ISSN 1818-6769
© IDOSI Publications, 2014
DOI: 10.5829/idosi.aejaes.2014.14.05.12326
Corresponding Author: Jiménez-García, D., 14 sur 6301. Col. San Manuel, C.U. C.P. 72570. Puebla, Pue. Mexico.
Tel/Fax: +52-222 2295500 Ext. 7064.
Agroecosystems Management and Biodiversity Loss in an Intensification Gradient in Traditional Agriculture in Mexico
L. Jiménez-García, G. Sánchez-Rojas, O. Villarreal, H. Bernal and D. Jiménez-García1 2 1 2 3
Master in Sustainable Agroecosystem Management. Science Institute of the BUAP
1
Centro de Investigaciones Biológicas, Universidad Autónoma del Estado de Hidalgo
2
Center of Agroecology and Environment of the Science Institute of the Benemérita
3
Universidad Autónoma de Puebla (BUAP)
Abstract: Agroecosystems are systems managed by man for food production, in the past centuries these systems were changed by the green revolution causing great damage, by changing the structure and form of the traditional handling process (conservation of natural vegetation edge, heterogeneous landscapes and lower costs in its production), turning it into homogeneous systems, monoculture, with higher maintenance costs, as well as reducing the fauna. The main objective of this work is to determine the different assemblies of rodents in agroecosystems in the Valley of Libres-Oriental Puebla (Mexico). The field work was carried out in five different sites (traditional agriculture "active and inactive", irrigation agriculture, "active and inactive" and natural vegetation). There were 126 individuals found, the most representative in the frequency of occurrence of the species P. maniculatus, presented different assemblages in agro-ecosystems and in the natural vegetation, which is why the gradient of agricultural intensification is not important, on the other hand human intervention is important because this provides benefits for its distribution and permanence in man-made habitats. While, the species with less abundance was the M. mexicanus with 1%. In the statistical analysis it was observed there was no significant difference only within the sampling seasons (dry and wet), except with the species L. Irr (U = 33; Z = 2.6231; p = 0.008). Our results support the hypothesis that traditional agricultural systems are important for maintaining the diversity of mammals in processed ecosystems because composition is very similar to the natural vegetation.
Key words: Traditional agriculture Irrigation Diversity Micro-mammals Agro-ecosystem
INTRODUCTION these ¨traditional¨ systems a large loss of biodiversity has At present day, the human population has increased landscapes [3].
exponentially and in the same way food demand and Over time, changes in the usage of land has led production. Faced with these situation intensive governments of different countries to generate different agricultural practices, increasing a specialization in the conservation, strategies, being one of the most used to production process, which have often resulted in the declare Protected Natural Areas (ANP´s in Spanish;
creation of monocultures. One of the key characteristics However, it has observed that the ANP´s are insufficient of this type of agriculture is that these systems depend by themselves to conserve biodiversity at long term [4]
on external inputs [1]. At the landscape level, this and cover less than 12% of the Earth's surface, in addition 'conventional' or monoculture agriculture tends to to concentrated ecosystems of mild temperature and homogenize the landscapes, reducing the spatial and mountainous areas [5], thereby excluding many temporal variation of soil usage [2]. In addition, within landscapes.
been observed, soil deterioration and fragmentation of
For this reason, some researchers have been modified habitats, which are usually isolated or interested in agro-ecosystems to help maintain local and fragmented [34, 35]. More than 40% of the planet's surface regional biodiversity while these landscapes, modified by is occupied by agricultural systems [36, 37] and it is in the man cover most of the surface of the world [6, 7]. these areas where biodiversity must be present.
