Resumen: Ante el cambio climático, las especies pueden perder representación de su nicho en el biotopo, viéndose afectado el riesgo de extinción. Esta breve revisión de la literatura pretende establecer las bases del estado del conocimiento sobre riesgo de extinción en función al nicho climático. Esto permitirá formular futuros abordajes tales como predicciones de riesgo en base al nicho climático. Según la literatura, la amplitud del nicho y la posición relativa de sus componentes determinan el riesgo de extinción. Esta información puede complementar el conocimiento sobre el riesgo de extinción relacionado a la distribución geográfica. También se puede utilizar para planificar estrategias de conservación específicas para cada situación. Las características de los nichos climáticos pueden interactuar con factores externos (amenazas, competencia) e intrínsecos (área ocupada, dispersión), afectando el riesgo de extinción. Aún persisten vacíos de información sobre los nichos climáticos y limitaciones en sus métodos de estudio. La literatura existente se ha enfocado en vertebrados paleárticos y nichos realizados. Por último, se presenta un caso de estudio que ilustra diferencias entre los nichos climáticos realizados de especies de aves según su riesgo de extinción, mediante la comparación de estadísticas descriptivas. Estas confirman en parte lo que menciona la literatura, pero requieren mejoras para garantizar que proporcionen información veraz. En el futuro, sería interesante explorar estas estadísticas como predictores climáticos para conocer el estado de especies poco conocidas y entender mejor el riesgo de extinción, agregando la dimensión climática a las evaluaciones de riesgo.

Abstract: Species could lose part of their niche representation in the biotope due to climate change, potentially affecting extinction risk. This brief review of the literature aims to establish the basic aspects of our current knowledge concerning extinction risk related to climatic niches. This will enable the formulation of future approaches such as predictions of extinction risk based on the climatic niche. The literature indicates that niche width and relative position of niche components determine extinction risk. This information could complement our knowledge of extinction risk based on geographic distributions. It could also be used to plan specific conservation strategies for each situation. Climatic niche characteristics may interact with external factors (threats and competition) and intrinsic factors (occupied area and dispersal), affecting extinction risk. Information gaps about climatic niches persist as well as limitations of their study methods. Most studies have focused on paleartic vertebrates and realized niches. Finally, a case study is presented in which differences among bird realized climatic niches according to their extinction risk are illustrated by comparing descriptive statistics. These partially confirm what is mentioned in the literature but should be improved to guarantee that they provide accurate information. In the future, it would be interesting to explore these descriptive statistics as climatic predictors of conservation status for data deficient species and to gain a better understanding of extinction risk by adding the climatic dimension to risk evaluations.

Abstract: Jaguar populations have declined dramatically in the last century. The Maya Biosphere Reserve (MBR) within the Selva Maya (SM) is a priority area for jaguar conservation. Influential factors in the jaguar seasonal distribution include the availability of surface water in wetlands such as the “aguadas” and the availability of prey. Aguadas are formed by isolated depressions in the landscape and serve as a water supply for wildlife during dry periods. The goal of this study was to describe the visitation patterns of jaguars to aguadas in a Tropical forest at Dos Lagunas Protected Biotopo, a core zone of the MBR, Guatemala. We used camera-trap data from seven aguadas during the dry seasons 2014-2017. We determined visitation rates (VR, records for 1,000 trap-days) and activity patterns (AP) of jaguars for all years, aguadas, and sexes. We tested for significant differences in AP between sexes, and we estimated the coefficient of overlap (D) for female and male jaguar activity. We recorded 14 individuals (five females, eight males, and one unsexed) in 60 visit events. Jaguars have significant more diurnal activity at aguadas, and showed a VR = 13.1 for 1,000 trap-days. VR varied between aguadas (VR = 9.5 - 19.4), years (VR = 1.9 - 39.2) and sexes (VR = 6.1 for females and 5.5 for males). We did not find significant differences in the AP of female and male jaguars (P > 0.05). The coefficient of overlap between activity of females and males was D = 0.77 (95 % confidence interval: 0.70 to 0.84; P > 0.05). Aguadas may represent regular sites of jaguar home-ranges overlap for the important resources they provide for wildlife during the dry season. Aguadas could play an important role in the conservation and management of jaguar populations since the spatial distribution of these bodies of water is scattered, but ecologically important for jaguars within the MBR and the SM. Aguadas also, are important landscape features that could influence the spatial interactions of individuals. We encourage jaguar researchers to increase investigation on jaguars visiting aguadas and other wetlands in the SM to better understand the jaguar activity patterns and sex-specific habitat requirements.

