Open Journal of Forestry
2014. Vol.4, No.1, 1-7
Published Online January 2014 in SciRes (http://www.scirp.org/journal/ojf) http://dx.doi.org/10.4236/ojf.2014.41001
1
Synergic Effect of Mucuna pruriens var. Utilis (Fabaceae) and
Pontoscolex corethrurus (Oligochaeta, Glossoscolecidae) on the
Growth of Quercus insignis (Fagaceae) Seedlings, a Native
Species of the Mexican Cloud Forest
María L. Avendaño-Yáñez1*, Ángel I. Ortiz-Ceballos1, Lázaro R. S ánchez-Velásquez1*,
María R. Pineda-López1, Jorge A. Meave2
1Instituto de Biotecnología y Ecología Aplicada (INBIOTECA), Universidad Veracruzana, Veracruz, México
2Departamento de Ecología y Recursos Naturales, Facultad de Ciencias, Universidad Nacional Autónoma de
México, México D.F., México
Received October 19th, 2013; revised November 23rd, 2013; accepted December 9th, 2013
Copyright © 2014 María L. Avendañ o-Yáñez et al. This is an open access article distributed u nder the Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited. In accordance of the Creative Commons Attribution License all
Copyrights © 2014 are reserved for SCIRP and the own er of the in tellectual property Marí a L. Av en dañ o-Yáñez
et al. All Copyright © 2014 are guarded by law and by SCIRP as a guardian.
Propagation of native species in local nurseries is an important activity in reforestation and forest restora-
tion programs. A requisite for successful plantation is that nursery produced plants are of a size and qual-
ity that allows optimal establishment under field conditions. Manipulation of edaphic processes through
the combined use of the earthworm Pontoscolex corethrurus, Mucuna pruriens and inorganic fertilizers
may promote faster biomass gain. This study assessed the activity of P. corethrurus, its association with
M. pruriens (green manure) and inorganic fertilizers, on the growth of Quercus insignis seedlings under
greenhouse conditions. Measured variables were basal diameter, height, biomass and foliar nitrogen con-
tent. Growth rates of basal diameter (F = 5.33; P < 0.0001) and height (F = 2.84; P < 0.0087) were sig-
nificantly greater in the treatment of P. corethrurus-M. pruriens-inorganic fertilizer, relative to the control.
Also, leaf biomass and total biomass of the seedlings were greater in the treatment of P. corethrurus-fer-
tilizer (F = 2.32; P < 0.0290, F = 3.71; P < 0.0011, respectively) compared to the control treatment. Foliar
nitrogen content was significantly higher (F = 2.54; P < 0.01742) in the treatment of P. corethru-
rus-inorganic fertilizer. Incorporating biological soil management techniques in propagation of native
species is a good choice to assist reforestation and forest restoration.
Keywords: Nursery; Oak Seedlings; Earthworms; Green Manure; Inorganic Fertilizers; Plant Propagation
Introduction
Cloud forest hosts around 6790 plant species (Villaseñor,
2010). Regrettably, this diversity is in decline due to several
factors of disturbance, most of which are anthropogenic
(Ramírez-Marcial et al., 2001; Lamb et al., 2005). This situa-
tion affects the population dynamics of plant species that are
endangered, threatened or susceptible to forest fragmentation
(Saunders et al., 1991; Cayuela et al., 2006). This is the case
with Quercus insignis, a species native to this ecosystem. De-
spite a broad geographic range that spreads from eastern-central
Mexico to Costa Rica, this species is a narrow habitat-spe-
cialist and is highly susceptible to disturbance (Valencia, 2004).
It was included in the Red List of Oaks under the endangered
category (Oldfield & Eastwood, 2007). More recently, and due
to the accelerated destruction of its habitat, this species was
re-classified to the Critically Endangered category in the Red
List of Mexican cloud forest trees (González-Espinosa et al.,
2011).
A potential mechanism to reverse this situation and restore
degraded areas is the establishment of forest plantations, or the
reintroduction of locally extinct species (Vázquez-Yanes &
Cervantes, 1993; Meli, 2003; Pedraza & Williams-Line ra, 2003;
Lamb et al., 2005). This process must be complemented by the
production of native species in nurseries (Benítez et al., 2002).
At present, there is nil to very low availability of native species
in local nurseries in Mexico, and the few plants that are pro-
duced are lacking in both quality and size (Arriaga et al., 1994;
Meza-Sánchez et al., 2009). Moreover, the use of black plastic
bags with repeated watering causes the soil compaction and
poor root development in the seedlings. Novel propagation
techniques are therefore required in order to improve seedling
quality in nurseries (Benítez et al., 2002), as well as comple-
mentary strategies with which to facilitate the future field es-
tablishment in the field.
In nurseries that are devoted to the massive production of na-
tive forest species, common use is made of organic remains,
*Corresponding authors.

M. L. AVENDAÑO-YÁÑEZ ET AL.
2
sand, fertilizers and pesticides. However, the use of green ma-
nure could become an important source of nutrients (mainly
nitrogen) to increase soil fertility (Smyth et al., 1991; Blanchart
et al., 2006). The legume Mucuna pruriens var. utilis has been
used as a cover crop for these purposes (Hulugalle et al., 1986;
Smyth et al., 1991; Buckles, 1995; Ortiz-Ceballos et al., 2012)
and its use has also enabled the biological control of weeds,
pests and diseases, while it acts to influence the composition
and activity of the soil biota, particularly the earthworms. All of
these effects may indirectly favor plant growth (Ortiz-Ceballos
& Fragoso, 2004; Blanchart et al., 2006).