Traditional farming systems have lower costs of Intensification has caused the decrease in flora and production, not being dependent of external inputs [8], wildlife [38]. The gradual process of agricultural as well as being heterogeneous, a great percentage have intensification has been altered, therefore, also included natural vegetation edges around crops, allowing to retain the diversity of wildlife and ecosystems interactions greater abundance and diversity of wildlife species [9- 11], [39, 40], as well as the interactions between diversity and providing shelter [12]. To maintain biodiversity in the functionality of ecosystems [41]. Which is why, high agroecosystems it is necessary to preserve the physical technique irrigation systems have negatively changed the structure and floristry composition, [13], which is why territory, in addition to promoting the use of external traditional systems are very complex and tend to be inputs (practices of the Green Revolution) to achieve compared to those of many natural systems [14]. It is extensive productions, promoting the "Elimination of because of all these reasons that traditional agriculture is hunger" [42]. These practices tend to homogenize the considered to provide environmental services [15, 16], landscape and sometimes provide shelter for some such as the fixation of nitrogen, shade, organic material animals and plants for a short term [43, 44]. However, the (which improves fertility and minimizes soil erosion), in most common consequence is that these conditions affect addition to promoting food security [17]. the diversity of flora and fauna associated with these The usage of biodiversity establishes an essential crops [45]. In some cases, a few wildlife species have element from an agricultural production perspective, for benefited from the intensification of the agricultural the food supply. [18]. In addition, diversity usage is one system, but in most cases, they have been reduced or of the methods for biological process optimization and for extinguished [46].
the functions of the ecosystem in order to reach In Latin America and specially in Mexico the so- sustainability for the agroecosystems. Agricultural called "green revolution" was established, which sought biodiversity contributes to stabilization [19], productivity the changes in agriculture and the way of practice of [20], real estate income and services produced, [21], for agricultural technology [47]. To make this revolution better nutrition, which at the same time is relevant for work, the use of seed variations of high performance the improvement of health and life of poor people [22], (VAR) was promoted, mainly using wheat and rice, as well obtaining construction materials, fuel, fencing and as the adoption of a package of "modern" tools and fodder for livestock [23], etc. Biodiversity has a high agricultural practices that use chemical fertilizers, importance in agro-ecosystems and for traditional farmers. pesticides, tractors, controlled water, mechanical Promoting sustainable agricultural production, reducing threshers, pumps, diesel, etc. [48].
the problems of pests and diseases in agricultural systems Taking into account that wildlife fauna species have [24, 25], favoring the inclusion of more breeds of livestock survived throughout fragmentation, changes in the use of [26], favoring the use of agroforestry species [27], soil and agricultural modernization processes, it is one of promoting the presence of pollinators [28], maintaining the outstanding issues to develop in the field of the soil biota [29] and finally, favoring the conservation of assessment of agricultural systems. For a good analysis, wildlife fauna [30, 31]. The traditional agricultural it is proposed to use species as an indicator for landscapes, therefore, are areas in which natural and biodiversity, such as small mammals (rodents); which are anthropic elements interact [32], forming a complex mosaic known to be very sensitive to changes in the of patches of land that differ in the type and intensity of heterogeneity of the habitat in natural areas [49] and human intervention [33]. modifications in agricultural habitats [50, 51]. Micro- The landscape has been severely changed since mammals are considered pest in agro-ecosystems, causing more productive areas were required for different benefits great damage to crops [52, 53]. However, taking a different of the human population (food and economic), which has perspective into account, these animals are an interesting led to a dramatic decrease in spatial areas, forcing many biological model since they play an important ecological species of wildlife, to persist in the remains of highly role. Rodents are different species of carnivores and prey
of birds’ species. [54]. Additionally rodents are seed and September being the rainiest months, with maximum fruit consumers [55, 56]; and therefore play an important measurements of 50 to 140 mm [57]. The dominant use of role in the dispersion of different plant species, being an land reported by ……..[58] are primarily agricultural interesting bio-indicator group to analyze. Our work aims systems which occupy 63% of the territory (32374.93 ha), to determine how modernization impacts the degree of forest take second place with 15% of the territory automation (using a gradient of greater - irrigated areas, (7798.394 ha), followed by 14% (7771.994 ha) which the traditional agriculture - to lower modernization - traditional secondary vegetation and scrub which takes 6% (3291.363 agriculture and natural environments) for the abundance ha) and finally the use of the soil with less representation of rodents in the state of Puebla, Mexico. It is estimated in the study area was grassland (214.77 ha) along with that the composition of the small mammal community will urban area (205.8 ha) with only 1%.