Resumen: Las poblaciones de jaguares disminuyeron drásticamente en el último siglo. La Reserva de la Biosfera Maya (RBM), en la Selva Maya (SM) es un área prioritaria para su conservación. Entre los factores que afectan su distribución estacional están la disponibilidad de agua en humedales como las aguadas, y la disponibilidad de presas. Las aguadas son formadas por depresiones en el paisaje y sirven de abastecimiento de agua para la fauna silvestre. El objetivo de este estudio fue describir los patrones de visita de jaguares a las aguadas en un bosque tropical en el Biotopo Protegido Dos Lagunas, una zona núcleo de la RBM, Guatemala. Se emplearon datos de trampas-cámara en siete aguadas durante las épocas secas 2014-2017. Se determinaron tasas de visita (TV, registros por 1,000 días-trampa) y patrones de actividad (PA) de jaguares por todos los años, aguadas y sexos. Se evaluaron diferencias significativas en los PA de ambos sexos, y se estimó el coeficiente de traslape (D) en los patrones de actividad de hembras y machos. Se registraron 14 individuos (cinco hembras, ocho machos, uno indeterminado) en 60 eventos independientes. Los jaguares se catalogaron con mayor actividad diurna, presentando una TV = 13.1 eventos por 1,000 días-trampa. Las TV variaron entre aguadas (TV = 9.5 - 19.4), años (TV = 1.9 - 39.2) y sexos. Las hembras presentaron una mayor TV en comparación a los machos (TV = 6.1 y 5.5, respectivamente). No se encontraron diferencias significativas en la actividad de ambos sexos, con un nivel de traslape de D = 0.77 (95 % de intervalo de confianza: 0.70 a 0.84; P > 0.05). Las aguadas podrían representar sitios de traslape en los ámbitos hogareños de los jaguares, debido a su importancia como recurso vital durante la época seca. Además, las aguadas pueden ejercer un importante rol en la conservación y manejo de poblaciones de jaguares debido a su distribución aislada, pero ecológicamente importante, que influye en las interacciones espaciales de los individuos. Recomendamos incrementar la investigación en jaguares y sus visitas a las aguadas y otros humedales para una mejor comprensión de sus patrones de actividad y requerimientos del hábitat específicos para ambos sexos.

Abstract: The conservation of biodiversity in Mediterranean Chile requires a greater coverage than that represented in the Protected Wild Areas of the State (SNASPE) and Private Protec ted Areas (APP) are complementary alternative for conservation. The study of biodiver sity in APP is scarce, ignoring its contribution to the conservation. The small mammals assemblage of the APP Bioparque Puquén and surroundings was described comparing the species richness, relative abundance and diversity index of Margalef inside and out side the park. Using the Morisita-Horn similarity index and a cluster analysis, the small mammals assemblage was compared between sampling points categorized in different biotopes. Endemic and native species were more abundant outside the APP. There were no significant differences in specific richness or diversity inside and outside the APP. The small mammals assemblage was grouped into biotopes of dense native vegetation and prairies, ravines and seasonal waters. The park would act as buffer area, protecting the nearby areas of the Los Molles-Pichidangui Priority Site. The importance of rocky outcrops as a habitat for endemic species of small mammals and protecting the areas adjacent to the BioParque is discussed.

Resumen: La conservación de la biodiversidad en Chile Mediterráneo requiere una mayor cobertura en el Sistema Nacional de Áreas Silvestres Protegidas del Estado, por lo que las Áreas Pro tegidas Privadas (APP) son alternativas complementarias para la conservación. El estudio de la biodiversidad en las APP es escaso, desconociendo su aporte en la conservación. Se describió el ensamble de micromamíferos del APP Bioparque Puquén y alrededores comparando la riqueza de especies, abundancia relativa e índice de diversidad de Marga- lef al interior y exterior del parque. Mediante el índice de similitud de Morisita-Horn y un análisis de agrupamientos se comparó el ensamble de micromamíferos entre puntos de muestreos categorizados en distintos biotopos. Las especies endémicas y nativas fueron más abundantes fuera del APP. No hubo diferencias significativas en la riqueza específica ni diversidad dentro y fuera del APP. El ensamble de micromamíferos se agrupó en bioto pos de vegetación nativa densa y de praderas, quebradas y aguas estacionales. El parque actuaría como área de amortiguación, protegiendo las áreas aledañas del Sitio Prioritario Los Molles-Pichidangui. Se discute la importancia de los escollos como hábitat de es pecies endémicas de micromamíferos y de proteger las áreas adyacentes al BioParque.

RESUMO Organismos com populações-fonte restritas ao biótopo subterrâneo (troglóbios) são excelentes modelos para estudos evolutivos comparativos, devido à especialização resultante do isolamento sob um regime seletivo particular, com ênfase na permanente falta de luz. A regressão do olho e da pigmentação são características dos troglobites. Apesar do avanço do conhecimento sobre os mecanismos subjacentes à regressão ocular em peixes de caverna, pouco se sabe sobre mudanças de pigmentação. Os estudos foram focados em três espécies do gênero Pimelodella. Exemplares das espécies troglóbias P. spelaea e P. kronei foram comparados com a epígea P. transitoria, provável espécie-irmã dessa última. As áreas e densidades dos melanóforos são significativamente menores nas espécies troglóbias. Avaliando a resposta in vitro dessas células à adrenalina, acetilcolina e MCH, observamos uma resposta reduzida em ambos os troglóbios à adrenalina. A mesma tendência foi observado com o MCH, mas não estatisticamente. Nenhuma resposta à acetilcolina foi detectada três. Contrariamente às expectativas, embora a regressão ocular em P. spelaea seja bem menor do que em P. kronei, a regressão na pigmentação foi mais acentuada. Múltiplos mecanismos de regressão, mostrando um mosaico de características em peixes troglóbios, são discutidos aqui.

