ECOFISIOLOGÍA DE LA GERMINACIÓN DE TRES MALEZAS EFÍMERAS PERIURBANAS EN MORELIA, MICHOACÁN, MÉXICO

Se determinaron las características ambientales que conducen a la germinación de tres especies comunes encontradas durante la temporada de lluvias entre junio-octubre de 2009 en un área periurbana de Morelia, Michoacán, México, donde se llevaba a cabo la construcción de un campus de la Universidad Nacional Autónoma de México (UNAM). En particular, se evaluaron en el laboratorio las respuestas a la estratificación a baja temperatura, la temperatura del aire en el día/noche y el potencial de agua para los nativos Onagraceae Lopezia racemosa y Ludwigia octovalvis, y las exóticas Polygonaceae Rumex crispus. La estratificación a baja temperatura no tuvo ningún efecto sobre la germinación por L. racemosa, para lo cual la germinación máxima promedio 88% fue óptima a 25/15 y 30/20 C. La germinación a 21 d se redujo a la mitad a –0,5 MPa e inhibió por completo a –1,0 MPa. Las semillas de L. octovalvis tampoco mostraron sensibilidad a la estratificación a baja temperatura y su germinación nunca superó el 70%, siendo las dos temperaturas más altas de 30/20 y 35/25 C las óptimas. Para esta especie la germinación fue máxima a 0,0 MPa, disminuyendo significativamente bajo cada tratamiento con una germinación mínima del 21% para las semillas incubadas a –0,1 MPa. La germinación para R. crispus se retrasó por la estratificación a baja temperatura, aunque todas sus semillas germinaron independientemente de la temperatura o el tratamiento potencial de agua. Si bien los requisitos ambientales para la germinación de especies efímeras a menudo coinciden con el clima típico de su temporada de crecimiento, las respuestas diferenciales encontradas para las especies consideradas en el presente estudio proporcionan una cierta visión de los mecanismos que conducen a cambios en la composición de las especies para las comunidades de ambientes perturbados, incluyendo el desplazamiento de especies nativas y la proliferación de plantas exóticas y potencialmente invasoras.//The environmental requirements leading to germination were determined by three common species found during the June-October 2009 rainy season in a peri-urban site from Morelia, Michoacán, Mexico, where the construction of a campus of the Universidad Nacional Autónoma de México (UNAM) was underway. In particular, we evaluated responses in the laboratory to low-temperature stratification, day/night air temperature, and water potential for the native Onagraceae Lopezia racemosa and Ludwigia octovalvis, and the exotic Polygonaceae Rumex crispus. Low-temperature stratification had no effect on germination by L. racemosa, for which maximum germination averaging 88% was optimal at 25/15 and 30/20 C. Germination at 21 d was halved at –0.5 MPa and completely inhibited at –1.0 MPa. The seeds of L. octovalvis were also insensitive to low temperature stratification and their germination never exceeded 70%, with the two highest temperatures of 30/20 and 35/25 C being the optimum. For this species germination was maximal at 0.0 MPa, decreasing significantly under every treatment with a minimum germination of 21% for seeds incubated at –0.1 MPa. Germination for the exotic R. crispus was delayed by low-temperature stratification, although all its seeds germinated regardless of the temperature or water potential treatment. While the environmental requirements for germination of ephemeral species often match the typical climate of their growing season, the differential responses found for the species considered in the present study provide some insight into the mechanisms leading to changes in species composition for communities from disturbed environments, including the displacement of native species and the proliferation of exotic, potentially invasive plants

Socio-ecological considerations on the persistence of Mexican heirloom maize

The vulnerability of 59 Mexican landraces of maize was assessed in relation to five socio-ecological factors, namely, social and economic marginalization, association with indigenous peoples, high biodiversity regions, environmental suitability for cultivation, and climate change effects. The most marginalized states had the highest number of landraces, 80% of which were found in predominantly or substantially indigenous municipalities. While only one third of 152 regions of high biodiversity had collection records, 47 landraces had at least one collection record in these regions. Eleven races can be cultivated in at least 10% of the Mexican territory, while 13 can occupy less than 1% under current environmental conditions. Given a projected temperature increase of 0.5 ºC and a 5% reduction in annual precipitation, 66% of the landraces could disappear during the current decade. A normalized Vulnerability Index was constructed (can have values from 0.00 for non-threatened landraces to 1.00 for the most vulnerable) that averaged 0.76 ± 0.02 for the 59 landraces. The most vulnerable third of the landraces were threatened by being from a region of low marginalization combined with a limited potential distribution both under current conditions and under the climate change scenario considered

