Evaluation of the Protection Effectiveness of Natural Protected Areas on the Qinghai-Tibet Plateau Based on Ecosystem Services.

Evaluating the protection effectiveness of natural protected areas is an important step in successful management. Adopting 330 natural protected areas on the Qinghai-Tibet Plateau as research subjects, the regional dominant ecosystem service function was selected, and various temporal and spatial analysis methods were employed to analyze the evolution characteristics and influencing factors of ecosystem service patterns from 2000 to 2020. Our results indicated that (1) the water conservation function stabilized after fluctuation and decline, the soil conservation function fluctuated upward, and the windbreak and sand fixation function exhibited an increase after a decreasing fluctuation. (2) The protection effectiveness of25 protected areas significantly improved, that of 151 protected areas improved, that of 84 protected areas stabilized, that of 56 protected areas worsened, and that of 14 protected areas significantly worsened. (3) The top three influencing factors in descending order were precipitation change > altitude > mining area density. (4) Remarkable protection results were achieved in national protected areas, established management institutions, earlier established areas (before 2000), and areas exhibiting alow built-up area density (<0.75%) and low mining density (<1%). Our study provides technical support for the construction and management of protected areas and improvement in ecosystem service functions on the Qinghai-Tibet Plateau.

Nesting substrates and nest density of stingless bees in the Petenes Biosphere Reserve, Mexico / Sustratos de nidificación y densidad de nidos de abejas sin aguijón en la reserva de la biósfera de los petenes, méxico

RESUMEN Las abejas sin aguijón (ASA) son organismos relevantes en los ecosistemas por su desempeño como polinizadores. En México, la mayor diversidad de ASA se encuentra en el sureste. En este estudio se determinaron las especies de ASA y densidad de nidos en dos sitios con diferente perturbación dentro de la Reserva de la Biósfera de los Petenes (RBLP) Campeche (México). Asimismo, se identificaron los sustratos y las especies arbóreas de nidificación. En total se realizaron diez muestreos en transectos entre los meses de enero a mayo de 2018. Se registraron 56 nidos pertenecientes a ocho especies diferentes de ASA (Cephalotrigona zexmeniae, Frieseomelitta nigra, Lestrimellita niitkib, Nannotrigona perilampoides, Partamona bilineata, Plebeia frontalis, Scaptotrigona pectoralis y Trígona fulviventris). Las especies con mayor número de nidos correspondieron a F. nigra (41,07 %) y S. pectoralis (28,57 %). No se encontraron diferencias significativas en la densidad de nidos entre los sitios Hecelchakán (2,15 nidos/ha) y Calkiní (0,19 nidos/ha). El sustrato preferido para anidación son las cavidades en árboles vivos (78,57 %). En total 15 especies arbóreas fueron identificadas como sustrato de nidificación y la especie más abundante correspondió a Crescentia cujete (n = 18, 40,9 %). El grado de perturbación tuvo poco efecto en el número y densidad de nidos de ASA, sin embargo, en general, la RBLP presentó una composición de especies y densidad de nidos reducida. Por lo tanto, este estudio permitió establecer las bases para futuros estudios sobre estrategias de manejo y conservación de estas especies para evitar su desaparición en la RBLP.

ABSTRACT Stingless bees (ASA) are relevant organisms in ecosystems because of their performance as pollinators. In Mexico, the higher diversity of ASA is found in the southeast. In this study, the ASA species and nest density of nests were identified at two sites with different disturbances (Hecelchakán and Calkiní) within the Petenes Biosphere Reserve (RBLP), Campeche (Mexico). Also, the substrates and the nesting tree species were identified. In total, ten sampling transects were performed between January and May 2018. In total 56 nests belonging to eight different species of ASA (Cephalotrigonazexmeniae, Frieseomelitta nigra, Lestrimellita niitkib, Nanotrigonaperilampoides, Partamona bilineata, Plebeia frontalis, Scaptotrigona pectoralis and Trigona fulviventris) were found. The species with the highest number of nests corresponded to F. nigra (41.07 %) and S. pectoralis (28.57 %). No significant differences were found in nest density between the Hecelchakán (2.15 nests/ha) and Calkiní (0.19 nests/ha) site. The preferred substrate for nesting is cavities in living trees (78.57 %). In total 15 tree species were identified as nesting substrate and the most abundant species corresponded to Crescentia cujete (n = 8, 40.90 %). The degree of disturbance had little effect on the number and density of ASA nest, however, in general, the RBLP presented low species composition and nest density. Therefore, this study allowed to establish the bases for future studies on management and conservation strategies of these species to avoid their loss in the RBLP.