The soil biota is known to regulate the availability of nu-
trients necessary for plant growth and development (Wardle et
al., 2004). There is also evidence of the important role of
earthworms in the functioning of natural- and agro-ecosystems
through the conservation of soil fertility (Wardle, 2002; Bha-
dauria, 2010) and enhancement of plant growth (Lee, 1985;
Haimi & Einbork, 1992; Pashanasi et al., 1992; Edwards &
Bohlen, 1996; Doube et al., 1997; Scheu, 2003; Ortiz-Ceballos
et al., 2007). However, most information published to date on
plant-earthworm interactions is derived from studies based on
domesticated plants (Edwards & Bater, 1992; Brown et al.,
1999; Scheu, 2003; Ortiz-Ceballos & Fragoso, 2004). It is
therefore important to examine the influence of earthworms on
plants from natural environments (Scheu, 2003), such as cloud
forest. The earthworm Pontoscolex corethrurus (Müller, 1857)
is a peregrine species of the Glossoscolecidae family and native
to the Neotropics. It is an endogeic earthworm with a broad
environmental tolerance that occurs in various habitats and soil
types (Lavelle et al., 1987; Lee, 1985; Fragoso et al., 1999;
Buch et al., 2011), including cloud forest (Fragoso et al., 1999).
This species plays a crucial role in organic matter decomposi-
tion as well as the mineralization of nitrogen and phosphorous
(Barois et al., 1999; Bhadauria & Saxena, 2010) and has been
successfully used in bio-fertilization and bio-stimulation tech-
niques, producing significant positive effects on crop yields
(Lavelle & Pashanasi, 1989; López-Hernández et al., 1993;
Senapati et al., 1999).
Obtaining information on the interaction between P. coreth-
rurus and native cloud forest plant species in general and Q.
insignis in particular may be of great relevance, as this can
allow us to develop new practices aimed at supplementing and
reinforcing the management and propagation of native plant
species within conservation and restoration programs for this
mountain ecosystem. The goal of this study was to evaluate
integrated soil fertility management, i.e., how the combination
of biomass (Mucuna pruriens var. utilis), inorganic fertilizer,
and earthworms could impact the soil fertility as well as the
growth and leaf nitrogen content of Quercus insignis seedlings
under nursery conditions.
Methods
Study Site and Soil
The study was conducted in the greenhouse and laboratory of
the Instituto de Biotecnología y Ecología Aplicada (INBI-
OTECA) in the center of Veracruz State, a region of Mexico
that features cloud forest. A total of 200 kg of soil was col-
lected to a depth of 40 cm from the Plan de San Antonio cloud
forest (19˚26'N, 96˚59'W; 1430 m elevation), located 20 km
from the town of Coatepec city. Soil samples were sealed in
plastic bags and transported to the INBIOTECA greenhouse
where they were air-dried at ambient temperature. The physical
and chemical soil properties of the collected soils were; pH 5.7,
organic matter content 16.6%, total nitrogen 0.68%, 0.32
cmol∙kg−1 K, 0.4 cmol∙kg−1 Ca, 1.7 cmol∙kg−1 Mg, 26.9
cmol∙kg−1 cation exchange capacity, 54% moisture content (soil
collected), 17% clay, 32% silt, 49% sand.
Earthworms, Green Manure and Oak Seedlings
Juvenile individuals of P. c orethrurus used in this study cor-
responded to the first generation obtained under laboratory
conditions from earthworms collected in a secondary cloud
forest. Pontoscolex corethrurus is an exotic species that has
been reported in Mexican cloud forests and is also commonly
found in areas that have been transformed from cloud forest to
pastureland or crops, such as maize or beans, among others
(Fragoso et al., 1999; Fragoso, 2001).
Juvenile P. corethrurus earthworms were raised following
the protocol of Ortiz-Ceballos et al. (2005): (1) two adult
earthworms, each with a conspicuous clitellum, were placed in
plastic boxes (12 × 12 × 8 cm) filled with 300 g of soil, mixed
with 3% Mucuna and wetted to field capacity (42%). The boxes
were incubated at 26˚C ± 2˚C, and the soil replaced and co-
coons collected fortnightly. These cocoons were incubated in
Petri dishes at 27˚C. In the greenhouse, plants of M. pruriens
were grown for a period of three months (September - Novem-
ber 2009). The foliage was then collected, dried (63˚C ± 3˚C,
48 h), ground (to 2 mm), and placed in paper bags; total nitro-
gen content of the M. pruriens was determined (2.23%) using
the Kjeldahl digestion method following the Mexican Official
Norm NOM-021 (SEMARNAT, 2002). Seeds of the studied
oak species, Quercus insignis were collected in November 2009
from cloud forest fragments located at 19˚12'N, 96˚59'W, at an
elevation of 1460 m . This species bears large acorns (5 cm
diameter) and its seeds may be classed as recalcitrant. Seeds
were placed in nursery beds (1 × 8 m), where they germinated
between 15 - 20 days after sowing, presenting a germination
rate > 60%.