ABSTRACT Organisms with source-populations restricted to the subterranean biotope (troglobites) are excellent models for comparative evolutionary studies, due to their specialization to permanent absence of light. Eye and dark pigment regression are characteristics of most troglobites. In spite of the advance in knowledge on the mechanisms behind eye regression in cave fishes, very little is known about pigmentation changes. Studies were focused on three species of the genus Pimelodella. Exemplars of the troglobitic P. spelaea and P. kronei were compared with the epigean (surface) P. transitoria, putative sister-species of the latter. Melanophore areas and densities are significantly lower in the troglobitic species. Evaluating the in vitro response of these cells to adrenaline, acetylcholine and MCH, we observed a reduced response in both troglobites to adrenaline. The same trend was observed with MCH, but not statistically significant. No response to acetilcholine was detected in all the three. Contrary to expectations, even though eye-regression in P. spelaea was much lower than in P. kronei, pigmentation regression was more advanced. Multiple mechanisms of loss showing a mosaic of traits in troglobitic fishes are discussed here.

RESUMO O costão rochoso de Praia Grande (Ubatuba, SP) é formado por matacões rochosos e recifes de areia formados por poliquetas sabelarídeos. Essas estruturas oferecem abrigo e área de forrageamento para diversos organismos marinhos, e atraem muitos turistas. O caranguejo Eriphia gonagra (Fabricius, 1781) habita essas estruturas, podendo ser utilizado como bioindicador, uma vez que estas podem ser afetadas por ações antrópicas. Por meio deste estudo avaliou-se o conteúdo estomacal e caracterizou-se os hábitos alimentares de uma população de E. gonagra, levando em consideração o sexo, tamanho e microhabitat. Amostragens mensais foram realizadas em 1996 e 1997 e os caranguejos foram capturados manualmente na Praia Grande. Assim, os espécimes amostrados foram caracterizados de acordo com o local de captura (microhabitat) como recife rochoso (RO) ou de areia (SR). Os itens mais abundantes foram moluscos, algas, poliquetos e crustáceos, sendo observada a importância destes grupos como recurso alimentar no ambiente estudado. Os moluscos foram mais abundantes nos estômagos dos caranguejos amostrados no RO, enquanto os demais item aumentavam nos caranguejos dos recifes de areia. Dentre os espécimes amostrados no SR, poliquetos foi o alimento foi mais comum, indicando que esse biótopo também é utilizado como fonte rica em proteínas. A proporção de itens diferiu também entre classes de tamanho. Conhecer tais hábitos é essencial para estudos de requisitos nutricionais, monitoramento de relações entre organismos, bem como para avaliação de impactos ecossistêmicos em costões rochosos.

ABSTRACT The rocky shores of Praia Grande, in Ubatuba (São Paulo, Brazil), are formed by rock and Sabellaridae polychaete sandy reefs. These microenvironments offer shelters and foraging areas for several marine organisms and attracts many tourists. The crab Eriphia gonagra (Fabricius, 1781) inhabits these structures and can be used as a bioindicator, since they may be affected by anthropogenic actions. This study evaluated the stomach contents and characterized the feeding habits of an E. gonagra population, inhabiting the rocky shores from Praia Grande, taking into account the sex, size, and microhabitat. Monthly samplings were performed in 1996 and 1997 and the crabs were manually captured on the rocky surface or into of the sand reefs. So, the specimens sampled were characterized according to their capture site (microhabitat) as rocky (RO) or sand reef (SR). The most abundant food items were Mollusca, algae, Polychaeta, and Crustacea, being observed the importance of these groups as a nutritive resource in the studied environment. Mollusks were more abundant in the stomachs of crabs sampled on the rocks, while the other items increased in the sand reefs crabs. In the specimens sampled in the SR, polychaetes were the item food more common, indicating that this biotope is also used as a rich source of protein. The proportion of items differed also between size classes. Knowledge of such habits is essential for nutritional requirements studies, monitoring relationships among organisms, as well as assessing future environmental impacts in consolidated coastal regions.