Marine diversity in the biosphere reserve of the most oceanic island in the Gulf of California: San Pedro Mártir.

San Pedro Mártir island is of high biological, ecological, and fishery importance and was declared a biosphere reserve in 2002. This island is the most oceanic in the Gulf of California, and information on its rocky reefs is scarce. The present study aimed to generate the first list of conspicuous invertebrate and fish species based on in situ observations and to examine the community structure of the shallow rocky reefs of the reserve. In addition, we estimated the ecological indicators of richness, abundance, Shannon diversity, and Pielou evenness to evaluate the conservation status of the biosphere reserve. Data were collected annually from 2007 to 2017 through 2,192 underwater SCUBA transects. A total of 35 species of invertebrates and 73 species of fish were recorded. Most of the species are widely distributed along the eastern Pacific. Overall, 64% of the species found in this study are commercially important, and 11 species have been listed as protected. The abundance of commercially important invertebrate species (i.e., the sea cucumber Isostichopusfuscus and the spiny oyster Spondyluslimbatus) is decreasing, while commercially important fish species have maintained their abundance with periods of increase. The ecological indicators and the abundance and size of the commercial species indicate that the reserve is in good condition while meeting its conservation objectives.

Riqueza de aves en la Reserva de la Biosfera Sierra del Abra Tanchipa en San Luis Potosí, México / Birds richness of Sierra del Abra Tanchipa Biosphere Reserve in San Luis Potosi, Mexico

Resumen El conocimiento de la biodiversidad en un área natural protegida es fundamental para el desarrollo de acciones para su manejo y conservación. El objetivo del presente trabajo fue determinar los patrones de riqueza, categorías de endemismo, así como el estatus de conservación y vulnerabilidad de las aves en la Reserva de la Biosfera Sierra del Abra Tanchipa, ubicada en el noreste del estado de San Luis Potosí, México. Se incluye la información generada por el programa de monitoreo comunitario de aves y otros esfuerzos de muestreo realizados en el área. Se desarrolló trabajo de campo con base en el método de censado de conteo por puntos, los cuales fueron establecidos a lo largo de transectos en el área de estudio. Se registraron 279 especies de aves pertenecientes a 23 órdenes y 54 familias, correspondiendo el mayor porcentaje a las especies residentes permanentes (64.16 %). Del total de especies reportadas, 37 se encuentran bajo alguna categoría de riesgo y 25 presentan alguna categoría de endemismo. El 54.12 % de las especies tienen afinidad neotropical, 26.88 % neártica y 19 % neártica/neotropical. Por otro lado, alrededor del 22.22 % de las aves registradas tienen un nivel de sensibilidad al disturbio de medio a alto, que puede incrementarse debido a los cambios en los hábitats generados por las actividades humanas en la zona de influencia de la reserva. Los monitores comunitarios aliados al programa contribuyeron significativamente en las actividades de campo y la difusión de las acciones orientadas al conocimiento de las aves en la reserva. Los datos obtenidos permiten actualizar la información en el programa de manejo del área natural protegida de la reserva, lo que favorecerá la conservación de las aves en la zona.

