scholarly journals Reproductive phenology of Sambucus nigra subsp. canadensis in the Abies religiosa temperate forest of the Magdalena river basin, Mexico City

2017 ◽  
Vol 95 (1) ◽  
pp. 23 ◽  
Author(s):  
Leticia Bonilla-Valencia ◽  
Silvia Castillo-Argüero ◽  
Yuriana Martínez-Orea
Keyword(s):  
Environmental Factors ◽  
River Basin ◽  
Temperate Forest ◽  
Chemical Properties ◽  
Reproductive Phenology ◽  
Sambucus Nigra ◽  
Precipitation Temperature ◽  
Magdalena River ◽  
Abies Religiosa ◽  
Study Species

<p><em>Background. </em>Reproductive phenology studies in temperate forests of Mexico are scarce and none of them takes into account micro-environmental factors. As an example, there are no studies of the reproductive dynamics of <em>Sambucus nigra </em>subsp. <em>canadensis</em>, the elderberry. </p><p><em>Questions. </em>How do environmental factors, at general and micro-scales are related to the production of<em> </em>flowers and fruits of<em> </em><em>Sambucus nigra </em>subsp. <em>canadensis</em>?</p><p><em>Study species. Sambucus nigra </em>subsp. <em>canadensis </em>is distributed in<em> Abies religiosa </em>(fir)<em> </em>forests of Mexico and it is associated to areas of anthropogenic disturbance.</p><p><em>Study site and dates. </em>Temperate forest in the Magdalena river basin, April 2012 to May 2013.</p><p><em>Methods. </em>The percentages of flowers and fruits of 103 individuals were registered and precipitation, temperature, light and soil chemical properties were characterized as well. To find out the relation between reproductive phenology and the environmental factors we carried out Spearman´s correlations as well as a Canonical<em> </em>Correspondence Analysis for the micro- environmental factors.</p><p><em>Results. </em>Percentages of flowers and fruits showed a relation with the general factors of precipitation, temperature and light. In the micro-environments with the highest light amounts the percentages of fruits were the highest, while<em> </em>the microenvironments with the highest nitrogen, organic matter concentrations and soil moisture, showed the highest flower percentages.</p><p><em>Conclusions. </em>We showed that general factors as well as micro-environmental ones have an influence on the proportions of flowers and fruits of the study species in different ways, these knowledges show the reproductive dynamics of this species.</p>

Reproductive phenology of understory species in anAbies religiosa(Pinaceae) forest in the Magdalena River Basin, Mexico City

2017 ◽  
Vol 144 (3) ◽  
pp. 313-327 ◽  
Author(s):  
Leticia Bonilla-Valencia ◽  
Yuriana Martínez-Orea ◽  
Silvia Castillo-Argüero ◽  
Guadalupe Barajas-Guzmán ◽  
Marco Antonio Romero-Romero ◽  
...  
Keyword(s):  
Mexico City ◽  
River Basin ◽  
Reproductive Phenology ◽  
Understory Species ◽  
Magdalena River

Effects of environmental factors on reproductive seasonality of Magdalena River basin fish: need for answers in the ecophysiology

2010 ◽  
Vol 30 (9) ◽  
pp. 1353-1356
Author(s):  
Andrés Montoya-López ◽  
Mauricio Torres-Mejia ◽  
Jaime Palacio ◽  
Luz Jiménez-Segura
Keyword(s):  
Environmental Factors ◽  
River Basin ◽  
Reproductive Seasonality ◽  
Magdalena River

Chemical Ecology and Off-Flavour Substances

1988 ◽  
Vol 20 (8-9) ◽  
pp. 167-178
Author(s):  
O. M. Skulberg
Keyword(s):  
Environmental Factors ◽  
Chemical Ecology ◽  
Aquatic Environment ◽  
Metabolic Pathways ◽  
Chemical Properties ◽  
Relevant Research ◽  
Fundamental Research ◽  
Biotic Effects ◽  
Ecological Mechanisms ◽  
Ecological Importance

Off-flavour substances may be regarded as a resource which can be used to study special ecological mechanisms. Relevant research on off-flavours is inextricably combined with the study of perception, ethology, genetic control etc. The chemicals concerned are commonly perceived by the senses of olfaction and gustation. Thus research on the chemical ecology of off-flavour substances in the aquatic environment involves the study of a variety of disciplines. For example the biochemistry of the relevant substances and appropriate metabolic pathways must be considered. Chemical properties are important for the behaviour of the substances. The production of off-flavours by organisms is related to phenological circumstances. The biotic effects of ecologically significant substances are dependent on several environmental factors. This paper draws attention to the possible application of fundamental research in this area to selected problems of ecological importance.

scholarly journals The Rise of Climate-Driven Sediment Discharge in the Amazonian River Basin