Experimental Setup
The experiment was conducted in the greenhouse of INBI-
OTECA from May to November 2010. We used eight treat-
ments: 1) Pontoscolex (P); 2) Pontoscolex-Mucuna (PM); 3)
Pontoscolex-fertilizer (PF); 4) Pontoscolex-Mucuna-fertilizer
(PMF); 5) Mucuna (M); 6) fertilizer (F); 7) Mucuna-fertilizer
(MF); 8) Control (C) [only soil]. There were 20 replicates (15 ×
25 cm plastic containers) by treatment. The containers were
filled with 540 g of dry soil that was then wetted to field capac-
ity (43%), and placed on a metallic table. One day later, an 8 -
12 day old Q. insignis seedling of approximate height 15 cm
was planted in each container. One week later, two juvenile P.
corethrurus earthworms (106 ± 12 mg) were added to the ap-
propriate treatments, and Mucuna foliage was added to the soil
surface (8 g; 2.23 N%) (nitrogen content of Mucuna is equiva-
lent to that of the applied inorganic fertilizer), as well as the
slow-release fertilizer (ammonium nitrate [0.7 g; 26 N 13 S%])
according to the requirements of each treatment. Seedlings
were grown for a period of 180 days and watered weekly to
maintain the soil moisture at field capacity (43%). Mean tem-
perature in the greenhouse was 25.6˚C ± 4.3˚C, and weeds were
manually removed from the soil. During the experiment, aphids

M. L. AVENDAÑO-YÁÑEZ ET AL.
3
were found on the back of some leaves, these were controlled
manually and no pesticide was applied.
We recorded seedling height and basal diameter monthly. A
destructive harvest of all plants from all treatments was carried
out 180 days after the start of the experiment. For each plant,
the biomass weight was calculated (dried 65˚C ± 3˚C; 72 h) in
roots, stem and leaves. To determine leaf nitrogen content a
sample of the leaves was taken for each treatment and nitrogen
content was determined with the Kjeldahl digestion method,
following the Mexican Official Norm NOM-021 (SEMARNAT,
2002). At the end of the study, the number of earthworms and
cocoons in each treatment was recorded.
Statistical Analysis
Analysis of variance (ANOVA) was performed to compare
between treatments for each of the following variables: a)
growth rate in height, b) growth rate in basal diameter, c) total
and component-specific dry biomass, and d) total foliar nitro-
gen content. When the ANOVA yielded a significant result,
means were compared with a Tukey multiple-comparison test.
Prior to the ANOVA, numeric values were transformed to nat-
ural logarithm, the normality and homogeneity of variance were
fulfilled. Growth rate (TC) was estimated with the following
equation:
( )
21
ln ln
C
TC Ct= −
where C2 is final seedling height or diameter, C1 is initial
seedling height (cm) or diameter (mm), and t is elapsed time
(months). In addition, biomass allocation to leaves (L) was
assessed relative to root biomass (R), and expressed as the L/R
ratio between treatments. Percentage values of tot al nitroge n con-
tent in the leaves were also compared between treatments with
a Tukey test (GLM Proc, SAS 9.2; SAS Institute Inc., 2009).
Results
Growth of Quercus insignis Seedlings
Basal diameter growth rate of the Q. insignis was signifi-
cantly hi gher in the trea tment PMF (F = 5.33; P < 0.0001) than
in all the other treatments (Figure 1).
Regarding plant height, significant differences were found (F
= 2.84; P < 0.0087) among the treatments PMF, fertilizer (F)
and the control treatment (C) (Figure 2). However this trait did
not differ significantly between the treatments P. corethru-
rus-M. Pruriens-fertilizer (PMF), P. corethrurus-fertilizer (PF)
and M. pruriens-fertilizer (MF).
Total Leaf Nitrogen
Total foliar nitrogen content in Q. insignis seedlings was sig-
nificantly different between treatments (F = 2.54; P < 0.01742).
Values of this trait were significantly higher in the treatment PF
compared to the other treatments. It is noteworthy that the Q.
insignis plants that grew in the control treatment (soil only)
presented the lowest values of foliar nitrogen, as is shown in
Figure 3.
Biomass in Q. insignis Seedlings
Significant differences between treatments (F = 2.32; P <
0.0290) were recorded for leaf biomass values in Q. insignis.
This was particularly noteworthy in the contrast between the P.
Figure 1.
Effects of eight treatments on growth of Quercus insignis
seedlings. Abbreviations: P. corethrurus (P), P. corethru-
rus-M. pruriens (PM), P. corethrurus-fertilizer (PF), P. co-
rethrurus-M. pruriens-fertilizer (PMF), M. pruriens (M),
fertilizer (F), M. pruriens-f ertilizer (MF), Control (C). Mean
values of seedling basal diameter are shown. Vertical lines
represent standard errors. Different letters indicate signifi-
cant differences between treatments.
Figure 2.
Effects of eight treatments on growth of Quercus insignis
seedlings. Mean values of seedling height are shown. Ver-
tical lines represent standard errors. Different letters indi-
cate significant differences between treatments.
Figure 3.
Effects of treatments with P. corethrurus (P), M. pruriens
(M) and fertilizer (F), and combinations of these, on total
leaf nitrogen content in seedlings of Quercus insignis.
Values are means f or plants grown in each treat ment. Ver-
tical lines represent standard errors. Different letters indi-
cate significant differences between treatments.

M. L. AVENDAÑO-YÁÑEZ ET AL.
4
corethrurus-fertilizer (PF) treatment and the control. However
the root and shoot biomass Q. insignis seedlings did not differ
significantly between treatments (see Table 1).
Total biomass was similar between treatments, and signifi-
cant differences (F = 3.71; P < 0.0011) were only found among
the treatments PF, F and the control (Table 1). The leaf/root
biomass ratio was >1 in all treatments, indicating a larger re-
source allocation to photosynthetic tissues in Q. insignis seedl-
ings, regardless of treatment. No significant differences were
observed between treatments in this trait.
