 4.
rainforest
Ecology
11-12.
vertical stratification
stratification of
of nematode
nematode communities
communities in
in aa Costa
Costa Rican
Rican humid
humid lowland
lowland rainforest.
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Molecular Ecology.
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pp. 14. YEATES,
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G. W.,
W.,
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-an
BONGERS,
Feedi
genera
BONGERS, T.,
T., DE
DE GOEDE,
GOEDE, R.
R. G.
G. M.,
M., FRECKMAN,
FRECKMAN, D.
D. W.
W. && GEORGIEVA,
GEORGIEVA, S.S. S.S. 1993.
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Feeding
habits in
in soil
soil nematode
nematode families
families and
and generagenera-an
outline
-331.
315
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soilecologists.
ecologists.Journal
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