be more similar between natural vegetation and traditional
agriculture areas, whereas the irrigated (intensified) areas Cartography: To determinate the agricultural systems that are very different in rodents assemblages. were sampled, a characterization of land uses was made in MATERIALS AND METHODS were obtained from the website of the United States Study Area: This study was conducted in the Valley of downloading them, they were imported to the Geographic Libres in the towns of ¨Libres¨ and ¨Oriental¨ located on Information System (GIS) IDRISI V. 16.0 format. This GIS the central eastern region of the state of Puebla (Mexico). specializes in the processing of images, by which a Its geographical coordinates are the Parallels in UTM X supervised classification was used to compile the land 625156.493687 and 660187.773909 and, Y 2162311.213249 uses. After the import process, the images were processed and 2126239.656131, 14N (WGS84). These areas are in the using the SEGMENTATION module which allows us to region of the Transverse Volcanic Axis. ¨Libres-Oriental¨ generate an image of pixel segments, which have similar is known for having a semidry and mild temperate climate reflectance values and can be identified within a range of with an annual average temperature of 14°C and average homogeneous spectral similarity. The SEGTRAIN module annual precipitation of 590 mm, the rainy season spanding was subsequently used, which allows us to assign the from the months of April to October, with August and names polygons classification directly from the file
the two municipalities. We used satellite images which Geological Service (USGS: http://glovis.usgs.gov/). After
Fig. 1: Study area of ¨Libres Oriental: Land uses and geopolitical division of the Libres-Oriental Valley.
segmentation and generate spectral signatures. Finally the In order to make the identification of rodent, hairs MaxLike module was used which is based on the were sampled to flake and marrow, so that they could be probability of density function associated with a compared with the collection of hair from the Center for particular training site signature. Pixels are assigned to the Agroecology and Environment [61, 62]. None of the most likely class, based on a comparison of the latter organisms were sacrificed, once the sample was taken, the probability, that it belong to each of the signatures being critter was released, in the same place where it was considered [59]. Altogether seven land uses were captured.
detected: grassland (Pst), uncovered soil (Brsl), natural Each of samples was tagged based on the types of vegetation (Ntr), irrigation (Irrg) agriculture, traditional management, the trap is in which they were captured, (Agr) agriculture, urban areas (UrbAr) and water (Wtr). date, type of agroecosystem, farming, System Once completed, the classification took place with a Management (active and inactive), season (dry or wet), as stratification that included different categories, selecting well as different morphometric: length of ear, leg, body, areas that are in the same range of surface-level plots. tail and sex. Each one of the samples was tracked through This in order to reduce the effects of edge spots. Likewise a TRIMBLE GPS.
different selected areas were grouped in bases to
similarities of physical characteristics (usually of a factor Statistical Analysis: The accumulation Patterns rodent of environment of topographic types, urban area, rivers, species of sampling effort were analyzed for the different lagoons, elevations, locations, municipalities etc). The types of agricultural systems (active irrigation, inactive Libres-Oriental Region presents to have a reduction in the irrigation, active and inactive temporary), the natural area natural area (composed of coniferous forest, pinus and and the clustered alternative management (irrigation and tazcate forest), caused by the intensive use of agricultural temporary); The first step consisted in prove that the areas. Farming systems are distinguished by various sample was representative of the total richness existing types of management: Seasonal agriculture (active and through the analysis of the sampling effort reached. For inactive), generally with traditional practices, which this, accumulation curves were realized [63, 64], in which present edge of vegetation and/or secondary vegetation the number of the registered species were presented as the boundary between each crop and practices that according to increase of the sampling effort, the species involve (maize-zucchini, maize and squash and maize- accumulation curve as a function of the sampling effort, alfalfa) and crop rotation practices. On the other hand where it is assumed that the total richness is the number irrigation agriculture (active and inactive), are mostly used of species that would be found with an infinite effort with external inputs and does not have edges of (asymptote) [65], this serves to avoid bias comparisons vegetation or traditional practices that were mentioned when the density of individuals vary between such
above. sampling units.