Abstract: The aims of this research are to identify and describe a periphyton community of thermophilic microalgae in order to expand our knowledge on biodiversity of a particular environment. Conspicuous biomass of thermophilic microalgae (48 °C) inhabits the cooling towers of the thermoelectric power plant of Villa de Reyes (Central Mexico). Aggregate samples or microalgal mats were taken in three different areas of the top of a cooling tower, for identification. According to the sequencing analysis of 16S and 18S rDNA genes, the community is dominated by 3 species of Cyanoprokaryota: Chlorogloeopsis fritschii, Arthronema africanum and Chroococcidiopsis sp., previously reported as thermophiles. Also, 2 species of the Chlorophyte or green algae Scenedesmus. Finally, 12 species of diatoms comprise the microalgal community; diatoms were only microscopically identified within the mats, suggesting that the mats constitute a suitable microenvironment in thermal ambiences. The identified species are of particular interest because their habitat represents an extreme and an artificial biotope. To the best of our knowledge, this is the first report of thermophilic communities of microalgae in Mexico from a power plant; also, this is the first report of A. africanum for the country.

Resumen: Esta investigación tiene por objetivo identificar y describir la comunidad perifítica de microalgas termófilas, para expandir nuestro conocimiento de la biodiversidad en ambientes particulares, como las microalgas termófilas (48 °C) que crecen de manera conspicua en la zona superior de la torre de enfriamiento de la central termoeléctrica de Villa de Reyes (centro de México). Se tomaron muestras de agregados o tapetes microalgales en 3 zonas distintas de la parte superior de una torre de enfriamiento, para su identificación. Una vez realizada la amplificación, la clonación y el análisis de los genes que codifican para las subunidades 16S y 18S del rDNA, se observó el predominio de 3 especies de Cyanoprokaryota: Chlorogloeopsis fritschii, Arthronema africanum y Chroococcidiopsis sp., especies descritas como termófilas en trabajos previos. Además, se identificaron 2 especies de Chlorophyta (algas verdes) del género Scenedesmus y 12 especies de diatomeas; la identificación de diatomeas se realizó a partir de observaciones por microscopia electrónica de barrido. Característicamente, las diatomeas solo se observaron dentro los densos tapetes algales que se conforman, sugiriendo que estos tapetes constituyen un microambiente conveniente en ambientes térmicos. Las especies identificadas son de particular interés, ya que su hábitat representa un biotopo extremo y artificial. Por lo que sabemos, este trabajo constituye el primer registro de microalgas termófilas que habitan en torres de enfriamiento y Arthronema africanum se documenta por primera vez para México.

The diversity of annelids polychaete associated with intertidal mangrove biotope of the Santuario Nacional los Manglares de Tumbes is studied. Sampling was conducted at two sites, one near the river mouth and the other distant about 6 km upstream. In each place, two fixed stations were established, one associated to high intertidal zone with the presence of Anadara tuberculosa (ZBI) and other associated to low intertidal zone with the presence of Ucides occidentalis (ZAI). The samples were taken in December 2012 and March 2013. The total number of species registered was 57 species composition was not similar between associations and between fixed stations. The stations associated to ZBI had more number of species abundances and indices greater diversity than to ZAI. As trophic groups, the stations associated to ZAI had four groups whereas stations associated to ZBI had 6 trophic groups. The poliquetofauna associated with ZBI dominated in number of species, the carnivores while poliquetofauna associated to ZAI, was carnivores and surface deposit feeders also dominated in abundance subsurface deposit feeders. Multivariate analysis showed significant differences in the structure and trophic composition of partnerships, with greater dispersion and variability in the ZAI.

Se estudia la diversidad de anélidos poliquetos asociados al biotopo intermareal del manglar del Santuario Nacional los Manglares de Tumbes, Perú. El muestreo se realizó en dos sitios, uno cercano a la desembocadura y el otro distante aproximadamente 6 km rio arriba. En cada lugar se establecieron dos estaciones fijas, una asociada a zonas bajas del intermareal con presencia de Anadara tuberculosa (ZBI) y otra asociada a la zona altas del intermareal con presencia de Ucides occidentalis (ZBI). Los muestreos se repitieron en diciembre del 2012 y marzo del 2013. El número total de especies de poliquetos registrado fue 57, la composición de especies no fue similar entre las asociaciones y entre las estaciones fijas. Las estaciones asociadas a ZBI tuvieron un mayor número de especies, abundancias e índices de diversidad mayores que las estaciones asociadas a ZAI. En cuanto a los grupos tróficos, las estaciones asociadas a ZAI tuvieron 4 grupos mientras que las estaciones asociadas a ZBI tuvieron 6 grupos tróficos. En la poliquetofauna asociada a ZBI dominaron, en número de especie los carnívoros mientras que en la asociada a ZAI, fueron los carnívoros y los alimentadores de depósito superficial, asimismo dominaron en abundancia los alimentadores de depósito sub superficial. El análisis multivariado demostró diferencia significativa en la estructura y composición trófica de las asociaciones, con mayor dispersión y variabilidad en el ZAI.