Discussion
It is widely accepted that the presence of earthworms is gen-
erally beneficial to plant growth (Edwards & Bohlen, 1996;
Bohlen et al., 2002, 2004; Scheu, 2003; Eisenhauer et al., 2009).
Similarly, the addition of organic matter to the soil, mediated
by leguminous plants such as M. pruriens, is known to provide
nutrients such as nitrogen, and to improve soil fertility and thus
increase plant productivity (Becker et al., 1995; Konboon et al.,
2000). In our study, the treatments with P. corethrurus, M.
pruriens, inorganic fertilizer and the interaction between these,
presented similar values in terms of growth variables. However,
significantly higher values in all plant growth variables were
found between P. corethrurus-M. pruriens-fertilizer (PMF)
treatment versus the control treatment. Brown et al. (2004) and
Scheu (2003) reported increases in the growth of several culti-
vated plant species, mostly cereals and grasses, in the presence
of earthworms. Likewise, other studies have led to the conclu-
sion that the use of Mucuna pruriens favors the growth and
productivity of Zea mays (Ile et al., 1996; Buckles & Triomphe,
1999; Eilitta et al., 2003).
Our results indicate that the combination of P. corethrurus-M.
pruriens-fertilizer (PMF) positively affects the growth in height
of Q. insignis plants. However, the combination P. corethru-
rus-M. pruriens (PM) and P. corethrurus-fertilizer (PF) can be
equally effective in producing increased height, an aspect
which is of vital importance to tree species that are propagated
in greenhouses. The use of inorganic fertilizers may potentially
induce variability in the effects of earthworms on plants, which
may largely depend on soil nutrient status (Laossi et al., 2010a).
According to our findings, inorganic fertilizer appears to in-
teract synergistically with P. corethrurus and M. pruriens, or
with M. pruriens only, promoting the growth of Q. insignis
during early stages of its life cycle. This condition is likely to
be the result of the relatively rapid liberation of nitrogen pro-
vided by the synthetic fertilizer. If true, this would partly ex-
plain the improved plant growth in the treatments with P. co-
rethrurus, M. pruriens and synthetic fertilizer, and in combina-
tions of these. The fact that the inorganic fertilizer alone cannot
produce a growth increase in these seedlings must not be over-
looked.
Increases in stem and root biomass in plants that have been
exposed to earthworm activity have been repeatedly docu-
mented (Wurst & Jones, 2003); however, other studies have
reported contrasting results (Scheu, 2003). Ortiz-Ceballos et al.,
(2007) observed increased root biomass in plants of Zea mays
exposed to the combined effects of the activity of the earth-
worm Balanteodrilus pearsei with the leguminous M. pruriens.
Conversely, the presence of P. corethrurus, and its combination
with M. pruriens, did not significantly affect root and stem
biomass in Q. insignis seedlings. It must be stressed that most
studies reporting increases in root and stem biomass have fo-
cused on species with short life cycles (annual or biennial) that
are often herbaceous, while the effect of this interaction with
long-lived trees is less well understood. Moreover, the effect of
earthworms on plant growth may also vary depending on the
functional traits of the different plant and earthworm species
(Brown et al., 2004; Eisenhauer et al., 2009; Laossi et al.,
2010b). As a long-lived tree species, Q. insignis could respond
differently in terms of resource allocation to different tissues
during a very early phase of its juvenile development. Ulti-
mately, this possibility could obscure the synergistic effect of P.
corethrurus and M. pruriens on root and shoot biomass alloca-
tion in Q. insignis seedlings at the early stages of their devel-
opment in a nursery.
Leaf biomass is seldom assessed as a response in studies of
plant-earthworm interactions. In our analysis, the comparison
of leaf biomass of Q. insignis revealed a homogeneous increase
between the various treatments, with the exception of the con-
trol. The uniform increase of leaf biomass among treatments
Table 1.
Effects of treatments with P. corethrurus (P), M. pruriens (M) and fertilizer (F), and combination s of these, on the biomass of aboveground and un-
derground components and leaf/root ratio of Q. insignis seedlings.
Treatments (n) Root biomass
(g dry weight) Stem biomass Leaf biomass Total biomass Leaf/root ratio
P (17) 2.2 ± 0.9a 2.3 ± 1.2a 3.7 ± 1.7ab 8.3 ± 2.2ab 2.1 ± 1. 2a
PM (16) 2.1 ± 0.8a 1.9 ± 0.7a 3.2 ± 1.3ab 7.1 ± 1.5ab 2 ± 1.1a
PF (18) 2 ± 0.9a 2.6 ± 1a 4.1 ± 1.3a* 8. 8 ± 2.3a** 2.4 ± 1.6a
PMF (16) 1.9 ± 0.9a 1.8 ± 0.8a 3.4 ± 0. 7ab 7 .0 ± 2.1ab 2.2 ± 1.3a
M (16) 1.8 ± 0.8a 1.8 ± 1a 2.9 ± 1. 5 ab 6.5 ± 2.2ab 2 ± 1.2a
F (17) 1.9 ± 0.6a 1.7 ± 0.9a 2.7 ± 1.4ab 6 .3 ± 2.1b 1.6 ± 0.9a
MF (17) 2 ± 0.6a 1.9 ± 0.8a 2.9 ± 1.2ab 6.7 ± 2.5ab 1.7 ± 1. 1a
C (17) 1.7 ± 0.4a 1.8 ± 1a 2.6 ± 1.4b 6.1 ± 1.6b 1.6 ± 1a
Note: Values are means ± SE. Values in parentheses (n) indicate the number of plants per treatment at the end of the experiment. Different letters within the same column
indicate signific ant differences between treatments. *p < 0.0290; **p < 0.0011.