Sampling Design: In the study area, four types of measures of completeness of inventories the sample agro-ecosystem were taken into account: 1) active coverage (sample coverage), which represents the fraction agricultural, 2) inactive agricultural, 3) active irrigation and of the total abundance of the community that is 4) inactive watering. Likewise, in order to compare if there represented in the sample: which means the number of is a significant loss of biodiversity sampling areas were individuals of universe from which the sample is obtained, established in natural areas. All sampling sites were divided by the number of individuals observed in the established based on a design at random with five sample [66]. One reason to use the sample coverage is sampling sites by type, with four replicas of each of the that the representativeness of a sample depends not only five sampling sites during the dry season (February, on numbers of missing species, but also their average March and May 2013) and rainy (August, September and abundances [67]. Each estimator predicts a completeness
October, 2013). of the inventory, which shows an acceptable percentage
A total of 40 samples of rodents were done, in which according to the biological group [68, 69].
all sites were sampled during 2 consecutive days. A total A U analysis designed by Mann-Whitnney was of 41 traps were placed at each site in the form of asterisk performed to determine if there are differences in the with five traps for each of the lines that make up the sampling seasons (dry and wet). On the other hand a asterisk [60] each one of the traps was separated five factorial correspondence analysis was performed (AFC) in meters apart. 1640 Sherman traps were baited with a order to determine what species of rodents are spatially mixture of oats, vanilla extract and peanut butter. related to the type of management, structure and The SPADE Program was also used, which shows the
cultivation of agrosystems. Finally Kruskall Wallis and species with lower abundance were M. mexicanus 1%
Dunn tests were conducted to determine if there are frequency of occurrence FA, D. phillipsii and R.
significant differences in relation to the management of megalotis had 2% of FA, being the rarest species.
agro-systems. According to the obtained results from the
RESULTS obtained 100% of inventory in the area of natural One hundred sixteen two (126) small mammals that active irrigation (6.61 species richness) 100% in areas of represent two taxonomical families Muridae and inactive irrigation (two species richness), 88.89% in areas Heteromyidae were collected and 10 species (Dipodomys of active temporary (4.46 species richness) and 100% in phillipsii, Liomys irroratus, Microtus mexicanus, Mus areas of inactive temporary (two species richness) (Fig. 2).
musculus, Peromyscus difficilis, Peromyscus levipes, Grouping the types of management in agricultural Peromyscus maniculatus, Peromyscus melanotis, irrigation and temporary agricultural and maintaining Peromyscus mexicanus y Reithrodontomys megalotis) natural vegetation areas, our work continues according to the sampling (Table 1), the site with the maintaining high levels of inventory completeness, since largest number rodents were the ones located in the 100% inventory is observed in the natural vegetation natural vegetation (Ntr) with 72% of frequency (7 species richness) and in the temporary agricultural appearance (FA), followed by active agricultural areas (5 species richness), while for irrigation agriculture had (Agr Act) with 11% of FA, areas of active irrigation (Irrg 85.71% (6.94 species richness) (Fig. 3).