Fenología reproductiva y tolerancia a temperaturas altas en Stenocereus queretaroensis

Numerosas especies de cactáceas presentan frutos comestibles, por lo que han adquirido un papel importante dentro de la agricultura de zonas áridas y semiáridas, tanto para el comercio regional como para el internacional. Las pitayas son el tercer cultivo más importante dentro de las cactáceas después del nopal y la pitahaya. La fenología reproductiva deStenocereus queretaroensisrequiere condiciones específcas de temperatura y precipitación, así como también de la existencia de los polinizadores para asegurar la producción de frutos. Se cuantificó la producción de botones, flores abiertas y frutos de 2010 a 2012. Y se evaluó el efecto de temperaturas altas en la integridad celular de tejidos florales. Se midió la producción de néctar y la concentración de solutos a través del tiempo durante la antesis. La temperatura letal (LT50) para el ovario en promedio fue de 34.5 ± 0.4°C no varió para los botones y las flores. Por su parte los pétalos de los botones presentan una LT50 21.5 ± 1.6°C y que para el caso de las flores en antesis fue 33% mayor. El desarrollo reproductivo frecuentemente requiere de la acumulación de cierta cantidad de estas unidades de frío. El tejido de estructuras jóvenes tolera más el aumento de la temperatura, que sus contrapartes maduras

Germinación y desarrollo in vitro de dos orquídeas amenazadas endémicas de Colombia, Cattleya mendelii y Cattleya quadricolor

Cattleya mendelii and C. quadricolor are endemic orchids from Colombia, which have been subjected to extraction fromtheir natural environments for commercial purposes, becoming critically endangered. However, there is no sustainablemanagement practice for the conservation of these species. The aim of this study was to establish a protocol of in vitroculture for both species. The effects of different combinations of GA3 and NAA amending MS and KC culture mediawere assessed for the in vitro germination and plant growth. Plant development was assessed monthly over 120 days. Ahigher percentage of explant production for both species was observed with MS than KC. The higher GA3 proportion of1.5 ?M resulted in enhanced germination, while the higher NAA concentration of 1.5 ?M favored later stages of plantdevelopment. For instance, the number of roots and the length of roots and shoots were higher under incubation on MS thatunder KC for both species. In vitro germination for C. mendelii and for C. quadricolor was successful for their propagationand could be useful in future conservation programs for these species.Cattleya mendelii y C. quadricolor son dos orquídeas endémicas de Colombia que han sido sujetas a extracción de susambientes naturales para la venta, esto ha conducido a estas plantas a estar críticamente amenazadas. En la actualidad, noexiste una práctica sustentable para el manejo de estas especies. El objetivo de este estudio fue establecer un protocolo decultivo in vitro para ambas especies. El efecto de diferentes combinaciones de medios de cultivo MS y KC modificados conAG3 y ANA fueron evaluados para la germinación y desarrollo in vitro. El desarrollo fue evaluado cada 30 días, durante120 días. La mayor producción de explantes para ambas especies fue observada con MS. Mayor proporción de AG3 de 1.5?M resultó en el aumento de la germinación, asimismo mayores concentraciones de ANA de 1.5 ?M favorecen los estadiostardíos del desarrollo vegetal in vitro. El número y la longitud de los brotes y las raíces fueron mayores cuando las plantasde ambas especies se cultivaron en medio MS. La germinación y desarrollo in vitro de C. mendelii and C. quadricolor eneste estudio fue una aproximación exitosa para la propagación y puede ser considerada para programas de conservación deestas orquídeas

INTERACCIONES ENTRE ESPECIES HIDRÓFITAS DOMINANTES DE HUMEDALES DEL OCCIDENTE DE MÉXICO MEDIADAS POR EL FUEGO Y LA CONCENTRACIÓN DE NITRATOS