M. L. AVENDAÑO-YÁÑEZ ET AL.
5
involving the addition of P. corethrurus, M. pruriens, the inor-
ganic fertilizer, or combinations of these, suggests that plants
tend to accumulate photosynthetic tissue when they have unli-
mited access to sufficient nutrients provided through biological
and/or inorganic fertilization. Moreover, the comparison of
total biomass in Q. insignis showed similar patterns among
those treatments that combined biological fertilization with
inorganic fertilizer, the only significant differences being in the
treatment that only included fertilizer, and in the control. Laossi
et al. (2010a) reported that the interaction of Lumbricus terre-
stris with a fertilizer had significant effects on the total biomass
of two herb species, Poa annua and Veronica persica. Similarly,
the increase in total biomass of Q. insignis suggests a positive
effect of this endogeic earthworm, provided its activity is sup-
plemented by an external source of nitrogen that can be assimi-
lated by the plant in the short term. Thus, the activity of P. co-
rethrurus, combined with the use of M. pruriens and/or chemi-
cal fertilizer positively affects both leaf and total biomass in Q.
insignis seedling.
Total foliar nitrogen content was significantly higher in the
treatment P. corethrurus-fertilizer (PF). This result is to be
expected given that an increase of leaf nitrogen is related to
greater photosynthetic activity, which in theory makes it easier
for a plant to access higher quantities of useful resources vital
to growth and biomass accumulation in different tissues (Gar-
nier, 1991; Gleeson, 1993; Hikosaka, 2004). Although leaf
nitrogen concentration often decreases as plants grow (Gastal &
Lemaire, 2002), this does not seem to be the case in Q. insignis.
This may change, however, later in the life of the plant after its
stage transition from sapling to young adult. Plants tend to op-
timize resources, and they therefore require a balance in the
allocation of nutrients, such as nitrogen, in order to maximize
growth (Hilbert, 1990; Gleeson, 1993; Göran & Franklin, 2003).
However, the effect of earthworms on this plant resource allo-
cation has been poorly documented and understood (Scheu,
2003). In this context, we observed that leaf biomass is gener-
ally greater than root biomass in seedlings of Q. insignis, re-
gardless of treatment. This situation suggests that the priority
for seedlings of this oak species is to produce more photosyn-
thetic tissues, which is logical considering that this is a late
successional species that establishes under limited light condi-
tions in its natural habitat.
Conclusion
The integration of a biological component such as the earth-
worm P. corethrurus into soil management, along with use of
M. Pruriens, could favor the growth of Q. insignis. This could
be further optimized by the addition of inorganic fertilizer. This
combination represents a good option for soil enrichment, di-
versification of the practices of plant propagation and reduced
use of inorganic fertilizers. Day-to-day practices in nurseries
include the application of inorganic fertilizers; however, as this
study shows, their use does not necessarily translate into im-
proved plant growth. The ultimate goal of biological soil man-
agement, including the use of earthworms and green manure, is
to promote the integration of edaphic processes such as natural
nutrient cycling and degradation to forms that plants can readily
assimilate. These processes play decisive roles in the soil dy-
namics of an ecosystem and promote robust plant development.
Full consideration should therefore be given to the integration
of soil biological management into the propagation techniques
of native species aimed at conserving and restoring fragmented
forest ecosystems.
Acknowledgemen ts
We thank everyone who helped with this work, Clara Cor-
doba-Nieto, Raquel Cervantes-Alday, Álvaro Soberanes and
Carolina Cruz. M.L. Avendaño-Yáñez acknowledges the Con-
sejo Nacional de Ciencia y Tecnología (CONACYT) for the
scholarship granted for this research (Num. Reg. 223896). We
also thank the funding received by the Sectorial Fund for Edu-
cation Research SEP-CONACYT (project CB-2010-0-156053).
REFERENCES
Arriaga, V., Cervantes, V., & Vargas-Mena, A. (1994). Manual de
reforestación con especies nativas. México: Instituto Nacional de
Ecología, Secretaría de Desarrollo Social and Universidad Nacional
Autónoma de México.
Barois, I., Lav elle, P., Bros sard, M. , Ton doh , J., Mártin ez, M. A., Rossi,
J. P., Senapati, B. K., Angeles, A., Fragoso, C., Jiménez, J. J.,
Decaëns, T., Lattaud, C., Kanyonyo, J., Blanchart, E., Chapuis, L.,
Brown, G. G., & Moreno, A. (1999). Ecology of earthworm species
with large environmental tole rance and/or extended d istributions. In:
P. Lavelle, L. Brussard, & P. Hendrix (Eds.), Earthworm manage-
ment in tropical agroecosystems (pp. 57-85). Wallingford, UK: CA-
BI.
Becker, M., Lad ha, J. K., & Ali, M. (1 995). Green manure technolo gy:
Potential, usage and li mitations. A case stud y for lowland rice. Plant
Soil, 174, 181-194. http://dx.doi.org/10.1007/BF00032246
Benítez, G., Equihua, M ., & Pulido-Salas, M. T. (2002). Diagnóstico d e
la situación de los viveros oficiales de Veracruz y su papel para
apoyar programas de reforestación y restauración. Revista Chapingo.