ResumoComo os artistas podem permanecer autônomos e manter viva sua criatividade na sociedade contemporânea? Neste artigo afirmamos que o modelo individual do artista burguês não é mais suficiente para se fazer arte autônoma e para ser criativo a longo prazo. Se os artistas desejam permanecer móveis e autônomos, precisam construir estruturas organizacionais coletivas, que são chamadas de "caravanas viajantes". Nas mudanças históricas paralelas entre 1970 e 2000, do liberalismo ao neoliberalismo, do fordismo ao pós-fordismo e da arte moderna para a contemporânea, os artistas precisam construir seu próprio biótopo artístico se quiserem fazer seu trabalho sem interferência governamental (subsídios) e soluções de mercado. O cooperativo pode ser visto como um modelo interessante para desenvolver tal 'autonomia móvel'.

AbstractHow can artists stay autonomous, and keep their creativity alive in the contemporary society? In this paper is stated that the individual bourgeois model of the artist is not sufficient any more to make autonomous art and to stay creative on the long run. If artists want to stay mobile and autonomous they need to build collective organizational structures, which are called 'traveling caravan'. In the parallel historical shifts between 1970 and 2000 from liberalism to neo-liberalism, from Fordism to post-Fordism and from modern to contemporary art, artists need to build up their own artistic biotope if they need to make their work without governmental interference (subsidizes) and free market solutions. The cooperative can be seen as an interesting model to develop such a 'mobile autonomy'.

We studied the relationships between mesoclimate variations of rock outcrops and the composition of the chasmophytic communities over a W-E altitudinal gradient (500-1243 m a.s.l.) in the Sierras Australes (Ventania). In transitory weather stations located on 5 sites we recorded climatic variables hourly and simultaneously during 3-4 days at each season for 2 years. We used phytosociological data obtained with the relevé method by Frangi y Bottino (1995) in sites with same topography that weather stations. The analysis showed the influence of aspect on mesoclimates, since physical properties of rocks enhance thermal contrast originated in direct sun radiation, then, it showed altitudinal gradients. Sites to S (550 m a.s.l.) and SW (850 m a.s.l.) was shadowy, humid with low evaporation, and have a common species assemblage; at higher altitude lower temperatures favour microthermic species: endemic, Subantarctic or Andean. North-facing lower site was the hottest and driest biotope; includes endemisms, xerothermophilous southern-Brazilian, and northwestern Argentina species connected through the Andean-pampean mountainous arch. Northeast-facing mid-elevation outcrops were floristically and mesoclimatically transitional between both lower sites, lacking xerothermophilous and Subantarctic species. Summit outcrops, evaporative, sunny and relatively cold, had lower richness. These mountains enclose mesoclimates, species and communities exclusive to the Pampas, whose arrangement in the landscape are coherent with their lineage.

Estudiamos las relaciones entre las variaciones mesoclimáticas de roquedales y la composición de las comunidades casmofíticas sobre un gradiente altitudinal (500-1243 m s.n.m.) W-E en las Sierras Australes (Ventania). En 5 estaciones meteorológicas transitorias se registraron variables climáticas horaria y simultáneamente durante 3-4 días cada estación del año durante 2 años. Se utilizaron datos de censos fitosociológicos (20 relevés) realizados por Frangi y Bottino (1995) en sitios con topografía similar a las estaciones meteorológicas. El análisis mostró la influencia de la exposición sobre los mesoclimas, ya que las propiedades físicas de las rocas aumentan los contrastes térmicos causados por la radiación solar directa, luego evidenció gradientes altitudinales. Los sitios S (550 m s.n.m.) y SW (850 m s.n.m.) fueron sombríos, húmedos, poco evaporantes, y compartieron especies; a mayor altitud las bajas temperaturas favorecieron las especies microtérmicas: endémicas, subantárticas y andinas. El sitio basal al N fue el biotopo más caliente y seco; incluyó endemismos y especies xerotermófilas austrobrasileñas y del NW argentino. Los faldeos NE fueron florística y mesoclimáticamente transicionales entre los roquedales basales; sin especies subantárticas y xerotermófilas. Las cumbres, evaporantes, soleadas y frescas, poseyeron menor riqueza. Las sierras albergan mesoclimas, especies y comunidades exclusivas para las Pampas, cuya disposición en el paisaje es coherente con su linaje.

The ecologic influence of in-stream large wood (LW) was evaluated at reach scale in a third-order channel located in the Coastal Mountain Range, southern Chile. The tested hypotheses were that Coarse Particle Organic Matter (CPOM) retention is higher and benthic macro-invertebrates are more diverse in channel reaches storing higher volumes of LW. Three LW-low-volume reaches (mean LW volume of 8 m³ 100m-1 of reach channel length; plane bed morphology) and three LW-high-volume reaches (mean volume 262 m³ 100m-1; forced pool riffle bed morphology) were selected within a 1557 m-long segment of the study channel. CPOM retention was inferred from the difference between the number of leaves collected in the downstream end of each reach and the leaves introduced in the upstream end. Mean CPOM retention was 72 and 90% among LW-low and high volume reaches, and showed a positive correlation (R = 0.61) with LW volume. Macro-invertebrates were more diverse and abundant in LW-high-volume reaches and the richness was twice than in LW-low-volume reaches. Bray-Curtis similarity index was low (40%) between LW-high and low volume reaches, while it was high (> 60%) among LW-low-volume reaches. Results confirm the hypothesis that OM retention and benthic macro-invertebrate diversity and abundance were higher in high LW volume reaches. The higher diversity and abundance of macro-invertebrates associated with LW accumulations confirm that logjams constitute a biotope that offers shelter and food. These results can guide the assessment of environmental impacts of stream intervention and restoration projects. The study was undertaken within the framework of Project Fondecyt 1110609.