Act) with 10% of FA, the areas of inactive irrigation (Irrg According to the results, there are not significant Inc) with 4% of FA and finally areas of inactive agriculture differences in the sampling seasons (dry and rainy), (Agr Inc) with 3% of FA. In order to concentrate data, except with the species L. Irr (U = 33; Z = 2.6231;
temporally agriculture areas (Agr Act and Agr Inc) p = 0.008).
agricultural areas, areas of irrigation (Irr Act and Irr Inc) The values of the AFC represents the spatial and natural vegetation (Ntr) were grouped together; this aggregation that represents the community of rodents new category was named ¨alternative management¨; in with the types of management (active agriculture, inactive which the biggest contribution of samples were agriculture, irrigation active and inactive irrigation) and in determined with 72% of FA in abundance, however the natural area. There is a clear difference between the agricultural and irrigation sites had the same percentages families Muridae and Heteromyidae. The first family is with 14% of FA in abundance. Species with greater represented by the species L. Irr and D.Phi, which are abundance in the management and alternative associated with the handling of agricultural asset. On the management was P. maniculatus 31%, followed by the other hand, the family Muridae and in particular the species P. melanotis 20% of FA. On the other hand the mouse genus and species R.Mgl are found to be completeness analysis of the inventory, our work vegetation (7 species richness), a 89.55% in areas of
Table 1: Relative abundance of small mammals in different types of management: management in: Natural vegetation (Ntr), Agriculture active inactive (Agr Act), Agriculture (Agr Inc), irrigation active inactive (Irrg Act), irrigation (Irrg Inc). Alternative management: natural vegetation (Ntr), traditional agriculture (Agr) and irrigation (Irrg).
Management Alternative management
--- ---
Species Ntr Irrg Act Irrg Inc Agr Act Agr Inc Total AGR Ntr Irrg Total
Family Heteromyidae
Kangaroo rat (Gray, 1841) 3 3 3 3
Toothrow irroratus (Gray, 1868) 14 1 8 23 8 14 1 23
Family Muridae 0 0
Microtus mexicanus (Saussure, 1861) 1 1 1 1
Mus musculus (Linnaeus, 1758) 2 2 4 2 2 4
Peromyscus difficilis (J. a. Allen, 1891) 10 2 12 10 2 12
Peromyscus levipes (Merriam, 1898) 4 1 1 6 2 4 6
Peromyscus maniculatus (Wagner, 1845) 31 2 3 3 39 3 31 5 39
Peromyscus melanotis (J. A. Allen and Chapman, 1897) 19 4 2 25 19 6 25
Peromyscus mexicanus (Saussure, 1860) 10 10 10 10
Harvest mouse megalotis (Baird, 1858) 3 3 3 3
Total 91 12 5 14 4 126 18 91 17 126
Fig. 2: Richness estimate for rodents species (Agricultural types). Ntr= natural vegetation, Irrg Act= active irrigation, Irrg Inc= inactive irrigation, Agr Act= active temporary and Agr Inc= inactive temporary
Fig. 3: Richness estimation for rodent species (grouping land uses). Nrt= natural vegetation, Agr= temporary agricultural and Irrg= irrigation agriculture.
Fig. 4: Correspondence Analysis of rodent's abundance and management.-Rodent species abundance has important spatial relationships with traditional management. Curve lines represent the most important spatial relationships.
Natural vegetation (Ntr), Agriculture active inactive (Agr Act),
Fig. 5: Correspondence Analysis between the main matrix land uses and rodents abundance. The most important abundance are close to natural vegetation (Ntr), whereas three species are associated to Traditional Agricultute (Agr) and one species is spatially associated to Irrigated areas (Irrg).