Abstract Knowledge about biodiversity in a natural protected area is essential for the development of actions for its management and conservation. The objective of this work was to determine the richness patterns, endemism categories, as well as the conservation and vulnerability status of birds in the Sierra del Abra Tanchipa Biosphere Reserve, located in the northeastern region of the state of San Luis Potosí, Mexico. The information generated by the community bird monitoring program and other sampling efforts in the area was included. Fieldwork was carried out based on the census method of counting by points established along transects in the study area. A total of 279 bird species belonging to 23 orders and 54 families were registered, of which the highest percentage are permanent resident species (64.16 %). Of the species recorded, 37 are under some risk category, and 25 species have some endemism category. 54.12 % of the species have a Neotropical affinity, 26.88 % a Nearctic one, and 19 % a Nearctic/Neotropical one. On the other hand, around 22.22 % of the registered birds have a medium to high sensitivity to disturbance, which may increase due to changes in habitats generated by human activities in the reserve's area of influence. The community allies linked to the monitoring program contributed significantly to the field activities and the dissemination of the actions aimed at bird awareness in the reserve. The obtained data allow the updating of information in the management program of the natural protected area, which will favor the birds' conservation in the zone.

Multi-taxonomic survey in the Sierra del Abra Tanchipa Biosphere Reserve / Estudio multitaxonómico en la Reserva de la Biosfera Sierra del Abra Tanchipa

Abstract: Studies on biological diversity are essential to generate baseline information in natural protected areas. In the present study, we developed a multi-taxonomic inventory in the Sierra del Abra Tanchipa Biosphere Reserve, located northeast of San Luis Potosí, Mexico. Systematic samplings were performed between January 2017 to May 2018, for the taxonomic groups of flora, amphibians, reptiles, birds, and mammals. A total of 3 730 records of 683 species were obtained, corresponding to 427 species of flora, 10 of amphibians, 20 of reptiles, 192 of birds, and 34 of mammals, from which 47 species are threatened. The results obtained represent the critical biodiversity that can be found in this natural protected area. The information will be useful for decision-making on the management and conservation of biodiversity in the Sierra Madre Oriental's ecological corridor.

Resumo: Los estudios sobre biodiversidad son fundamentales para generar información de línea base para las áreas naturales protegidas. En el presente estudio se desarrolló un inventario multitaxonómico de la Reserva de la Biosfera Sierra del Abra Tanchipa, ubicada al noreste del estado de San Luis Potosí, México. Se realizaron muestreos sistemáticos para los grupos taxonómicos de flora, anfibios, reptiles, aves y mamíferos y se construyó una base de datos donde se incluyeron todos los registros por grupo taxonómico. Se obtuvieron un total de 3 730 registros de 683 especies, que corresponden a 427 especies de flora, 10 especies de anfibios, 20 especies de reptiles, 192 especies de aves y 34 especies de mamíferos; de las que 47 especies se encuentran en alguna categoría de riesgo. Los resultados obtenidos son una muestra representativa de la importante biodiversidad que es posible encontrar en esta Área Natural Protegida. La información será útil para la toma de decisiones sobre las acciones de manejo y conservación de la biodiversidad en el Corredor Ecológico de la Sierra Madre Oriental.

Diversity and conservation of amphibians and reptiles of a protected and heavily disturbed forest of central Mexico.

The high loss rate of forest ecosystem by deforestation in the Trans-Mexican Volcanic Belt is one of the principal ecological problems of central Mexico, even in natural protected areas. We compiled a checklist and determined ß-diversity indexes of amphibians and reptiles of the highly disturbed protected area, La Malinche National Park (LMNP) in Mexico, to determine the principal habitats for herpetofaunal conservation. After our extensive eight-year field sampling, we documented 28 species (nine amphibians and 19 reptiles), representing 11 families and 18 genera; four of these species are new records for LMNP. Of the species, 89% are endemic to Mexico. The IUCN Red List considers 22 species as Least Concern, one as Near Threatened, and four as Vulnerable. Meanwhile, the Environmental Viability Scores categorize three species as low vulnerability, 15 as medium, and 10 as high. According to the Mexican list of protected species, eight species are under Special Protection and nine are considered Vulnerable. The dissimilarity index between habitat types (ßsør) in both groups is high, principally due to the environmental gradient generated by the altitudinal range. Abies and Pine forest are high diversity areas for amphibians and reptiles, respectively, and must be considered for special protection. LMNP hosts more than 60% of the herpetofauna of Tlaxcala and is the principal "conservation island" for this state. Therefore, based on the percentage of state species represented, endemism and the current social and ecological problems, additional efforts that involve the local communities to protect the biodiversity of this National Park are necessary.