La influencia ecológica de la madera en el cauce (LW) fue evaluada a nivel de tramo en un canal de tercer orden localizado en la Cordillera de La Costa, sur de Chile. Las hipótesis planteadas fueron que la retención de Materia Orgánica Particulada Gruesa (CPOM) es mayor y que la diversidad de macro-invertebrados bentónicos es también mayor en tramos que almacenan una mayor cantidad de LW. Tres tramos con bajo volumen de LW (volumen medio de 8 m³ 100m-1 de largo de tramo; morfología de lecho plano) y tres tramos con alto volumen de LW (volumen medio de 262 m³ 100m-1; morfología de lecho de rápidos y pozas) se seleccionaron dentro de un segmento de 1557 m de largo en el canal estudiado. La retención de CPOM fue inferida de la diferencia entre el número de hojas recogidas al final de cada tramo y las hojas introducidas al canal en el extremo de aguas arriba. La retención promedio de CPOM fue 72 y 90% en tramos con bajo y alto volumen de LW, y mostró una correlación positiva (R = 0,61) con el volumen de LW. La diversidad y abundancia de macro- invertebrados fuero mayor en tramos con mayor volumen de LW y la riqueza fue el doble que en tramos con bajo volumen de LW. El índice de similaridad de Bray-Curtis fue bajo (40%) entre tramos con alto y bajo volumen de LW, mientras que fue alto (> 60%) entre tramos con bajo volumen de LW. Los resultados confirman la hipótesis que la retención de CPOM y la diversidad y abundancia de macro-invertebrados bentónicos fueron mayores en tramos con mayor volumen de LW. La mayor diversidad y abundancia de macro-invertebrados asociadas con acumulaciones de LW confirman que los diques de madera constituyen un biotopo que ofrece protección y alimento. Estos resultados pueden guiar la evaluación de los impactos ambientales de proyectos de intervención o restauración de cauces. Este estudio fue desarrollado en el marco del Proyecto Fondecyt 1110609.

Several biotopes in the riparian forest of Punta Lara, Buenos Aires province, Argentina, were sampled for oribatid mites. Twenty eight species were found, of which seven are recorded for Argentina for the first time: Epilohmannia sculpturata Balogh & Mahunka, Nothrus willmanni Mahunka, Xenillus (Xenillus) fecundus P. Balogh, Xenillus (Xenillus) superbus (Perez-Íñigo & Baggio), Zetomimus (Protozetomimus) polpaicoensis (Hammer), Pseudotocepheus (Pseudotocepheus) pauliensis Pérez-Íñigo & Baggio and Lohmannia (Lohmannia) juliae Mahunka. The most diverse biotope was forest litter, with 20 species. Some zoogeographical issues are discussed.

En el presente trabajo se relevaron diversos biotopos de la Selva Marginal de Punta Lara, provincia de Buenos Aires, Argentina, para conocer el elenco de ácaros oribátidos que allí habitan. Se hallaron 28 especies, de las que siete resultaron nuevas para Argentina: Epilohmannia sculpturata Balogh & Mahunka, Nothrus willmanni Mahunka, Xenillus (Xenillus) fecundus P. Balogh, Xenillus (Xenillus) superbus (Perez-Íñigo & Baggio), Zetomimus (Protozetomimus) polpaicoensis (Hammer), Pseudotocepheus (Pseudotocepheus) pauliensis Pérez-Íñigo & Baggio y Lohmannia (Lohmannia) juliae Mahunka. El biotopo más diverso resultó la hojarasca de la selva con 20 especies. Se discuten cuestiones zoogeográficas del sistema estudiado.