Serie Ciencias Forestales y del Ambiente, 8, 5-12.
Bhadauria, T., & Saxena, K. G. (2010). Role of earthworms in soil
fertility maintenance through the production of biogenic structures.
Applied and Envi r onmental Soil Science, 2010, Article ID: 816073.
http://dx.doi.org/10.1155/2010/816073
Blanchart, E., Villenave, C., Viallatoux, A., Barthes, B., Girardin, C.,
Azontonde, A., & Feller, C. (2006). Long-term effect of a legume
cover crop (Mucuna pruriens var. utilis) on the communities of soil
macrofauna and nematofauna, under maize cultivation, in southern
Benin. European Journal of Soil Biology, 42, 136-144.
http://dx.doi.org/10.1016/j.ejsobi.2006.07.018
Bohlen, P. J., Edwards, C.A., Zhang, Q., Parmelee, R. W., & Allen, M.
(2002). Indirect effects of earthworms on microbial assimilation of
labile carbon. Applied Soil Ecology, 20, 255-261.
http://dx.doi.org/10.1016/S0929-1393(02)00027-6
Bohlen, P. J., Parmelee, R. W., & Blair, J. M. (2004). Integrating the
effects of earthworms on nutrient cyclin g across spatial and temporal
scales. In: C. A. Edwards (Ed.), Earthworm ecology (pp. 161-180).
Boca Raton, FL: CRC Press.
http://dx.doi.org/10.1201/9781420039719.ch9
Brown, G. G., Pashanasi, B., Villenave, C., Patron, J. C., Senapati, B.
K., Giri, S,, Barois, I., Lavelle, P., Blanchart, E., Blakemore, R. J.,
Spain, A. V., & Boyer, J. (1999). Effects of earthworms on plant
production in the tropics. In: P. Lavelle, L. Brussard, & P. Hendrix
(Eds.), Earthworm management in tropical agroecosystems (pp. 87-
137). Wallingford, UK: CABI.
Brown, G. G., Edwards, C. A., & Brussaard, L. (2004). How earth-
worms affect plant growth: b urrowing in to the mechanisms. In: C. A.
Edwards (Ed.), Earthworm ecology (pp. 13-49). Boca Raton, FL:
CRC Press.
Buch, A. C., Brown, G. G., Niva, C. C., Sautterc , K. D., & Lourenc, L.
F. (2011). Life cycle of Pontoscolex corethrurus (Müller, 1857) in
tropical artificial soil. Pedobiologia, 54, S19-S25.
http://dx.doi.org/10.1016/j.pedobi.2011.07.007
Buckles, D. (1995). Velvetb ean: A new plan t with a history. Economic

M. L. AVENDAÑO-YÁÑEZ ET AL.
6
Botany, 49, 151-162. http://dx.doi.org/10.1007/BF02862271
Buckles, D., & Triomphe, B. (1999). Adoption of mucuna in the farm-
ing system s of northern Honduras. Agroforestry Systems, 47, 67-91.
http://dx.doi.org/10.1023/A:1006205702691
Cayuela, L., Golich er, D. J., Benayas, J. M. R., González-Espino sa, M.,
& Ramírez-Marcial, N. (2006). Fragmentation, disturbance and tree
diversity conservation in tro pical mon tan e f orests . Journal of Applied
Ecology, 43, 1172-1181.
http://dx.doi.org/10.1111/j.1365-2664.2006.01217.x
Doube, B. M., Williams, P. M. L., & Willmott, P. J. (1997). The influ-
ence of two species of earthworm (Aporrectodea trapezoids and
Aporrectoedea rosea) on the growth of wheat, barley and faba beans
in three soil types in the greenhouse. Soil Biology and Biochemistry,
29, 503-509. http://dx.doi.org/10.1016/S0038-0717(96)00037-5
Edwards, C. A., & Bater, J. E. (1992). The use of earthworms in envi-
ronmental management. Soil Biology and Biochemistry, 24, 1683-
1689. http://dx.doi.org/10.1016/0038-0717(92)90170-3
Edwards, C. A., & Bohlen, P. (1996). Biology and ecology of earth-
worms. New York: Chapman and Hall.
Eisenhauer, N., Milcu, A., Sabais, A. C. W., & Scheu, S. (200 9). Earth -
worms enhance plant regrowth in a grassland plant diversity gradient.
European Journal of Soil Biology, 45, 455-458.
http://dx.doi.org/10.1016/j.ejsobi.2009.06.001
Eilitta, M., Sollenberger, L. E., Littell, R. C., & Harrington, L. W.
(2003). On-farm experiments with maize-mucuna systems in the Los
Tuxtlas region of Veracruz, Mexico. I. Mucuna biomass and maize
grain yield. Experimental Agriculture, 39, 5-17.
http://dx.doi.org/10.1017/S0014479702001126
Fragoso, C., Kanyonyo, J., Moreno, A., Senapati, B., Blanchart, E., &
Rodríguez, C. (1999). A survey of tropical earthworms: Taxonomy,
biogeography and environmental plasticity. In: P. Lavelle, L. Brus-
sard, & P. Hendrix (Eds.), Earthworm management in tropical
agroecosystems (pp. 1-26). Wallingford, UK: CABI.
Fragoso, C. (2001). Las lombrices de tierra de México (Annelida,
Oligochaeta): Diversidad, ecología y manejo. Acta Zoológica Mex-
icana, 1, 131-171.