associated with inactive irrigation, inactive agriculture and agriculture inactive, therefore inactive agriculture natural area management. However the species P. Lev is behaves in the similar form with active and inactive associated with inactive agriculture and natural area watering. P. Mni presents differences between natural
(Fig. 4). areas and management; However between these
Agriculture (Agr Inc), irrigation active inactive (Irrg there is no difference between active agriculture, Act), irrigation (Irrg Inc) the species D.Phi (Dipodomys active irrigation and agriculture inactive; However phillipsii), L. Irr (Liomys irroratus), M. Mx (Microtus inactive watering presents differences compared to the mexicanus), M. Mu (Mus musculus) P.Dfi (Peromyscus rest of the management, being more similar to the difficilis), P. Lev (Peromyscus levipes), P. Mni inactive watering. P. Mln presents significant differences (Peromyscus maniculatus), P. Mln (Peromyscus in abundances with respect to natural areas and the melanotis), P. Mx (Peromyscus mexicanus) and R.Mgl different types of management; being the active (Reithrodontomys megalotis). management of the same statistical group and the inactive Regarding the grouping of the types of management, belong to another statistical group. The natural area has the species D. Phi, L Irro, M. Mus, P. Lev were observed a greater presence of P. Mx compared to all the other within the AFC to be associated with traditional managements, however the presence of this species in agriculture, the only species spatially associated with the inactive agriculture is not different from the inactive management of irrigation is the species M. Mx, the same irrigation.
pattern is also observed but with a different system in the In relation to the grouping of the types of area of the species R. Mgl and P. Mx. although the P. Mln, management, the natural area and traditional agriculture P. Mni and P. Dfi species, are mainly present in the natural do not show significant differences in the L. Irr, P. Diff area and in watering (Fig. 5). and P. Mx species, however, there is a significant According to Kruskal Wallis and Dunn tests the difference between these and irrigated agriculture. On the L. Irr species does not present significant other hand P. Mni and P. Mln species show significant differences between traditional agricultural areas and the differences between natural areas and agricultural areas, natural area; However there are differences between without there being any differences between these two agriculture irrigation (active and inactive) and traditional (Table 2).
Table 2: Statistical analysis of management and alternative management: Ntr (natural vegetation), Agr Act (active agriculture), Agr Inc (inactive agriculture), Irrg Act irrigation active, Irrg Inc (inactive irrigation) and Agr (traditional agriculture) Irrg (irrigation).
Species
---
L.Irr P.Dfi P.Mni P.Mln P.Mx
--- --- --- --- ---
Management Avr Sig df p H Not significant Avr Sig df p H Avr Sig df p H Avr Sig df p H
Ntr 141.5 A 4 0.029 10.170 179 a 4 0.0003 21.227 158 a 4 0.004 14.1579 144 a 4 0.03 10.147
Agr Act 129 52 b 74.5 b 92 b
Irrg Act 45.5 B 48.5 64 57.5 c
Agr Inc 21 Bc 39 bc 30.5 c 34.5 de
Irrg Inc 14 C 32.5 c 24 23 e
Management
Alternative Avr Sig df p H AVR GIS DF p H AVR GIS DF p H AVR GIS DF p H AVR GIS DF p H
Agr 150 A 2 0.059 6.373 140 a 2 0.022 7.212 179 a 2 0.0001 18.293 158 a 2 0.0005 14.1542 144 a 2 0.005 10.147
Ntr 141.5 121 91 b 105 b 126.5
Irrg 59.5 B 90 b 81 88 80.5 b
DISCUSSION changes, being the anthropic pressure the spark of Although the agrosystems have been considered as they depend on certain physical and/or environmental habitats with low diversity [70], mainly elicted by the features.
change of soil uses and the agriculture intensification, it These organisms are considered as a plague owing to has provoked the simplification of landscapes and then the confusion with the exotic species, which were the loss of a high number of species. That could be true introduced by man. For instances, the Mus musculus for some places and agricultural regimens [71]. Our system species, which is present in the area of study, is the has an intermediate diversity due to it has been observed indicator of habitat alterations by anthropogenic activities 10 species. Peromyscus maniculatus, which is the most [75]. Its presence was also detected in different abundant, was found in all the analyzed systems except in managements; in the active irrigation agricultural (alfalfa the inactive agricultural. The agricultural spaces with less y maíz) and traditional agricultural (maiz with calabaza diversity and abundance were inactive irrigation and the crops), also in edges of secondary vegetation and inactive agricultural zones which have just two species harvested crops [76, 77].