Through an oceanographic cruise carried out between the southern area of Aysén and the northern one of Magallanes, Canal Trinidad to Canal Smyth (50º00'S, 75º00'W to 52º00'S, 73º48'W), 13 collecting stations were made to gather biological material to record and characterizing the intertidal biotopes of this extended area. A total of 19 biotopes were identified, from which 12 of those had been recorded previously at more septentrional areas of Aysén; other 6 represented variations of those previously recorded in other areas and only 1 was described as a new intertidal biotope. Among the former ones are rocky shore biotopes belonging to the dominant species Bostrychia harveyi, Acrosiphonia pacifica, Porphyra sp., Adenocystis utricularis, Iridaea tuberculosa and Mazzaella laminarioides-Nothogenia fastigiata. Among the 6 ones which represent variations of some biotopes before described there are 2 of Porphyra sp., 3 of Bostrychia harveyi and 1 of Mazzaella laminarioides-Nothogenia fastigiata. Just the rocky shore biotope integrated by the macroalgae Caepidium antarcticum and crustose coralline algae was the only new one. This new biotope is distributed in the lower eulitoral subzone of sheltered areas and it is characterized by having a strong subantarctic influence. Coastal biotope biodiversity was high, as a consequence of the multiple geographic, geologic, oceanographic and climatic factors interacting in this extended region. In general, the area was characterized by exhibiting a high biological diversity reflected through the diversity of observed biotopes, which demonstrated the presence of highly productive ecosystem.

Durante un crucero oceanográfico realizado entre el sector sur de la región de Aysén y sector norte de Magallanes, Canal Trinidad a Canal Smyth (50º00'S,75º00'W a 52º00'S, 73º48'W), sur de Chile, se efectuaron 13 estaciones de recolección de material biológico para registrar y caracterizar los biotopos del intermareal rocoso del área. Se identificaron 19 biotopos, 12 de los cuales eran biotopos reconocidos para otras áreas más septentrionales de Aysén; 6 correspondían a variantes de los anteriores y uno sólo fue reconocido y descrito como biotopo nuevo. Entre los primeros están los biotopos de litoral rocoso correspondientes a las especies dominantes Bostrychia harveyi, Acrosiphonia pacifica, Porphyra sp., Adenocystis utricularis, Iridaea tuberculosa y Mazzaella laminarioides-Nothogenia fastigiata. Entre los 6 que representaban variantes de algunos de los biotopos anteriormente descritos hubo 2 de Porphyra sp., 3 de Bostrychia harveyi y 1 de Mazzaella laminarioides-Nothogenia fastigiata. Sólo el biotopo de litoral rocoso integrado por la macroalga Caepidium antarcticum y algas coralináceas crustosas, constituyeron un biotopo nuevo para el área que se distribuye en la subzona eulitoral inferior de frentes protegidos y se caracteriza por presentar una fuerte influencia subantártica. La diversidad de biotopos costeros fue alta, como consecuencia de los múltiples factores geográficos, geológicos, oceanográficos y climáticos que interactúan en esta extensa región. En general, el área se caracterizó por presentar una alta diversidad biológica reflejada en la diversidad de biotopos encontrados, que indicaría la presencia de ecosistemas altamente productivos.

Embora os eucaliptos sejam considerados como tendo um elevado grau de resistência ao ataque de pragas e doenças, por vezes podem sofrer ataques intensos de insetos tais como a broca do eucalipto, Phoracantha semipunctata (Fab.). Em Marrocos esta praga introduzida foi detetada pela primeira vez na zona de Selouane, a 9km da cidade de Nador, por Chararas em 1973. Este inseto aparenta ter sido raro até 1980-1981, quando uma seca severa que durou de 1980 a 1986 provavelmente contribuiu para a sua instalação e dispersão em Marrocos. Atualmente esta praga pode ser encontrada dispersa por todo o país, desde Oujda a Este até à costa Atlântica a Oeste, e de Tânger a Norte a Agadir no Sul. Neste trabalho compara-se a resiliência de diferentes espécies de eucaliptos plantados em diversos arboretos e a sua relação com ataques da broca do eucalipto. Os resultados revelam a existência de diferenças na adaptação das espécies de acordo com o seu biótopo e casca, que condicionam e influenciam a sua suscetibilidade e resistência aos ataques de P. semipunctata.

Although eucalyptus is regarded as having resistance to various insect pests and diseases, it can also suffer from heavy attacks by the eucalyptus longhorned borer, Phoracantha semipunctata (Fab.). In Morocco, this introduced pest was reported for the first time in Selouane, 9km from Nador, by Chararas in 1973. The species appears to have been rare until 1980-1981, but the exceptional drought occurring from 1980 to 1986 probably contributed to its installation and dispersal in Morocco. Nowadays this pest can be found widespread throughout the country, from Oujda in the east to the Atlantic coast and from Tangiers in the north to Agadir in the south. In this study we compare the resilience of different eucalyptus species from various arboretums within Morocco and the relation with attacks by the longhorned borer. The results reveal the existence of differences in adaptation of the different eucalyptus species according to their biotope and bark, influencing their susceptibility and resistance to attacks by P. semipunctata.

