Pedregal De San Angel Research Articles

New Records of Staphylinids1 in the Pedregal De San Angel Ecological Reserve, Mexico City, Mexico

New Records of Staphylinids1 in the Pedregal De San Angel Ecological Reserve, Mexico City, Mexico

Urban green spaces and their relationship with groundwater quality: the case of a shallow aquifer in the south of Mexico City

Water supply security is a top priority for decision-makers in cities. Urban population growth increases water demand from aquifers, while urban expansion reduces water infiltration and boosts water pollution sources. Urban green spaces are a few of the remaining infiltration areas. Therefore, they are essential for water supply and urban hydric resilience. The urban dynamic directly influences shallow aquifers, but they usually are unappreciated. This work illustrates the relationship between urban green spaces and city water quality by evaluating the influence of urban green space, Reserva Ecológica del Pedregal de San Angel (REPSA), on a shallow aquifer in Mexico City. Five springs were sampled: two upstream of REPSA, a spring within REPSA, and two downstream. Because the study area is mainly residential but with an industrial history, water quality was tested based on microbiological pathogens, nutrients, pharmaceutical drugs, and heavy metals. Results showed an enhancement of water quality of the shallow aquifer in the sampling points downstream of REPSA for some of the pollutants. These results illustrate how urban green spaces can help to dilute pollutants present in the water of shallow aquifers, increasing water quality in cities.

A quick evaluation of ecological restoration based on arthropod communities and trophic guilds in an urban ecological preserve in Mexico City

BackgroundRestoration practices usually emphasize on the structural part of the biodiversity; also, most studies have focused on plants and very few have been conducted on arthropods and its function after restoration. The Pedregal de San Angel Ecological Reserve (PSAER) is a protected area immersed in Mexico City and it has been drastically affected by different anthropogenic disturbances. The aim of this study was to compare the relative diversity, richness, and abundance of species level identification, but also the composition through an analysis of ordination of taxonomic (species, family, and order level) and functional (trophic guild) traits of arthropods in three sites subjected to ecological restoration within the PSAER. Restored sites were also compared to conserved and disturbed sites, to evaluate whether restoration efforts are effective at the reserve.MethodsArthropods were sampled using pan traps during September 2013 in 11 sites (three restored, four conserved and four disturbed) inside the PSAER. All sampled species were taxonomically identified at species of morphospecies (inside a family) and assigned to a trophic guild. Differences in diversity, richness and abundance were evaluated through effective number of species, comparisons of Chao’s1 estimated richness and a non-parametric Kruskal–Wallis test, respectively. Both taxonomic and trophic guild composition were evaluated using a multivariate analysis and a post hoc test.ResultsWe found some differences in richness, abundance, and diversity between sites, but not a clear pattern of differentiation between restored to disturbed sites. The NMDS showed differences at species and order level, and with trophic guilds, among site types. Families were not useful to differentiate types of sites. Regarding guilds, predators were more abundant in conserved sites, while phytophagous insects were more abundant in disturbed sites.ConclusionsSpecies and order level were useful to identify differences in communities of arthropods in sites with different management. The trophic guild approach provides information about the functional state of the restored sites. Nevertheless, our quick evaluation shows that restoration efforts at PSAER have not been successful in differentiate restored to disturbed sites yet.

Rehabilitation of a whiskered screech-owl (Megascops trichopsis) in a wildlife care center in Mexico City

A whiskered screech-owl (Megascops trichopsis), the second smallest owl of the genus Megascops in Mexico, was admitted at the Wildlife Care Center of El Pedregal de San Angel Ecological Reserve. After performing the physical examination we found no pathologies, but the owl was not able to fly or to hunt successfully. Based on these we determined that the owl was candidate for rehabilitation for the purpose of reintroducing it to the wild. During the rehabilitation, short indoor, long outdoor and vertical flights were carried out. In addition, we offered different live preys to simulate hunting behavior. After rehabilitation, we take blood and fecal samples. Also, a complete ophthalmological examination was carried out. Before the release, a general physical evaluation was carried out where the owl showed an adequate weight (120 g). We did not find endoparasites, or alterations in the ophthalmological exam. The owl was alert and elusive, with no signs of habituation to human contact. Also, a successful flight and hunting behavior was observed. Their hematological values were within the optimal ranges reported for Megascops asio and Asio flammeus. This is the first report of hematological and biochemical values of this species.

Molecular detection of Bartonella, Ehrlichia and Mycoplasma in feral dogs of El Pedregal de San Angel Ecological Reserve in Mexico City.