Impactos por cambio de uso de suelo en las áreas naturales protegidas de la región central de la Sierra Madre Oriental, México / Impact of land use cover change on protected natural areas in central region of Sierra Madre Oriental, Mexico

Resumen Los cambios en el uso de suelo y la cubierta vegetal, derivados de la expansión y extensión de асtividades antrópicas, generan impactos negativos en la biodiversidad y la provisión de servicios ecosistémicos, y contribuyen significativamente en los procesos de cambio climatico a nivel regional. Las Áreas Naturales Protegidas (ANP) representan un instrumento de política pública para hacer frente a las tendencias de cambio y transformación de los ecosistemas, además de permitir la conservación de los recursos. El objetivo de este estudio fue determinar el impacto potencial del cambio en el uso de suelo y la cobertura vegetal de las ANP de la región сеntral de la Sierra Madre Orientai (SMO), en México, a través del análisis espacial y la simulación de escenarios de cambio potencial. Se usaron imágenes satelitales para elaborar mapas de cambio en coberturas vegetales, entre los años 1989, 2000 y 2005, y con base en un conjunto de variables biofísicas y socioeconómicas, se simuló un escenario de cambio al 2025. Se determinó que la tasa de cambio de las cubiertas vegetales de la SMO en el periodo estudiado fue de 0.54 % en selvas, 0.22 % en bosques y 0.23 % en matorrales; y en las ANP fue de 0.34 % y 0.60 % para selvas y bosques, respectivamente. En este lapso se perdieron 1 578.26 ha de selvas, bosques y matorrales, al interior de las ANP. De mantenerse las tendencias actuales de cambio en el uso de la tierra, otras 4 542.17 ha estarán en riesgo de perderse en un futuro cercano. Los resultados indican que las ANP estudiadas están sometidas a presiones de cambio en el uso de la tierra, que amenazan la conservación del patrimonio natural que resguardan, por 10 que deberían rediseñarse las estrategias de manejo y monito reo a corto y mediano plazo.

Abstract Land use cover change, resulting from the expansion and extension of human activities, generates negative impact on biodiversity and the provision of ecosystem services, as well as contributing significantly to climate change processes at a regional level. Natural Protected Areas (NPA) represent a public policy instrument to address the trends of change and ecosystem transformation, while allowing the conservation of resources. The objective of this study was to determine the potential impact of the processes involved in land use cover change on the NPA as part of the central region at the Sierra Madre Oriental (SMO) in Mexico by using the special analysis and the scenery simulation of potential change. Satellite imagery was used to determine the changes in natural vegetation cover between 1989, 2000 and 2005 and, using a set of biophysical and socioeconomic variables, a change scenario was simulated for 2025. This study found that the rate of change of vegetation cover at the SMO over the research period was 0.54 % in tropical forests, 0.22 % in forests and 0.23 % in scrublands, while those in NPA were 0.34 % and 0.60 % in tropical forests and forests respectively; 1 578.26 ha of tropical semi-deciduous temperate forest and scrublands were lost from the NPA. If the current land use trends change continues, another 4 542.17 ha are likely to be modified in the future. These results indicate that NPA under study are subject to the pressures of land use change that threaten the natural heritage under protection and that, therefore, management strategies and monitoring need to be redesigned in the short and medium term.