El objetivo principal de la investigación fue obtener una línea base de la composición de las comunidades de esponjas, corales y gorgonias que pueda ser utilizada como referencia para futuros análisis de impacto antrópico. Nuestra hipótesis es que un arrecife relativamente homogéneo y bien conservado, presenta una variabilidad natural notable en la composición de sus comunidades, lo cual no está asociado con cambios en la proximidad a tierra o a un gradiente de impacto humano. La investigación se llevó a cabo en julio de 2006, en 12 estaciones de muestreo ubicadas en el arrecife de Los Colorados, en la región noroccidental de la Provincia de Pinar del Río, Cuba. Los biotopos seleccionados fueron cresta, veril y camellones. Los indicadores ecológicos estimados fueron: diversidad de corales, composición por especies, densidad de corales, hidrocorales, gorgonias y esponjas, y densidad de especies de corales seleccionadas. Se contaron 2 659 colonias de corales escleractíneos pertenecientes a 36 especies. Las especies más abundantes en el biotopo de cresta fueron: Millepora alcicornis, Acropora palmata y Porites astreoides; mientras que en el veril y los camellones fueron Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites y Montastraea cavernosa. Entre sitios, se encontraron diferencias significativas estadísticamente para varios indicadores (densidad de corales, esponjas y gorgonias y densidad de especies seleccionadas), pero ello no pudo asociarse con ningún gradiente de uso de la tierra o de impacto humano. Por lo tanto, sitios dentro de un arrecife relativamente homogéneo pueden presentar diferencias notables en la composición de sus comunidades.

The main goal of this research was to obtain baseline field data of the composition of sponges, corals, and gorgonian assemblages that can be used as a reference for future analyses of anthropogenic impact. We tested the hypothesis that relatively homogeneous and well preserved reef units can present notable natural variability in the composition of their communities which are unassociated with changes in land proximity or a human impact gradient. Research was carried out in July 2006 at Los Colorados reef, located in the northwestern region of Pinar del Río Province, Cuba at 12 sampling stations. The biotopes selected were crest, terrace edge and spur and grove. Ecological indicators were diversity of corals, species composition, density of corals, hydrocorals, gorgonians and sponges, and density of selected coral species. A total of 2659 colonies of scleractineans corals representing 36 species were counted. The most abundant species in the crest biotope were Millepora alcicornis, Acropora palmata and Porites astreoides; in the terrace edge and spur and grove, the most abundant species were Siderastrea siderea, Stephanocoenia intersepta, Porites astreoides, Agaricia agaricites and Montastraea cavernosa. We found differences among sites for several indicators (e.g. density of corals, sponges and gorgonians and for selected species), but they could not be associated to any gradient of land influence or human impact. Therefore, sites inside a relatively homogeneous reef unit can present notable natural differences in the composition of their communities. Rev. Biol. Trop. 58 (2): 621-634. Epub 2010 June 02.

Se describen y comparan los patrones de abundancia de colémbolos de hojarasca y suelo de dos cuencas hidrológicas de la Estació n de Biología Chamela (EBCh, UNAM) en Jalisco, México, con base en colectas mensuales durante un año. Esta localidad, donde el tipo de vegetación dominante es la selva baja caducifolia, presentó un año de precipitación pluvial atípico durante los muestreos realizados, con la mayor cantidad de lluvia durante enero. El muestreo de ambos biotopos fue aleatorio, los núcleos fueron de igual tamaño (95 cm²) y se procesaron in situ mediante embudos de Berlese. Adicionalmente, se cuantificaron diferentes variables edáficas. Se analizó el efecto de los factores cuenca, biotopo y estacionalidad sobre la abundancia de las familias de Collembola. Mediante análisis de conglomerados (AC) se exploran las relaciones faunísticas entre los ensamblajes, y mediante análisis de correspondencia canónica (ACC), las relaciones entre los ensamblajes y las variables fisicoquímicas del suelo. Se obtuvieron 24.253 colémbolos pertenecientes a trece familias. Las más abundantes fueron Isotomidae, Entomobryidae, Hypogastruridae y Sminthuridae. El AC mostró mayor similitud entre biotopos que entre cuencas, mientras que en el ACC la variable más importante para explicar la distribución y abundancia de los Collembola fue la humedad.

The abundance patterns of leaf litter and soil springtails (Hexapoda: Collembola) from two hydrological watersheds of the Chamela Biological Statión (EBCh, UNAM) in Jalisco, México are described and compared based on monthly sampling over one year. This locality, where the dominant vegetatión is tropical dry forest, had an atypically high rainfall during the sampling period, with the greatest amount of rain during January. Sampling in both biotopes was random, the areas sampled were of the same size (95 cm²), and these were processed in situ using Berlese funnels. In addition, different edaphic characteristics were quantified. The effect of watershed, biotope and seasonality factors on the abundance of Collembola families was analysed. Using Cluster Analysis (CA), the faunistic relationships between the assemblages were explored, and using Canonical Correspondence Analysis (CCA) the relationships between assemblages and the physico-chemical variables of the soil. A total of 24.253 Collembola were obtained, belonging to 13 families. The most abundant were Isotomidae, Entomobryidae, Hypogastruridae and Sminthuridae. The CA showed more similarity between biotopes than between hydrological watersheds, while in the CCA the most important variable to explain the distributión and abundance of the Collembola was humidity.