Free-ranging and feral dogs represent a group of unattended companion animals. They impact wild animal populations by predating native species, displacing predators and introducing exotic pathogens. The aim of this work was to describe the molecular occurrence of Rickettsia, Ehrlichia, Anaplasma, Mycoplasma and Bartonella in feral dogs. The study was carried out in the last relict of a protected area in Mexico City. Blood clots samples from 19 dogs were obtained and analyzed for detection of specific fragments of the 16S-rRNA gene for Anaplasma, Ehrlichia and Mycoplasma and citrate synthase (gltA) for Bartonella and Rickettsia. Our results showed that DNA from three bacteria species (Bartonella vinsonii subsp. berkhoffii, Ehrlichia canis and Mycoplasma haemocanis) was present with frequencies ranging from 5.3 to 15.8%. This is the first record of B. vinsonii subsp. berkhoffii and M. haemocanis in dogs from México, and also the first finding of Ehrlichia canis in Mexico City. It is important to perform surveillance of feral dog populations in order to identify the impact of these pathogens on wild animal populations and Public Health in order to establish prevention and protection programs.

Evaluating Socio-Ecological Interactions for the Management of Protected Urban Green Spaces

Protected urban green spaces (PUGS) are exposed to numerous disturbances and threats since they are immersed in highly dynamic socio-ecological systems. PUGS in highly urbanized cities require particular conservation strategies. Here, we propose an approach for PUGS management which integrates three components: i) scientific knowledge (monitoring/restoration), ii) community interaction with the environment, and iii) management decision. Our hypothesis asserts that the intersection of these components should produce a solid management program, provided that the obtained multidisciplinary knowledge meets the needs of information required by the community and decision makers. We tested this hypothesis for a small PUGS located within Mexico City at the National Autonomous University of Mexico campus that holds the Ecological Reserve of Pedregal de San Angel. Through a participatory approach we built a mental model to understand the perceptions of different campus actors (students, academics and administrators), and their social and ecological relationships with this PUGS. Our findings provide insight into the actors’ perceptions and concerns and suggest that the interactions among the three components, although important, are not self-generated and must be constructed. The findings also suggest that one of the management problems is the mismatch between scientific knowledge and conservation programs. It is paramount to include generated knowledge into management and monitoring programs. The complexity of the PUGS requires an active collaboration among actors and monitoring the development of management strategies using the three components while taking the conservation goals into account.

First quantitative data on the ectoparasitic mites of Sceloporus torquatus (Squamata) from the Ecological Reserve of Pedregal de San Angel in Central Mexico

Twenty four live lizards Sceloporus torquatus were collected in the rainy season in the Reserva Ecológica del Pedregal de San Ángel (REPSA) in Mexico City to establish their ectoparasite census. A total of 1251 mites belonging to four species in three families (Ornithodoros talaje in Argasidae, Geckobiella pelaezi and Geckobiella texana in Pterygosomatidae, and Eutrombicula alfreddugesi in Trombiculidae) were collected. This is the first record of O. talajei for this host species. We detected some differences in the infestation parameters of the four mite species. The prevalence of G. pelaezi, G. texana, and E. alfreddugesi was relatively high (>70%) and statistically different from that of O. talaje (<20%). Abundances of G. pelaezi and E. alfreddugesi were higher than in O. talaje and G. texana, and the latter species showed the lowest mean intensity. Further investigations are necessary to verify these differences and reveal their causes.

Phylogenetic study and taxonomic revision of the Xanthoparmeliamexicana group, including the description of a new species (Parmeliaceae, Ascomycota).

Xanthoparmelia (Parmeliaceae, Ascomycota) is the most species-rich genus of lichen-forming fungi. Species boundaries are based on morphological and chemical features, varying reproductive strategies and, more recently, molecular sequence data. The isidiate Xanthoparmeliamexicana group is common in arid regions of North and Central America and includes a range of morphological variation and variable secondary metabolites – salazinic or stictic acids mainly. In order to better understand the evolutionary history of this group and potential taxonomic implications, a molecular phylogeny representing 58 ingroup samples was reconstructed using four loci, including ITS, mtSSU, nuLSU rDNA and MCM7. Results indicate the existence of multiple, distinct lineages phenotypically agreeing with X.mexicana. One of these isidiate, salazinic acid-containing lineages is described here as a new species, X.pedregalensis sp. nov., including populations from xerophytic scrub vegetation in Pedregal de San Angel, Mexico City. X.mexicana s. str. is less isidiate than X.pedregalensis and has salazinic and consalazinic acid, occasionally with norstictic acid; whereas X.pedregalensis contains salazinic and norstictic acids and an unknown substance. Samples from the Old World, morphologically agreeing with X.mexicana, are only distantly related to X.mexicana s. str. Our results indicate that X.mexicana is likely less common than previously assumed and ongoing taxonomic revisions are required for isidiate Xanthoparmelia species.