Tourism in protected areas: Disentangling road and traffic effects on intra-guild scavenging processes.

The expansion of road networks and the increase in traffic have emerged in recent years as key threats to the conservation of biodiversity. This is particularly concerning in many protected areas because the increase of recreational activities requiring the use of vehicles. Effects of roads and traffic within guild scenarios and ecological processes remain however poorly known. Here we examined how road proximity and traffic intensity influence patterns of resource use in an Old-World avian scavenger guild living in a protected natural park in northern Spain. We experimentally placed 130 carcasses at different distances from a scenic road in the centre of the park. Vehicles were recorded by means of traffic counters which revealed that maximum numbers were reached during weekends and holidays and during the middle hours of the day. Avian scavenger attendance at carcasses was recorded by means of camera-traps. Obligated scavengers, Eurasian griffon (Gyps fulvus) and Egyptian vultures (Neophron percnopterus) were frequently observed (59.4% and 37.7% of the consumed carcasses) together with five other facultative scavenger species. We found that the richness (number of species) and the probability of consumption of the resource were reduced the smaller the distance to the road and in days with higher traffic intensity. The same factors affected the probability of presence of all the scavenger species. Moreover, some of them, notably griffon vultures, showed hourly patterns of carcass attendance suggesting avoidance of maximum traffic levels. Our results highlight that roads and traffic would trigger consequences on the structure and functioning of scavenger food webs, which may be particularly concerning in protected areas with remarkable levels of biodiversity. Future regulations at protected areas should couple both traffic and tourist affluence with wildlife conservation. In this way important ecological processes would be preserved while maintaining a good dissemination of natural values.

Coastal dynamics vs beach users attitudes and perceptions to enhance environmental conservation and management effectiveness.

This work carries out a landscape analysis for the last 60years to compare the degree of preservation of two areas on the same Italian coastline characterized by different environmental protection levels: a National designated protected areas and a highly tourist coastal destination. The conversion of natural land-covers into human land uses were detected for protected and unprotected coastal stretches highlighting that the only establishment of a protected area is not enough to stem undesirable land-use outcomes. A survey analysis was also conducted to assess attitudes of beach users and to evaluate their perception of natural habitats, beach and coastal water quality, and coastal dynamic over time. The results of 2071 questionnaires showed that there is similarity between subjective and objective data. However, several beach users perceived a bad quality of coastal water in the legally unprotected coastal area. The implications from a planning and management perspective are discussed.

GIS Fuzzy Expert System for the assessment of ecosystems vulnerability to fire in managing Mediterranean natural protected areas.

A significant threat to the natural and cultural heritage of Mediterranean natural protected areas (NPAs) is related to uncontrolled fires that can cause potential damages related to the loss or a reduction of ecosystems. The assessment and mapping of the vulnerability to fire can be useful to reduce landscape damages and to establish priority areas where it is necessary to plan measures to reduce the fire vulnerability. To this aim, a methodology based on an interactive computer-based system has been proposed in order to support NPA's management authority for the identification of vulnerable hotspots to fire through the selection of suitable indicators that allow discriminating different levels of sensitivity (e.g. Habitat relevance, Fragmentation, Fire behavior, Ecosystem Services, Vegetation recovery after fire) and stresses (agriculture, tourism, urbanization). In particular, a multi-criteria analysis based on Fuzzy Expert System (FES) integrated in a GIS environment has been developed in order to identify and map potential "hotspots" of fire vulnerability, where fire protection measures can be undertaken in advance. In order to test the effectiveness of this approach, this approach has been applied to the NPA of Torre Guaceto (Apulia Region, southern Italy). The most fire vulnerable areas are the patch of century-old forest characterized by high sensitivity and stress, and the wetlands and century-old olive groves due to their high sensitivity. The GIS fuzzy expert system provides evidence of its potential usefulness for the effective management of natural protected areas and can help conservation managers to plan and intervene in order to mitigate the fire vulnerability in accordance with conservation goals.