Garnier, E. (1991). Reso urce capture, bio mass allocation and growth in
herbaceous plants. Trends in Ecology & Evolution, 6, 126-131.
http://dx.doi.org/10.1016/0169-5347(91)90091-B
Gastal, F., & Lemaire, G. (2002). N uptake and distribution in crops:
An agronomical and ecophysiological perspective. Journal of Expe-
rimental Botany, 53, 789-799.
http://dx.doi.org/10.1093/jexbot/53.370.789
Gleeson, S. K. (1993). Optimization of tissue nitrogen and root-shoot
allocation. Annals of Botany, 71, 23-31.
http://dx.doi.org/10.1006/anbo.1993.1003
González-Espinosa, M., Meave, J. A., Lorea-Hernández, F. G., Ibarra-
Manríquez, G., & Newton, A. C. (2011). The red list of Mexican
cloud forest trees. Cambridge: Fauna and Flora International (FFI).
Göran, I. A., & Franklin, O. (2003). Root: Shoot ratios, optimization
and nitrogen productivity. Annals of Botany, 92, 795-800.
http://dx.doi.org/10.1093/aob/mcg203
Haimi, J., & Einbork, M. (1992). Effects of endogeic earthworms on
soil processes and plan t growth in con iferous forest so il. Biology and
Fertility of Soils, 13, 6-10. http://dx.doi.org/10.1007/BF00337230
Hilbert, D. W. (1990). Optimization of plant root: Shoot ratios and
internal nitrogen concentration. Annals of Botany, 66, 91-99.
Hikosaka, K. (2004). Interspecific difference in the photosynthesis-
nitrogen relationship: Patterns, physiological causes, and ecological
importance. Journal of Plant Research, 6, 481-494.
http://dx.doi.org/10.1007/s10265-004-0174-2
Hulugalle, N. R., Lail, R., & Kuile, C. H. H. (1986). Amelioration of
soil physical properties by Mucu na after mechan ized land clearing o f
tropical rain forest. Soil Science, 14, 219-224.
http://dx.doi.org/10.1097/00010694-198603000-00007
Ile, E., Hamadin a, M. K., Zufa , K., & Henrot, J. (1996 ). Note on effects
of a Mucuna pruriens var. utilis crop on the growth of maize (Zea
mays) on an acid ultisol in southeastern Nigeria. Field Crops Re-
search, 48, 135-140.
http://dx.doi.org/10.1016/S0378-4290(96)01028-3
Konboon, Y., Blair, G. J., Lefroy, R. D. B., & Whitbread, A. M. (2000).
Tracing the nitrogen, sulfur and carbon released from plant residues
in a soil/plant system. Australian Journal of Soil Research, 38, 699-
710. http://dx.doi.org/10.1071/SR99075
Lamb, D., Erskine, P. D., & Parrota, J. A. (2005). Restoration of de-
graded tropical forests landscapes. Science, 310, 1628-1632.
http://dx.doi.org/10.1126/science.1111773
Laossi, K. P., Ginot, A., Noguera, D. C., Blouin, M., & Barot, S.
(2010a). Earthworm effects on plant growth do not necessarily de-
crease with soil fertility. Plant and Soil, 328, 109-118.
http://dx.doi.org/10.1007/s11104-009-0086-y
Laossi, K. P., Noguera, D. C., & Barot, S. (2010b). Earthworm me-
diated maternal effects on seed germination and seedling growth in
three annual plants. Soil Biology and Biochemistry, 42, 319-323.
http://dx.doi.org/10.1016/j.soilbio.2009.11.010
Lavelle, P., Ba rois, I., Cruz, I. , Fragoso, C., He rnández, A., Pin eda, A.,
& Rangel, P. (1987). Adaptative strategies of Pontoscolex corethru-
rus (Glossoscolecidae, Oligochaeta), a peregrine geophagous earth-
worm of the hum id tropics. Biology and Fertility of Soils, 5, 188-194.
http://dx.doi.org/10.1007/BF00256899
Lavelle, P., & Pashanasi, B. (1989). Soil macrofauna and land man-
agement in Peruvian A mazonia (Yurimaguas, Loreto). Pedobiologia,
33, 283-291.
Lee, K. E. (1985). Earthworms: Their ecology and relationships with
soils and land use. Sydney: Academic Press.
López-Hernández, D., Lavelle, P., Fardeau, J. C., & Niño, M. (1993).
Phosphorus transformations in two P-sorption contrasting tropical
soils during transit through Pontoscolex corethrurus (Glossoscoleci-
dae: Oligochaeta). Soil Biology and Biochemistry, 25, 789-792.
http://dx.doi.org/10.1016/0038-0717(93)90124-T
Meli, P. (2003). Restauración ecológica de bosques tropicales: Veinte
años de investigación académica. Interciencia, 28, 581-589.
Meza-Sánchez, R., Ruiz-Espin oza, F. H., & Navejas-Jiménez, J. (2009).
Guía para la producc ión de planta y plantaci ón con especies nativas.
Baja California Sur: Instituto Nacio nal de Investig aciones Forestales,
Agrícolas y Pecuarias (INIFAP).
Müller, F. (185 7). II. Description of a new species of earthwo rm (Lum-
bricus corethrurus). Journal of Natural History Series 2, 20, 13-15.
http://dx.doi.org/10.1080/00222935709487865
Oldfield, S., & Eastwood, A. (2007). The red list of oaks. Cambridge:
Fauna and Flora International (FFI).