respectively. Because of the composition and structure of the
However in the agrosystems, particularly in the secondary natural vegetation of edges in the crops, a agricultural systems with traditional management of the greater abundance of rodents was obtained in the natural area of study, have been created refuge zones for the little zone and in the traditional systems. The agrobiodiversity mammals. They are distinguished by natural vegetation inside the crops constitutes a structural mosaic extremely edges (Pinus sp. Quercus sp. agaves, etc.) or fruit trees interesting and useful for species such as the rodents (peaches, capulín) around crops. On the other hand, the [78]. As can be seen in this study and according to the risk zones present the least abundant of rodents due to results, there is a greater relative abundance in the natural the lack of edges, which has provoked the total or zone and in the traditional agricultural without differences partial loss of species inside and outside of the for species such as Peromyscus maniculatus y agrosystems. Hence the importance of preserving Peromyscus melanotis, between these kind of vegetation.
the edges in the agricultural systems, which allows the Therefore, the traditional agricultural zones are those species conservation working as biological corridors places that could maintain the same management level and (small and medium scale) of some species [72, 73]. conserve an important rodent group. In the area of study This supports our hypothesis that gives a nesting of exists a great modernization in the irrigation systems since several species as occurs with the Dipodomys phillipsii the 1970s, nonetheless there are remaining population of species, which are in the traditional agricultural systems, micromammals. It has been observed different species since this specie is in the Mexican Official Standard 059, assemblages and it has been demonstrated that the Semarnat 2010 is in the category subjected to special composition of rodents communities could vary greatly
protection. with little changes in the vegetation structure [10, 51, 79].
The rodents are widely studied owing to its biology, In the majority of rodents species exists similar broad distribution and biodiversity. They are key groups, abundances between the natural and agricultural systems, because the birth rate is high. Generally, they do not such as Peromyscus maniculatus, Liomys irroratus, present conservation problems and the most of the Peromyscus melanotis,Peromyscus difficilis y species survive in trouble regions [74]. Nevertheless, Peromyscus mexicanus, which are linked to natural zones some rodent species are very sensitive to environmental and species as P. Mni, which is considered generalist abundant reduction or the loss of biodiversity; besides
[80, 81]. Hence, all of them can resist some degree of temporary and it is because these are annual, intensive agricultural intensification. For them are not important the and highly mechanized crops, many occasions tend to be gradient of management intervention by people (presence homogeneous, provide suitable conditions habitat for of human beings in the agricultural spaces), but the some plants and animals in the short term as it was intensification degree (use of agrochemicals). Human mentioned before [43, 44]. Moreover, the active irrigation intervention gives permanency benefits in the habitats agro ecosystems and the temporary one, it was observed created by man, due to it provides resources (crop’s the presence of rodents because of the availability of food stubbles) and habitat (natural vegetation edges). On the and the type of management than men give to the other hand, the rodents community presents a species systems. As for the alternative management arrangement, that is related to only active agricultural spaces it was observed that the natural area presents higher (traditional agriculture): D. phillipsii, however it has been species richness, however it was also observed almost the reported that it prefers an habitat as grassland and low same richness, without forgetting that this system is very shrub [82]; As it has been mentioned, the traditional homogeneous and could take a few to safeguard these agricultural zones have these two semi-natural vegetation species or other guild, in contrast to the temporary spaces that allow to find the ideal conditions for it. The L. agricultural system is a system that presents edges that Irr. and P.Diff. species has been reported in the nearby allow to these species remain in the area.