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 208 ◽  
Author(s):  
Nazzareno Diodato ◽  
Naziano Filizola ◽  
Pasquale Borrelli ◽  
Panos Panagos ◽  
Gianni Bellocchi
Keyword(s):  
River Basin ◽  
Amazon Basin ◽  
Global Climate ◽  
Climate Extremes ◽  
Temporal Variations ◽  
Sediment Discharge ◽  
Storm Events ◽  
Discharge Data ◽  
Magdalena River ◽  
Sediment Export

The occurrence of hydrological extremes in the Amazon region and the associated sediment loss during rainfall events are key features in the global climate system. Climate extremes alter the sediment and carbon balance but the ecological consequences of such changes are poorly understood in this region. With the aim of examining the interactions between precipitation and landscape-scale controls of sediment export from the Amazon basin, we developed a parsimonious hydro-climatological model on a multi-year series (1997–2014) of sediment discharge data taken at the outlet of Óbidos (Brazil) watershed (the narrowest and swiftest part of the Amazon River). The calibrated model (correlation coefficient equal to 0.84) captured the sediment load variability of an independent dataset from a different watershed (the Magdalena River basin), and performed better than three alternative approaches. Our model captured the interdecadal variability and the long-term patterns of sediment export. In our reconstruction of yearly sediment discharge over 1859–2014, we observed that landscape erosion changes are mostly induced by single storm events, and result from coupled effects of droughts and storms over long time scales. By quantifying temporal variations in the sediment produced by weathering, this analysis enables a new understanding of the linkage between climate forcing and river response, which drives sediment dynamics in the Amazon basin.

Species Responses to Grazing and Environmental-Factors in an Arid Halophytic Shrubland Community

1987 ◽  
Vol 35 (2) ◽  
pp. 135 ◽  
Author(s):  
RB Hacker
Keyword(s):  
Environmental Factors ◽  
Soil Salinity ◽  
Large Scale ◽  
Chemical Properties ◽  
Grazing Pressure ◽  
Aerial Photographs ◽  
Small Scale ◽  
Factors Affecting ◽  
Species Responses

Species responses to grazing and environmental factors were studied in an arid halophytic shrubland community in Western Australia. The grazing responses of major shrub species were defined by using reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological variation and the influence of cryptogamic crusts on seedling establishment.

Evidence of river flow regulation loss over time in the Magdalena river basin 

2021 ◽  
Author(s):  
Diver E. Marín ◽  
Juan F. Salazar ◽  
José A. Posada-Marín
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
River Basin ◽  
River Flow ◽  
Southern Oscillation ◽  
Scaling Theory ◽  
Scaling Properties ◽  
Low Flows ◽  
High Flows ◽  
Magdalena River

&lt;p&gt;Some of the main problems in hydrological sciences are related to how and why river flows change as a result of environmental change, and what are the corresponding implications for society. This has been described as the Panta Rhei context, which refers to the challenge of understanding and quantifying hydrological dynamics in a changing environment, i.e. under the influence of non-stationary effects. The river flow regime in a basin is the result of a complex aggregation process that has been studied by the scaling theory, which allows river basins to be classified as regulated or unregulated and to identify a critical threshold between these states. Regulation is defined here as the basin&amp;#8217;s capacity to either dampen high flows or to enhance low flows. This capacity depends on how basins store and release water through time, which in turn depends on many processes that are highly dynamic and sensitive to environmental change. Here we focus on the Magdalena river basin in northwestern South America, which is the main basin for water and energy security in Colombia, and at the same time, it has been identified as one of the most vulnerable regions to be affected by climate change. Building upon some of our previous studies, here we use data analysis to study the evolution of regulation in the Magdalena basin for 1992-2015 based on the scaling theory for extreme flows. In contrast to most previous studies, here we focus on the scaling properties of events rather than on long term averages. We discuss possible relations between changes in the scaling properties and environmental factors such as climate variability, climate change, and land use/land cover change, as well as the potential implications for water security in the country. Our results show that, during the last few decades, the Magdalena river basin has maintained its capacity to regulate low flows (i.e. amplification) whereas it has been losing its capacity to regulate high flows (i.e. dampening), which could be associated with the occurrence of the extremes phases of&amp;#160; El Ni&amp;#241;o Southern Oscillation (ENSO) and anthropogenic effects, mainly deforestation. These results provide foundations for using the scaling laws as empirical tools for understanding temporal changes of hydrological regulation and simultaneously generate useful scientific evidence that allows stakeholders to take decisions related to water management in the Magdalena river basin in the context of environmental change.&lt;/p&gt;

scholarly journals Breeding sites of Culicoides pachymerus Lutz in the Magdalena River basin, Colombia

2010 ◽  
Vol 105 (2) ◽  
pp. 216-219 ◽  
Author(s):  
María Cristina Carrasquilla ◽  
Felipe Guhl ◽  
Yaneth Zipa ◽  
Cristina Ferro ◽  
Raúl Hernando Pardo ◽  
...  
Keyword(s):  
River Basin ◽  
Breeding Sites ◽  
Magdalena River
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