La dinámica de comunidades vegetales de humedales está influenciada por factores abióticos, como los nutrimentos y el fuego. En humedales en donde hay especies invasoras, determinar el papel de factores abióticos en las interacciones planta-planta es fundamental para entender la dinámica de la comunidad y para su manejo. En este estudio, la interacción entre pares de especies fue cuantificada entre una no invasora (Schoenoplectus americanus), una que puede volverse sobredominante como consecuancia de disturbios humanos (Typha domingensis) y una que posee un linaje que es invasor en norteamérica (Phragmites australis), las cuales crecieron bajo diferentes concentraciones de nitrato y fueron sometidas al efecto del fuego. Todas las especies respondieron a la adición de nitratos incrementando su crecimiento.Phragmitesrespondió en altura y biomasa de raíces,Typhaen biomasa aérea y de raíces ySchoenoplectuspara todas las variables. Las interacciones entre especies fueron complejas y variaron entre años. Durante el primer año, sólo el efecto deTyphaen si misma fue significativo. Para el segundo año, el efecto deTyphafue negativo en Phrangmites, el efecto deSchoenoplectusfue negativo en sí mismo y el efecto deTyphayPhragmitesfue negativo enTypha. El fuego fue significativo paraPhragmitesySchoenoplectus, las plantas no quemadas fueron más altas. Se detectaron efectos del fuego en las interacciones, la presencia de Schoenoplectus benefició el desempeño deTypha, y viceversa. En etapas tempranas, las interacciones más fuertes ocurrieron entre las especies no invasoras, permitiendo a la invasora responder a la concentración de nitratos, y el fuego tuvo su mayor efecto en la interacción entre nativas y no con la invasora

Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: Reflections and a horizon scan

Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has becomecommonplace and confers an ability to understand mechanistic processes,develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of \u27success stories\u27 is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider howconservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative.Using a \u27horizon scan\u27,we further exploreways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), aswell as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmentalmanagementand ecosystemrestoration,we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users

One hundred research questions in conservation physiology for generating actionable evidence to inform conservation policy and practice

Environmental change and biodiversity loss are but two of the complex challenges facing conservation practitioners and policy makers. Relevant and robust scientific knowledge is critical for providing decision-makers with the actionable evidence needed to inform conservation decisions. In the Anthropocene, science that leads to meaningful improvements in biodiversity conservation, restoration and management is desperately needed. Conservation Physiology has emerged as a discipline that is well-positioned to identify the mechanisms underpinning population declines, predict responses to environmental change and test different in situ and ex situ conservation interventions for diverse taxa and ecosystems. Here we present a consensus list of 10 priority research themes. Within each theme we identify specific research questions (100 in total), answers to which will address conservation problems and should improve the management of biological resources. The themes frame a set of research questions related to the following: (i) adaptation and phenotypic plasticity; (ii) human-induced environmental change; (iii) human-wildlife interactions; (iv) invasive species; (v) methods, biomarkers and monitoring; (vi) policy, engagement and communication; (vii) pollution; (viii) restoration actions; (ix) threatened species; and (x) urban systems. The themes and questions will hopefully guide and inspire researchers while also helping to demonstrate to practitioners and policy makers the many ways in which physiology can help to support their decisions

Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan

Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of ‘success stories’ is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a ‘horizon scan’, we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users

Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan

Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become common place and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of 'success stories' is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider howconservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a 'horizon scan', we further exploreways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmenta lmanagement and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users

Depression and anxiety in decision-making, existential isolation, death and lack of vital sense in religious and non-religious people

El presente estudio tiene como objetivo describir la ansiedad ante las situaciones existenciales en religiosos y no religiosos en una muestra 100 universitarios colombianos, con una edad promedio de 22 años. Los participantes completaron el ANSIV que mide ansiedad existencial (ANSIV) y la Escala de Depresión de Zung. Los hallazgos comprueban que los no religiosos presentaron mayor ansiedad que los religiosos frente a la toma de decisiones; que no se observaron diferencias en relación al sentido de vida en ambos grupos; que los no religiosos presentaron ansiedad más exacerbada frente a la muerte que los religiosos y que los religiosos se encontraron menos ligeramente deprimidos que los no religiosos.The present study aims to describe the anxiety in existential situations in religious and non-religious people in a sample of 100 students from Colombia with an average age of 22 years. The participants completed the ANSIV that measures Existential Anxiety and SelfRating Depression Scale. The findings show that the non-religious presented higher anxiety than the religious people in decision-making process; no differences were observed in relation to the meaning of life in both groups; non-religious presented anxiety more exacerbated in the face of death than religious people and the religious were found slightly less depressed than non-religious