bushes in the nopales [80], but in this study was found In the total inventory obtained was good because it that it is linked to the traditional agricultural and in the had 100 % of estimated species by nonparametric natural zone, in the case of the first species and in the estimators for the natural area, inactive irrigation, inactive irrigation zone and natural zone, in the second. temporary inactive and temporary, which show a good full It should be noted that the most tolerant species to a high sample register and it was also sufficient to cover all intensification was M. Mx. The others are but in a lower present species in these agricultural systems and natural degree such as M. Mu, P.Dfi, P. Lev, D. Phi, L. Irr, P. Min area, however there was an area which had less than 100%
y P. Mnl. There are species which are exclusives of the as occurred with the active irrigation system, irrigation natural zone as P. Mx and R. Mgl. and temporary that had almost 90% of completeness of In spite of the high agricultural intensification, abiotic the inventory, which indicates that a specie was not factors (weather, precipitation, availability of resources, registered, it has to denote that, there were few species in etc.) and biotics (inter-specific interactions, competence, these areas because this place is Puebla barn, which has predation, etc) the Libres-Oriental’s micro-mammals provoked the richness reduction and the abundance of present different assemblages. It should be recalled that these organisms and has also been reduced temporary the biotic and abiotic factors could be independent or agricultural systems, obviously the total loss or partial dependent in spatial and temporal scales in the edges of natural vegetation, because small mammals that assemblages [83]. By understanding the general patterns have adapted to the adverse conditions that men proved of the communities for the habitat, it is important to as reflected in this area as tech.
evaluate the community structure in multiple spatial scales
[84], to be emphasize there are few work about this habitat CONCLUSION trough the spatial scales [85].
Other species such as P. mexicanus y R. megalotis Heterogeneity of agro ecosystems of Libres-Oriental, presented just in the natural zone, being these exclusive has an important presence of small mammals, these of natural systems; meanwhile L. irroratus y D. phillipsii species are in function of the dynamic agriculture and were found just in the traditional agricultural systems of hydric that is developed there and seems that the maíz crop. The latter two species could present a good agricultural intensification significantly impacts the tolerance of management. diversity of rodents, because it allows to the generalist The accumulation curve of the generated species a use of an extensive landscape. However, management by the nonparametric estimators for coniferous forest and pine forest are unique habitats presence-absence data, indicate the richness (P. mexicanus and R. megalotis), apparently associated (Number of species) and the local assemblies integration. with soil structure and availability of seeds and organic Furthermore, the complementarity that exhibit rodents’ matter, so that the loss of these natural areas and assemblies established in each of the Libres Oriental agro traditional agricultural practices (use of natural vegetation ecosystems evidenced by the richness of these edges) that would mean the disappearance of species that individuals. However, there are agro ecosystems with the apparently cannot take advantage of the highly modified presence of only 2 species in the irrigation systems or habitats.
The main threats to biodiversity can be divided into 4. Rosenzweig, M.L., 2003. Reconciliation ecology and two categories: inactive crops (land abandonment) and
the intensification of agriculture. For the conservation of these places as reservoirs of diversity depend on good management of traditional agricultural systems, because these provide suitable habitat for mammals and for some species that are strictly dependent on this type of habitat, while others adopt to a wide range of habitats. Some species reach their cycle throughout the year at the cultivation edges, but for species that use the crop matrix as habitats for certain periods of time, it is vitally important to conserve these agro ecosystems, especially those holding traditional practices. These could have implications for the management of inactive habitats and generally in agricultural landscapes. So the conservation of fauna in the Libre-Oriental agro ecosystems does not be based on Generic Management Guidelines. The habitat diversity and the different species needs, require counseling for the local management with the support of multi-disciplinary experts to provide information, monitoring and the implementation of a control system.
Moreover, the development of indexes and innovative models with realistic exposure scenarios, that could be used to evaluate the habitat requirements and evaluate the cost taking into account the specificities of the region.
ACKNOWLEDGMENT
We thank the National Council for Science and Technology (CONACYT) for funding the project
"Landscape and mosaic stricture ideas importance in bioindicator groups (vertebrates and beetles) in the State of Puebla" Project Reference. CB-2008-01-100715 also to Biol Yuliana Grisel García Martínez and Luis Daniel Garcia Jimenez for their advices. Juan Jiménez García, Javier Cordero Valeriano and Jorge Ramirez Domínguez for their company and help in the field work. Three anonymous reviewers and the Editor of the magazine.
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