Evaluación de la sustentabilidad en espacios rurales relacionados con el ecoturismo. estudio de caso en la selva lacandona, chiapas,México / Assesment of thee sutainability in rural spaces related to ecotouriism. case study in lacandon jungle, chiapas, Mexico

Esta investigación realiza una evaluación ex-post de la sustentabilidad en espacios rurales relacionados con el ecoturismo, centrada en un estudio comparativo de tres empresas enclavadas en la Reserva de la Biosfera Montes Azules (REBIMA) y una empresa más ubicada fuera de ella, todas en el municipio de Ocosingo, Chiapas, México. 75% de los entrevistados son hombres con edad promedio de 36 años, siete años de escolaridad y 1,9 hectáreas. La principal fuente de ingresos es el ecoturismo, que presenta una relación beneficio-costo venida a menos de 2,7 a 1,7, entre 2007 y 2011, respectivamente. La evidencia indica un desequilibrio en el acceso a subsidios, donde la pertenencia étnica desempeña un rol trascendental.

This research performs an ex-post evaluation of the sustainability in rural spaces related to ecotourism, focused on a comparative study of three companies located in the Montes Azules Biosphere Reserve (MABR) and another company located outside, all of them in the town of Ocosingo, Chiapas, México. 75% of respondents are male with an average age of 36 years, seven years of schooling and 1,9 hectares. The main source of income is ecotourism, which presents a cost-benefit relationship that has ran down from 2,7 to 1,7 between 2007 and 2011, respectively. The evidence indicates an imbalance in the access to subsidies, where the ethnical ownership plays a transcendental role.

Diversidad alfa y beta de los artrópodos en diferentes ambientes del Parque Nacional Los Cardones, Salta (Argentina) / Alpha and beta arthropods diversity from the different environments of Parque Nacional Los Cardones, Salta, Argentina

The essential role of the National Parks is to protect nature, in order to prevent the deterioration and loss of the ecosystem under protection. Very few records about the diversity of arthropods are known from Los Cardones National Park, where three eco-regions are protected: Puna and Monte eco-regions and the High Andean Grassland of the Yungas. Here, we aimed to compare the alpha and beta diversity of arthropods in these eco-regions, and to prove if sites from the same ecoregion, show greater similarity between them in their assemblages, than with sites of the other eco-regions. We also identified arthropod orders with higher species richness, and indicated the families that contribute the most to the registered beta diversity. Three sampling sites were established on each eco-region and the arthropods were sampled using pitfall traps and suction samples. We evaluated the obtained inventory through nonparametric estimators of species richness, and compared diversity among eco-regions through “diversity profiles” and “effective number of species”. Beta diversity was assessed by different methods such as the Morisita Index, nonmetric multidimentional scaling analysis, a multiple permutation procedure, and a Similarity Percentage analysis. We recorded 469 spp/morphospecies and recognized three arthropod orders (spiders, dipterans and hymenopterans) that are diverse and abundant in the Park. Besides, the diversity in Los Cardones National Park was found to be high, but it was observed higher in the High Andean Grassland of the Yungas, and lower in the Puna. The inventory obtained was good, reached up to the 81% of the species richness estimated by nonparametric estimators. Each eco-region of the park showed a very particular arthropod community that was tested by a multi-response permutation procedure. The species turnover between eco-regions was high, so that the different environments of the protected area are contributing to the maintenance of the regional diversity of arthropods in the park. The assemblages of arthropods belonging to the same eco-region sites showed greater similarity among themselves than with those of more distant sites. This represents the first attempt for biodiversity studies in these areas, but more evaluations are required to detail on the possible climate change and human impacts in the ecosystem.