Ortiz-Ceballos, A. I., & Fragoso, C. (2004). Earthworm populations
under tropical maize cultivation: The effect of mulching with vel-
vetbean. Biology and Fertility of Soils, 39, 438-445.
http://dx.doi.org/10.1007/s00374-004-0732-8
Ortiz-Ceballos, A. I., Frago so, C ., Eq u ihu a, M. , & Bro wn , G. G. (2005).
Influence of food quality, soil moisture and the earthworm Pontos-
colex corethrurus on the growth, reproduction and activity of a trop-
ical earthworm Balanteodrilus pearsei. Pedobiologia, 49, 89-98.
http://dx.doi.org/10.1016/j.pedobi.2004.08.006
Ortiz-Ceballos, A. I., Frag oso, C., & Brown, G. G. (2007). Synergistic
effect of a tropical earthworm Balanteodrilus pearsei and velvetbean
Mucuna pruriens var. utilis on maize growth and crop production.
Applied Soil E cology, 35, 356-362.
http://dx.doi.org/10.1016/j.apsoil.2006.07.009
Ortiz-Ceballos, A. I., Aguirre-Rivera, J. R., Osorio-Arce, M. M., &
Peña-Valdivia, C. (201 2). Velvet Bean (Mucuna pruriens var. utilis)
a cover crop as Bioherbicide to preserve the environmental services
of soil. In: R. Alvarez-Fernandez (Ed.), Herbicides-environmental
impact studies and management approaches (pp. 167-184). Cam-
bridge: University of Cambridge.
Pashanasi, B., Meléndez, G., Szott, L., & Lavelle, P. (1992). Effect of
inoculation with the endogeic earthworm Pontoscolex corethrurus
(Glossoscolecidae) on availability, soil microbial biomass and the
growth of three tropical f ruit tree seedlings in a pot experiment. Soil
Biology and Biochemistry, 24, 1655-1659.
http://dx.doi.org/10.1016/0038-0717(92)90165-T
Pedraza, R. A., & Williams-Linera, G. (2003). Evaluat ion o f nativ e tree
species for the rehabilitation of deforested areas in a Mexican cloud
forest. New Forests, 26, 83-99.

M. L. AVENDAÑO-YÁÑEZ ET AL.
7
http://dx.doi.org/10.1023/A:1024423511760
Ramírez-Marcial, N., González-Espinosa, M., & Williams-Linera, G.
(2001). Anthropogenic d isturbance a nd tree diversit y in montane rain
forests in Chiapas, Mexico. Forest Ecology and Management, 154,
311-326. http://dx.doi.org/10.1016/S0378-1127(00)00639-3
Saunders, D. A., Hobbs, R. J., & Margules, C. R. (1991). Biological
consequences of ecosystem fragmentation: A review. Conservation
Biology, 5, 18-32.
http://dx.doi.org/10.1111/j.1523-1739.1991.tb00384.x
Senapati, B. K., Lavelle, P., Giri, S., Pashanasi, B., Alegre, J., Decaëns ,
T., Jimenez, J. J., Albrecht, A., Blanchart, E., Mahieux, M., Rous-
seaux, L., Thomas, R., Panigrahi, P. K., & Venkatachalam, M.
(1999). In-soil earthworm technologies for tropical agroecosystems.
In: P. Lavelle, L. Brussaard, & P. Hendrix (Eds.), Earthworm man-
agement in tropical agr oecosystems (pp. 199-237). Wallingford, UK:
CABI.
SAS Institute Inc. (2009). SAS system for windows version 9.2.
http://www.sas.com/
SEMARNAT (2002). Nom -021-SEMARNAT-2000 Que establece las
especificaciones de fertilidad, salinidad y clasificación de suelos,
estudio, muestreo y análisis, 2nd Sect. México : Secretaría del Medio
Ambiente y Recursos Naturales (SEMARNAT).
Scheu, S. (2003). Effects of earthworms on plant growth: Patterns and
perspectives. Pedobiologia, 47, 846-856.
http://dx.doi.org/10.1078/0031-4056-00270
Smyth, T. J., Cravo, M. S., & Melgar, R. J. (1991). Nitrogen supplied to
corn by legumes in a Central Amazon Oxisol. Tropical Agriculture
(Trinidad), 68, 366-372.
Valencia, A. S. (2004). Diversidad del género Quercus (Fagaceae) en
México. Boletin de la Sociedad Botanica de México, 75, 33-53.
Vázquez-Yanes, C., & Cervantes, V. (199 3). Reforestación con árboles
nativos de México. Ciencia y Desarrollo, 19, 52-58.
Villaseñor, J. L. (2 0 1 0 ). El bosque húmedo de montaña en México y sus
plantas vasculares: Catálogo florístico-taxonómico. México: Comi-
sión Nacional para el Conocimiento y Uso de la Biodiversidad
(CONAB IO) —Universidad Nacional Autónoma de México (UNAM).
Wardle, D. A. (2002). Communities and ecosystems: Linking above-
ground and belowground components. Princeton, NJ: P rinceton Uni-
versity Press.
Wardle, D. A., Bardgett, R. D., Kironomos, J. N., Setälä, H., Van der
Putten, W. H., & Wall, D. H. (2004). Ecological linkages between
aboveground and belowground biota. Science, 304, 1629-1633.
http://dx.doi.org/10.1126/science.1094875
Wurst, S., & Jon es, T. H. (2003 ). Indirect eff ects of earthworms (Apor-
rectodea caliginosa) on an above-ground tritrophic interaction. Pe-
dobiologia, 47, 91-97. http://dx.doi.org/10.1078/0031-4056-00173