Mobilization and synthesis of seed storage and LEA proteins during natural priming of Buddleja cordata and Opuntia tomentosa

Background: In crop plants, the induction of seed storage protein mobilization and synthesis of LEA family proteins has been extensively described.Question: Natural priming promotes mobilization and synthesis of seed storage and LEA proteins in wild plants?Species studied: Buddleja cordata and Opuntia tomentosa. Study site: Reserva Ecológica del Pedregal de San Angel (REPSA).Methods: Natural priming treatments were applied to B. cordata and O. tomentosa seeds during one and six months respectively. Phosphorylated proteins fractions were obtained by affinity chromatography from control and treated seeds. Differences in protein pattern between control and treated seeds were determined by electrophoresis and the treated seed proteins were identified by LS/LS/MALDITOF. Results: The phosphorylated fraction of B. cordata treated seeds presented two proteins that were absent in the control protein fraction. These two proteins were identified as two different 11S globulins. The phosphorylated fraction of O. tomentosa treated seeds also presented two proteins that were absent in the control protein fraction. These two proteins were identified as a 12S globulin and a LEA protein.Conclusion: Seeds are subjected to changes in soil water content during their permanence in soil; this natural priming process promotes mobilization and synthesis of storage and LEA proteins that are involved in stress resistance.

Recovery of Basalt Substrate for Xeric Scrub Restoration in a Lava Field in Mexico City

The alteration of biophysical conditions in cities limits restoration and management of ecosystems in urban areas. The Pedregal de San Angel Ecological Reserve (PSAER) protects important remnants of a unique type of xeric scrub in a lava field embedded in Mexico City. Unearthing and replacing basalt rock have been carried out in PSAER to recover rocky basalt substrate, a physical feature in this type of location, in areas where it has been removed or buried and invading species have become predominant. To obtain an overview of the recovery of the plant community following restoration actions, we sampled and compared vegetation structure in terms of species richness, composition, relative coverage and diversity in 12 sites of PSAER: five conserved areas, three restored areas, and four disturbed areas. Restored areas presented intermediate values with respect to those in conserved and disturbed areas for total and non-ruderal native species richness, Simpson dominance index, and relative cover of non-ruderal and exotic species. Our results show that replacing and unearthing rock are still insufficient but are promising methods to promote restoration of this xeric scrub and similar plant communities that develop on lava fields.

Recent Collecting Reveals the Presence ofBoettgerilla pallens(Stylommatophora, Boettgerillidae) in Mexico

Abstract: An introduced slug, Boettgerilla pallens Simroth, 1912, was found both in the Pedregal de San Angel Ecological Reserve, Ciudad Universitaria, Mexico City and Teopancingo, Puebla. Although this slug is native to Europe, it has been recently recorded from various locations around the world. Through dissection, the diagnostic characters were identified as the spindle shaped swelling along the vas deferens characteristic of the genus, and the elongate shape of the bursa copulatrix typical of this species. In addition, cytochrome oxidase I mtDNA, and 16S and 28S ribosomal RNA genes were sequenced and used in a phylogenetic analysis to confirm its identity.

Soil microarthropods and their relationship to higher trophic levels in the Pedregal de San Angel Ecological Reserve, Mexico.

Soil fauna is essential for ecosystem dynamics as it is involved in biogeochemical processes, promotes nutrient availability, and affects the animal communities associated with plants. In this study, we examine the possible relationship between the soil microarthropod community on foliage production and quality of the shrub Pittocaulon praecox. We also examine the arthropods associated to its foliage, particularly the size of the main herbivores and of their natural enemies, at two sites with contrasting vegetation cover and productivity. The diversity of soil microarthropods was assessed from soil samples collected monthly under P. praecox individuals over 13 mo. Specimens collected were identified to species or morphospecies. Shrub foliage productivity was evaluated through the amount of litter produced. Resource quality was assessed by the mean content (percentage by weight) of N, C, S, and P of 30 leaves from each shrub. The mean size of herbivores and their natural enemies were determined by measuring 20 adult specimens of each of the most abundant species. We found a higher species richness of soil microarthropods and foliar arthropods in the open site, although the diversity of foliage arthropods was lower in the closed site. Shrubs growing in the closed site tend to produce more, larger, and nutritionally poorer (lower nitrogen content) leaves than open site. Herbivores and their natural enemies were also larger in the closed site. We found a significant positive relationship between the diversity and species richness of foliar arthropods and the nitrogen content of leaves. In general, species richness and diversity of both the foliar and soil fauna, as well as the size of organisms belonging to higher trophic levels, were affected by vegetation cover and primary productivity at each site. These findings highlight the need to simultaneously consider at least four trophic levels (soil organisms, plants, herbivores, and natural enemies) to better understand the functioning of these systems and their responses to environmental changes.