El Parque Nacional Los Cardones ubicado en la provincia de Salta protege las ecorregiones de Puna, Monte y Pastizal Altoandino Nublado de la Yungas. Nuestro objetivo es evaluar la diversidad alfa y beta de artrópodos en las ecorregiones del Parque. Se muestrearon tres sitios en cada ecorregión utilizando Pit-fall y G-Vac. Se calcularon estimadores no paramétricos de riqueza de especies, la diversidad entre ecorregiones se comparó a través de los “perfiles de diversidad” y “números efectivos de especies”, se analizó el recambio de especies y la complementariedad entre las ecorregiones y sitios de una misma ecorregión. Se registraron 469 spp/morfoespecies, la diversidad en el Parque fue alta, siendo mayor en los Pastizal Altoandino Nublado, y la más baja en la Puna. El inventario llegó al 81% de completitud. El recambio de especies entre ecorregiones fue alto, de esa manera los diferentes ambientes del Parque contribuyen a conservar la diversidad regional de artrópodos. Las ensambles de artrópodos en sitios de una misma ecorregión mostraron mayor similitud entre sí que con sitios más distantes. Se pudo reconocer tres grupos de artrópodos (arañas, dípteros e himenópteros) que son diversos y abundantes, los que podrían ser utilizados en futuros estudios como grupos focales.

Spatial patterns of diversity at local and regional scales in a tropical lagoon

The present study reports estimates of alpha (α), beta (β) and gamma (Γ) diversity for the fish community of Chacmochuch Lagoon (SE Mexico), a natural protected area located in the northern portion of the Mesoamerican Barrier Reef System. Fish specimens were sampled in 2004 and 2006. Field work was carried out at three climatic peaks: at 13 stations using a 70 m-long beach seine. The collected data were supplemented with information obtained from a previous work conducted in 2002 and were then analyzed with multivariate statistical methods. In addition, fish composition results from this study were compared to those reported for other similar ecosystems of the region. A total of 68 fish species were recorded, determined as peripheral (high-salinity species, usually marine affinity) most of them. Most of the fish species collected were determined as rare, and a few number of species were determined as common and dominant. Salinity, TSD, temperature, dissolved oxygen and other variables were measured to determine the influence over the fish communities, four groups of sites where determined. Results indicated a gradual decrease in the degree of species replacement towards the interior of the system (away from the coast). The estimated value of gamma diversity was high compared to that reported for other coastal systems of the region and, due to the high degree of habitat heterogeneity found in this system; beta diversity had a greater contribution to gamma diversity than alpha diversity. This lagoon acts as a nursing area for many of the fish species collected in this study as indicated by the presence of juvenile stages.

En el presente estudio, se midió y se determinó la biodiversidad alfa (α), beta (β) y gamma (Γ) de la comunidad de peces en el Sistema Lagunar Chacmochuch, un Área Natural Protegida (ANP) localizada en la zona norte del Sistema Arrecifal Mesoamericano. El trabajo de campo se realizó en 13 sitios de muestreo durante los ciclos anuales 2004 y 2006, considerando los tres picos climáticos representativos de la región. Para la captura se utilizo un chinchorro de 70 m de largo. La matriz de información utilizada para el análisis se complemento con datos obtenidos a partir de un trabajo realizado durante el periodo 2002. Análisis multivariados fueron utilizados para la generación de resultados. Los resultados de la composición de peces se compararon con los reportados para otros ecosistemas similares de la región. Un total de 68 especies fueron registradas siendo periféricas (especies de alta salinidad y afinidad marina) la mayoría de ellas. Del registro, la mayoría de las especies se determinaron como especies raras, un número menor fueron especies comunes y dominantes. La salinidad, SDT, temperatura, oxigeno disuelto y otras variables fueron medidas para determinar su efecto sobre la comunidad de peces, encontrando cuatro agrupaciones de sitios. Los resultados indican una disminución gradual de las especies hacia el interior del sistema (al alejarse de la costa). La diversidad gamma es alta comparada a otros sistemas costeros de la región; sin embargo la taza de recambio beta es la que determina su alta heterogeneidad. Especies en estadios juveniles y de importancia económica fueron dominantes en el sistema, lo que determinan la zona como un área de crianza.