First report of the genus Physaloptera (Nematoda: Physalopteridae) in Lithobates montezumae (Anura: Ranidae) from Mexico

Nematode third stage larvae of the genus Physaloptera (Nematoda: Physalopteridae) were recovered from the stomach of Lithobates montezumae (Anura: Ranidae) collected in the Pedregal de San Angel Ecological Reserve in Mexico D. F. (19º11’6.50” N, 99º11’41.42” W; 2 312 m asl). The morphology of the larvae is briefly described and a list of previously recorded localities and hosts in Mexico is given. This study is the first record of Physaloptera sp. parasitizing L. montezumae, and also represents the first helminthological record for anurans in this locality, as well as a new locality record for the nematode genus.

Seed rain after a fire in a xerophytic shrubland

Fire causes a reduction of plant cover due to the death of several structures, especially of those that are not isolated from high temperatures; such as seeds and fruits. After a disturbance the availability of diaspores is crucial for the recovery of the community. This work studied the composition and abundance of the seed rain in the xerophytic shrubland of the Pedregal de San Angel Ecological Reserve, located at the Universidad Nacional Autonoma de Mexico campus in Mexico City, which was affected by a surface fire. In order to understand the role of diaspores in the natural regeneration of a burned site, seed traps were placed on 2 sites, one affected by the fire and the other in an unburned location. During 1 year the dispersed seeds and fruits were collected and identified. Results showed that species richness, life forms, and dispersal syndromes were different between sites. The highest abundance and richness values were observed in the burned site. This work offers basic data on the availability of species as diaspores, information which is useful for potential restoration strategies especially in those areas under constant anthropogenic disturbances.

Citogenética de Calochortus barbatus (Liliaceae: Calochortoideae) de la Reserva Ecológica del Pedregal de San Ángel, en México, Distrito Federal

Meristematic root cells from seeds of individuals of Calochortus barbatus from Reserva Ecologica del Pedregal de San Angel, Distrito Federal, Mexico were analyzed cytogenetically using a surface spreading and airdrying method. The chromosomal number, 2n = 4x = 36 (x = 9) was corroborated. The mitotic karyotype was established for the first time for this species as 14m + 22st. The asymmetric karyotype, which includes 4 small subtelocentric chromosomes bearing a secondary constriction with its corresponding satellites, allows to discard previous reports of chromosomal fragments. Total haploid chromosomal length (53.48 μm), chromosomal length range (1.85 – 4.27 μm) and the asymmetry index (T.F. % = 23.13) add new information on chromosome architecture. The role of intraspecific hybridization and autoploidy in shaping the karyotype of this species and the need of performing similar analyses in related species are discussed.

Patterns of Arthropod Diversity in Contrasting Habitats of El Pedregal de San Angel, a Preserve in Mexico City

We studied the community of arthropods inhabiting the ecological preserve El Pedregal de San Angel, in Mexico City. We estimated morphospecies richness, abundance, and diversity patterns in two contrasting habitats, open and closed, during four seasons of the year. Because closed-habitat sites have greater net primary productivity than open habitats, we predicted arthropod diversity would be greater in closed than in open habitats. Morphospecies richness of Acari and Arachnida was similar in both types of habitats throughout the year, whereas richness of some orders of Insecta such as Coleoptera, Diptera, Hemiptera, and Hymenoptera was greatest in open habitats. Mites were the most abundant arthropods and were always more abundant in open than closed habitats. Diversity of arthropods was greater in closed habitats during fall and spring, suggesting that habitat characteristics related to primary productivity might affect this community. We suggest that studies of patterns of arthropod diversity and factors associated with the maintenance of such diversity should be considered in the preservation of these organisms and of their natural habitats.

La heterogeneidad ambiental en un matorral xerófilo

Se caracterizó la heterogeneidad biótica y abiótica tanto espacial como temporal en dos zonas del matorral xerófilo de la Reserva Ecológica del Pedregal de San Ángel(REPSA). Se identificaron nueve grupos florísticos, los cuales presentaron una distribución diferencial de las especies vegetales presentes en la zona. Cada uno de los grupos fue nombrado respecto a las especies indicadoras, las cuáles fueron consideradas como determinantes de la fisonomía de la comunidad. Utilizando los análisis multivariados(TWINSPAN y CANOCO) se observó que la composición de especies de los grupos se modifica espacial y temporalmente. Este estudio sugiere que la variación de algunos factores abióticos como la profundidad del suelo y la pendiente influye de diferente manera en la heterogeneidad del sistema. La heterogeneidad temporal fue evidente al existir una diferente composición florística en la zona a lo largo de la temporada de lluvias y la temporada de secas.

Implications for Conservation of the Species Diversity and Population Dynamics of Small Mammals in an Isolated Reserve in Mexico City

ABSTRACT: We studied the influence of habitat loss and fragmentation in species diversity, population dynamics, and habitat use in a small mammal community in xeric palo loco (Senecio praecox) thickets at Reserva Ecologica del Pedregal de San Angel, a completely isolated nature reserve in Mexico City, Distrito Federal, from 1989 through 1990. It is a heterogeneous region, dominated by an old lava flow, with many boulders and crevices. Small mammals were captured using Sherman live traps in two 0.81-ha grids; each grid contained 10 rows and 10 columns, separated by 10 m. Nine species have disappeared since 1957 as a result of the loss of particular habitat such as grasslands, habitat fragmentation, and other causes. In our study, we recorded nine species; five species were exclusively recorded in the continuous native scrub of the reserve. Therefore, they are good indicators of the sites in the reserve that maintain the less perturbed habitats. Interestingly, no introduced rodents (i.e., roof rat (Rattus r...

Análisis de la riqueza vegetal y el valor de conservación de tres áreas incorporadas a la Reserva Ecológica del Pedregal de San Ángel, Distrito Federal (México)

Se evaluó la riqueza vegetal y el valor de conservación de tres zonas incorporadas recientemente a la Reserva Ecológica del Pedregal de San Ángel: dos añadidas a la zona núcleo suroriente (SO 1 y S02) y el área de amortiguamiento A13. Se registraron 199 especies (57.6% de las reportadas). Se registraron 148, 152 y 149 especies en SOi, S02 y A13, respectivamente. En Al3 se registró a Mammillaria haageana subsp. san-angelensis, una subespecie en peligro de extinción, a Bletia urbana, clasificada como amenazada, y a dos nuevos registros para la reserva: Eupatorium pazcuarense y Adiantum andicola. Se reconoce también a Pennisetum clandestinum, por lo que se eleva a 340 especies el número de especies registradas en esta reserva. Utilizando un índice de valor para la conservación basado en ocho parámetros, se encontró que el sitio Al3 tiene mayor valor (21 puntos), seguido por el S02 y SO 1, con 16.5 y 10.5 puntos, respectivamente.

Dinámica y conservación de la flora del matorral xerófilo de la Reserva Ecológica del Pedregal de San Ángel (D. F., México)

El matorral xerófilo del derrame del Xitle ha sido destruido casi completamente por el desarrollo urbano de la ciudad de México. La Reserva Ecológica del Pedregal de San Ángel (1.77 km2) protege una de las porciones remanentes más importantes. A pesar de su estatus de protección, esta comunidad vegetal continúa siendo afectada por invasión de especies exóticas, contaminación, saqueo de especies y fuegos recurrentes. El objetivo de este trabajo fue actualizar el conocimiento florístico de la Reserva y analizar posibles cambios en la composición y la riqueza de las especies ocurridos en la zona en los últimos 50 años. De las 337 especies incluidas en él (193 géneros, 74 familias), 152 especies ya habían sido citadas por Rzedowski (1954) en un estudio que abarcó todo el derrame de lava (??80 km2). En contraste, 166 especies que dicho autor consignó para este matorral xerófilo no fueron encontradas durante el desarrollo de este estudio, aunque 21 de ellas sí están presentes en otra reserva ecológica situada en el mismo derrame pero a una altitud mayor (Lomas del Seminario). El análisis de la distribución de las especies del nuevo listado por tipo de vegetación mostró que sólo 34 de ellas son exclusivas de matorral xerófilo, mientras que las restantes se presentan también en otras comunidades. La información presentada en este trabajo servirá de base para futuros estudios de monitoreo en esta reserva orientados a evaluar las transformaciones de la flora a través del tiempo.